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Home My WebLink AboutDRC-2012-001274 - 0901a068802bcfe0C-2ul2-001195 DENISO MINES February 29 2012 VIA E MAIL AND OVERNIGHT DELIVERY Mr RustyLundberg Department of Environmental Quality 195 North 1950 West PO Box 144850 Salt Lake City UT 84114 4850 Denison Mines (USA) Corp 105017th Street Suite 950 Denver CO 80265 USA Tel 303 628 7798 Fax 303 389 4125 www denisonmines com Re State of Utah Groundwater Discharge Permit { GWDP ) No UGW370004 Transmittal of Revised Discharge Minimization Technology Monitonng { DMT ) Revision 11 5 dated February 2012 DearMr Lundberg Reference is made to the Division of Radiation Control ( DRC ) letters dated September 13 2011 December 14 2011 December 22 2011 and February 15 2012 regarding the White Mesa Mill Tailings Management System and Discharge Minimization Technology ( DMT ) Monitonng Plans dated June 2011 (Revision 11 2) July 2011 (Revision 11 3) and January 2012 (Revision 11 4) This letter transmits Denison Mines (USA) Corp s ( Denison s ) proposed revisions to the White Mesa Mill DMT Plan These revisions include changes made to 1 Respond to the DRC Letter dated February 15 2011 which incorporated specific comments from the DRC letters dated September 13 2011 December 14 2011 December 22 2011 2 Correct additional errors and inconsistencies in the January 2012 Revision of the DMT Plan For ease of review we have provided both redline and clean versions of each document The attached DMT Plan Revision 11 5 has accepted all the redline changes proposed in Denison s January 2012 submittal as the base version in black type Changes resulting from the above referenced DRC comment letter are provided in redline/strikeout format We have also provided below specific responses to each request in DRC s February 15 2011 letter The sections and numbenng of the remainder of this letter follow the DRC February 15 2011 letter Each DRC request is shown in italics below followed by Denison s response Responses to Comments Provided to DUSA in the September 13 2011 DRC RFI/Confirmatory Action Letter (as re transmitted in a DRC letter dated February 15 2011) DRC Comment The comment shown immediately below corresponds to comment number three (3) in the subject September 13 2011 DRC CAL DUSA States that Denison has developed other means to accurately measure cell solution level elevations prior to construction of any walkways However the CAL states that The procedures Letter to Mr Rusty Lundberg February 29 2012 Page 2 for this method to measure the water level elevation will be submitted by DUSA for approval in a revised DMT Plan Please propose the other means to measure the water level as discussed above It is not apparent in the DMT plan what the other means to measure the solution elevation are Denison Response As previously stated in Denison s January 30 2012 response letter tailings cell wastewater pool elevations will be monitored within 30 days of authonzation for use in accordance with the existing survey procedures specified in the DMT Plan and in accordance with Mill health and safety requirements The text refernng to other methods was removed from the DMT Plan Revision 11 4 submitted in January 2012 The tailings cell wastewater pool elevations will be measured using the standard survey procedures as descnbed in the DMT Plan No further descnptions of additional procedures are needed because the procedures are already descnbed in Section 3 1 d) of the DMT Plan Additional text has been added clarifying that for newly constructed cells the same procedure will be used DRC Comment The comment numbers below correspond to the comment numbers in the subject December 22 2011 DRC Letter 3 Part ID 3(b)(3) of the Permit states that Annual Slimes Dram Compliance - shall be achieved when the average annual wastewater recovery elevation in the slimes dram access pipe as determined pursuant to the currently approved DMT Monitoring Plan meets the conditions in Equation 1 below Thus the DMT Plan needs to state how the slimes dram recovery elevations are to be calculated A DUSA letter dated January 27 2012* shows DUSA s current method of calculating the slimes dram recovery elevation as well as the annual average slimes dram recovery elevation This method is clarified in the second full paragraph on page 2 of that letter One may call the current DUSA method of calculating recovery elevations a relative elevation method Although this method is valid for comparison purposes it appears correct elevations with respect to the true elevation above mean sea level (fmsl) are not being used As mentioned in the January 27 2012 letter the standpipe elevation was re surveyed in 2011 which indicated that the elevation of the measurement point of 5614 83 fmsl reported to date was 3 07 feet higher than the 2011 sun/ey result of 5611 76 fmsl To avoid the complex adjustments to calculate relative elevations and to avoid future errors DUSA must convert to using actual fmsl elevations not relative elevations in all of its slimes dram recovery elevation determinations and calculations DUSA s method to do this must be stated in the DMT Plan Notwithstanding the above the DMT Plan needs to state how the slimes dram recovery elevations are to be calculated Denison Response The current correct elevation of the measunng point as surveyed by a Utah Licensed surveyor has been added to the DMT Plan The calculation of the Cell 2 slimes dram elevation (SDRE) has been added to Section 3 1 b)(v) showing how the elevation of the fluid is calculated relative to the surveyed measunng point on the Cell 2 slimes dram access pipe ' January 27 2012 DUSA response letter on Failure to Meet Affirmative Defense Requirements on Cell 2 Slimes Drain Recovery Elevation DENISO MINES .Aii Letter to Mr Rusty Lundberg February 29 2012 Page 3 As we discussed with DRC on February 14 2012 the elevation of the Cell 2 slimes dram access pipe of 5611 76 fmsl is a correct value representing the elevation pnor to the addition in 2011 of the 6 97 foot extension All entnes and calculations (for every penod from 1/25/2008 through 12/19/2011) in the table in Attachment 3 of Denison s January 17 2012 letter using this value are correct The surveyed elevation of the slimes dram access pipe of 5618 73 fmsl used in Attachment 3 of Denison s January 27 2012 letter is a correct value surveyed by a Utah Licensed surveyor after the installation of the 6 97 foot extension to the slimes dram access pipe The entry and calculations for 12/19/2011 in the table in Attachment 3 based on this value are also correct The plots of slimes dram elevation based on these values and measured depths to slimes dram solution as provided in the DMT reports to date are also correct As we agreed on February 14 2012 since the elevations in fmsl are correct there is no need to further revise any of the table entnes or the plots and as the calculations indicate the Cell 2 slimes dram recovery is in compliance with Part I D 3(b)(3) of the Groundwater Discharge Permit As we discussed on February 14 2012 the value of 5614 83 fmsl which was identified in Denison s January 27 2012 letter is not a correct value This entnes and calculations in the table in Attachment 3 of the letter and the data used to prepare the slimes dram elevation plots in the DMT reports were based on the correct values discussed above not on the incorrect value Therefore as we agreed on February 14 2012 since the elevations used are correct there is no need to further revise any of the table entnes or the plots As we discussed on February 14 2012 all calculation are based on the subtraction of an actual surveyed value in fmsl for the slimes dram access pipe elevation and an actual measured depth to fluid for the slimes dram solution and are not based on relative elevations The text in Section 3 1 b)(v) has been revised to include a descnption of the process DRC Comment 5 In Appendix F of the DMT Plan additionally the first bullet Ime should refer to Cell 4B instead of Cell 4A Please make this correction Denison Response The text has been changed as requested DRC Comment 6 The previous comment was Paragraph 6 2 needs to be revised due to the construction of Cell 4B It needs to be corrected to refer to the current exterior dikes required to have movement monitoring However DUSA s response that The text corrections have been made as requested is incorrect as no changes were made It appears dikes 4A E 4A S and 4B S are the current dikes exposed exterior dikes subject to movement monitoring Please indicate such in this paragraph of the plan Denison Response The text has been changed as requested DRC Comment 7 See Appendix A page 28 Table III Since the freeboard in Cell 1 is always exposed and the water level IS often changing all the dikes m Cell 1 become visible from time to time Columns need to be made available so inspection entries can be made for all the dikes of Cell 1 Similarly all the dikes of Cells 4A and 48 need to be included in the table Denison Response Per Denison s discussion with DRC on February 14 2012 Denison understands the need to include in the Daily Inspection Form a place to record observations from inspections of the intenor walls of all four DENISO MINES tJDii Letter to Mr Rusty Lundberg February 29 2012 Page 4 dikes of Cells 1 4A and 4B Consistent with our discussion with DRC Denison has revised Table II of the Daily Inspection Form to include space for these observations The title of Table II has been modified to clarify that it addresses inspection of the intenor conditions and issues at Cells 1 4A and 48 As we discussed the contents of Table III which addressed inspection of geotechnical components of the extenor of visible dikes have not been changed The notes inside Table III have been edited to clarify that the table addresses extenor dikes Please contact me if you have any questions or require any further information Yours very truly DENISON MINES (USA) CORP Jo Ann Tischler Director Compliance and Permitting cc David C Frydenlund Ron F Hochstein Harold R Roberts David E Turk Kathy A Weinel Attachments DENISO MINES CLEAN 1 i-I •J If WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMUMIZATION TECHNOLOGY (DMT) MONITORING PLAN Revision 11 5 February 2012 Prepared by Denison Mines (USA) Corp 1050 17* Street, Suite 950 Denver, CO 80265 White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 2 of 55 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN TABLE OF CONTENTS Contents 1 INTRODUCTION 4 2 DAILY TAILINGS INSPECTIONS 4 2 1 Daily Comprehensive Tailings Inspection 4 2 2 Daily Operations Inspection 7 2 3 Daily Operations Patrol 7 2 4 Training 7 2 5 Tailings Emergencies 7 3 WEEKLY TAILINGS AND DMT INSPECTION 8 3 1 Weekly Tailings Inspections 8 Northing 13 Easting 13 3 2 Weekly Inspection of Solution Levels in Roberts Pond 16 3 3 Weekly Feedstock Storage Area Inspections 16 4 MONTHLY TAILINGS INSPECTION 16 5 QUARTERLY TAILINGS INSPECTION 17 6 ANNUAL EVALUATIONS 18 6 1 Annual Technical Evaluation 18 6 2 Movement Monitors 19 6 3 Freeboard Limits 19 6 3 1 Cell 1 20 6 3 2 Cell 2 20 6 3 3 Cell 3 20 6 34 CelUA 20 63 5 Cell4B 21 6 3 6 Roberts Pond 23 6 4 Annual Leak Detection Fluid Samples 24 6 5 Annual Inspection of the Decontamination Pads 24 7 OTHER INSPECTIONS 24 N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 ^ Page 3 of 55 8 REPORTING REQUIREMENTS 8 1 Monthly Tailings Reports 8 2 DMT Reports 8 3 TAILMGS INSPECTOR TRAINING 24 25 25 42 N \DMT PlanVDMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 4 of 55 1 INTRODUCTION This Tailings Management System and Discharge Minimization Technology Monitoring Plan (the Plan ) for the White Mesa Mill (the Mill ) provides procedures for monitoring of the tailings cell system as required under State of Utah Radioactive Materials License No UTI900479 (the Radioactive Materials License ) as well as procedures for operating and maintenance of momtonng equipment and reporting procedures that are adequate to demonstrate DMT compliance under State of Utah Ground Water Discharge Permit No 370004 for the Mill (the GWDP ) This Plan is designed as a systematic program for constant surveillance and documentation of the integnty of the tailings impoundment system including dike stability liner integrity and transport systems as well as monitoring of water levels in Roberts Pond and feedstock storage areas at the Mill The Plan requires daily weekly quarterly monthly and annual inspections and evaluations and monthly reporting to Mill management / 2 DAILY TAILINGS INSPECTIONS The following daily tailings inspections shall be performed 2 1 Daily Comprehensive Tailings Inspection On a daily basis including weekends all areas connected with the evaporation cell (Cell 1) and thefour tailings cells (Cells 2 3 4A and 4B) will be inspected Observations will be made of the current condition of each cell noting any corrective action that needs to be taken The Radiation Safety Officer (RSO) or his designee is responsible for performing the daily tailings inspections The RSO may designate other individuals with training as described in Section 2 4 below to perform the daily tailings inspection Observations made by the inspector will be recorded on the Daily Inspection Data form (a copy of which IS attached in Appendix A) The Daily Inspection Data form contains an inspection checklist which includes a tailings cells map and spaces to record observations especially those of immediate concem and those requiring corrective action The inspector will place a check by all inspection Items that appear to be operating properly Those items where conditions of potential concem are observed should be marked with an X A note should accompany the X specifying what the concem is and what corrective measures will resolve the problem This observation of concem should be noted on the form until the problem has been remedied The date that corrective action was taken should be noted as well Areas to be inspected include the following Cell 1 2 3 4A and 4B Dikes 4A S 4A E and 4B N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 5 of 55 S Wind movement of tailings effectiveness of dust nunmuzation methods spray evaporation Cell 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and 4B liquid pools and associated liquid return equipment and cell leak detection systems Operational features of the tailings area are checked for conditions of potential concem The following Items require visual inspection during the daily tailings inspection a) Tailings slurry and SX raffinate transport systems from the Mill to the active disposal cell(s) and pool retum pipeline and pumps Daily inspections of the tailings lines are required to be performed when the Mill IS operating The lines to be inspected include the tailings slurry lines from CCD to the active tailings cell SX raffinate lines that can discharge into Cell 1 Cell 4A or Cell 4B the pond retum line from the tailings area to the Mill and lines transporting pond solutions from one cell to another b) Cell 1 c) Cell 2 d) Cell 3 e) Cell 4A f) Cell 4B g) Dike stmctures including dikes 4A S 4A E and 4B S h) The Cell 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and Cell 4B liquid pools and associated liquid retum equipment i) Presence of wildlife and/or domesticated animals m the tailings area including waterfowl and burrowing animal habitations j) Spray evaporation pumps and lines k) Wind movement of tailings and dust minmuzation Wind movement of tailings will be evaluated for conditions which may require initiation of preventative dust minimization measures for cells containing tailings sand Dunng tailings inspection general surface conditions will be evaluated for the following 1) areas of tailmgs subject to blowing and/or wind movement 2) N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 6 of 55 liquid pool size 3) areas not subject to blowing and/or wind movement expressed as a percentage of the total cell area The evaluations will be reviewed on a weekly basis or more frequently if warranted and will be used to direct dust nunimization activities 1) Observation of flow and operational status of the dust control/spray evaporation system(s) m) Observations of any abnormal variations in tailings pond elevations in Cells 1 3 4A and4B n) Locations of slurry and SX discharge within the active cells Slurry and SX discharge points need to be indicated on the tailmgs cells map included in the Daily Inspection Data form o) An estimate of flow for active tailings slurry and SX line(s) p) An estimate of flow in the solution retum line(s) q) Daily measurements in the leak detection system sumps of the tailings cells will be made when warranted by changes in the solution level of the respective leak detection system The trigger for further action when evaluating the measurements in the Cell 1 and Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours The solution level in Cell 4A or 4B leak detection system is not allowed to be more than 1 0 foot above the lowest point on the bottom flexible membrane liner (FML) (Cell 4A FML elevation is 5555 14 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5556 14 feet amsl For Cell 4B the FML elevation is 5557 50 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5558 50 feet amsl) If any of these observations are made the Mill Manager should be notified immediately and the leak detection system pump started In addition the requirement to notify the Executive Secretary in accordance with Parts ID 6 and IG 3 of the Groundwater Discharge Permit must be adhered to when the solution level tngger for Cell 4A or 4B has been exceeded Whenever the leak detection system pump is operating and the flow meter totalizer is recording a notation of the date and the time will be recorded on the Daily Inspection Data form This data will be used in accordance with License Condition 11 3 B through 11 3 E of the Mill s Radioactive Materials License to determine whether or not the flow rate into the leak detection system is in excess N \DMT PlanNDMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 7 of 55 of the License Conditions Items (a) (m) (n) and (o) are to be done only when the Mill is operating When the Mill is down these Items cannot be performed 2 2 Dailv Operations Inspection During Mill operation the Shift Foreman or other person with the training specified in Section 2 4 below designated by the Radiation Safety Officer will perform an inspection of the tailings line and tailmgs area at least once per shift paying close attention for potential leaks and to the discharges from the pipelines Observations by the Inspector will be recorded on the appropriate line on the Operating Foreman s Daily Inspection form 2 3 Daily Operations Patrol In addition to the inspections described in Sections 2 1 and 2 2 above a Mill employee will patrol the tailings area at least twice per shift dunng Mill operations to ensure that there are no obvious safety or operational issues such as leaking pipes or unusual wildlife activity or incidences No record of these patrols need be made but the inspectors will notify the RSO and/or Mill management in the event that during their inspection they discover that an abnormal condition or tailings emergency has occurred 2 4 Training All individuals performing inspections described in Sections 2 1 and 2 2 above must have Tailings Management System training as set out in the Tailmgs Inspection Training procedure which is attached as Appendix B This training will include a training pack explaining the procedure for performing the inspection and addressing inspection items to be observed In addition each individual after reviewing the training pack will sign a certification form indicating that training has been received relative to his/her duties as an inspector 2 5 Tailings Emergencies Inspectors will notify the RSO and/or Mill management immediately if dunng their inspection they discover that an abnormal condition exists or an event has occurred that could cause a tailings emergency Until relieved by the Environmental or Technician or RSO inspectors will have the authonty to direct resources dunng tailings emergencies Any major catastrophic events or conditions pertaining to the tailmgs area should be reported immediately to the Mill Manager or the RSO one of whom will notify Corporate Management If N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 8 of 55 dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) 3 WEEKLY TAILINGS AND DMT INSPECTION 3 1 Weeklv Tailmgs Inspections Weekly tailings inspections are to be conducted by the Radiation Safety Department and include the following a) Leak Detection Systems Each tailings cell s leak detection system shall be checked weekly (as well as daily) to detemune whether it is wet or dry If marked wet the liquid levels need to be measured and reported In Cell 1 and Cell 3 the leak detection system is measured by use of a dual probe system that senses the presence of solutions in the LDS system (comparable to the systems in Cells 4A and 4B) and indicates the presence of solution with a waming light The Cell 4A and 4B leak detection systems are monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector The pressure transducer is calibrated for fluid with a specific gravity of 1 0 The water levels are measured every hour and the information is stored for later retrieval The water levels are measured to the nearest 0 10 inch The data collector is currently programmed to store 7 days of water level information The number of days of stored data can be increased beyond 7 days if needed For Cells 1 and 3 the water level data is recorded on the Daily Tailings Inspection Form For Cells 4A and 4B the water level data is downloaded to a laptop computer penodically and incorporated mto the Mill s environmental monitonng data storage and into the files for weekly inspection reports of the tailings cell leak detection systems If sufficient fluid is present m the leak detection system of any cell the fluid shall be pumped from the LDS to the extent reasonably possible and record the volume of fluid recovered Any fluid pumped from an LDS shall be retumed to a disposal cell For Cells 1 and 3 if fluid is pumped from an LDS the flow rate shall be calculated by dividing the recorded volume of fluid recovered by the elapsed time since fluid was last pumped or increases m the LDS fluid levels were recorded whichever is the more recent This calculation shall be documented as part ofthe weekly inspection N VDMT PlanVDMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 9 of 55 For Cells 1 and 3 upon the initial pumping of fluid from an LDS a fluid sample shall be collected and analyzed in accordance with paragraph 11 3 C of the Radioactive Materials License For Cell 4A and 4B under no circumstance shall fluid head in the leak detection system sump exceed a 1 foot level above the lowest point in the lower flexible membrane liner To determine the Maximum Allowable Daily LDS Flow Rates in the Cell 4A and 4B leak detection systems the total volume of all fluids pumped from the LDS on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145 gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1A and IB (for Cells 4A and 4B respectively) in Appendix E to determine the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A and4B b) Slimes Drain Water Level Monitoring (i) Cell 3 is nearly full and will commence closure when filled Cell 2 is partially reclaimed with the surface covered by platform fill Each cell has a slimes drain system which aids in dewatering the slimes and sands placed m the cell (u) Denison re graded the intenm fill on Cell 2 in order to reduce the potential for the accumulation of stormwater on the surface of Cell 2 As a result of the re grading of the interim cover and the placement of an additional 62 000 cubic yards of fill material on Cell 2 the slimes drain access pipe was extended 6 97 feet The extension pipe is 6 97 feet in length and therefore the new measuring point is 37 97 feet from the bottom of the slimes drain The measunng point on the extension pipe was surveyed by a Utah Certified Land Surveyor The measuring point elevation is 5618 73 fmsl For the quarterly recovery test described in section vi below this extension has no effect on the data measurement procedures Cell 2 has a pump placed inside of the slimes drain access pipe at the bottom of the slimes dram As taken from actual measurements the bottom of the slimes drain is 37 97 feet below a water level measuring point which is a notch on the side of the Cell 2 slimes drain access pipe This means that the bottom of the slimes drain pool and the location of the pump are one foot above the lowest point of the FML in Cell 2 which based on constmction reports is at a depth of 38 97 feet below the water level measunng point on the slimes drain access pipe for Cell 2 (ill) The slimes dram pump in Cell 2 is activated and deactivated by a float mechanism and water level probe system When the water level reaches the level of N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 10 of 55 the float mechanism the pump is activated Pumping then occurs until the water level reaches the lower probe which tums the pump off The lower probe is located one foot above the bottom of the slimes drain standpipe and the float valve is located at three feet above the bottom of the slimes drain standpipe The average wastewater head in the Cell 2 slimes drain is therefore less than 3 feet and is below the phreatic surface of tailings Cell 2 about 27 feet below the water level measuring point on the slimes drain access pipe As a result there is a continuous flow of wastewater from Cell 2 into the slimes drain collection system Mill management considers that the average allowable wastewater head in the Cell 2 slimes drain resulting from pumping in this manner is satisfactory and is as low as reasonably achievable (iv) The Cell 2 slimes drain pump is checked weekly to observe that it is operating and that the water level probe and float mechanism are working properly which is noted on the Weekly Tailings Inspection Form If at any time the pump is observed to be not working properly it will be fixed or replaced withm 15 days (v) Depth to wastewater in the Cell 2 slimes drain access pipe shall be monitored and recorded weekly to determine maximum and minimum fluid head before and after a pumping cycle respectively The extension of the Cell 2 slimes drain access pipe did not require any changes to the measurement procedure The surveyed measunng point on the extended pipe is used as required The elevation of the measuring point is 5618 73 fmsl The head measurements are calculated in the same manner using the same procedures as those used pnor to the extension of the Cell 2 slimes drain access pipe however the total depth to the bottom of the pipe is now 37 97 feet as noted on the corrected form in Attachment A All head measurements must be made from the same measuring point (the notch at the north side of the access pipe 5618 73 fmsl) and made to the nearest 0 01 foot The results will be recorded as depth in pipe measurements on the Weekly Tailings Inspection Form The equation specified in the GWDP will be used to calculate the slimes drain recovery elevation (SDRE) To calculate the SDRE contemplated by the GWDP the depth to wastewater in the Cell 2 slimes drain access pipe (in feet) will be subtracted from the surveyed elevation of the measuring point The calculation is as follows 5618 73 Depth to wastewater in the Cell 2 shmes drain access pipe = SDRE It IS important to note that the extension of the Cell 2 slimes access pipe has not changed the method of calculation of the pre and post pump head calculations only the constant (Cell 2 slimes dram access pipe height) used in the calculation has changed The head is calculated by subtracting the depth to liquid from 37 97 feet rather than from the previous measurement of 38 feet The weekly Tailings Inspection form included in Attachment A has been changed to reflect the extension height (vi) Effective July 11 2011 on a quarterly basis the slimes drain pump will be tumed off and the wastewater in the slimes drain access pipe will be allowed to stabilize for at N \DMT PlanXDMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 11 of 55 least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level of the wastewater will be measured and recorded as a depth in pipe measurement on Quarterly Data form by measunng the depth to water below the water level measuring point on the slimes dram access pipe (vn) No process liquids shall be allowed to be discharged into Cell 2 (vill) If at any time the most recent average annual head in the Cell 2 slimes drain is found to have increased above the average head for the previous calendar year the Licensee will comply with the requirements of Part IG 3 of the GWDP including the requirement to provide notification to the Executive Secretary orally within 24 hours followed by written notification (ix)Because Cell 3 and Cell 4A are currently active no pumping from the Cell 3 or Cell 4A slimes drain is authorized No pumping from the Cell 4B slimes drain will be authorized once it is put into service and while it is active Prior to initiation of tailings dewatering operations for Cell 3 Cell 4A or Cell 4B a similar procedure will be developed for ensuring that average head elevations in the Cell 3 and Cell 4A slimes drains are kept as low as reasonably achievable and that the Cell 3 Cell 4A and Cell 4 slimes drains are inspected and the results reported in accordance with the requirements of the permit c) Wind Movement of Tailings An evaluation of wind movement of tailmgs or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 1 4A and 4B and Roberts Pond are to be taken by survey on a weekly basis The beach area m Cell 4B with the maximum elevation is to be taken by survey on a monthly basis when beaches are first observed as follows (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (u) The survey will be performed using a survey instmment (the Survey Instmment ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a survey rod (the Survey Rod ) having a visible scale in 0 01 foot increments (iii)The Reference Points for Cells 1 Cell 4A and 4B and Roberts Pond are known points established by professional survey For Cell 1 and Roberts Pond the Reference Point is a wooden stake with a metal disk on it located on the southeast corner of Cell 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 4A and 4B the Reference Point is a piece of stamped metal monument located N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 12 of 55 next to the transformer on the south side of Cell 4A and 4B The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A and 4B) is 5600 49 fmsl The Surveyor will set up the Survey Instmment in a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this IS typically on the road on the Cell 1 south dike between Cell 1 and Roberts Pond approximately 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4A and Cell 4B this is typically on the south side of Cell 4A and 4B (iv) Once m location the Surveyor will ensure that the Survey Instmment is level by centenng the bubble in the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor has established a level reading (vi) The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instmment is reading above the Reference Point (vn) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the main solution pond in the Cell 1 Cell 4A Cell 4B or Roberts Pond or the area of the beach in Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistently use the same locations are as follows For a newly constmcted cell when the cell is first placed into operation the solution level is typically zero feet above the FML or a minimal elevation above the FML due to natural precipitation For newly constmcted cells measurement of solution level will commence within 30 days of authorization for use Measurements will be conducted as descnbed above in items d) (i) through d) (vii) of this Section consistent with current Mill health and safety procedures The measurements will be completed using survey equipment and the appropriate length survey rod (either 25 or 45 ) A Pond Surface Measurements I Cell 4A The Assistant will walk down the slope in the northeast comer of Cell 4A and place the Survey Rod at the liquid level n Cell 4B The Assistant will walk down the slope in the southeast comer of Cell 4B and place the Survey Rod at the liquid level N \DMT Plan\DMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 13 of 55 m Cell 1 A mark has been painted on the north side of the ramp going to the pump platform in Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and IV Roberts Pond A mark has been painted on the railing of the pump stand in Roberts Pond The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface Based on the foregoing methods the approximate coordinate locations for the measunng points for Roberts Pond and the Cells are Northing Easting Roberts Pond 323 041 2 579 697 Cell 1 322 196 2 579 277 Cell 4A 320 300 2 579 360 Cell 4B 320 690 2 576 200 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells B Cell 4B Beach Elevation Beach elevations m Cell 4B will commence when beaches are first observed The Assistant will place the Survey Rod at the point on the beach area of Cell 4B that has the highest elevation If it is not clear which area of the beach has the highest elevation then multiple points on the beach area will be surveyed until the Surveyor is satisfied that the point on the Cell 4B beach area with the highest elevation has been surveyed If it is clear that all points on the Cell 4B beach area are below 5 593 FMSL then the Surveyor may rely on one survey point (vill) The Assistant will hold the Survey Rod vertically with one end of the Survey Rod just touching the pond surface The Assistant will ensure that the Survey Rod IS vertical by gently rocking the rod back and forth until the Surveyor has established a level reading (ix)The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Pond Surface Reading ) which N \DMT PlanXDMT Plan 02 29 12 Rev 11 5\DMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 14 of 55 represents the number of feet the Survey Instmment is reading above the pond surface level The Surveyor will calculate the elevation of the pond surface as FSML by adding the Reference Point Reading for the Cell or Roberts Pond as the case may be to the Reference Point Elevation for the Cell or Roberts Pond and subtracting the Pond Surface Reading for the Cell or Roberts Pond and will record the number accurate to 0 01 feet e) Decontamination Pads (i) New Decontamination Pad The New Decontamination Pad is located in the southeast comer of the ore pad near the Mill s scale house A In order to ensure that the primary containment of the New Decontamination Pad water collection system has not been compromised and to provide an inspection capability to detect leakage from the primary containment vertical inspection portals have been installed between the pnmary and secondary containments B These portals will be visually observed on a weekly basis as a means of detecting any leakage from the pnmary containment into the void between the primary and secondary containment The depth to water m each portal will be measured weekly by physically measuring the depth to water with an electrical sounding tape/device All measurements must be made from the same measuring point and be made to the nearest 0 01 foot C These inspections will be recorded on the Weekly Tailings Inspection form D The water level shall not exceed 0 10 foot above the concrete floor m any standpipe at any time This will be determined by subtracting the weekly depth to water measurement from the distance from the measuring point in the standpipe to the dry concrete floor The depth to water from the top (elevation 5589 8 feet amsl) of any of the three (3) observation ports to the standing water shall be no less than 6 2 feet Depths less than 6 2 feet shall indicate more that 0 1 foot of standing water above the concrete floor (elev 5583 5 feet amsl) and shall indicate a leak in the primary containment N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 15 of 55 E Any observation of fluid between the pnmary and secondary containments will be reported to the Radiation Safety Officer (RSO) F In addition to inspection of the water levels m the standpipes the New Decontanunation Pad including the concrete integrity of the exposed surfaces of the pad will be inspected on a weekly basis Any soil and debns will be removed from the New Decontamination Pad immediately prior to inspection of the concrete wash pad for cracking Observations will be made of the current condition of the New Decontamination Pad Any abnormalities relating to the pad and any damage to the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired (ll) Existing Decontamination Pad The Existing Decontamination Pad is located between the northwest comer of the Mill s maintenance shop and the ore feeding grizzly A The Existing Decontamination Pad will be inspected on a weekly basis Any soil and debns will be removed from the Existing Decontamination Pad immediately prior to inspection of the concrete wash pad for cracking Observations will be made of the cunent condition of the Existing Decontamination Pad including the concrete integrity of the exposed surfaces of the pad Any abnormalities relating to the pad and any damage or cracks on the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired f) Summary In addition the weekly inspection should summarize all activities conceming the tailings area for that particular week Results of the weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection form An example of the Weekly Tailings and DMT Inspection form is provided m Appendix A N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 16 of 55 3 2 Weeklv Inspection of Solution Levels in Roberts Pond On a weekly basis solution elevations are taken on Roberts Pond in accordance with the procedures set out in Section 3 1 d) above The Weekly solution level in Roberts Pond is recorded on the Weekly Tailings and DMT Inspection form Based on historical observations the FML at the Pond Surface Reading area for Roberts Pond is approximately six inches above the lowest point on the pond s FML Ifthe pond solution elevation at the Pond Surface Reading area is at or below the FML for that area the pond will be recorded as being dry 3 3 Weeklv Feedstock Storage Area Inspections Weekly feedstock storage area inspections will be performed by the Radiation Safety Department to confirm that a) the bulk feedstock materials are stored and maintained withm the defined area described in the GWDP as indicated on the map attached hereto as Appendix D b) a 4 ft buffer is maintained at the periphery of the storage area which is absent bulk material in order to assure that the matenals do not encroach upon the boundary of the storage area and c) all altemate feedstock located outside the defined Feedstock Area are maintained within water tight containers The results of this inspection will be recorded on the Ore Storage/Sample Plant Weekly Inspection Report a copy of which is contained in Appendix A Any vanance in stored materials from this requirement or observed leaking altemate feedstock dmms or other containers will be brought to the attention of Mill Management and rectified within 15 days 4 MONTHLY TAILINGS INSPECTION Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from the Radiation Safety Department and recorded on the Monthly Inspection Data form an example of which is contained in Appendix A Monthly inspections are to be performed no sooner than 14 days since the last monthly tailings inspection and can be conducted concunently with the quarterly tailings inspection when applicable The following items are to be inspected a) Tailings Slurry Pipeline When the Mill is operating the slurry pipeline will be visually inspected at key locations to determine pipe wear The critical points of the pipe include bends slope changes valves and junctions which are critical to dike stability These locations to N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 17 of 55 be monitored will be determined by the Radiation Safety Officer or his designee from the Radiation Safety Department during the Mill mn b) Diversion Ditches Diversion ditches 1 2 and 3 shall be monitored monthly for sloughing erosion undesirable vegetation and obstmction of flow Diversion berm 2 should be checked for stability and signs of distress c) Sedimentation Pond Activities around the Mill and facilities area sedimentation pond shall be summanzed for the month d) Overspray Dust Minimization The inspection shall include an evaluation of overspray minimization if applicable This entails ensunng that the overspray system is functioning properly In the event that overspray is carried more than 50 feet from the cell the overspray system should be immediately shut off e) Remarks A section is included on the Monthly] Inspection Data form for remarks in which recommendations can be made or observations of concem can be documented f) Summary of Daily Weekly and Quarterly Inspections The monthly inspection will also summarize the daily weekly and if applicable quarterly tailings inspections for the specific month In addition settlement monitors are typically surveyed monthly and the results reported on the Monthly Inspection Data form | 5 QUARTERLY TAILINGS INSPECTION The quarterly tailings inspection is performed by the Radiation Safety Officer or his designee from the Radiation Safety Department having the training specified in Section 2 4 above once per calendar quarter A quarterly inspection should be performed no sooner than 45 days since the previous quarterly inspection was performed Each quarterly inspection shall include an Embankment Inspection an Operations/Maintenance 1 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 18 of 55 Review a Constmction Review and a Summary as follows a) Embankment Inspection The Embankment inspection involves a visual inspection of the crest slope and toe of each dike for movement seepage [Severe erosion subsidence shrinkage cracks and exposed Imer b) Operations/Maintenance Review The Operations/Maintenance Review consists of reviewing Operations and Maintenance activities pertaining to the tailmgs area on a quarterly basis c) Construction Review The Constmction Review consists of reviewing any constmction changes or modifications made to the tailings area on a quarterly basis d) An estimate of the percentage of the tailings beach surface area and solution pool area is made including estimates of solutions cover areas and tailmgs sands for Cells 3 4A and 4B e) Summary The summary will include all major activities or observations noted around the tailings area on a quarterly basis If any of these conditions are noted the conditions and corrective measures taken should be documented in the Quarterly Inspection Data form An example of the Quarterly Inspection Data form IS provided in Appendix A 6 ANNUAL EVALUATIONS The following annual evaluations shall be performed 6 1 Annual Technical Evaluation An annual techmcal evaluation of the tailings management system is performed by a registered professional engineer (PE) who has expenence and training in the area of geotechnical aspects of retention stmctures The technical evaluation includes an on site inspection of the tailings management system and a thorough review of all tailings records for the past year The Technical Evaluation also includes a review and summary of the annual movement monitor survey (see Section 5 2 below) N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 19 of 55 All tailings cells and corresponding dikes will be inspected for signs of erosion subsidence shrinkage and seepage The drainage ditches will be inspected to evaluate surface water control stmctures In the event tailmgs capacity evaluations (as per SOP PBL 3) were performed for the receipt of altemate feed material during the year the capacity evaluation forms and associated calculation sheets will be reviewed to ensure that the maximum tailings capacity estimate is accurate The amount of tailings added to the system since the last evaluation will also be calculated to determine the estimated capacity at the time of the evaluation Tailings inspection records will consist of daily weekly monthly and quarterly tailings inspections These inspection records will be evaluated to determine if any freeboard limits are being approached Records will also be reviewed to summanze observations of potential concem The evaluation also involves discussion with the Environmental and/or Radiation Technician and the Radiation Safety Officer regarding activities around the tailings area for the past year During the annual inspection photographs of the tailings area will be taken The training of individuals will be reviewed as a part of the Annual Technical Evaluation The registered engineer will obtain copies of selected tailings inspections along with the monthly and quarterly summaries of observations of concem and the conective actions taken These copies will then be included in the Annual Technical Evaluation Report The Annual Technical Evaluation Report must be submitted by November 15* of every year to the Executive Secretary 6 2 Movement Monitors A movement monitor survey is to be conducted by a licensed surveyor annually during the second quarter of each year The movement monitor survey consists of surveying monitors along dikes 4A E 4A S and 4B S to detect any possible settlement or movement of the dikes The data generated from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the tailings management system 6 3 Freeboard Lirmts The freeboard limits set out m this Section are intended to capture the Local 6 hour Probable Maximum Precipitation (PMP) event which was determined in the January 10 1990 Drainage Report (the Drainage Report ) for the White Mesa site to be 10 inches The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas was calculated in the Drainage Report to be 103 acre feet of water with a wave mn up factor of N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 20 of 55 0 90 feet The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas plus the adjacent drainage areas was calculated m the Drainage Report to be 123 4 acre feet of water The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage Report to be 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres) times the PMP of 10 inches) with a wave mn up factor of 0 77 feet The flood volume from the PMP event over the Cell 4B area has been calculated to be 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 72 acres) times the PMP of 10 inches with a wave mn up factor of 0 77 feet The total pool surface area in Cell 1 is 52 9 acres in Cell 4A is 40 acres and in Cell 4B is 40 acres The top of the flexible membrane liner ( FML ) for Cell 1 is 5 618 2 FMSL for Cell 4A is 5 598 5 FMSL and for Cell 4B is 5600 4 FMSL Based on the foregoing the freeboard limits for the Mill s tailings cells will be set as follows 63 1 Cell 1 The freeboard limit for Cell 1 will be set at 5 615 4 FMSL This will allow Cell 1 to capture all of the PMP volume associated with Cell 1 The total volume requirement for Cell 1 is 103 acre feet divided by 52 9 acres equals 1 95 feet plus the wave mn up factor of0 90 feet equals 2 85 feet The freeboard limit is then 5 618 2 FMSL minus 2 85 feet equals 5 615 4 FMSL Under Radioactive Materials License condition 10 3 this freeboard limit is set and is not recalculated annually 63 2 Cell 2 The freeboard limit for Cell 2 is inapplicable since Cell 2 is filled with solids All of the PMP volume associated with Cell 2 will be attnbuted to Cell 4A (and/or any future tailings cells) 633 Cell 3 The freeboard limit for Cell 3 is inapplicable since Cell 3 is close to being filled with solids and all of the PMP flood volume associated with Cell 3 will be attributed to Cell 4B (and/or any future tailmgs cells) 634 Cell 4A The freeboard limit for Cell 4A is inapplicable since all of the PMP flood volume associated with Cell 4A will be attributed to Cell 4B A spillway has been added to Cell 4A to allow overflow mto Cell 4B N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 21 of 55 635 Cell 4B The freeboard limit for Cell 4B will be set assuming that the total PMP volume for Cells 2 3 4A and 4B of 159 4 acre feet will be accommodated in Cell 4B The procedure for calculating the freeboard limit for Cell 4B is as follows (a) When the Pool Surface Area is 40 Acres When the pool surface area in Cell 4B is 40 acres (i e when there are no beaches) the freeboard limit for Cell 4B will be 5 594 6FMSL which is 5 7 feet below the FML This freeboard value was developed as follows PMP Flood Volume 38 1 acre feet Overflow from Cell 4A assunung no storage in Cell 3 or 4A 159 4 acre feet Sum of PMP volume and overflow volume 197 5 acre feet Depth to store PMP an overflow volume = 197 5 acre feet/40 acres 4 9 feet Wave mn up factor 0 77 feet Total required freeboard 5 7 feet (all values in the above calculation have been rounded to the nearest one tenth of afoot) (b) When the Maximum Elevation ofthe Beach Area is 5 594 FMSL or Less When the maximum elevation of the beach area in Cell 4B is 5594 FMSL or less then the freeboard limit will be 5 594 6 FMSL which is the same as in (a) above This allows for the situation where there may be beaches but these beaches are at a lower elevation than the freeboard limit established m (a) above and there is therefore ample freeboard above the beaches to hold the maximum PMP volume The maximum elevation of the beach area will be determined by monthly surveys performed by Mill personnel in accordance with the Mill s DMT Plan (c) When the Maximum Elevation ofthe Beach Area First Exceeds 5 594 FMSL When the maximum elevation of the beach area in Cell 4B first exceeds 5 594 FMSL then the freeboard limit for the remainder of the ensuing year (period t=0) (until the next November 1) will be calculated when that elevation is first exceeded (the Initial Calculation Date ) as follows i) The total number of dry tons of tailmgs that have historically been deposited into Cell 4B prior to the Initial Calculation Date ( To ) will be determined u) The expected number of dry tons to be deposited into Cell 4B for the remainder of the ensuing year (up to the next November 1) based on production estimates for that period ( Ao* ) will be determined 111) Ao* will be grossed up by a safety factor of 150% to allow for a potential underestimation of the number of tons that will be deposited m the cell during the N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 22 of 55 remainder of the ensuing year This grossed up number can be refened to as the modeled tonnage for the period iv) The total design tailings solid storage capacity of Cell 4B will be accepted as 2 094 000 dry tons of tailings v) The available remaining space in Cell 4B for solids as at the Initial Calculation Date will be calculated as 2 094 000 dry tons minus To VI) The reduction m the pool surface area for the remainder of the ensuing year will be assumed to be directly proportional to the reduction in the available space in Cell 4B for solids That is the reduced pool surface area for period t=0 ( RPAo ) after the reduction will be calculated to be (1 - (Ao* X 1 5) / (2 094 000 To)) x 40 acres = RPAo VII) The required freeboard for Cell 4B for the remainder of the period t=0 can be calculated in feet to be the wave mn up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAo The freeboard limit for Cell 4B for the remainder of period t=0 would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of afoot and vill) The foregoing calculations will be performed at the Initial Calculation Date and the resulting freeboard limit will persist until the next November 1 An example of this calculation is set out in Appendix F (d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds 5 594 FMSL On November 1 of each year (the Annual Calculation Date ) the reduction m pool area for the ensuing year (refened to as period t) will be calculated by i) First calculating the Adjusted Reduced Pool Area for the previous penod (ARPAt i) to reflect actual tonnages deposited in Cell 4B for the previous period (penod t 1) The RPAt 1 used for the previous period was based on expected tonnages for period t 1 grossed up by a safety factor The ARPAt i is merely the RPA that would have been used for period t 1 had the actual tonnages for year t 1 been known at the outset of period t 1 and had the RPA been calculated based on the actual tonnages for penod t 1 This allows the freeboard calculations to be conected each year to take into account actual tonnages deposited m the cell as of the date of the calculation The ARPAt 1 can be calculated using the following formula (1 - At 1 / (2 094 000 - Tt 0) x ARPAt 2 = ARPAt i Where • At 1 IS the actual number of dry tons of tailings solids deposited in Cell 4B dunng penod t 1 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 23 of 55 • Tt 1 IS the actual number of dry tons of tailings solids historically deposited in Cell 4B prior to the beginning of penod t 1 and • ARPAt 2 IS the Adjusted Reduced Pool Area for period t 2 If period t 2 started at the Initial Calculation! Date then ARPAt 2 is 40 acres II) Once the ARPAt 1 for the previous period (period t 1) has been'calculated the RPA for the subject period (period t) can be calculated as follows (1 - (At* X 1 5) / (2 094 000 Tt)) x ARPAt 1 = RPAt Where • At* IS the expected number of dry tons of tailings to be deposited into Cell 4B for the ensuing year (period t) based on production estimates for the year (as can be seen from the foregoing formula this expected number is grossed up by a safety factor of 1 5) • Tt is the actual number of dry tons of tailings solids historically deposited in Cell 4B pnor to the beginning of period t and • ARPAt 1 IS the Adjusted Reduced Pool Area for period t 1 which is the pool surface area for the previous period (period t 1) that should have applied during that period had modeled tonnages (1 e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod III) The required freeboard for period t can be calculated in feet to be the wave mn up factor for Cell 4B of0 77 feet plus the quotient of 197 5 acre feet divided by the RPAt The freeboard limit for Cell 4B for penod t would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of a foot and ' iv) The foregoing calculations will be performed at the Annual Calculation Date for period t and the resulting freeboard limit will persist until the next Annual Calculation Date for period t+1 An example of this calculation is set out in Appendix F (e) When a Spillway is Added to Cell 4B that Allows Overflow Into a New Tailings Cell When a spillway is added between Cell 4B and a new tailings cell then if an approved freeboard linut calculation method for the new cell is set to cover the entire PMP event for Cells 2 3 4A 4B and the new tailings cell the freeboard linut for Cell 4B will be inapplicable except for approved provisions to prevent storm water mnoff from overtopping dikes 6 3 6 Roberts Pond 1 The freeboard limit for Roberts Pond is a liquid maximum elevation of 5 624 0 feet above mean sea level as specified in the GWDP N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 24 of 55 6 4 Annual Leak Detection Fluid Samples In the event solution has been detected in a leak detection system a sample will be collected on an annual basis This sample will be analyzed according to the conditions set forth in License Condition 11 3 C The results of the analysis will be reviewed to determine the origin of the solution 6 5 Annual Inspection of the Decontanunation Pads a) New Decontamination Pad During the second quarter of each year the New Decontamination Pad will be taken out of service and inspected to ensure the integnty of the wash pad s exposed concrete surface If any abnormalities are identified i e cracks in the concrete with greater than 1/8 inch separation (width) or any significant deterioration or damage of the pad surface repairs will be made pnor to resuming the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontamination Pad Inspection form The inspection findings any repairs required and repairs completed shall be summarized in the 2"^ Quarter DMT Monitoring Report due September 1 of each calendar year b) Existing Decontamination Pad Dunng the second quarter of each year the Existing Decontamination Pad will be taken out of service and inspected to ensure the integrity of the steel tank Once the water and any sediment present is removed from the steel tank containment the walls and bottom of the tank will be visually inspected for any areas of damage cracks or bubbling indicating conosion that may have occuned since the last inspection If any abnormalities are identified defects or damage will be reported to Mill management and repairs will be made pnor to resuming the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontamination Pad Inspection form A record of the repairs will be maintained as a part of the Annual Inspection records at the Mill site The inspection findings any repairs required and repairs completed shall be summarized in the 2nd Quarter DMT Monitoring Report due September 1 of each calendar year 7 OTHER INSPECTIONS All daily weekly monthly quarterly and annual inspections and evaluations should be performed as specified in Sections 2 3 4 5 and 6 above However additional inspections should be conducted after any significant storm or significant natural or man made event occurs 8 REPORTING REQUIREMENTS N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 25 of 55 In addition to the Daily Inspection Data Weekly Tailings Inspection Monthly Inspection Data and Quarterly Inspection Data forms included as Appendix A and described in Sections 2 3 4 and 5 respectively and the Operating Foreman s Daily Inspection and Weekly Mill Inspection forms described in Sections 2 and 3 respectively the following additional reports shall also be prepared 8 1 Monthlv Tailmgs Reports Monthly tailings reports are prepared every month and summanze the previous month s activities around the tailings area If not prepared by the Radiation Safety Officer the report shall be submitted to the Radiation Safety Officer for review The Mill Manager will review the report as well before the report is filed in the Mill Central File The report will contain a summary of observations of concem noted on the daily and weekly tailings inspections Conective measures taken during the month will be documented along with the observations where appropnate All daily and weekly tailings inspection forms will be attached to the report A monthly inspection form will also be attached Quarterly inspection forms will accompany the report when applicable The report will be signed and dated by the preparer in addition to the Radiation Safety Officer and the Mill Manager 82 DMT Reports Quarterly reports of DMT monitoring activities which will include the following information will be provided to the Executive Secretary on the schedule provided in Table 5 of the GWDP a) On a quarterly basis all required information required by Part 1 F 2 ofthe GWDP relating to the inspections described in Section 3 1(b) (Slimes Dram Water Level Monitonng) 3 1(d) (Tailings Wastewater Pool and Beach Area Elevation Monitoring) 3 2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3 3 (Weekly Feedstock Storage Area Inspections) b) On a quarterly basis a summary of the weekly water level (depth) inspections for the quarter for the presence of fluid in all three vertical inspection portals for each of the three chambers in the concrete settling tank system for the New Decontamination Pad which will include a table indicating the water level measurements in each portal dunng the quarter c) With respect to the annual inspection of the New Decontamination Pad descnbed in Section 6 5(a) the inspection findings any repairs required and repairs completed shall be summarized in the 2"^* Quarter report due September 1 of each calendar year d) With respect to the annual inspection of the Existing Decontanunation Pad descnbed in Section 6 5(b) the inspection findings any repairs required and N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 26 of 55 e) repairs completed shall be summarized in the 2"^ Quarter report due September 1 of each calendar year and An annual summary and graph for each calendar year of the depth to wastewater in the Cell 2 slimes drain must be included in the fourth quarter report After the first year and beginning in 2008 quarterly reports shall include both the cunent year monthly values and a graphic comparison to the previous year ,'1, N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 27 of 55 APPENDIX A FORMS N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc S Q < H T3 s O Q PQ 13 U <\ U PQ 13 U 13 13 U «n in c o I ^ Q ITS OH C o > c c« 2 2 o O B -o 2 03 I 1 « t/1 1—1 B M o ^ OQ < O Z u o IX) W PH T3 1-H P pt: c o o X o s o TD .<-> c 3 o o T3 <U CA s S o o c S B HH csl 13 U U e o c o U OH o c o U c o Q c o o -I 00 S 3 o 3 -g X) 3 00 3 O O o 3 Od > 00 2^ 3 l/l O a U Ul O c > Ul I u > o U Ul (U 3 c o c/1 C u Q c o > 0\ CN OH too c c o o 00 a. O TJ C B c e c o c« " s :: 3 (U .<-> o PlH 3 O -3 3 O U 3 O 1—1 o 0) T3 o CD'::' 1) OH <^ X ^ la (D c« ^ fe 00 00 o 3 3 ^ ^ I c« i> CD 00 XH CM 00 « OH g O. (U on TD 3 *-> fe o o o 52 «^ < O > (U 00 (U o 3 "2 c« X) 3 00 cS O U Ut u tu > 00 >-2 oU 00 00 o o iz; iz; c/a c« (U (U S Wl PIH ^ -g Si TH t/3 ^ -o PQ 13 U < 13 U cn 13 U Csl 13 U o H Z o u H 3 JS o 3 3 H MH o HH 3 s > o 00^ 3 3 Q lo in TH t4_| a o o o Q ^ c ^ o > a; CN PQ 13 U 13 U U TD o ,3 U. o T3 o 2 D (U o s 3 o O Q > •-I c >i T3 (U O S 3 O 13 O Q S 13 2 > o s 3 o 13 O ^ I sl A . C ^ OS 2 2 a 3 o* O « I c i c US o U ? = ci rn c« *^ O ^ PQ 3 O •*—> -3 3 o 5b o o B 13 u 1-H 3 s 1> T3 <o O S 3 a a;* > TJ T3 a e 3 O O ai 1-H t4H e o 0 ^ 1 cn > CS -O 00 el 3 c 2 2 o. « 53 ^ I I c „ o " u t/1 ^ o X , -1 Tailings Dail> Inspection Repoit Tailings Sluny Dbchaige Location >n irj c o Q OO C3 C ^ o > CN c c« 2 3 <u al 2 2 T3 JH 53 ^ -§ 2 S c I c Ul ? ^ ca m t/3 ^ :: ^ o ^ CQ MILLSITE CELL NO 1 r— It) k DtkelL CELL NO 2 FiUetf CELL NO 4B CELL NO 4A Date Inspect 01 N White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 33 of 55 APPENDIX A (CONT) DENISON MINES (USA) CORP WEEKLY TAILINGS INSPECTION Date Inspectors 1 Pond and Beach Cell 1 (a) Pond SoluUon Elevation elevations (msl ft) (b) FML Bottom ElevaUon 5597. (c) Depth of Water above FML ((a) (b)) Cell4A (a)Pond SoluUon Elevation (b) FML Bottom Elevation 5555 14_ (c) Depth of Water above FML ((a) (b)) Cell 4B (a)Pond SoluUon ElevaUon (b) FML Bottom ElevaUon 5557 50 (c) Depth of Water above FML ((a) (b)) (d) ElevaUon of Beach Area with Highest ElevaUon (monthly) Roberts Pond (a)Pond SoluUon Elevation (b) FML Bottom ElevaUon 5612 3_ (c) Depth of Water above FML ((a) (b)) 2 Slimes Drain Liquid Levels Cell 2 Pump funcUoning properly _Depth to Liquid pre pump .Depth to Liquid Post pump (all measurements are depth in pipe) Pre pump head is 37 97 Depth to Liquid Pre pump = Post pump head is 37 97 -Depth to Liquid Post pump = N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual Section 3 1 ' 2/12Revision Denisonll 5 Page 34 of 55 3 Leak Detection Systems (Same data as Daily InspecUon Form Record data on daily form) Observation New Decon Pad. Portal 1 New Decon Pad. Portal 2 New Decon Pad Portal 3 Is LDS (Portal) wet or dry*^ _wet dry _wet dry .wet dry If wet Record liquid level Liquid Ft to Liquid Ft to Liquid Ft to If wet Report to RSO 4 Tailings Area Inspection (Note dispersal of blowing taihngs) 5 Control Methods Implemented 6 Remarks 7 Designated Disposal Area for Non Taihngs Mill Waste (awaiUng DRC approval) * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane hner (solution elevaUon of 5556 14 amsl for Cell 4A and 5558 50 for Cell 4B)'? no yes If Cell 4A leak detection system level exceeds 12 inches above the lowest point on the bottom flexible membrane liner (elevation 5556 14 amsl) notify supervisor or Mill manager immediately N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 35 of 55 APPENDIX A (CONT) MONTHLY INSPECTION DATA Inspector Date 1 Slurry Pipehne 2 Diversion Ditches and Diversion Berm Observation Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2 Diversion Ditches Sloughing Erosion Undesirable VegetaUon ObstmcUon of Flow Diversion Berm Stability Issues Signs of Distress .yes. .yes. .yes. jes_ _no _no _no no .yes. jes_ ^es_ _yes_ _no .no _no no _yes_ ^es_ ^es_ ^es_ _no _no _no no _yes_ _yes_ .no no Comments 3 Summary of Activities Around Sedimentation Pond N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental ProtecUon Manual Section 3 1 2/12Revision Denisonll 5 Page 36 of 55 4 Overspray Dust Minimization Overspray system functioning properly ^es_ Overspray earned more than 50 feet from the cell If yes was system immediately shut off? Comments no _yes_ _yes_ no no 5 Remarks 6 Settlement Momtors Cell 2 Wl Cell 2 W2 Cell 2 W3 Cell 2 W4 Cell 2W7 C Cell 2 W7N Cell2W6C Cell 4A Toe Cell 3 2C Cell 3 3S Cell 3 4N Cell 3 7C Cell 3 8C Cell 2W3 S Cell 2E1 N Cell 2E1 IS Cell 2E1 2S Cell 2 East Cell 2 W7S Cell 2 W6S Cell 2 W4S Cell 3 2S _ Cell 3 3C _ Cell 3 6N _ Cell 3 7N _ Cell 3 8N Cell 3 IN _ Cell 3 IC _ Cell 3 IS _ Cell 3 2N _ Cell 2W5 N Cell 2 W6N Cell 2 W4N Cell 2 W5C Cell 2 W5S Cell3 3N _ Cell 3 7S _ Cell 3 8S 7 Movement Momtors surfaces)*^ (Is there visible damage to any movement momtor or to adjacent 8 Summary of Daily, Weekly and Quarterly Inspections N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual SecUon 3 1 2/12Revision Denisonll 5 Page 37 of 55 •t 1 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc I 1 White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual Section 3 1 2/12 Revision Denisonll 5 Page 38 of 55 APPENDIX A (CONT) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector Date 1 Embankment Inspection 2 Operations/Maintenance Review 3 Construction Activities 4 Estimated Areas Cell 3 Cell 4A Cell 4B Estimated percent of beach surface area Estimated percent of solution pool area Estimated percent of cover area Comments N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 Siclean doc White Mesa Mill - Standard OperaUng Procedures 2/12 Revision Denison 11 5 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 39 of 55 APPENDIX A (CONT) ORE STORAGE/SAMPLE PLANT WEEKLY INSPECTION REPORT Week of through Date of Inspection Inspector Weather conditions for the week Blowing dust conditions for the week Corrective actions needed or taken for the week Are all bulk feedstock matenals stored in the area indicated on the attached diagram yes no comments Are all altemate feedstock matenals located outside the area indicated on the attached diagram maintained within water tight containers yes no comments (e g conditions of containers) Are all sumps and low lying areas free of standing solutions'? Yes No If No how was the situation corrected supervisor contacted and correction date*? Is there free standing water or water mnning off of the feedstock stockpiles'? Yes No Comments N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual SecUon 3 1 2/12 Revision Denisonll 5 ^ Page 40 of 55 Other comments N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental ProtecUon Manual Section 3 1 Page 41 of 55 APPENDIX A (CONT) ANNUAL DECONTAMINATION PAD INSPECTION Date of Inspection Inspector New Decontamination Pad Are there any cracks on the wash pad surface greater than 1/8 inch of separation'? Yes No Is there any significant detenoration or damage of the pad surface'? Yes No Findings Repair Work Required Existing Decontamination Pad Were there any observed problems with the steel tank'? Yes ^No Findings Repair Work Required Note For the annual inspection of the both the Existing and New Decontamination Pads the annual inspection findings any repairs required and repairs completed along with a summary of the weekly inspections shall be discussed in the 2^^ Quarter report due September 1 of each calendar year N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 42 of 55 APPENDIXB 8 3 TAILINGS INSPECTOR TRAINING This document provides the training necessary for qualifying management designated individuals for conducting daily tailings inspections Training information is presented by the Radiation Safety Officer or designee from the Environmental Department Daily tailmgs inspections are conducted in accordance with the White Mesa Mill Tailings Management System and Discharge Minmuzation Technology (DMT) Monitonng Plan The Radiation Safety Officer or designee from the Radiation Safety Department is responsible for performing monthly and quarterly tailings inspections Tailings inspection forms will be included in the monthly tailings inspection reports which summarize the conditions activities and areas of concem regarding the tailings areas Notifications The inspector is required to record whether all inspection items are normal (satisfactory requinng no action) or that conditions of potential concem exist (requiring action) A check mark indicates no action required If conditions of potential concem exist the inspector should mark an X in the area the condition pertains to note the condition and specify the conective action to be taken If an observable concem is made it should be noted on the tailings report until the conective action is taken and the concem is remedied The dates of all conective actions should be noted on the reports as well Any major catastrophic events or conditions pertaining to the tailings area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) Inspections All areas of the teulmgs disposal system are routmely patrolled and visible observations are to be noted on a daily tailmgs inspection form Refer to Appendix A for an example of the daily tailings inspection form The inspection form consists of three pages and is summanzed as follows 1 Tailings Slurry Transport System The slurry pipeline is to be inspected for leaks damage and sharp bends The pipeline joints are to be monitored for leaks and loose connections The pipeline supports are to be inspected for damage and loss of support Valves are also to be inspected particularly for N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual SecUon 3 1 Page 43 of 55 leaks blocked valves and closed valves Points of discharge need to be inspected for improper location and orientation Operational Systems Operating systems including water levels beach liners and covered areas are items to be inspected and noted on the daily inspection forms Sudden changes in water levels previously observed or water levels exceeding the operating level of a pond are potential areas of concem and should be noted Beach areas that are observed as having cracks severe erosion or cavities are also items that require investigation and notation on daily forms Exposed liner or absence of cover from erosion are potential items of concem for ponds and covered areas These should also be noted on the daily inspection form Cells 1 3 4A and 4B solution levels are to be monitored closely for conditions nearing maximum operating level and for large changes m the water level since the last inspection All pumping activities affecting the water level will be documented In Cells 1 and 3 the PVC liner needs to be monitored closely for exposed liner especially after storm events It is important to cover exposed liner immediately as exposure to sunlight will cause degradation of the PVC liner Small areas of exposed liner should be covered by hand Large sections of exposed liner will require the use of heavy equipment These conditions are considered senous and require immediate action After these conditions have been noted to the Radiation Safety Officer a work order will be written by the Radiation Safety Officer and tumed into the Maintenance Department All such repairs should be noted in the report and should contain the start and finish date of the repairs Dikes and Embankments Inspection items include the slopes and the crests of each dike For slopes areas of concem are sloughs or sliding cracks bulges subsidence severe erosion moist areas and areas of seepage outbreak For crests areas of concem are cracks subsidence and severe erosion When any of these conditions are noted an X mark should be placed in the section marked for that dike In addition the dikes in particular dikes 4A S 4A E and4B S should be inspected closely for mice holes and more importantly for prairie dog holes as the prairie dogs are likely to bunow in deep possibly to the liner If any of these conditions exist the inspection report should be marked accordingly N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 44 of 55 4 Flow Rates Presence of all flows in and out of the cells should be noted Flow rates are to be estimated in gallons per minute (GPM) Rates need to be deternuned for slurry lines pond retum SX tails and the spray system During non operational modes the flow rate column should be marked as 0 The same holds tme when the spray system is not utilized 5 Physical Inspection of Slurry Line(s) A physical inspection of all slurry lines has to be made every 4 hours during operation ofthe mill If possible the inspection should include observation of the entire discharge line and discharge spill point into the cell If fill to elevation flags are in place the tailings and build up is to be monitored and controlled so as to not cover the flags 6 Dust Control Dusting and wind movement of tailings should be noted for Cells 2 3 4A and 4B Other observations to be noted include a bnef description of present weather conditions and a record of any precipitation received Any dusting or wind movement of tailings should be documented In addition an estimate should be made for wind speed at the time of the observed dusting or wind movement of tailmgs The Radiation Safety Department measures precipitation on a daily basis Daily measurements should be made as near to 8 00 a m as possible every day Weekend measurements will be taken by Environmental Health and Safety personnel as close to 8 00 a m as possible All snow or ice should be melted before a reading is taken 7 Observations of Potential Concern All observations of concem dunng the inspection should be noted m this section Conective action should follow each area of concem noted All work orders issued contacts or notifications made should be noted in this section as well It is important to document all these Items in order to assure that the tailings management system records are complete and accurate 8 Map of Tailings Cells The last section of the inspection involves drawing as accurately as possible the following Items where applicable N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 45 of 55 1 Cover area 2 Beach/tailmg sands area 3 Solution as it exists 4 Pump lines 5 Activities around tailings cell (i e hauling trash to the dump liner repairs etc ) 6 Slurry discharge when operating 7 Over spray system when operating 9 Safety Rules All safety mies applicable to the mill are applicable when in the tailings area These mies meet the required MSHA regulations for the tailings area Please pay particular notice to the following mies 1 The posted speed limit on Cell 4A and 4B dike is 5 mph and the posted speed limit for the tailings area (other than the Cell 4A and 4B dike) is 15 mph These limits should not be exceeded 2 No food or drink is permitted in the area 3 All personnel entering the tailings area must have access to a two way radio 4 Horseplay is not permitted at any time 5 Only those specifically authorized may operate motor vehicles in the restncted area 6 When road conditions are muddy or slick a four wheel drive vehicle is required in the area 7 Any work perfonned in which there is a danger of falling or slipping in the cell will require the use of a safety belt or hamess with attended life line and an approved life jacket A portable eyewash must be present on site as well 8 Anytime the boat is used to perform any work an approved life jacket and goggles must be wom at all times There must also be an approved safety watch with a two way hand held radio on shore A portable eyewash must be present on site as well 10 Preservation of Wildlife Every effort should be made to prevent wildlife and domesticated animals from entering the tailings area All wildlife observed should be reported on the Wildlife Report Worksheet during each shift Waterfowl seen near the tailings cells should be discouraged from landing by the use of noisemakers 11 Certification Following the review of this document and on site instmction on the tailings system inspection program designated individuals will be certified to perfonn daily tailings inspections The Radiation Safety Officer authorizes certification Refer to the Certification N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 ^ Page 46 of 55 Form Appendix C This form should be signed and dated only after a thorough review of the ^ tailings information previously presented The form will then be signed by the Radiation ^ ^ Safety Officer and filed N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc -i T White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Envu-onmental Protection Manual Section 3 1 Page 47 of 55 APPENDIX C CERTIFICATION FORM Date Name I have read the document titled Tailings Management System White Mesa Mill Tailings Inspector Training and have received on site instmction at the tailings system This instmction included documentation of daily tailings inspections analysis of potential problems (dike failures unusual flows) notification procedures and safety Signature I certify that the above named person is qualified to perform the daily inspection of the tailings system at the White Mesa Mill Radiation Safety Personnel/ Tailings System Supervisor N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual Section 3 1 Page 48 of 55 APPENDDC D FEEDSTOCK STORAGE AREA N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental Protection Manual Section 3 1 2/12Revision Denisonll 5 Page 49 of 55 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan February 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 2/12 Revision Denisonl l 5 ' Page 50 of 55 APPENDIX E TABLES N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 51 of 55 Table lA Calculated Action leakage Rates for Various head Conditions Cell 4A White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate ( gallons / acre / day) 5 222 04 10 314 01 15 384 58 20 444 08 25 496 50 30 543 88 35 587 46 37 604 01 Table IB Calculated Action leakage Rates for Vanous head Conditions Cell 4B White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate ( gallons / acre / day) 5 21140 10 317 00 15 369 90 20 422 70 25 475 60 30 528 40 35 570 00 37 581 20 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard OperaUng Procedures . 2/12 Revision Denisonll 5 Book 11 Envu-onmental Protection Manual SecUon 3 1 Page 52 of 55 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12 Revision Denisonll 5 Page 53 of 55 APPENDIX F Example of Freeboard Calculations For Cell 4B Assumptions and Factors o Total PMP volume to be stored m Cell 4B - 159 4 acre feet o Wave mnup factor for Cell 4B - 0 77 feet o Total capacity of Cell 4B - 2 094 000 dry tons o Elevation of FML of Cell 4B - 5 600 35 FMSL o Maximum pool surface area of Cell 4B - 40 acres o Total tailings solids deposited mto Cell 4B at time beach area first exceeds 5 594 FMSL - 1 000 000 dry tons* o Date beach area first exceeds 5 594 FMSL - March 1 2012* o Expected and actual production is as set forth in the following table Time Period Expected Tailings Solids Disposition mto Cell 4B Determined at the beginning of the period (dry tons)* Expected Tailings Sohds Dispositio n into Cell 4B at the beginning of the period, multiplied by 150% Safety Factor (dry tons) Actual Tailings Sohds Disposition into Cell 4B determmed at end of the period (dry tons)* March 1 2012 to November 1 2012 150 000 225 000 225 000 November 1 2012 to November 1 2013 300 000 450 000 275 000 November 1 2013 to November 1 2014 200 000 300 000 250 000 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev U 5 clean doc White Mesa Mill - Standard OperaUng Procedures 2/12 Revision Denison 11 5 Book 11 Environmental Protection Manual SecUon 3 1 Page 54 of 55 *These expected and actual tailmgs and production numbers and dates are fictional and have been assumed for illustrative purposes only Based on these assumptions and factors the freeboard limits for Cell 4B would be calculated as follows 1 Prior to March 1.2012 Prior to March 1 2012 the maximum elevation of the beach area m Cell 4B is less than or equal to 5 594 FMSL therefore the freeboard limit is set at 5 594 6 FMSL 2 March 1. 2012 to November 1. 2012 The pool surface area would be reduced to the following amount (1-225 000/ (2 094 000 - 1 000 000)) x 40 acres = 31 77 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 31 77 acres equals 6 22 feet When the wave mn up factor for Cell 4B of0 77 feet is added to this the total freeboard required is 6 99 feet This means that the freeboard limit for Cell 4B would be reduced from 5594 6 FMSL to 5592 2 FMSL (5594 6 FMSL minus 6 22 feet rounded to the nearest one tenth of a foot) This calculation would be performed at March 1 2012 and this freeboard limit would persist until November 1 2012 3 November 1, 2012 to November 1. 2013 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied during the previous period had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the period Smce the actual tonnage of 225 000 dry tons was the same as the modeled tonnage of 225 000 dry tons the recalculated pool surface area is the same as the modeled pool surface area for the previous period which is 31 77 acres Then calculate the modeled pool surface area to be used for the penod (1-450 000/ (2 094 000 - 1 000 000 225 000)) x 31 77 acres = 15 32 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 15 32 acres equals 12 89 feet When the wave mn up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 13 66 feet This means that the freeboard limit for Cell 4B would be reduced from 5592 2 FMSL to 5586 7 FMSL (5600 35 FMSL minus 13 66 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2012 and this freeboard limit would persist until November 1 2013 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 2/12Revision Denisonll 5 Page 55 of 55 4 November 1. 2013 to November 1. 2014 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied during the previous period had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the period Since modeled tonnages exceeded actual tonnages j the pool area was reduced too much during the previous period and must be adjusted The recalculated pool area for the previous penod is (1-275 000 / (2 094 000 - 1 000 000 225 000) x 31 77 acres = 2172 acres This recalculated pool surface area will be used as the starting point for the freeboard calculation to be performed at November 1 2013 Then calculate the modeled pool surface area to be used for the period (1-300 000 / (2 094 000 - 1 000 000 225 000 - 275 000)) x 21 72 acres 10 75 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 10 75 acres equals 18 37 feet When the wave mn up factor for Cell 4B of0 77 feet is added to this the total freeboard required is 19 14 feet This means that the freeboard limit for Cell 4B would be reduced from 5586 7 FMSL to 5581 2 FMSL (5600 4 FMSL minus 18 4 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2013 and this freeboard limit would persist until November 1 2014 N VDMT PlanVDMT Plan 02 29 12 Rev 11 5VDMT Plan Febmary 2012 Rev 11 5 clean doc REDLINE ) 1 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMUMIZATION TECHNOLOGY fPMTl MONITORING PLAN Revision 11 5 February 2012 Prepared bv Denison Mines (USA) Corp 1050 17^ Street. Suite 950 Denver. CO 80265 I White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Denison 11 45 Book 11 Environmental Protection Manual Section 3 1 Page 2 of 55 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN TABLE OF CONTENTS Contents 1 INTRODUCTION 4^ 2 DAILY TAILINGS INSPECTIONS 4^ 2 1 Daily Comprehensive Tailings Inspection 4^ 2 2 Daily Operations Inspection 7§ 2 3 Daily Operations Patrol 7^ 2 4 Training 76 2 5 Tailings Emergencies 76 3 WEEKLY TAILINGS AND DMT INSPECTION 87 3 1 Weekly Tailings Inspections 8? Northing 1343 Easting 1343 3 2 Weekly InspecUon of Solution Levels in Roberts Pond 3 3 Weekly Feedstock Storage Area InspecUons 1615 4 MONTHLY TAILINGS INSPECTION 16i5 5 QUARTERLY TAILINGS INSPECTION 1746 6 ANNUAL EVALUATIONS 1847 6 1 Annual Technical Evaluation 1847 6 2 Movement Monitors 194^ 6 3 Freeboard Limits 194^ 6 3 1 Cell 1 2019 6 3 2 Cell 2 2019 6 3 3 CeU 3 2019 6 3 4 Cell 4A 2019 6 3 5 Cell 4B 2130 6 3 6 Roberts Pond 2333 6 4 Annual Leak DetecUon Ruid Samples 243^ 6 5 Annual Inspection of the Decontamination Pads 243^ 7 OTHER INSPECTIONS 243^ N,\DMT Plan\DMT Plan 02 29.12 Rev 11.5\DMT Plan February 2012 Re 11.5 redline.docNDMT PlanVDN4T Plan 01 30 12 Rovioion U 4\Tiulmg3 Mgnt Syatom end DMT Mon Plan January 2012 rov 11 4 clooadoc I White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 4-2/12 Revision Denison 11 45 Page 3 of 55 REPORTING REQUIREMENTS 8 1 Monthly Tailings Reports 8 2 DMT Reports 8 3 TAILINGS INSPECTOR TRAINING 253^ 2534 2534 4244 N.NDMT Plan\DMT Plan 02.29.12 Re 11.5\DMT Plan February 2012 Rev 11.5 redhne.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailinga Mgnt Syatom ond DMT Mon Plan Jonuary 2012 rov 1M clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Denison 11 45 Book 11 Environmental ProtecUon Manual Section 3 1 Page 4 of 55 1 INTRODUCTION This Tailings Management System and Discharge Minimization Technology Monitonng Plan (the Plan ) for the White Mesa Mill (the Mill ) provides procedures for monitonng of the tailings cell system as required under State of Utah RadioacUve Matenals License No UTI900479 (the Radioactive Matenals License ) as well as procedures for operaUng and maintenance of monitonng equipment and reportmg procedures that are adequate to demonstrate DMT compliance under State of Utah Ground Water Discharge Penrnt No 370004 for the MiU (the GWDP ) This Plan is designed as a systematic program for constant surveillance and documentation of the integnty of the tailings impoundment system including dike stability liner integnty and transport systems as well as monitonng of water levels in Roberts Pond and feedstock storage areas at the Mill The Plan requires daily weekly quarterly monthly and annual mspections and evaluations and monthly reporting to Mill management 2 DAILY TAILINGS INSPECTIONS The following daily tailmgs inspections shall be performed 2 1 Daily Comprehensive Tailings Inspection On a daily basis including weekends all areas connected with the evaporation cell (Cell 1) and thefour tailings cells (Cells 2 3 4A and 4B) will be inspected Observations will be made of the current condition of each cell noting any corrective action that needs to be taken The Radiation Safety Officer (RSO) or his designee is responsible for performing the daily tailings inspections The RSO may designate other individuals with training as descnbed m Section 2 4 below to perform the daily tailings inspection Observations made by the inspector will be recorded on the Daily Inspection Data form (a copy of which IS attached in Appendix A) The Daily Inspection Data form contains an mspection checklist which includes a tailings cells map and spaces to record observations especially those of immediate concem and those requinng conective action The inspector will place a check by all inspection items that appear to be operating properly Those items where conditions of potential concem are observed should be marked with an X A note should accompany the X specifying what the concem is and what corrective measures will resolve the problem This observation of concem should be noted on the form until the problem has been remedied The date that corrective action was taken should be noted as well Areas to be inspected include the following Cell 1 2 3 4A and 4B Dikes 4A S 4A E and 4B N.VDMT PlanVDMT Plan 02.29.12 Rev 1 l.SVDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 ilVTailuiga Mgnt SyBtcm ond DMT Mon Plan January 2012 rov 11 4 clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental ProtecUon Manual Section 3 1 Page 5 of 55 S wind movement of tailings effectiveness of dust minimization methods spray evaporation CeU 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and 4B liquid pools and associated liquid retum equipment and cell leak detection systems Operational features of the tailings area are checked for conditions of potential concem The following Items require visual inspection dunng the daily tailings inspection a) Tailings slurry and SX raffinate transport systems from the Mill to the active disposal cell(s) and pool retum pipehne and pumps Daily inspections of the tailmgs lines are required to be performed when the Mill is operating The lines to be inspected include the tailings slurry lines from CCD to the active taihngs cell SX raffinate lines that can discharge into Cell 1 Cell 4AorCell4B the pond retum line from the tailings area to the Mill and lines transporting pond solutions from one cell to another b) Cell 1 c) Cell 2 d) Cell 3 e) Cell 4A f) Cell 4B g) Dike stmctures including dikes 4A S 4A E and 43 S h) The Cell 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and Cell 4B liquid pools and associated liquid retum equipment i) Presence of wildlife and/or domesticated animals in the tailings area mcluding waterfowl and burrowing animal habitations j) Spray evaporation pumps and lines k) Wind movement of tailings and dust minimization Wind movement of tailmgs will be evaluated for conditions which may require initiation of preventative dust mimnuzation measures for cells contammg tailings sand Dunng tailings inspection general surface conditions will be evaluated for the following 1) areas of tailings subject to blowing and/or wind movement 2) N.VDMT PlanVDMT Plan 02.29.12 Re 11.5VDMT Plan February 2012 Re 11.5 edl ne.dncN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 'IVToilinga Mgnt Syatom and DMT Mon Plon Jonuory 2012 rev 11 4 clooadoo White Mesa Mill - Standard OperaUng Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental ProtecUon Manual Section 3 1 Page 6 of 55 liquid pool size 3) areas not subject to blowing and/or wind movement expressed as a percentage of the total cell area The evaluations will be reviewed on a weekly basis or more frequently if warranted and will be used to direct dust minmuzation activities 1) Observation of flow and operational status of the dust control/spray evaporation system(s) m) Observations of any abnormal vanations m tailings pond elevations in Cells 1 3 4A and4B n) Locations of slurry and SX discharge within the active cells Slurry and SX discharge points need to be indicated on the tailings cells map included in the Daily Inspection Data form o) An estimate of flow for active tailings slurry and SX line(s) p) An estimate of flow in the solution retum line(s) q) Daily measurements in the leak detection system sumps of the tailings cells will be made when wananted by changes in the solution level of the respective leak detection system The tngger for fiirther action when evaluating the measurements m the Cell 1 and Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours The solution level in Cell 4A or 4B leak detection system is not allowed to be more than 1 0 foot above the lowest point on the bottom flexible membrane liner (FML) (Cell 4A FML elevation is 5555 14 amsl and widi the addition of the 1 0 foot of solution the solution elevation is 5556 14 feet amsl For Cell 4B the FML elevation is 5557 50 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5558 50 feet amsl) If any of these observations are made the Mill Manager should be notified immediately and the leak detection system pump started In addition the requirement to notify the Executive Secretary m accordance with Parts ID 6 and IG 3 of the Groundwater Discharge Permit must be adhered to when the solution level tngger for Cell 4A or 4B has been exceeded Whenever the leak detection system pump is operating and the flow meter totalizer is recording a notation of the date and the time will be recorded on the Daily Inspection Data form This data will be used in accordance with License Condition 11 3 B through 11 3 E of the Mill s Radioactive Matenals License to determine whether or not the flow rate into the leak detection system is m excess N.VDMT PlanVDMT Plan 02.29.12 Rev 11.5VDMT Plan February 2012 Re 11.5 redline.docN VDMT PlanVDMT Plan 01 30 12 Reviaion 11 IVToihnga Mgnt Syatom ond DMT Mon Plan Januory 2012 rev II 1 cleoadoc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental ProtecUon Manual Section 3 1 Page 7 of 55 of the License Conditions Items (a) (m) (n) and (o) are to be done only when the Mill is operating When the Mill is down these Items cannot be performed 2 2 Dailv Operations Inspection Dunng Mill operation the Shift Foreman or other person with the training specified in Section 2 4 below designated by the Radiation Safety Officer will perform an inspection of the tailings hne and tailings area at least once per shift paying close attention for potential leaks and to the discharges from the pipelines Observations by the Inspector will be recorded on the appropnate line on the Operating Foreman s Daily Inspection form 2 3 Dailv Operations Patrol In addition to the inspections descnbed m Sections 2 1 and 2 2 above a Mill employee will patrol the tailings area at least twice per shift dunng Mill operations to ensure that there are no obvious safety or operational issues such as leaking pipes or unusual wildlife activity or incidences No record of these patrols need be made but the inspectors will notify the RSO and/or Mill management m the event that dunng their inspection they discover that an abnormal condition or tailings emergency has occuned 2 4 Training All individuals performing inspections descnbed m Sections 2 1 and 2 2 above must have Tailmgs Management System training as set out in the Tailings Inspection Training procedure which is attached as Appendix B This training will include a training pack explaimng the procedure for performing the inspection and addressing inspection items to be observed In addition each individual after reviewing the training pack will sign a certification form indicating that training has been received relative to his/her duties as an inspector 2 5 Tailings Emergencies Inspectors will notify the RSO and/or Mill management immediately if dunng their mspection they discover that an abnormal condition exists or an event has occuned that could cause a tailings emergency Until relieved by the Environmental or Technician or RSO inspectors will have the authonty to direct resources dunng tailings emergencies Any major catastrophic events or conditions pertaining to the tailings area should be reported immediately to the Mill Manager or the RSO one of whom will notify Corporate Management If N.VDMT PlanVDMT Plan 02.29.12 Re 11 5VDMT Plan February 2012 Re 11.5 redl e.docN VDMT PlanVDMT Plan 01 30 12 Rovioion 11 4VTailmg3 Mgnt System and DMT Mon Plan January 2012 rov 11 4 clean doc White Mesa Mill - Standard OperaUng Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual SecUon 3 1 Page 8 of 55 dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) 3 WEEKLY TAILINGS AND DMT INSPECTION 3 1 Weeklv Tailings Inspections Weekly tailmgs inspections are to be conducted by the Radiation Safety Department and include the following a) Leak Detection Systems Each tailings cell s leak detection system shall be checked weekly (as well as daily) to determine whether it is wet or dry If marked wet the liquid levels need to be measured and reported In Cell 1 and Cell 3 the leak detection system is measured by use of a dual probe system that senses the presence of solutions in the LDS system (comparable to the systems m Cells 4A and 4B) and indicates the presence of solution with a waming light The Cell 4A and 4B leak detection systems are monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electromc data collector The pressure transducer is cahbrated for fluid with a specific gravity of 1 0 The water levels are measured every hour and the information is stored for later retneval The water levels are measured to the nearest 010 inch The data collector is cunently programmed to store 7 days of water level information The number of days of stored data can be increased beyond 7 days if needed For Cells 1 and 3 the water level data is recorded on the Daily Tailmgs Inspection Form For Cells 4A and 4B the water level data is downloaded to a laptop computer penodically and incorporated into the Mill s environmental momtonng data storage and mto the files for weekly inspection reports of the tailings cell leak detection systems If sufficient fluid is present in the leak detection system of any cell the fluid shall be pumped from the LDS to the extent reasonably possible and record the volume of fluid recovered Any fluid pumped from an LDS shall be retumed to a disposal cell For Cells 1 and 3 if fluid is pumped from an LDS the flow rate shall be calculated by dividing the recorded volume of fluid recovered by the elapsed time smce fluid was last pumped or increases m the LDS fluid levels were recorded whichever is the more recent This calculation shall be documented as part of the weekly inspection N.VDMT PlanVDMT Plan 02.29.12 Re 11.5VDMT Plan February 2012 Re 11.5 ledl ne docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailinga Mgnt Syatom and DMT Mon Plan January 2012 rov 11 4 cloan.doc White Mesa Mill - Standard OperaUng Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 9 of 55 For Cells 1 and 3 upon the imtial pumping of fluid from an LDS a fluid sample shall be collected and analyzed in accordance with paragraph 11 3 C of the Radioactive Matenals License For Cell 4A and 4B under no circumstance shall fluid head in the leak detection system sump exceed a 1 foot level above the lowest point in the lower flexible membrane liner To detemune the Maximum Allowable Daily LDS Flow Rates in the Cell 4A and 4B leak detection systems the total volume of all fluids pumped from the LDS on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145 gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1A and IB (for Cells 4A and 4B respectively) in Appendix E to determine the maximum daily allowable LDS flow volume for varying head conditions m Cell 4A and 4B b) Slimes Drain Water Level Monitoring (i) Cell 3 IS nearly full and will commence closure when filled Cell 2 is partially reclaimed with the surface covered by platform fill Each cell has a slimes dram system which aids in dewatenng the slimes and sands placed m the cell (u) Denison re graded the intenm fill on Cell 2 in order to reduce the potential for the accumulation of stormwater on the surface of Cell 2 As a result of the re grading of the intenm cover and the placement of an additional 62 000 cubic yards of fill matenal on Cell 2 the slimes drain access pipe was extended 6 97 feet The extension pipe is 6 97 feet m length and therefore the new measunng point is 37 97 feet from the bottom of the shmes drain The measunng point on the extension pipe was surveyed by a Utah Certified Land Surveyor The measunng point elevation is 5618 73 fmsl For the quarterly recovery test descnbed in section vi below this extension has no effect on the data measurement procedures Cell 2 has a pump placed mside of the shmes drain access pipe at the bottom ofthe shmes dram As taken from actual measurements the bottom of the slimes drain is 37 97 feet below a water level measunng point which is a notch on the side of the Cell 2 shmes drain access pipe This means that the bottom of the shmes dram pool and the location of the pump are one foot above the lowest point of the FML in Cell 2 which based on constmction reports is at a depth of 38 97 feet below the water level measunng point on the shmes dram access pipe for Cell 2 On) The shmes drain pump in Cell 2 is activated and deactivated by a float mechanism and water level probe system When the water level reaches the level of N.VDMT PlanVDMT Plan 02.29 12 Re 1 l.SVDMT Plan February 2012 Re 11.5 redl e.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailing3 Mgnt Syatem and DMT Mon Plon January 2012 rov 11 4 clooadoo I White Mesa Mill - Standard OperaUng Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 10 of 55 the float mechamsm the pump is acti vated Pumpmg then occurs until the water level reaches the lower probe which tums the pump off The lower probe is located one foot above the bottom of the shmes drain standpipe and the float valve is located at three feet above the bottom of the shmes drain standpipe The average wastewater head in the Cell 2 shmes dram is therefore less than 3 feet and is below the phreatic surface of tailings Cell 2 about 27 feet below the water level measunng point on the shmes drain access pipe As a result there is a continuous flow of wastewater from Cell 2 into the shmes drain collection system Mill management considers that the average allowable wastewater head in the Cell 2 shmes drain resulting from pumping in this manner is satisfactory and is as low as reasonably achievable (iv) The Cell 2 shmes drain pump is checked weekly to observe that it is operating and that the water level probe and float mechanism are working properly which is noted on the Weekly Tailings Inspection Form If at any time the pump is observed to be not working properly it will be fixed or replaced withm 15 days (v) Depth to wastewater in the Cell 2 shmes drain access pipe shall be monitored and recorded weekly to determine maximum and minimum fluid head before and after a pumping cycle respectively The extension of the Cell 2 shmes drain access pipe did not require any changes to the measurement procedure The surveyed measunng point on the extended pipe is used as required The elevation of the measunng point IS 5618 73 fmsl The head measurements are calculated in the same manner using the same procedures as those used pnor to the extension of the Cell 2 shmes drain access pipe however the total depth to the bottom of the pipe is now 37 97 feet as noted on the conected form in Attachment A All head measurements must be made from the same measunng point (the notch at the north side of the access pipe 5618 73 fmsl) and made to the nearest 0 01 foot The results will be recorded as depth in pipe measurements on the Weekly Tailings Inspection Form The equation specified in the GWDP will be used to calculate the shmes drain recoverv elevation (SDRE) To calculate the SDRE contemplated bv the GWDP. the depth to wastewater in the Cell 2 shmes drain access pipe (m feet) will be subtracted from the surveyed elevation of the measunng point The calculation is as follows 5618 73 Depth to wastewater m the Cell 2 shmes drain access pipe = SDRE It IS important to note that Tthe extension of the Cell 2 shmes access pipe has not changed the method of calculation of the pre and post pump head calculations only the constant (Cell 2 shmes drain access pipe height) used in the calculation has changed The head is calculated by subtracting the depth to liquid from 37 97 feet rather than from the previous measurement of 38 feet The weekly Tailings Inspection form included m Attachment A has been changed to reflect the extension height (vi) Effective July 11 2011 on a quarterly basis the shmes drain pump will be mmed off and the wastewater in the shmes drain access pipe will be allowed to stabilize for at N.VDMT PlanVDMT Plan 02.29.12 Re 11.5VDMT Plan February 2012 Re 115 inline docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailme3 Mgnt Syatom ond DMT MOD Plan Januory 2012 rev 11 4 clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 11 of 55 least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level of the wastewater will be measured and recorded as a depth in pipe measurement on Quarterly Data form by measunng the depth to water below the water level measunng point on the shmes drain access pipe (vii) No process liquids shall be allowed to be discharged into Cell 2 (vm) If at any time the most recent average annual head m the Cell 2 shmes dram is found to have increased above the average head for the previous calendar year the Licensee will comply with the requirements of Part IG 3 of the GWDP mcluding the requirement to provide notification to the Executive Secretary orally within 24 hours followed by wntten notification (ix) Because Cell 3 and Cell 4A are currently active no pumping from the Cell 3 or CeU 4A shmes drain is authonzed No pumping from the Cell 4B shmes drain will be authonzed once it is put into service and while it is active Pnor to mitiation of tailings dewatenng operations for Cell 3 Cell 4A or Cell 4B a similar procedure will be developed for ensunng that average head elevations in the CeU 3 and Cell 4A shmes drains are kept as low as reasonably achievable and that the Cell 3 Cell 4A and CeU 4 shmes drains are mspected and the results reported in accordance with the requirements of the pemut c) Wind Movement of Tailings An evaluation of wind movement of tailings or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 1 4A and 4B and Roberts Pond are to be taken by -(Fomiatted Justified survey on a weekly basis The beach area in Cell 4B with the maximum elevation is to be taken by survey on a monthly basis when beaches are first observed as follows (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (ll) The survey will be performed using a survey instmment (the Survey Instrament ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a survey rod (the Survey Rod ) having a visible scale in 0 01 foot increments (iii)The Reference Points for Cells 1 Cell 4A and 4B and Roberts Pond are known points established by professional survey For Cell 1 and Roberts Pond the Reference Point is a wooden stake with a metal disk on it located on the southeast comer of CeU 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 4A and 4B the Reference Point is a piece of stamped metal monument located N.VDMT PlanVDMT Plan 02.29.12 Re 11 5\DMT Plan February 2012 Rev 11.5 redl e.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VToilmga Mgnt Syatom ond DMT Mon Plan January 2012 rov 11 4 cloaadoc White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 12 of 55 next to the transformer on the south side of Cell 4A and 4B The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A and 4B) is 5600 49 fmsl The Surveyor will set up the Survey Instmment m a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this IS typically on the road on the Cell 1 south dike between Cell 1 and Roberts Pond approximately 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4A and Cell 4B this is typically on the south side of CeU 4A and 4B (iv) Once in location the Surveyor will ensure that the Survey Instmment is level by centenng the bubble in the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by genfly rocking the rod back and forth until the Surveyor has established a level reading (vi) The Surveyor will focus the cross hairs of the Survey Instrament on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instrament is reading above the Reference Point (vu) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the mam solution pond in the Cell 1 Cell 4A Cell 4B or Roberts Pond or the area of the beach in Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistently use the same locations are as follows For a newly constmcted cell when the cell is first placed into operation the solution level is typically zero feet above the FML or a rmmmal elevation above the FML due to natural precipitation -For newly constmcted cells measurement of solution level will commence within 30 days of authonzation for use Measurements will be conducted consistent with the procedures as descnbed above in items d) (i) through d) (vn) of this Section in this DMT Plan and consistent with cunent Mill health and safety procedures The measurements will be completed using survey equipment and the appropnate length survey rod (either 25 or 45 ) A Pond Surface Measurements I Cell 4A The Assistant will walk down the slope in the northeast comer of Cell 4A and place the Survey Rod at the liquid level n Cell 4B N.VDMT PlanVDMT Plan 02.29.12 Rev 11.5VDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTQilmga Mgnt Syatem and DMT MOD Plan January 2012 rov 11 4 clooadoc White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 1 42/12 Revision Demsonl 1 45 Page 13 of55 The Assistant will walk down the slope in the southeast comer of Cell 4B and place the Survey Rod at the liquid level m Cell 1 A mark has been painted on the north side of the ramp going to the pump platform in Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and rv Roberts Pond A mark has been painted on the railing of the pump stand in Roberts Pond The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface Based on the foregoing methods the approximate coordinate locations for the measunng points for Roberts Pond and the Cells are Northing Easting Roberts Pond 323 041 2 579 697 CeU 1 322 196 2 579 277 CeU 4A 320 300 2 579 360 Cell 4B 320 690 2 576 200 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells CeU 4B Beach Elevation Beach elevations m Cell 4B will commence when beaches are first observed The Assistant will place the Survey Rod at the point on the beach area of Cell 4B that has the highest elevation If it is not clear which area of the beach has the highest elevation then multiple points on the beach area will be surveyed until the Surveyor is satisfied that the point on the CeU 4B beach area with the highest elevation has been surveyed If it is clear that all points on tiie Cell 4B beach area are below 5 593 FMSL then the Surveyor may rely on one survey point (vm) The Assistant will hold the Survey Rod vertically with one end of the Survey Rod just touching the pond surface The Assistant will ensure that the Survey Rod IS vertical by gently rocking the rod back and forth until the Surveyor has established a level reading N.VDMT PlanVDMT Plan 02.29.12 Re 1 l.SVDMT Plan February 2012 Rev 11.5 redl e.docN VDMT PInnVDMT Plan 01 30 12 Roviaion 11 4VTaihng9 Mgnt Syatom ond DMT Mon Plan Jonuary 2012 rov 11 4 clean doc I White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 14 of 55 (ix)The Surveyor will focus the cross hairs of the Survey Instrament on the scale on the Survey Rod and record the number (the Pond Surface Reading ) which represents the number of feet the Survey Instrament is reading above the pond surface level The Surveyor will calculate the elevation of the pond surface as FSML by adding the Reference Point Reading for the Cell or Roberts Pond as the case may be to the Reference Point Elevation for die CeU or Roberts Pond and subtracting the Pond Surface Reading for the CeU or Roberts Pond and will record tiie number accurate to 0 01 feet e) Decontamination Pads (i) New Decontamination Pad The New Decontamination Pad is located in the southeast comer of the ore pad near the Mill s scale house A In order to ensure that the pnmary containment of the New Decontanunation Pad water collection system has not been compromised and to provide an inspection capability to detect leakage from the pnmary containment vertical inspection portals have been installed between the pnmary and secondary containments B These portals will be visually observed on a weekly basis as a means of detecting any leakage from the pnmary containment into the void between the pnmary and secondary containment The depth to water m each portal will be measured weekly by physically measunng the depth to water with an electncal sounding tape/device AU measurements must be made from the same measunng point and be made to the nearest 0 01 foot C These inspections will be recorded on the Weekly Taihngs Inspection form D The water level shall not exceed 0 10 foot above the concrete floor in any standpipe at any time This will be determined by subtracting the weekly depth to water measurement from the distance from the measunng point in the standpipe to the dry concrete floor The depth to water from the top (elevation 5589 8 feet amsl) of any of the three (3) observation ports to the standing water shall be no less than 6 2 feet Depths less than 6 2 feet shall indicate more that 0 1 foot of standing water above the concrete floor (elev 5583 5 feet amsl) and N.VDMT PlanVDMT Plan 02.29 12 Re 11.5VDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailinea Mgnt System and DMT Mon Plon January 2012 rov 11 1 clean doc White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 15 of 55 shall indicate a leak in the pnmary containment E Any observation of fluid between the pnmary and secondary containments wdl be reported to the Radiation Safety Officer (RSO) F In addition to inspection of the water levels in the standpipes the New Decontamination Pad mcluding the concrete integnty of the exposed surfaces of the pad will be inspected on a weekly basis Any soil and debns wiU be removed from the New Decontamination Pad immediately pnor to inspection of the concrete wash pad for crackmg Observations will be made of the cunent condition of the New Decontamination Pad Any abnormalities relating to the pad and any damage to the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired (ll) Existing Decontamination Pad The Existing Decontamination Pad is located between the northwest comer of the Mill s maintenance shop and the ore feeding gnzzly A The Existing Decontamination Pad will be inspected on a weekly basis Any soil and debns will be removed from the Existing Decontamination Pad immediately pnor to inspection of the concrete wash pad for cracking Observations will be made of tiie cunent condition of the Existing Decontamination Pad including the concrete mtegnty of the exposed surfaces of the pad Any abnormalities relating to the pad and any damage or cracks on the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 mch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired f) Summary In addition the weekly inspection should summanze all activities concermng the tailings area for that particular week Results of the weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection N.VDMT PlanVDMT Plan 02.29.12 Re 115VDMT Plan February 2012 Rev 11.5 redl e.docN VDMT PlanVDMT Plon 01 30 12 Roviaion 11 4VTaihDga Mgnt Syatom ond DMT Mon Plon Januory 2012 rov 11 4 cloon doo I White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 16 of 55 form An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A 3 2 Weeklv Inspection of Solution Levels in Roberts Pond On a weekly basis solution elevations are taken on Roberts Pond in accordance witii the procedures set out m Section 3 1 d) above The Weekly solution level in Roberts Pond is recorded on the Weekly Tailings and DMT Inspection form Based on histoncal observations the FML at the Pond Surface Reading area for Roberts Pond is approximately six inches above the lowest point on tiie pond s FML If the pond solution elevation at the Pond Surface Reading area is at or below the FML for that area the pond will be recorded as being dry 3 3 Weeklv Feedstock Storage Area Inspections Weekly feedstock storage area inspections will be performed by tiie Radiation Safety Department to confirm that a) the bulk feedstock matenals are stored and maintained within the defined area descnbed in the GWDP as indicated on the map attached hereto as Appendix D b) a 4 ft buffer is maintained at the penphery of the storage area which is absent bulk matenal m order to assure that the matenals do not encroach upon tiie boundary of the storage area and c) all alternate feedstock located outside the defined Feedstock Area are maintained withm water tight containers The results of this inspection will be recorded on the Ore Storage/Sample Plant Weekly Inspection Report a copy of which is contained in Appendix A Any vanance in stored matenals from tins requirement or observed leaking altemate feedstock drams or other containers will be brought to the attention of Mill Management and rectified within 15 days 4 MONTHLY TAILINGS INSPECTION Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from the Radiation Safety Department and recorded on the Monthly Inspection Data form an example of which IS contained in Appendix A Monthly inspections are to be performed no sooner than 14 days since the last monthly tailmgs inspection and can be conducted concunently with the quarterly tailings inspection when applicable The following items are to be inspected a) Tailings Slurry Pipeline When the Mill is operating the slurry pipehne will be visually inspected at key N.VDMT PlanVDMT Plan 02.29 12 Re 11.5VDMT Plan February 2012 Rev 11.5 redl ne.docN VDMT PlonVDMT Plon 01 30 12 Roviaion 11 4VToilmg3 Mgnt Syatem ond DMT Mon Plan Jonuary 2012 rov 11 4 cloon doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Envu-onmental Protection Manual Section 3 1 Page 17 of 55 locations to determine pipe wear The cntical points of the pipe include bends slope changes valves and junctions which are cntical to dike stability These locations to be momtored will be deternuned by the Radiation Safety Officer or his designee from the Radiation Safety Department dunng the Mill ran b) Diversion Ditches Diversion ditches 1 2 and 3 shall be monitored monthly for sloughing erosion undesirable vegetation and obstraction of flow Diversion berm 2 should be checked for stability and signs of distress c) Sedimentation Pond Activities around the Mill and facihties area sedimentation pond shaU be summanzed for the month d) Overspray Dust Minimization The inspection shall include an evaluation of overspray mimnuzation if applicable This entails ensunng that the overspray system is functioning properly In the event that overspray is earned more than 50 feet from the cell the overspray system should be immediately shut off e) Remarks A section is included on the Monthly Inspection Data form for remarks in which recommendations can be made or observations of concem can be documented /) Summary of Daily Weekly and Quarterly Inspections The monthly inspection will also summanze the daily weekly and if applicable quarterly taihngs inspections for the specific month In addition settlement momtors are typically surveyed monthly and the results reported on the Monthly Inspection Data form 5 QUARTERLY TAILINGS INSPECTION The quarterly tailings inspection is performed by the Radiation Safety Officer or his designee from the Radiation Safety Department having the training specified in Section 2 4 above once per calendar quarter A quarterly inspection should be performed no sooner than 45 days since the previous quarterly inspection was performed N.VDMT PlanVDMT Plan 02.29 12 Re 11.5VDMT Plan February 2012 Re 11.5 redline.docN-VDMT PlanVDMT Plan 01 30 12 Revision •H- 4VToilmga Mgnt Syatom ond DMT Mon Plan January 2012 rev 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonll 45 Book 11 Envu-onmental Protection Manual Section 3 1 Page 18 of 55 Each quarterly inspection shall include an Embankment Inspection an Operations/Maintenance Review a Constmction Review and a Summary as follows a) Embankment Inspection The Embankment inspection involves a visual inspection of the crest slope and toe of each dike for movement seepage severe erosion subsidence shrmkage cracks and exposed liner b) Operations/Maintenance Review The Operations/Maintenance Review consists of reviewing Operations and Maintenance activities pertaining to the tailings area on a quarterly basis c) Construction Review The Constmction Review consists of reviewing any constraction changes or modifications made to the tailings area on a quarterly basis d) An estimate of the percentage of the tailings beach surface area and solution pool area is made including estimates of solutions cover areas and tailmgs sands for Cells 3 4Aand4B e) Summary The summary will include aU major activities or observations noted around the tailings area on a quarterly basis If any of these conditions are noted the conditions and conective measures taken should be documented in the Quarterly Inspection Data form An example of the Quarterly Inspection Data form is provided m Appendix A 6 ANNUAL EVALUATIONS The followmg annual evaluations shall be performed 6 1 Annual Technical Evaluation An annual techmcal evaluation of the taihngs management system is performed by a registered professional engineer (PE) who has expenence and training in the area of geotechnical aspects of retention stractures The techmcal evaluation includes an on site inspection of the tailings management system and a thorough review of all tailings records for the past year The Technical N VDMT PlanVDMT Plan 02.29.12 Re 1 l.SVDMT Plan February 2012 Rev 11.5 redl e.docN VDMT PlanVDMT Plon 01 30 12 Roviaion 11 4VTaihng9 Mgnt Syatom and DMT Mon Plan January 2012 rov 11 4 clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 19 of 55 Evaluation also includes a review and summary of the annual movement monitor survey (see Section 5 2 below) All tailings cells and conesponding dikes will be inspected for signs of erosion subsidence shnnkage and seepage The drainage ditches will be inspected to evaluate surface water control stractures In the event taihngs capacity evaluations (as per SOP PBL-3) were performed for the receipt of altemate feed matenal dunng the year the capacity evaluation forms and associated calculation sheets wiU be reviewed to ensure that the maximum taihngs capacity estimate is accurate The amount of tailings added to the system since the last evaluation will also be calculated to determine the estimated capacity at the time of the evaluation Taihngs inspection records will consist of daily weekly monthly and quarterly ladings inspections These inspection records will be evaluated to detemune if any freeboard limits are being approached Records will also be reviewed to summanze observations of potential concem The evaluation also involves discussion with the Environmental and/or Radiation Technician and the Radiation Safety Officer regarding activities around the tailings area for the past year Dunng the annual mspection photographs of tiie tailings area will be taken The trainmg of individuals wiU be reviewed as a part of the Annual Technical Evaluation The registered engineer will obtain copies of selected tailmgs inspections along with the monthly and quarterly summanes of observations of concem and the conective actions taken These copies will then be included in the Annual Technical Evaluation Report The Annual Technical Evaluation Report must be subnutted by November 15"' of every year to the Executive Secretary 6 2 Movement Monitors A movement momtor survey is to be conducted by a licensed surveyor annually dunng the second quarter of each year The movement monitor survey consists of surveying momtors along dikes 5-S- 4A W and ^ A S 4A E. 4A S. and 4B S to detect any possible settiement or movement of the dikes The data generated from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the tailings management system 6 3 Freeboard Limits The freeboard linuts set out in this Section are intended to capmre the Local 6 hour Probable Maximum Precipitation (PMP) event which was determined in the January 10 1990 Drainage Report (the Drainage Report ) for the White Mesa site to be 10 inches N.VDMT PlanVDMT Plan 02.29.12 Rev 11 SVDMT Plan February 2012 Re 11.5 redb e.docN VDMT PlanVDMT Plan 01 30 13 Roviaion 11 4VToiling3 Mgnt Syatom and DMT Mon Plan January 2012 rev 11 4 clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Envuonmental Protection Manual Section 3 1 Page 20 of 55 The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas was calculated in the Drainage Report to be 103 acre feet of water with a wave ran up factor of 0 90 feet The flood volume from tiie PMP event over the Cell 2 and Cell 3 pond areas plus the adjacent drainage areas was calculated m the Drainage Report to be 123 4 acre feet of water The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage Report to be 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres) times the PMP of 10 inches) with a wave ran up factor of 0 77 feet The flood volume from the PMP event over the Cell 4B area has been calculated to be 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 72 acres) times the PMP of 10 inches with a wave ran up factor of 0 77 feet The total pool surface area in CeU 1 is 52 9 acres in Cell 4A is 40 acres and in Cell 4B is 40 acres The top of the flexible membrane liner ( FML ) for Cell 1 is 5 618 2 FMSL for Cell 4A is 5 598 5 FMSL and for CeU 4B is 5600 4 FMSL Based on the foregoing the freeboard limits for the Mill s tailings cells will be set as follows 63 1 Cell 1 The freeboard limit for Cell 1 will be set at 5 615 4 FMSL This wiU allow Cell 1 to capture all of the PMP volume associated with Cell 1 The total volume requirement for Cell 1 is 103 acre feet divided by 52 9 acres equals 1 95 feet plus the wave ran up factor of0 90 feet equals 2 85 feet The freeboard limit is then 5 618 2 FMSL minus 2 85 feet equals 5 615 4 FMSL Under Radioactive Matenals License condition 10 3 this freeboard limit is set and is not recalculated annually 632 CeU 2 The freeboard limit for Cell 2 is inapplicable since Cell 2 is filled with solids All of tiie PMP volume associated with Cell 2 will be attnbuted to Cell 4A (and/or any future tailings cells) 633 CeU 3 The freeboard limit for Cell 3 is inapplicable since Cell 3 is close to being filled with sohds and all of tiie PMP flood volume associated witii Cell 3 wiU be attnbuted to Cell 4B (and/or any ftimre tailings cells) 6 3 4 CeU 4A N.VDMT PlanVDMT Plan 02 29.12 Re 1 l.SVDMT Plan February 2012 Re ll.Sredl e docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailing3 Mgnt Syatom ond DMT Mon Plan Januory 2012 rev 11 4 cloon doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 21 of 55 The freeboard linut for Cell 4A is inapplicable since all of the PMP flood volume associated with CeU 4A will be attnbuted to Cell 4B A spiUway has been added to Cell 4A to allow overflow into CeU 4B 635 CeU 4B The freeboard Imut for Cell 4B will be set assuming tiiat the total PMP volume for Cells 2 3 4A and 4B of 159 4 acre feet will be accommodated in Cell 4B The procedure for calculating the freeboard limit for Cell 4B is as follows (a) When the Pool Surface Area is 40 Acres When the pool surface area m Cell 4B is 40 acres (i e when there are no beaches) the freeboard limit for Cell 4B will be 5 594 6FMSL which is 5 7 feet below tiie FML This freeboard value was developed as follows PMP Hood Volume 38 1 acre feet Overflow from Cell 4A assuming no storage in Cell 3 or 4A 159 4 acre feet Sum of PMP volume and overflow volume 197 5 acre feet Depth to store PMP an overflow volume = 197 5 acre feet/40 acres 4 9 feet Wave ran up factor 0 77 feet Total required freeboard 5 7 feet (all values in the above calculation have been rounded to the nearest one tenth of afoot) (b) When the Maximum Elevation ofthe Beach Area is 5 594 FMSL or Less When the maximum elevation of the beach area in CeU 4B is 5594 FMSL or less then the freeboard limit will be 5 594 6 FMSL which is the same as in (a) above This allows for the simation where there may be beaches but these beaches are at a lower elevation than the freeboard limit estabhshed m (a) above and there is therefore ample freeboard above the beaches to hold the maximum PMP volume The maximum elevation of the beach area will be detemuned by monthly surveys performed by MiU personnel in accordance with the Mill s DMT Plan (c) When the Maximum Elevation ofthe Beach Area First Exceeds 5 594 FMSL When the maximum elevation of the beach area in Cell 4B first exceeds 5 594 FMSL then the freeboard linut for the remainder of the ensuing year (penod t=0) (until the next November 1) wiU be calculated when that elevation is first exceeded (the Imtial Calculation Date ) as follows i) The total number of dry tons of tailings that have histoncally been deposited mto Cell 4B pnor to the Initial Calculation Date ( To ) will be detemuned N.VDMT PlanVDMT Plan 02.29.12 R v 11 SVDMT Plan February 2012 Re 11.5 redl e.docN VDMT PlanVDMT Plon 01 30 13Roviaion 11 4VTaiLnga Mgnt Syatom ond DMT Mon Plan January 2012 rev 11 4 cloon doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 22 of 55 ll) The expected number of dry tons to be deposited into Cell 4B for the remainder of the ensuing year (up to the next November 1) based on production estimates for that penod ( Ao* ) will be determined in) Ao* will be grossed up by a safety factor of 150% to allow for a potential underestimation of the number of tons that wdl be deposited in the cell dunng the remainder of the ensuing year This grossed up number can be refened to as the modeled tonnage for the penod iv) The total design tailings solid storage capacity of CeU 43 will be accepted as 2 094 000 dry tons of ladings v) The available remaining space in Cell 43 for solids as at the Initial Calculation Date wiU be calculated as 2 094 000 dry tons minus To Vl) The reduction in the pool surface area for the remainder of the ensuing year will be assumed to be directly proportional to the reduction in the available space in Cell 43 for solids That is the reduced pool surface area for penod t=0 ( RPAo ) after the reduction will be calculated to be (1 - (Ao* X 1 5) / (2 094 000 To)) x 40 acres = RPAo vu) The required freeboard for Cell 4B for the remainder of the penod t=0 can be calculated in feet to be the wave ran up factor for CeU 43 of 0 77 feet plus tiie quotient of 197 5 acre feet divided by the RPAo The freeboard limit for Cell 43 for the remainder of penod t=0 would then be the elevation of the FML for Cell 43 of 5594 0 FMSL less this required freeboard amount rounded to tiie nearest one tenth of afoot and vm) The foregoing calculations will be performed at the Initial Calculation Date and the resulting freeboard limit will persist until the next November 1 An example of this calculation is set out in Appendix F (d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds 5 594 FMSL On November 1 of each year (tiie Annual Calculation Date ) the reduction in pool area for the ensuing year (refened to as penod t) wiU be calculated by i) First calculating the Adjusted Reduced Pool Area for the previous penod (ARPAt 0 to reflect acmal tonnages deposited in Cell 43 for the previous penod (penod t 1) The RPAt 1 used for the previous penod was based on expected tonnages for penod t 1 grossed up by a safety factor The ARPAt i is merely the RPA that would have been used for penod t 1 had the acmal tonnages for year t 1 been known at the outset of penod t 1 and had the RPA been calculated based on the acmal tonnages for penod t 1 This allows the freeboard calculations to be conected each year to take into account actual tonnages deposited in the cell as of the date of the calculation The ARPAt 1 can be calculated using the following formula (1 - At 1 / (2 094 000 - Tt 0) x ARPAt 2 = ARPAt 1 N.VDMT PlanVDMT Plan 02 29.12 Re ll.SVDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlonVDMT Plan 01 30 12 Roviaion 11 4VToilmg3 Mgnt Syatom and DMT Mon Plan January 2012 rev 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Denisonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 23 of 55 Where • At 1 IS the acmal number of dry tons of tailings solids deposited in Cell 43 dunng penod t 1 • Tt I IS the acmal number of dry tons of tailings solids histoncally deposited in Cell 43 pnor to the beginning of penod t 1 and • ARPAt 2 IS the Adjusted Reduced Pool Area for penod t 2 If penod t 2 started at the Imtial Calculation Date then ARPAt i is 40 acres ll) Once the ARPAt i for the previous penod (penod t 1) has been calculated the RPA for the subject penod (penod t) can be calculated as follows (1 - (A,* X 1 5) / (2 094 000 Tt)) x ARPAt i = RPAt Where • At* is the expected number of dry tons of tailmgs to be deposited into Cell 43 for the ensuing year (penod t) based on production estimates for the year (as can be seen from the foregoing formula this expected number is grossed up by a safety factor of 1 5) • Tt IS the acmal number of dry tons of tailings solids histoncally deposited m Cell 43 pnor to the beginning of penod t and • ARPAt 1 IS the Adjusted Reduced Pool Area for penod t 1 which is the pool surface area for the previous penod (penod t 1) that should have applied dunng that penod had modeled tonnages (i e expected tonnages grossed up by tiie 150% safety factor) equaled actual tonnages for the penod Ul) The required freeboard for penod t can be calculated in feet to be the wave ran up factor for Cell 43 of0 77 feet plus die quotient of 197 5 acre feet divided by tiie RPAt The freeboard limit for Cell 43 for penod t would then be the elevation of the FML for Cell 43 of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tentii of a foot and iv) The foregoing calculations will be performed at the Annual Calculation Date for penod t and the resulting freeboard limit will persist untd the next Annual Calculation Date for penod t-l-1 An example of this calculation is set out in Appendix F {e) When a Spillway is Added to Cell 4B that Allows Overflow Into a New Tailings Cell When a spillway is added between Cell 43 and a new tailings cell then if an approved freeboard limit calculation method for the new cell is set to cover the entire PMP event for Cells 2 3 4A 43 and the new tailings cell the freeboard linut for Cell 43 will be inapplicable except for approved provisions to prevent storm water ranoff from overtopping dikes 6 3 6 Roberts Pond N VDMT PlanVDMT Plan 02 29.12 Re ll.SVDMT Plan February 2012 Re 11 5 redl ne docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmg8 Mgnt System and DMT Mon Plan January 2012 rov 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demson 11 45 Book 11 Environmental Protection Manual Section 3 1 Page 24 of 55 The freeboard linut for Roberts Pond is a liquid maximum elevation of5 624 0 feet above mean sea level as specified m the GWDP 6 4 Annual Leak Detection Fluid Samples In the event solution has been detected in a leak detection system a sample will be collected on an annual basis This sample will be analyzed according to the conditions set forth m License Condition 11 3 C The results of the analysis will be reviewed to detemune the ongin of the solution 6 5 Annual Inspection of the Decontanunation Pads a) New Decontamination Pad Dunng the second quarter of each year the New Decontamination Pad will be taken out of service and inspected to ensure the integnty of the wash pad s exposed concrete surface If any abnormalities are identified i e cracks m the concrete with greater than 1/8 inch separation (width) or any significant detenoration or damage of the pad surface repairs will be made pnor to resunung the use of the facility All inspection findings and any repairs required shaU be documented on the Annual Decontamination Pad Inspection form The inspection findings any repairs required and repairs completed shaU be summanzed in tiie 2 Quarter DMT Monitonng Report due September 1 of each calendar year b) Existing Decontamination Pad Dunng the second quarter of each year the Existing Decontamination Pad will be taken out of service and inspected to ensure the integnty of the steel tank Once the water and any sediment present is removed from the steel tank containment the walls and bottom of the tank will be visually inspected for any areas of damage cracks or bubbling indicating conosion that may have occuned since the last inspection If any abnormalities are identified defects or damage will be reported to Mill management and repairs will be made pnor to resuming the use of the facility All inspection findings and any repairs requu-ed shall be documented on the Annual Decontamination Pad Inspection form A record of the repairs will be maintained as a part of the Annual Inspection records at the Mill site The inspection findings any repairs required and repairs completed shall be summanzed in the 2nd Quarter DMT Momtonng Report due September 1 of each calendar year 7 OTHER INSPECTIONS All daily weekly monthly quarterly and annual inspections and evaluations should be performed as specified m Sections 2 3 4 5 and 6 above However additional inspections should be conducted after any significant storm or significant namral or man made event occurs N VDMT PlanVDMT Plan 02.29.12 R 11 SVDMT Plan February 2012 Re llSredl .docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmg3 Mgnt System and DMT Mon Plan January 2012 rov 11 4 dean doo White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 25 of 55 8 REPORTING REQUIREMENTS In addition to the Daily Inspection Data Weekly Tailings Inspection Monthly Inspection Data and Quarterly Inspection Data forms included as Appendix A and descnbed m Sections 2 3 4 and 5 respectively and the Operating Foreman s Daily Inspection and Weekly Mill Inspection forms descnbed in Sections 2 and 3 respectively the following additional reports shall also be prepared 8 1 Monthlv Tailings Reports Monthly tailings reports are prepared every month and summanze the previous month s activities around the tailings area If not prepared by the Radiation Safety Officer the report shall be submitted to the Radiation Safety Officer for review The Mill Manager will review the report as well before the report is filed in the Mill Central File The report wdl contain a summary of observations of concem noted on the daily and weekly tailings inspections Corrective measures taken dunng the month will be documented along witii the observations where appropnate AU daily and weekly tailings inspection forms will be attached to the report A monthly inspection form will also be attached Quarterly inspection forms will accompany the report when apphcable The report will be signed and dated by the preparer in addition to the Radiation Safety Officer and the Mill Manager 82 DMT Reports Quarterly reports of DMT monitonng activities which wiU include the following mformation will be provided to the Executive Secretary on the schedule provided m Table 5 of tiie GWDP a) On a quarterly basis all required information required by Part 1 F 2 of the GWDP relating to the inspections descnbed in Section 3 1(b) (Shmes Drain Water Level Monitonng) 3 1(d) (Taihngs Wastewater Pool and Beach Area Elevation Momtonng) 3 2 (Weekly Inspection of Solution Levels m Roberts Pond) and 3 3 (Weekly Feedstock Storage Area Inspections) b) On a quarterly basis a summary of the weekly water level (depth) inspections for the quarter for the presence of fluid in all three vertical inspection portals for each of the three chambers in the concrete settling tank system for the New Decontanunation Pad which will include a table indicating the water level measurements in each portal dunng the quarter c) With respect to the annual inspection of the New Decontanunation Pad descnbed in Section 6 5(a) the inspection findings any repairs required and repairs completed shall be summanzed in the 2 Quarter report due September 1 of each calendar year N VDMT PlanVDMT Plan 02 29.12 Re ll.SVDMT Plan Febmary 2012 Re ll.Sredl e docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VToihnga Mgnt Syatom ond DMT Mon Plan January 2012 rov 11 4 clean doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 26 of 55 d) With respect to the annual inspection of the Existing Decontamination Pad descnbed in Section 6 5(b) the inspection findings any repairs required and repairs completed shall be summanzed in the 2 Quarter report due September 1 of each calendar year and e) An annual summary and graph for each calendar year of the depth to wastewater in the Cell 2 shmes drain must be included in the fourth quarter report After the first year and beginmng in 2008 quarterly reports shall include both the cunent year monthly values and a graphic companson to the previous year N.VDMT PlanVDMT Plan 02.29.12 Rev 1 l.SVDMT Plan February 2012 Re 11.5 redl ne docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmg3 Mgnt Syatom ond DMT Mon Plon Jonuory 2012 rov 11 4 cloon doo I White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Envu-onmental Protection Manual Section 3 1 Page 27 of 55 APPENDIX A FORMS N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan February 2012 Re 11 5 redl ne.docN VDMT PlanVDMT Plon 01 30 12 Revision 11 IVToihnga Mgnt Syatem and DMT Mon Plan January 2012 rev 11 4 cloaadoc «ol «n Q t2 CN f?l 2 2 •S c S3 <^ -§ « ^ i = s ? ^ [Tl (U QQ E a.S 8 S 52 «a o S £ Q < 3 < II X o II E oa U <l U U U 3 E O a < H H O Z H >^ P O c <u PQ CO PQ (U oo CO E Q cyj c (U c O PQ a £ fc 3 o a. a 3 PQ ^1 ""t nil 13 U 00! 13 U :z:l < 'St ^1 < 'St Ul Ce l l C/31 Ce l l 21 Ce l Ce l ^1 ^ Ul Ce l VA ZI II O P E R A T I O N A L S Y S T E M S a n d I N T E R I O R o f C E L L S 1 Co n d i t i o n s o f P o t e n t i a l C o n c e m 1 Ob s e r v a b l e L i n e r D a m a g e 1 Gr e a t e r T h a n O p e r a t i n g L e v e l L a r g e Ch a n g e S i n c e P r e v i o u s I n s p e c t i o n Cr a c k s S e v e r e E r o s i o n S u b s i d e n c e | Er o s i o n o f c o v e r E x p o s u r e o f L i n e r | II O P E R A T I O N A L S Y S T E M S a n d I N T E R I O R o f C E L L S 1 In s p e c t i o n I t e m s In t e n o r C e l l W a l l s Li n e r Wa t e r L e v e l Be a c h Li n e r a n d C o v e r on a <o •a Cfl 2 o CL O O I S c I c = s c« 1^ U 43 C/1 Ql <U| CO QI5 -a 0) o ^ - 5i O c« o « o o o ^ 2 o (U a u o "S S O o is o CL IU O Z > D O "2 <u <u o o ii o Q, <U c« T3 U O ° S o 1« -o 5 U cn ca o o o z z cn (» H) !U IU c •ti "O S o S QH X3 S Q s: o tn G o lU O Q -a E S > ea 2^ Q rj 2 <o 3 E > £ £ ii D. E^ 3 13 O u Q 13 1 £ ii a E^ 3 & o ^ E <ol in Q~ CO Pu 3 « O 3 eg c cS rij cfl Tailings Dail>' Inspection Report Tailings Sluny Dischaige Location <ol *n n C|_i ^ o I« Q OH CELL NO 1 Dikel MILLSITE 1 n on ?5| a cs 2 3 2 2 <U 3 CL, t) -§ 2 1 i I c ! ^ cs m cfl 1^ U B ^ I ° CELL NO 2 FUled / CELL NO 4A / Date Iiispectoi 0 N White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 33 of 55 APPENDIX A (CONT) DENISON MINES (USA) CORP WEEKLY TAILINGS INSPECTION Date Inspectors 1 Pond and Beach Cell 1 (a) Pond SoluUon Elevation elevations (msl ft) (b) FML Bottom Elevation 5597. (c) Depth of Water above FML ((a) (b)) Cell 4A (a)Pond Solution ElevaUon (b) FML Bottom ElevaUon 5555 14_ (c) Depth of Water above FML ((a) (b)) Cell4B (a)Pond Solution Elevation (b) FML Bottom Elevation 5557 50 (c) Depth of Water above FML ((a) (b)) (d) Elevation of Beach Area with Highest ElevaUon (monthly) Roberts Pond (a)Pond SoluUon Elevation (b) FML Bottom Elevation 5612 3_ (c) Depth of Water above FML ((a) (b)) 2 Shmes Drain Liquid Levels Cell 2 Pump functioning properly. _Depth to Liquid pre pump .Depth to Liquid Post pump (all measurements are depth in pipe) Pre pump head is 37 97 Depth to Liquid Pre pump = Post pump head is 37 97 -Depth to Liquid Post pump = N.VDMT PlanVDMT Plan 02.29 12 Re ll.SVDMT Plan February 2012 Re 11.5 redlme docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmga Mgnt Syatom and DMT Mon Plon Jonuary 2012 rov 11 4 clean doo White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 42/12 Revision Demsonl 1 45 Page 34 of 55 3 Leak Detection Systems (Same data as Daily Inspection Form Record data on daily form) Observation New Decon Pad. Portal 1 New Decon Pad. Portal 2 New Decon Pad Portal 3 Is LDS (Portal) wet or dry*^ _wet ^dry _wet ^dry _wet dry If wet Record hquid level Liquid Ft to Liquid Ft to Liquid Ft to If wet Report to RSO 4 Tailings Area Inspection (Note dispersal of blowing tailings) 5 Control Methods Implemented 6 Remarks, 7 Designated Disposal Area for Non Tailings Mill Waste (awaiting DRC approval) * Does Level exceed 12 inches above the lowest pomt on the bottom flexible membrane liner (solution elevation of 5556 14 amsl for Cell 4A and 5558 50 for Cell 4B)'? no yes If Cell 4A leak detection system level exceeds 12 inches above the lowest point on the bottom flexible membrane liner (elevation 5556 14 amsl) notify supervisor or Mill manager immediately N.VDMT PlanVDMT Plan 02 29.12 Re 11 SVDMT Plan Feb arv 2012 Re 11.5 redl .docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmga Mgnt Syatom ond DMT Mon Plan January 2012 rov 11 4 cloaadoc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 35 of 55 APPENDIX A (CONT) MONTHLY INSPECTION DATA Inspector Date 1 Slurry Pipehne 2 Diversion Ditches and Diversion Berm Observation Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2 Diversion Ditches Sloughing yes no yes no yes no Erosion yes no yes no yes no Undesirable yes no yes no yes no Vegetation Obstmction of Flow yes no ^yes no yes no Diversion Berm Stability Issues yes no Signs of Distress yes no Comments 3 Summary of Activities Around Sedimentation Pond N.VDMT PlanVDMT Plan 02.29.12 Re 11 SVDMT Plan February 2012 Re ll.Sredl e.docN VDMT PlanVDMT Plan 01 30 12 Reviaion 11 4\Toilmg9 Mgnt Syatom ond DMT Mon Plon January 2012 rov 11 4 cloon doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Envu-onmental Protection Manual Section 3 1 Page 36 of 55 4 Overspray Dust Mmimization Overspray system functioning properly yes no Overspray earned more than 50 feet from the cell yes If yes was system immediately shut off^ yes Comments 5 Remarks 6 Settlement Monitors Cell 2 WI Cell 2W3 S Cell 3 IN _ Cell 2 W2 CeU 2E1 N Cell 3 IC _ Cell 2 W3 Cell 2E1 IS Cell 3 IS _ Cell 2 W4 Cell 2E1 2S Cell 3 2N _ Cell 2W7 C Cell 2 East Cell 2W5 N Cell 2 W7N Cell 2 W7S Cell 2 W6N Cell2W6C Cell2W6S Cell2W4N Cell 4A Toe Cell 2 W4S Cell 2 W5C Cell3 2C Cell3 2S Cell2W5S Cell 3 3S Cell 3 3C Cell3 3N _ Cell 3-4N Cell 3 6N Cell 3 7S _ Cell 3 7C Cell 3 7N Cell 3 8S _ Cell 3 8C Cell 3 8N 7 Movement Monitors (Is there visible damage to any movement monitor or to adjacent surfaces)'^ 8 Summary of Daily Weekly and Quarterly Inspections N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan F bruarv 2012 Re 11.5 edl ne.docN VDMT PlanVDMT Plon 01 30 12 Roviaion 11 4VToilmga Mgnt Syatom ond DMT Mon Plon January 2012 rov 11 4 cloon doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 37 of 55 N.VDMT PlanVDMT Plan 02.29.12 Rev 1 l.SVDMT Plan February 2012 Rev 11.5 redb e.docN VDMT PlanVDMT Plon 01 30 12 RoviaiOB 11 4VTailmga Mgnt Syatom ond DMT Mon Plan Jonuary 2012 rov 11 4 cloon doc I White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 42/12 Revision Demson 11 45 Page 38 of 55 APPENDIX A (CONT) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector Date 1 Embankment Inspection 2 Operations/Maintenance Review 3 Construction Activities 4 Estimated Areas CeU 3 Cell 4A Cell 43 Estimated percent of beach surface area Estimated percent of solution pool area Estimated percent of cover area Comments N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan F bruarv 2012 Re ll.S redl e.docN VDMT PlpnVDMT Plon 01 30 12 Rcvittion 11 4VToiling9 Mgnt Syatem ond DMT Mon Plan Jonuory 2012 rov 11 4 clean doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 39 of 55 APPENDIX A (CONT) ORE STORAGE/SAMPLE PLANT WEEKLY INSPECTION REPORT Week of through Date of Inspection Inspector Weather conditions for the week Blowing dust conditions for the week Corrective actions needed or taken for the week Are all bulk feedstock matenals stored in the area indicated on the attached diagram yes no comments Are all alternate feedstock matenals located outside the area indicated on the attached diagram maintained withm water tight containers yes no comments (e g conditions of containers). Are all sumps and low lying areas free of standing solutions'' Yes No If No how was the situation corrected supervisor contacted and correction date'' Is there free standing water or water mnning off of the feedstock stockpiles'' Yes No Comments N VDMT PlanVDMT Plan 02.29.12 Re 11.5VDMT Plan February 2012 Re ll.S redl ne.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VToibng8 Mgnt Syatom and DMT Mon Plan January 2012 rov 11 4 clean doc White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Denisonl 1 45 Book 11 Envu-onmental Protection Manual Section 3 1 Page 40 of 55 Other comments N.VDMT PlanVDMT Plan 02.29.12 R 11 SVDMT Plan February 2012 Re ll.Sredl e.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailing3 Mgnt Syatom and DMT Mon Plan Jonuary 2012 rov 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 41 of 55 APPENDIX A (CONT) ANNUAL DECONTAMINATION PAD INSPECTION Date of Inspection Inspector New Decontamination Pad Are there any cracks on the wash pad surface greater than 1/8 mch of separation'' Yes No Is there any significant deterioration or damage of the pad surface'' Yes No Findings Repair Work Required Existing Decontanunation Pad Were there any observed problems with the steel tank'' Yes No Fmdings Repair Work Required Note For the annual inspection of the both the Existing and New Decontamination Pads the annual inspection findings any repairs required and repairs completed along with a summary of the weekly inspections shall be discussed m the 2 Quarter report due September 1 of each calendar year N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan Febniarv 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plon 01 30 12 Revision 11 4VTaihnga Mgnt Syatom ond DMT Mon Plon January 2012 rov 11 4 clean doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Denison 11 45 Book 11 Environmental Protection Manual Section 3 1 Page 42 of 55 APPENDIX B 8 3 TAILINGS INSPECTOR TRAINING This document provides the traming necessary for quahfying management designated mdividuals for conducting daily tailings inspections Training information is presented by the Radiation Safety Officer or designee from the Environmental Department Daily taihngs inspections are conducted in accordance with the White Mesa Mill Tailings Management System and Discharge Mimnuzation Technology (DMT) Monitonng Plan The Radiation Safety Officer or designee from the Radiation Safety Department is responsible for performing monthly and quarterly taihngs inspections Tadmgs inspection forms wdl be included in the monthly tailings inspection reports which summanze the conditions activities and areas of concem regarding the tailings areas Notifications The inspector is required to record whether all inspection items are normal (satisfactory requmng no action) or that conditions of potential concem exist (requinng action) A check mark indicates no action required If conditions of potential concem exist the inspector should mark an X in the area the condition pertains to note the condition and specify the conective action to be taken If an observable concem is made it should be noted on the tailings report until the conective action is taken and the concem is remedied The dates of all conective actions should be noted on the reports as well Any major catastrophic events or conditions pertaining to the tailmgs area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom wdl notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division ofDam Safety (801 538 7200) Inspections All areas of the tailmgs disposal system are routinely patrolled and visible observations are to be noted on a daily tailings inspection form Refer to Appendix A for an example of the daily tailings inspection form The inspection form consists of three pages and is summanzed as follows I Tailings Slurry Transport System The slurry pipeline IS to be inspected for leaks damage and sharp bends The pipelme joints are to be monitored for leaks and loose connections The pipeline supports are to be inspected for damage and loss of support Valves are also to be inspected particularly for N VDMT PlanVDMT Plan 02.29.12 Rev ll.SVDMT Plan February 2012 Rev 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Revision II IVToilmga Mgnt Syatom and DMT Mon Plan January 2012 rov 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 43 of 55 leaks blocked valves and closed valves Points of discharge need to be inspected for improper location and onentation Operational Systems Operating systems including water levels beach liners and covered areas are items to be inspected and noted on the daily inspection forms Sudden changes in water levels previously observed or water levels exceeding the operating level of a pond are potential areas of concem and should be noted 3each areas that are observed as havmg cracks severe erosion or cavities are also items that require investigation and notation on dady forms Exposed liner or absence of cover from erosion are potential items of concem for ponds and covered areas These should also be noted on the daily inspection form Cells 1 3 4A and 43 solution levels are to be monitored closely for conditions neanng maximum operating level and for large changes m the water level since the last inspection All pumping activities affecting the water level will be documented In Cells 1 and 3 the PVC liner needs to be monitored closely for exposed liner especially after storm events It is important to cover exposed liner immediately as exposure to sunlight wdl cause degradation of the PVC liner Small areas of exposed liner should be covered by hand Large sections of exposed liner will require the use of heavy equipment These conditions are considered senous and require immediate action After these conditions have been noted to the Radiation Safety Officer a work order will be wntten by the Radiation Safety Officer and mmed into the Maintenance Department All such repairs should be noted in the report and should contain the start and fimsh date of the repairs Dikes and Embankments Inspection items include the slopes and the crests of each dike For slopes areas of concem are sloughs or slidmg cracks bulges subsidence severe erosion moist areas and areas of seepage outbreak For crests areas of concem are cracks subsidence and severe erosion When any of these conditions are noted an X mark should be placed m the section marked for tiiat dike In addition theddces in particular dikes 4A S 4A E and 43 S should be inspected closely for mice holes and more importandy for praine dog holes as the praine dogs are likely to bunow in deep possibly to the liner If any of these conditions exist the inspection report should be marked accordingly N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan February 2012 Rev 11 5 redli e.docN VDMT PlanVDMT Plan 01 30 12Rovioion 11 4VTailmga Mgnt Syatem ond DMT Mon Plan Jonuory 2012 rov 11 4 cloon doo White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 44 of 55 4 Flow Rates Presence of all flows in and out of the cells should be noted Flow rates are to be estimated in gallons per nunute (GPM) Rates need to be determined for slurry lines pond remm SX tads and the spray system Dunng non operational modes the flow rate column should be marked as 0 The same holds tme when the spray system is not utilized 5 Physical Inspection of Slurry Line(s) A physical inspection of all slurry lines has to be made every 4 hours dunng operation ofthe null If possible the inspection should include observation of the entire discharge hne and discharge spill point into the cell If fill to elevation flags are in place the ladings and build up IS to be monitored and controUed so as to not cover the flags 6 Dust Control Dusting and wind movement of tailings should be noted for Cells 2 3 4A and 43 Other observations to be noted include a bnef descnption of present weather conditions and a record of any precipitation received Any dusting or wind movement of tailings should be documented In addition an estimate should be made for wind speed at the time of the observed dusting or wind movement of tailmgs The Radiation Safety Department measures precipitation on a daily basis Daily measurements should be made as near to 8 00 a m as possible every day Weekend measurements wiU be taken by Environmental Health and Safety personnel as close to 8 00 a m as possible All snow or ice should be melted before a reading is taken 7 Observations of Potential Concern All observations of concem dunng the inspection should be noted m this section Conective action should follow each area of concem noted All work orders issued contacts or notifications made should be noted in this section as well It is important to document all these items m order to assure that the tailings management system records are complete and accurate 8 Map of Tailings CeUs The last section of the inspection involves drawing as accurately as possible the following Items where apphcable N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan February 2012 Re 11 5 redl ne.docN VDMT PlonVDMT Plan 01 30 12 Roviaion 11 4VTaihnga Mgnt Syatem and DMT Mon Plan Jonuary 2012 rov 11 4 clean doc White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 45 of 55 1 Cover area 2 Beach/tailing sands area 3 Solution as it exists 4 Pump lines 5 Activities around tailings cell (i e hauling trash to the dump liner repairs etc ) 6 Slurry discharge when operating 7 Over spray system when operating 9 Safety Rules All safety mies applicable to the mill are applicable when in the tailings area These mies meet the required MSHA regulations for the tailmgs area Please pay particular notice to the foUowmg mies 1 The posted speed limit on Cell 4A and 43 dike is 5 mph and tiie posted speed limit for the tailings area (otiier than the Cell 4A and 43 dike) is 15 mph These limits should not be exceeded 2 No food or dnnk is permitted in the area 3 All personnel entenng the ladings area must have access to a two way radio 4 Horseplay is not pemutted at any time 5 Only those specifically authonzed may operate motor vehicles in the restncted area 6 When road conditions are muddy or slick a four wheel dnve vehicle is required m the area 7 Any work performed in which there is a danger of falling or slipping in the cell will require the use of a safety belt or hamess with attended life line and an approved life jacket A portable eyewash must be present on site as well 8 Anytime the boat is used to perform any work an approved life jacket and goggles must be wom at all times There must also be an approved safety watch with a two way hand held radio on shore A portable eyewash must be present on site as well 10 Preservation of Wildhfe Every effort should be made to prevent wildlife and domesticated ammals from entenng the taihngs area All wildlife observed should be reported on the Wildlife Report Worksheet dunng each shift Waterfowl seen near the tailings cells should be discouraged from landing by the use of noisemakers 11 Certification Following the review of this document and on site instmction on the tailings system inspection program designated individuals will be certified to perform daily tailmgs inspections The Radiation Safety Officer authonzes certification Refer to the Certification N VDMT PlanVDMT Plan 02 29.12 Rev 11 SVDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Reviaion 11 4VTaihnga Mgnt Syatem and DMT Mon Plan January 2012 rov 11 4 cloaadoc I White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 46 of 55 Form Appendix C This form should be signed and dated only after a thorough review of the taihngs information previously presented The form wdl then be signed by the Radiation Safety Officer and filed N.VDMT PlanVDMT Plan 02.29.12 Re U SVDMT Plan February 2012 Re ll.S redl ne.docN VDMT PlanVDMT Plnn 01 30 12 Revision 11 4VTaihng9 Mgnt Syatom and DMT Mon Plan Januory 2012 rov 11 4 olcon doc White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 47 of 55 APPENDIX C CERTIFICATION FORM Date Name I have read the document tided 'Tailings Management System White Mesa Mill Tailings Inspector Traimng and have received on site instmction at the taihngs system This instmction included documentation of daily tailmgs inspections analysis of potential problems (dike failures unusual flows) notification procedures and safety Signamre I certify that the above named person is qualified to perform the daily mspection of the tailings system at the White Mesa Mill Radiation Safety Personnel/ Tailings System Supervisor N.VDMT PlanVDMT Plan 02 29.12 Re 11.5VDMT Plan February 2012 Re 11.5 redline docN VDMT PlanVDMT Plon 01 30 12 Reviaion 11 4VTailmg3 Mgnt Syatom ond DMT Mon Plon January 2012 rov 11 4 cloon doo White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 48 of 55 APPENDIX D FEEDSTOCK STORAGE AREA N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan February 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Reviaion 11 4VTailmga Mgnt Syatem ond DMT Mon Plon Jonuory 2012 rov 11 4 oleon doo White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 1 42/12 Revision Demsonl 1 45 Page 49 of 55 N VDMT PlanPMT Plan 07.?9 12 Re 11 .SVDMT Plan Fp.hmarv 2012 Re 11 5 r«ll ne.^n^M \nMtT ninn\nAfr ninn nnn n nn.,.n.nn i 1 4VTaihng3 Mgnt Syatem and DMT MOD Plan Januory 2012 rov 11 4 cloon doo White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 42/12 Revision Demsonl 1 45 ( ! Page 50 of 55 APPENDIX E TABLES N.VDMT PlanVDMT Plan 02.29 12 Rev ll.SVDMT Plan Febroarv 2012 Re 11.5 redl ne.docN VDMT PlanVDMT Plan 01 30 12 Reviaion H 4VTailmga Mgnt Syatom and DMT Mon Plan Januory 2012 rov 11 4 clooadoo White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 4-2/12 Revision Denisonl 1 45 Page 51 of 55 Table lA Calculated Action leakage Rates for Vanous head Conditions Cell 4A White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate (gallons / acre / day) 5 222 04 10 31401 15 384 58 20 444 08 25 496 50 30 543 88 35 587 46 37 604 01 Table 13 Calculated Action leakage Rates for Vanous head Conditions Cell 4B White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate (gallons / acre / day) 5 21140 10 317 00 15 369 90 20 422 70 25 475 60 30 528 40 35 570 00 37 58120 N VDMT PlanVDMT Plan 02.29.12 Re 11 SVDMT Plan February 2012 Rev 11.5 redl e.docN VDMT PlanVDMT Plon 01 30 12 Revision 11 4VTailing3 Mgnt Syatem ond DMT Mon Plan January 2012 rov 11 4 cloon doc White Mesa Mill - Standard Operating Procedures 4-2/12 Revision Demsonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 52 of 55 N.VDMT PlanVDMT Plan 02.29 12 Re 11 SVDMT Plan February 2012 R 11 5 redl ne docN VDMT PlanVDMT Plan 01 30 12 Revision 11 4VToilmga Mgnt Syatom ond DMT Mon Plon Jonuory 2012 rov 11 4 clooadoc I White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 4-2/12 Revision Demsonl 1 45 Page 53 of 55 APPENDIX F Example of Freeboard Calculations For Cell 4B Assumptions and Factors o Total PMP volume to be stored in Cell 4BA - 159 4 acre feet o Wave mnup factor for Cell 43 - 0 77 feet o Total capacity of Cell 43-2 094 000 dry tons o Elevation of FML of Cell 43-5 600 35 FMSL o Maximum pool surface area of Cell 43 - 40 acres o Total tailings sohds deposited into Cell 43 at time beach area first exceeds 5 594 FMSL - 1 000 000 dry tons* o Date beach area first exceeds 5 594 FMSL - March 1 2012* o Expected and acmal production is as set forth in the following table Time Period Expected Taihngs Solids Disposition into CeU 4B Determined at the beginmng of the period (dry tons)* Expected Taihngs Sohds Dispositio n into Cell 4B at the beginmng ofthe period multiplied by 150% Safety Factor (dry tons) Actual Tailmgs Sohds Disposition into Cell 4B determined at end of the period (dry tons)* March 1 2012 to November 1 2012 150 000 225 000 225 000 November I 2012 to November I 2013 300 000 450 000 275 000 November 1 2013 to November 1 2014 200 000 300 000 250 000 N.VDMT PlanVDMT Plan 02.29 12 Re 1 l.SVDMT Plan February 2012 Re 11.5 redl ne docN VDMT PlanVDMT Plon 01 30 12 Roviaion 11 4VTQilinga Mgnt Syatom ond DMT Mon Plan Januory 2012 rov 11 4 clooadoo I White Mesa Mill - Standard Operating Procedures 42/12 Revision Demsonl 145 Book 11 Environmental Protection Manual Section 3 1 Page 54 of 55 *These expected and acmal tailmgs and production numbers and dates are fictional and have been assumed for illustrative purposes only Based on these assumptions and factors the freeboard limits for CeU 43 would be calculated as follows 1 Pnor to March 1.2012 Pnor to March I 2012 the maximum elevation of the beach area in Cell 43 is less than or equal to 5 594 FMSL therefore the freeboard limit is set at 5 594 6 FMSL 2 March 1. 2012 to November 1. 2012 The pool surface area would be reduced to the following amount (1-225 000/ (2 094 000 - 1 000 000)) x 40 acres = 31 77 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 31 77 acres equals 6 22 feet When the wave mn up factor for Cell 43 of0 77 feet is added to this the total freeboard required is 6 99 feet This means that the freeboard linut for Cell 43 would be reduced from 5594 6 FMSL to 5592 2 FMSL (5594 6 FMSL minus 6 22 feet rounded to the nearest one tenth of a foot) This calculation would be performed at March 1 2012 and this freeboard limit would persist until November 1 2012 3 November 1. 2012 to November 1. 2013 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since the acmal tonnage of 225 000 dry tons was the same as the modeled tonnage of 225 000 dry tons the recalculated pool surface area is the same as the modeled pool surface area for the previous penod which is 31 77 acres Then calculate the modeled pool surface area to be used for the penod (I - 450 000/ (2 094 000 -1 000 000 225 000)) x 31 77 acres = 15 32 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 15 32 acres equals 12 89 feet When the wave mn up factor for Cell 43 of 0 77 feet is added to this the total freeboard required is 13 66 feet This means that the freeboard linut for Cell 43 would be reduced from 5592 2 FMSL to 5586 7 FMSL (5600 35 FMSL minus 13 66 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2012 and this freeboard linut would persist until November 1 2013 N.VDMT PlanVDMT Plan 02.29.12 Re ll.SVDMT Plan February 2012 Re ll.Sredl e.docN VDMT PlanVDMT Plan 01 30 12 Roviaion 11 4VTailmg3 Mgnt Syatem and DMT Mon Plon Jonuory 2012 rov 11 4 cleoadoc I White Mesa Mill - Standard Operating Procedures 42/12 Revision Denisonl 1 45 Book 11 Environmental Protection Manual Section 3 1 Page 55 of 55 4 November 1. 2013 to November 1. 2014 The pool surface area would be reduced to the followmg amount First recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since modeled tonnages exceeded acmal tonnages the pool area was reduced too much dunng the previous penod and must be adjusted The recalculated pool area for the previous penod is (1-275 000 / (2 094 000 - I 000 000 225 000) x 31 77 acres = 2172 acres This recalculated pool surface area will be used as the starting point for the freeboard calculation to be performed at November I 2013 Then calculate the modeled pool surface area to be used for the penod (1-300 000 / (2 094 000 - 1 000 000 225 000 - 275 000)) x 21 72 acres: 10 75 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 10 75 acres equals 18 37 feet When the wave mn up factor for Cell 43 of0 77 feet is added to this the total freeboard required is 19 14 feet This means that the freeboard limit for CeU 43 would be reduced from 5586 7 FMSL to 5581 2 FMSL (5600 4 FMSL minus 18 4 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November I 2013 and this freeboard limit would persist until November I 2014 N.VDMT PlanVDMT Plan 02.29 12 Re ll.SVDMT Plan February 2012 R ll.Sredl e.docN VDMT PlanVDMT Plon 01 30 12 Roviaion 11 4VTailings Mgnt System und DMT Mon Plon Jonuory 2012 rov 11 4 clean doo DRC-201..-00 1086 DENISO MINES January 30 2012 VIA E MAIL AND OVERNIGHT DELIVERY Mr RustyLundberg Department of Environmental Quality 195 North 1950 West PO Box 144850 Salt Lake City UT 84114 4850 Received JAN 2012 Division of Rodiatior rontroi Demson Mines (USA) Corp 105017th Street Suite 950 Denver CO 80265 USA Tel 303 628-7798 Fax 303 389 4125 www denisonmines com Re State of Utah Groundwater Discharge Permit { GWDP ) No UGW370004 Transmittal of Revised Discharge Minimization Technology Monitonng { DMT ) Revision 11 4 dated January 2012 DearMr Lundberg Reference is made to the Division of Radiation Control ( DRC ) letters dated September 13 2011 December 14 2011 and December 22 2011 regarding the White Mesa Mill Tailings Management System and Discharge Minimization Technology ( DMT ) Monitonng Plans dated June 2011 (Revision 11 2) and July 2011 (Revision 11 3) This letter transmits Denison Mines (USA) Corp s ( Denison s ) proposed revisions to the White Mesa Mill DMT Plan These revisions include changes made to 1 Respond to the Request for Information ( RFI )/Confirmatory Action Letter dated September 13 2011 2 Respond to the comments provided in the December 22 2011 DRC letter and 3 Correct additional errors and inconsistencies in the June 2011 and July 2011 Revisions of the DMT Plan For ease of review we have provided both redline and clean versions of each document The attached DMT Plan Revision 11 4 has accepted all the redline changes proposed in Denison s June 23 2011 and July 11 2011 submittals as the base version in black type Changes resulting from the above referenced DRC comment letters are provided in redline/stnkeout format We have also provided below specific responses to each request in DRCs September 13 2011 and December 22 2011 letters The sections and numbenng of the remainder of this letter follow the DRC September 13 2011 and December 22 2011 letters Each DRC request is shown in italics below followed by Denison s response Letter to Mr Rusty Lundberg January 30 2012 Page 2 Responses to Comments Provided to DUSA in the September 13 2011 DRC RFI/Confirmatory Action Letter (as re transmitted in a DRC letter dated December 14 2011) DRC Comment 1 DUSA will provide the DRC the appropriate Mine Safety and Health Administration (MSHA) rule quotation(s) and citmg(s) that require the use of walkways with handrails when egressing active tailings cells According to our discussion these requirements precluded DUSA from making water level elevation measurements in Cell 48 Denison Response The requested MSHA citations are as follows 1 30 CFR 56 11001 - Safe Access - Safe means of access shall be provided and maintained to all working places 2 30 CFR 56 11002 - Handrails and toeboards - Crossovers elevated walkways elevated ramps and stairways shall be of substantial construction provided with handrails and maintained in good condition Where necessary toeboards shall be provided 3 Statutory Miners Rights - Right to refuse to work under conditions or practices believed to be unsafe unhealthy or illegal 4 Statutory Miners Rights - Right to protection from discnmination for exercising statutory nghts Under the requirements of MSHA if there is no MSHA regulation specific to a given issue but there is one under OSHA the OSHA rule does apply That being the case Denison is also required to comply OSHAs policies for nng buoys lifesaving skiffs and other requirements as prescnbed in 1910 and 1926 (General Industry and Construction) under OSHA s policies if a walkway with handrails is not avaialble DRC Comment 2 DUSA will commit to a period of time to construct walkways for new tailings cells after receiving authorization for use of any new tailings cell from the Executive Secretary This time period must be submitted for approval in a revised DMT Plan Denison Response It IS Denison s understanding that DRC s request for a time commitment to construct walkways in new cells IS based on the assumption that the initiation of solution level measurements in future cells will require a walkway That is Denison understands that DRC actually seeks a time commitment for initiating solution level measurement Tailings cell wastewater pool elevations will be monitored within 30 days of authonzation for use in accordance with the existing survey procedures specified in the DMT Plan and in accordance with Mill health and safety requirements The DMT Plan has been revised to reflect this requirement Health and safety requirements will dictate the methods such as floating walkways for providing worker access to the new cells are not discussed in the DMT Plan DRC Comment 3 DUSA will acquire a steel surveyors tape(s) of adequate length or develop other approved means to accurately measure water level elevations prior to construction of the walkway discussed in the two numbered items immediately above The procedures for this method to measure the water level elevation will be submitted by DUSA for approval in a revised DMT Plan Denison Response A steel surveyor s tape will not be used to measure tailings wastewater pool elevations Consistent with the remainder of Comment 3 Denison has developed other means to accurately measure cell solution level elevations pnor to construction of any walkways Therefore a descnption of procedure for use of a surveyor s tape is not necessary No changes to the text have been made DENISO MINES Letter to Mr Rusty Lundberg January 30 2012 Page 3 DRC Comment 4 DUSA will revise the DMT Plan reference (c) so the point designated for the water level measurement in Cell 4B will be the southeast corner rather than the current required location Denison Response The text has been changed as requested DRC Comment 5 DUSA must acquire a longer survey elevation rod eg a 45 rod) in order to survey the water level in the subject cell at lowest depths DUSA will revise the DMT Plan to include procedures for use of this longer survey rod Denison Response Denison has purchased a longer survey elevation rod 45 feet in length The procedures for use of the longer survey elevation rod are the same as those currently descnbed in the DMT plan The longer survey elevation rod does not require any procedural changes therefore no changes were made in the DMT Plan DRC Comment 6 A revised DMT Plan proposed in reference (e) contains a new paragraph on page 10 As discussed this specific proposed new verbiage is not acceptable The DMT Plan must be revised in accordance with the above commitments and requirements Denison Response The paragraph in question has been modified to specify that tailings wastewater pool elevations in new cells will be measured within 30 days of authonzation for use of the new cell DRC Comment 7 A new revised DMT Plan containing all the necessary verbiage changes from the items above will be submitted for approval Denison Response The revised DMT Plan Revision 11 4 dated January 2012 is attached Responses to Comments Provided to Denison m the DRC letter dated December 22 2011 DMT Plan Changes Required, from the Groundwater Discharge Permit Part I H 7 DRC Comment 1 Permit Part ID 3(b) paragraphs ii and in now that the slimes dram access pipe has been extended the corresponding measurements in the DMT Plan need to be corrected Denison Response The Cell 2 slimes dram access pipe measurements have been changed in the DMT Plan and the appropnate forms in the appendices to the Plan As a result of the changes in Cell 2 and the corrected measurements descnbed below the new depth of the Cell 2 shmes dram access pipe is 37 97 feet This modification has been made in the DMP Plan Revision 114 The changes to the Cell 2 slimes dram access pipe are descnbed in more detail below Two sets of measurements are routinely collected from the Cell 2 shmes dram access pipe for compliance with the GWDP and the RML The first measurement is the quarterly recovery test which is conducted to determine the compliance with the GWDP Part I D 3 (b)2 The second set of measurements are the weekly pre and post pump head measurements required by the License Changes to Cell 2 were completed dunng the second and third quarter 2011 which affect both sets of measurements collected from the Cell 2 shmes access dram Where these changes affect the DMT Plan or inspections forms the DENISO MINES Letter to Mr Rusty Lundberg January 30 2012 Page 4 Plan or forms have been revised A descnption of the changes and the effects on the measurements are as follows Summary of Changes to Cell 2 As detailed in letters to DRC dated May 27 June 17 and August 1 2011 Denison re graded the intenm fill on Cell 2 in order to reduce the potential for the accumulation of stormwater on the surface of Cell 2 which could potentially infiltrate into Cell 2 This re grading required 62 000 cubic yards of cut and fill and was completed on July 30 2011 As a result of the re grading of the intenm cover and the placement of additional fill the Cell 2 slimes dram access pipe was extended to bnng it above grade relative to the new cell surface elevation The extension pipe which is the same diameter as the existing access pipe was placed on top of the previous Cell 2 shmes dram access location and was mechanically attached using metal braces and plates The seam between the existing pipe and the extension were sealed with caulking and an external covenng to prevent infiltration by dirt and debns The measunng point for the extension of the shmes dram access pipe is directly above the previous measunng point The distance from the old measunng point to the new extended measunng point was measured to an accuracy of 0 01 feet The extension to the Cell 2 shmes dram access pipe measures 6 97 feet The extension was placed July 20 2011 Quarterly Recovery Test Data As noted above the quarterly recovery test is completed in accordance with the GWDP dated July 14 2011 Part I D 3 (b)(2) The recovery test data are collected by measunng the fluid level in the shmes dram over an extended penod of time (greater than 90 hours) The measurements for the recovery test are taken by measunng the distance from the measunng point to the top of the fluid present in the Cell 2 shmes dram access pipe The total depth of the Cell 2 shmes dram access pipe is not used in any of the calculations for determination of compliance with the GWDP Compliance determinations rely on elevation data generated by subtracting depth of the fluid levels measured from the top of the Cell 2 shmes dram access pipe from the elevation of the slimes dram access pipe There will be no change in the shmes dram elevation numbers generated because both the measurements used in the subtraction are adjusted by the same factor In order to make the data collected pnor to July 20 2011 comparable to the current data for use in the graphical representations 6 97 feet was added to all of the previous recovery data to adjust for the height added with the extension to the Cell 2 slimes dram access pipe Weekly Pre and Post Pump Head Measurements As noted above weekly pre and post pump head measurements are collected as required by the RML The weekly pre and post pump head measurements are taken by measunng the distance from the measunng point to the top of the fluid present in the Cell 2 shmes access pipe Two measurements are taken the first measurement is taken before the pump is started and the second is taken after the pump has run for 15 minutes The pre and post pump head is calculated by subtracting the liquid level from the total depth of the Cell 2 shmes dram Dunng the measurements of the extension to the Cell 2 slimes dram access pipe it was noted by the field personnel that the new length of the Cell 2 shmes dram access pipe is now approximately 38 feet The previous measurement used for the pre and post pumping head measurements was also 38 feet and the discrepancy was noted An investigation into the discrepancy between the previous total depth of the Cell 2 shmes dram and the current depth of the Cell 2 shmes dram was conducted The investigation included a review of the as built drawings for Cell 2 previous pre and post pump measurements and a review of the Cell 2 slimes dram access pipe procedures The as built drawings and the results of the investigation indicate that the previous total depth of the Cell 2 shmes dram was actually 31 feet With the extension of 6 79 feet to the previous total depth of 31 feet the current depth is now approximately 38 feet Pnor to the second quarter of 2011 the pre and post pump data was not reported to DRC The pre and post pump data were reported to DRC only in the second and third quarter 2011 DMT Reports The corrected DENISO MINES Letter to Mr Rusty Lundberg January 30 2012 Page 5 second and third quarter data will be included in the next quarterly DMT Report submitted on or before March 1 2012 DRC Comment 2 Part IE 7(b) paragraph (2) a professional survey of the new measurement point needs to be made Denison Response The Cell 2 slimes dram access pipe has been surveyed by a Utah certified Land Surveyor DRC Comment 3 Now that the Cell 2 slimes dram access pipe has been extended in height DUSA must state in the DMT Plan how the measurements to the water surface will be taken now and how DUSA will correlate these measurements correctly to earlier measurements Denison Response The weekly measurement procedure was not changed as a result of the extension of the Cell 2 slimes dram access pipe The head values are calculated in the same manner using the same procedures as those used pnor to the extension of the Cell 2 shmes dram access pipe however the total depth to the bottom of the pipe has changed to 37 97 feet as noted to the response to DRC comment number 1 above The new total depth is now used to calculate the pre and post pumping head The new measurement is noted on the Weekly Tailings Inspection form in Attachment A of the DMT Plan Correlation and/or adjustment for the height of the Cell 2 shmes dram access pipe for the calculation of the pre and post pumping head values is not necessary The pre and post head values are calculated by subtracting the liquid level measured pre and post pumping from the total depth of the Cell 2 shmes dram access pipe The pre and post pumping head value is a calculated difference that uses the total height of the Cell 2 shmes dram access pipe As can be seen in the following example the pre and post head values are the same regardless of the height of the Cell 2 shmes dram access pipe The pre and post pumping values are stored in hardcopy at the Mill site on the Weekly Inspection forms A note to the file will be stored with all of the hardcopy forms that show the incorrect total depth of 38 feet If recalculation were necessary the correct height measurement to complete the calculation will be used Q^^er Comments on the DMT Plan (reference (B) DRC Comment 4 On page 4 in the first sentence the items Cell 3 CeU 4A spillway should be reversed in their order in the sentence to be clearer in meaning Denison Response The text was changed as requested DRC Comment 5 In paragraph 6 35 there are several references to Cell 4A that apparently should refer to Cell 4B instead This occurs in paragraphs (c) iv vi vu and paragraph (d)iii In Appendix F of the DMT Plan this misreference appears to occur on page 56 in the second and fifth bullet line Please correct Denison Response The text corrections have been made as requested DRC Comment 6 Paragraph 6 2 needs to be revised due to the construction of Cell 4B ft needs to be corrected to refer to the current exterior dikes required to have movement monitoring DENISO MINES Letter to Mr Rusty Lundberg January 30 2012 Page 6 Denison Response The text corrections have been made as requested DRC Comment 7 Page 29 Table III Column under Dike 3 If there is visible embankment on the south dike of Cell 3 please adjust the form as appropriate Denison Response There is no visible embankment on the south dike of Cell 3 and no changes to the text were required DRC Comment 8 On page 36 paragraph 7 refers to a Contaminated Waste Dump awaiting DRC approval We are uncertain as to what this is Please clarify Denison Response The name Contaminated Waste Dump is an incorrect designation for the Designated Disposal Area for Non Tailings Mill waste discussed in SOP PBL 7 The form has been modified to refer to the area correctly The notation awaiting DRC approval on the form refers to an amendment request submitted to DRC by Denison in 2008 to revise the SOP to permit disposal of non tailings Mill waste in more than one cell To date DRC has not provided any response to that amendment request DRC Comment 9 Due to the installation of additional platform fill on Cell 2 slimes dram recovery elevation measurement related items m the DMT Plan need to be changed On the DMT Plan inspection form p 34 paragraph 2 the 38 foot figure appears to need adjustment Denison Response The form was changed as required Please contact me if you have any questions or require any further information Yours very truly DENISON MINES (USA) CORP •Oo Ann Tischler Director Compliance and Permitting cc David C Frydenlund Ron F Hochstein Harold R Roberts David Rupp David E Turk K Weinel Attachments DENISO MINES White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 Page 1 of 53 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN TABLE OF CONTENTS Contents 1 INTRODUCTION 3 2 DAILY TAILINGS INSPECTIONS 3 2 1 Daily Comprehensive Tailings Inspection 3 2 2 Daily Operations Inspection 6 2 3 Daily Operations Patrol 6 2 4 Training 6 2 5 Tailings Emergencies 6 3 WEEKLY TAILINGS AND DMT INSPECTION 7 3 1 Weekly Tailings Inspections 7 Northing 12 Easting 12 3 2 Weekly Inspection of Solution Levels m Roberts Pond 14 3 3 Weekly Feedstock Storage Area Inspections 15 4 MONTHLY TAILINGS INSPECTION 15 5 QUARTERLY TAILE^GS INSPECTION 16 6 ANNUAL EVALUATIONS 17 6 1 Annual Technical Evaluation 17 6 2 Movement Monitors 18 6 3 Freeboard Liimts 18 6 3 1 Cell 1 19 6 3 2 Cell 2 19 6 3 3 Cell 3 19 6 3 4 Cell 4A 19 6 3 5 Cell 4B 19 6 3 6 Roberts Pond 22 6 4 Annual Leak Detection Fluid Samples 22 6 5 Annual Inspection of the Decontanunation Pads 23 7 OTHER INSPECTIONS 23 N \DMT Plan\DMT Plan 01 30 12 Revision 11 4\Taihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 I 01/12 Revision Denisonll 4 Page 2 of 53 8 REPORTING REQUIREMENTS 8 1 Monthly Tailings Reports 8 2 DMT Reports 8 3 TAILINGS INSPECTOR TRAINING 23 23 24 40 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4\Tailmgs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 Page 3 of 53 1 INTRODUCTION This Teulings Management System and Discharge Minimization Technology Monitoring Plan (the Plan ) for the White Mesa Mill (the Mill ) provides procedures for monitoring of the tailings cell system as required under State of Utah Radioactive Materials License No UTI900479 (the Radioactive Materials License ) as well as procedures for operating and maintenance of momtonng equipment and reporting procedures that are adequate to demonstrate DMT compliance under State of Utah Ground Water Discharge Permit No 370004 for the Mill (the GWDP ) This Plan is designed as a systematic program for constant surveillance and documentation of the integrity of the tailings impoundment system including dike stability liner integrity and transport systems as well as monitoring of water levels m Roberts Pond and feedstock storage areas at the Mill The Plan requires daily weekly quarterly monthly and annual inspections and evaluations and monthly reporting to Mill management 2 DAILY TAILINGS INSPECTIONS The following daily tailings inspections shall be performed 2 1 Dailv Comprehensive Tailings Inspection On a daily basis including weekends all areas connected with the evaporation cell (Cell 1) and thefour tailings cells (Cells 2 3 4A and 4B) will be inspected Observations will be made of the current condition of each cell noting any corrective action that needs to be taken The Radiation Safety Officer (RSO) or his designee is responsible for performing the daily tailings inspections The RSO may designate other individuals with training as described in Section 2 4 below to perform the daily tailings inspection Observations made by the inspector will be recorded on the Daily Inspection Data form (a copy of which IS attached in Appendix A) The Daily Inspection Data form contains an inspection checklist which includes a tailings cells map and spaces to record observations especially those of immediate concem and those requiring corrective action The inspector will place a check by all inspection Items that appear to be operating properly Those items where conditions of potential concern are observed should be marked with an X A note should accompany the X specifying what the concem is and what corrective measures will resolve the problem This observation of concem should be noted on the form until the problem has been remedied The date that corrective action was taken should be noted as well Areas to be inspected include the following Cell 1 2 3 4A and 4B Dikes 4A S 4A E and 4B N \DMT Plan\DMT Plan 01 30 12 Revision 11 4\Tailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl I 4 Book 11 Environmental Protection Manual Section 3 1 Page 4 of 53 S wind movement of tailings effectiveness of dust minmuzation methods spray evaporation Cell 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and 4B liquid pools and associated liquid retum equipment and cell leak detection systems Operational features of the tailings area are checked for conditions of potential concem The following Items require visual inspection dunng the daily tailings mspection a) Tailings slurry and SX raffinate transport systems from the Mill to the active disposal cell(s) and pool retum pipeline and pumps Daily inspections of the tailmgs lines are required to be performed when the Mill IS operating The lines to be inspected include the tailings slurry lines from CCD to the active tailmgs cell SX raffinate lines that can discharge into Cell 1 Cell 4A or Cell 4B the pond retum line from the tailings area to the Mill and lines transporting pond solutions from one cell to another b) Cell 1 c) Cell 2 d) Cell 3 e) Cell 4A f) Cell 4B g) Dike stmctures including dikes 4A S 4A E and 4B S h) The Cell 2 spillway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and Cell 4B liquid pools and associated liquid retum equipment i) Presence of wildlife and/or domesticated animals in the tailmgs area including waterfowl and burrowing animal habitations j) Spray evaporation pumps and lines k) Wind movement of tailings and dust minimization Wind movement of tailings will be evaluated for conditions which may require initiation of preventative dust nunimization measures for cells containing tailings sand During tailings inspection general surface conditions will be evaluated for the following 1) areas of tailings subject to blowing and/or wind movement 2) N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 Page 5 of 53 liquid pool size 3) areas not subject to blowing and/or wind movement expressed as a percentage of the total cell area The evaluations will be reviewed on a weekly basis or more frequently if warranted and will be used to direct dust minmuzation activities 1) Observation of flow and operational status of the dust control/spray evaporation system(s) m) Observations of any abnormal variations in tailings pond elevations m Cells 1 3 4A and4B n) Locations of slurry and SX discharge within the active cells Slurry and SX discharge points need to be indicated on the tailings cells map included in the Daily Inspection Data form I o) An estimate of flow for active tailings slurry and SX line(s) p) An estimate of flow in the solution retum line(s) q) Daily measurements in the leak detection system sumps of the tailings cells will be made when warranted by changes in the solution level of the respective leak detection system The trigger for further action when evaluating the measurements in the Cell 1 and Cell 3 leak detection systems is a gain of more than 12 inches m 24 hours The solution level in Cell 4A or 4B leak detection system is not allowed to be more than 1 0 foot above the lowest point on the bottom flexible membrane liner (FML) (Cell 4A FML elevation is 5555 14 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5556 14 feet amsl For Cell 4B the FML elevation is 5557 50 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5558 50 feet amsl) If any of these observations are made the Mill Manager should be notified immediately and the leak detection system pump started In addition the requirement to notify the Executive Secretary in accordance with Parts ID 6 and IG 3 of the Groundwater Discharge Permit must be adhered to when the solution level trigger for Cell 4A or 4B has been exceeded Whenever the leak detection system pump is operating and the flow meter totalizer is recording a notation of the date and the time will be recorded on the Daily Inspection Data form This data will be used in accordance with License Condition 11 3 B through 11 3 E of the Mill s Radioactive Materials License to determine whether or not the flow rate into the leak detection system is m excess N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc ^ White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 6 of 53 of the License Conditions Items (a) (m) (n) and (o) are to be done only when the Mill is operating When the Mill is down these Items cannot be performed 2 2 Dailv Operations Inspection Dunng Mill operation the Shift Foreman or other person with the training specified m Section 2 4 below designated by the Radiation Safety Officer will perform an inspection of the tailings line and tailings area at least once per shift paying close attention for potential leaks and to the discharges from the pipelines Observations by the Inspector will be recorded on the appropriate line on the Operating Foreman s Daily Inspection form 2 3 Dailv Operations Patrol In addition to the inspections described in Sections 2 1 and 2 2 above a Mill employee will patrol the tailings area at least twice per shift dunng Mill operations to ensure that there are no obvious safety or operational issues such as leaking pipes or unusual wildlife activity or incidences No record of these patrols need be made but the inspectors will notify the RSO and/or Mill management m the event that during their inspection they discover that an abnormal condition or tailings emergency has occurred 2 4 Training All individuals performing inspections described m Sections 2 1 and 2 2 above must have Tailings Management System training as set out in the Tailings Inspection Training procedure which is attached as Appendix B This training will include a training pack explaining the procedure for performing the inspection and addressing inspection items to be observed In addition each individual after reviewing the training pack will sign a certification form indicating that training has been received relative to his/her duties as an inspector 2 5 Tailings Emergencies Inspectors will notify the RSO and/or Mill management immediately if dunng their inspection they discover that an abnormal condition exists or an event has occurred that could cause a tailings emergency Until relieved by the Environmental or Technician or RSO inspectors will have the authority to direct resources during tailings emergencies Any major catastrophic events or conditions pertaining to the tailings area should be reported immediately to the Mill Manager or the RSO one of whom will notify Corporate Management If N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 7 of 53 dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) 3 WEEKLY TAILINGS AND DMT INSPECTION 3 1 Weeklv Tailmgs Inspections Weekly tailings inspections are to be conducted by the Radiation Safety Department and include the following a) Leak Detection Systems Each tailings cell s leak detection system shall be checked weekly (as well as daily) to determine whether it is wet or dry If marked wet the liquid levels need to be measured and reported In Cell 1 and Cell 3 the leak detection system is measured by use of a dual probe system that senses the presence of solutions in the LDS system (comparable to the systems in Cells 4A and 4B) and indicates the presence of solution with a waming light The Cell 4A and 4B leak detection systems are monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector The pressure transducer is calibrated for fluid with a specific gravity of 1 0 The water levels are measured every hour and the information is stored for later retrieval The water levels are measured to the nearest 0 10 inch The data collector is currently programmed to store 7 days of water level information The number of days of stored data can be increased beyond 7 days if needed For Cells 1 and 3 the water level data is recorded on the Daily Tailmgs Inspection Form For Cells 4 A and 4B the water level data is downloaded to a laptop computer periodically and incorporated into the Mill s environmental monitoring data storage and into the files for weekly inspection reports of the tailmgs cell leak detection systems If sufficient fluid is present m the leak detection system of any cell the fluid shall be pumped from the LDS to the extent reasonably possible and record the volume of fluid recovered Any fluid pumped from an LDS shall be retumed to a disposal cell For Cells 1 and 3 if fluid is pumped from an LDS the flow rate shall be calculated by dividing the recorded volume of fluid recovered by the elapsed time since fluid was last pumped or increases m the LDS fluid levels were recorded whichever is the more recent This calculation shall be documented as part of the weekly inspection N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 8 of 53 For Cells 1 and 3 upon the initial pumping of fluid from an LDS a fluid sample shall be collected and analyzed in accordance with paragraph 11 3 C of the Radioactive Matenals License For Cell 4A and 4B under no circumstance shall fluid head m the leak detection system sump exceed a 1 foot level above the lowest point in the lower flexible membrane liner To detemune the Maximum Allowable Daily LDS Flow Rates in the Cell 4A and 4B leak detection systems the total volume of all fluids pumped from the LDS on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145 gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1A and IB (for Cells 4A and 4B respectively) in Appendix E to detemune the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A and 4B b) Shmes Drain Water Level Monitoring (i) Cell 3 IS nearly full and will commence closure when filled Cell 2 is partially reclaimed with the surface covered by platform fill Each cell has a shmes drain system which aids in dewatenng the shmes and sands placed m the cell (ll) Denison re graded the interim fill on Cell 2 in order to reduce the potential for the accumulation of stormwater on the surface of Cell 2 As a result of the re grading of the interim cover and the placement of an additional 62 000 cubic yards of fill material on Cell 2 the shmes drain access pipe was extended 6 97 feet The extension pipe is 6 97 feet in length and therefore the new measuring point is 37 97 feet from the bottom of the shmes drain The measuring point on the extension pipe was surveyed by a Utah Certified Land Surveyor For the quarterly recovery test descnbed in section vi below this extension has no effect on the data measurement procedures Cell 2 has a pump placed mside of the shmes drain access pipe at the bottom of the shmes dram As taken from actual measurements the bottom of the shmes drain is 37 97 feet below a water level measuring point which is a notch on the side of the Cell 2 shmes drain access pipe This means that the bottom of the slimes drain pool and the location of the pump are one foot above the lowest point of the FML in Cell 2 which based on constmction reports is at a depth of 38 97 feet below the water level measuring point on the shmes drain access pipe for Cell 2 (ill) The shmes drain pump in Cell 2 is activated and deactivated by a float mechanism and water level probe system When the water level reaches the level of N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 9 of 53 the float mechanism the pump is activated Pumping then occurs until the water level reaches the lower probe which tums the pump off The lower probe is located one foot above the bottom of the shmes dram standpipe and the float valve is located at three feet above the bottom of the shmes drain standpipe The average wastewater head in the Cell 2 shmes drain is therefore less than 3 feet and is below the phreatic surface of tailings Cell 2 about 27 feet below the water level measuring point on the shmes drain access pipe As a result there is a continuous flow of wastewater from Cell 2 into the shmes drain collection system Mill management considers that the average allowable wastewater head in the Cell 2 shmes drain resulting from pumping in this manner is satisfactory and is as low as reasonably achievable (iv) The Cell 2 shmes drain pump is checked weekly to observe that it is operating and that the water level probe and float mechanism are working properly which is noted on the Weekly Tailmgs Inspection Form If at any time the pump is observed to be not working properly it will be fixed or replaced within 15 days (v) Depth to wastewater in the Cell 2 shmes drain access pipe shall be monitored and recorded weekly to detemune maximum and minimum fluid head before and after a pumping cycle respectively The extension of the Cell 2 shmes drain access pipe did not require any changes to the measurement procedure The surveyed measuring point on the extended pipe is used as required The head measurements are calculated in the same manner using the same procedures as those used prior to the extension of the Cell 2 shmes drain access pipe however the total depth to the bottom of the pipe is now 37 97 feet as noted on the corrected form in Attachment A All head measurements must be made from the same measuring point (the notch at the north side of the access pipe) and made to the nearest 0 01 foot The results will be recorded as depth in pipe measurements on the Weekly Tailings Inspection Form The extension of the Cell 2 shmes access pipe has not changed the method of calculation of the pre and post pump head calculations only the constant (Cell 2 shmes drain access pipe height) used m the calculation has changed The head is calculated by subtracting the depth to liquid from 37 97 feet rather than from the previous measurement of 38 feet The weekly Tailings Inspection form included in Attachment A has been changed to reflect the extension height (vi) Effective July 11 2011 on a quarterly basis the shmes drain pump will be tumed off and the wastewater in the shmes drain access pipe will be allowed to stabilize for at least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level ofthe wastewater will be measured and recorded as a depth m pipe measurement on Quarterly Data form by measuring the depth to water below the water level measunng point on the shmes drain access pipe (vii) No process liquids shall be allowed to be discharged into Cell 2 (vill) If at any time the most recent average annual head in the Cell 2 shmes drain is found to have increased above the average head for the previous calendar year the Licensee will comply with the requirements of Part IG 3 of the GWDP including the N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 10 of 53 requirement to provide notification to the Executive Secretary orally within 24 hours followed by written notification (ix)Because Cell 3 and Cell 4A are currently active no pumping from the Cell 3 or Cell 4A shmes drain is authorized No pumping from the Cell 4B shmes drain will be authonzed once it is put mto service and while it is active Prior to initiation of tailings dewatering operations for Cell 3 Cell 4A or Cell 4B a similar procedure will be developed for ensuring that average head elevations in the Cell 3 and Cell 4A shmes drains are kept as low as reasonably achievable and that the Cell 3 Cell 4A and Cell 4 shmes drains are inspected and the results reported in accordance with the requirements of the pemut c) Wind Movement of Tailings An evaluation of wind movement of tailings or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 1 4A and 4B and Roberts Pond are to be taken by survey on a weekly basis The beach area in Cell 4B with the maximum elevation is to be taken by survey on a monthly basis when beaches are first observed as follows (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (ll) The survey will be performed using a survey instmment (the Survey Instmment ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a I survey rod (the Survey Rod ) having a visible scale m 0 01 foot increments (iii)The Reference Points for Cells 1 Cell 4A and 4B and Roberts Pond are known points established by professional survey For Cell 1 and Roberts Pond the Reference Point is a wooden stake with a metal disk on it located on the southeast comer of Cell 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 4A and 4B the Reference Point is a piece of stamped metal monument located next to the transformer on the south side of Cell 4A and 4B The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A and 4B) is 5600 49 fmsl The Surveyor will set up the Survey Instmment in a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this is typically on the road on the Cell 1 south dike between Cell 1 and Roberts Pond approximately 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4A and Cell 4B this is typically on the south side of Cell 4A and 4B N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 11 of 53 (iv) Once in location the Surveyor will ensure that the Survey Instmment is level by centering the bubble in the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor has established a level reading (vi) The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instmment is reading above the Reference Point (vii) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the main solution pond in the Cell 1 Cell 4A Cell 4B or Roberts Pond or the area of the beach in Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistently use the same locations are as follows For a newly constmcted cell when the cell is first placed into operation the solution level is typically zero feet above the FML or a minimal elevation above the FML due to natural precipitation For newly constmcted cells measurement of solution level will commence within 30 days of authorization for use Measurements will be conducted consistent with the procedures in this DMT Plan and consistent with current Mill health and safety procedures The measurements will be completed using survey equipment and the appropriate length survey rod (either 25 or 45 ) A Pond Surface Measurements I Cell 4A The Assistant will walk down the slope in the northeast comer of Cell 4A and place the Survey Rod at the liquid level n Cell 4B The Assistant will walk down the slope in the southeast comer of Cell 4B and place the Survey Rod at the liquid level m Cell 1 A mark has been painted on the north side of the ramp going to the pump platform in Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 1 01/12Revision Denisonll 4 Page 12 of 53 IV Roberts Pond A mark has been painted on the railing of the pump stand in Roberts Pond The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface Based on the foregoing methods the approximate coordinate locations for the measuring points for Roberts Pond and the Cells are Northing Easting Roberts Pond 323 041 2 579 697 Cell 1 322 196 2 579 277 Cell 4A 320 300 2 579 360 Cell 4B 320 690 2 576 200 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells B Cell 4B Beach Elevation Beach elevations m Cell 4B will commence when beaches are first observed The Assistant will place the Survey Rod at the point on the beach area of Cell 4B that has the highest elevation If it is not clear which area of the beach has the highest elevation then multiple points on the beach area will be surveyed until the Surveyor is satisfied that the point on the Cell 4B beach area with the highest elevation has been surveyed If it is clear that all points on the Cell 4B beach area are below 5 593 FMSL then the Surveyor may rely on one survey point (vill) The Assistant will hold the Survey Rod vertically with one end of the Survey Rod just touching the pond surface The Assistant will ensure that the Survey Rod IS vertical by gently rocking the rod back and forth until the Surveyor has established a level reading (ix)The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Pond Surface Reading ) which represents the number of feet the Survey Instmment is reading above the pond surface level The Surveyor will calculate the elevation of the pond surface as FSML by adding the Reference Point Reading for the Cell or Roberts Pond as the case may be to the Reference Point Elevation for the Cell or Roberts Pond and subtracting the Pond Surface Reading for the Cell or Roberts Pond and will record the number accurate to 0 01 feet N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 13 of 53 e) Decontamination Pads (i) New Decontamination Pad The New Decontanunation Pad is located m the southeast comer of the ore pad near the Mill s scale house A In order to ensure that the primary containment of the New Decontamination Pad water collection system has not been compronused and to provide an inspection capability to detect leakage from the primary containment vertical inspection portals have been installed between the primary and secondary containments B These portals will be visually observed on a weekly basis as a means of detecting any leakage from the primary containment into the void between the primary and secondary containment The depth to water in each portal will be measured weekly by physically measunng the depth to water with an electrical sounding tape/device All measurements must be made from the same measuring point and be made to the nearest 0 01 foot C These inspections will be recorded on the Weekly Tailings Inspection form D The water level shall not exceed 0 10 foot above the concrete floor in any standpipe at any time This will be determined by subtracting the weekly depth to water measurement from the distance from the measuring point in the standpipe to the dry concrete floor The depth to water from the top (elevation 5589 8 feet amsl) of any of the three (3) observation ports to the standing water shall be no less than 6 2 feet Depths less than 6 2 feet shall indicate more that 0 1 foot of standing water above the concrete floor (elev 5583 5 feet amsl) and shall indicate a leak in the primary containment E Any observation of fluid between the pnmary and secondary containments will be reported to the Radiation Safety Officer (RSO) F In addition to inspection of the water levels in the standpipes the New Decontamination Pad including the concrete integrity of the exposed surfaces of the pad will be inspected on a weekly basis Any soil and debris will be removed from the New Decontamination Pad N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mdl - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 14 of 53 immediately prior to inspection of the concrete wash pad for cracking Observations will be made of the current condition of the New Decontanunation Pad Any abnormalities relating to the pad and any damage to the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired (ll) Existing Decontamination Pad The Existing Decontanunation Pad is located between the northwest comer of the Mill s maintenance shop and the ore feeding gnzzly A The Existing Decontamination Pad will be inspected on a weekly basis Any soil and debris will be removed from the Existing Decontanunation Pad immediately prior to inspection of the concrete wash pad for cracking Observations will be made of the current condition of the Existing Decontamination Pad including the concrete integrity of the exposed surfaces of the pad Any abnormalities relating to the pad and any damage or cracks on the concrete wash surface of the pad will be noted on the Weekly Tailmgs Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired f) Summary In addition the weekly inspection should summarize all activities conceming the tailings area for that particular week Results ofthe weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection form An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A 3 2 Weeklv Inspection of Solution Levels in Roberts Pond On a weekly basis solution elevations are taken on Roberts Pond in accordance with the procedures set out in Section 3 1 d) above The Weekly solution level m Roberts Pond is recorded on the Weekly Tailings and DMT Inspection form Based on historical observations the FML at the Pond Surface Reading area for Roberts Pond is approximately six inches above the lowest point on the pond s FML If the pond solution elevation at the Pond Surface Reading area is at or below the FML N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 Page 15 of 53 for that area the pond will be recorded as being dry 3 3 Weeklv Feedstock Storage Area Inspections Weekly feedstock storage area inspections will be performed by the Radiation Safety Department to confirm that a) the bulk feedstock materials are stored and maintained within the defined area described in the GWDP as indicated on the map attached hereto as Appendix D b) a 4 ft buffer is maintained at the periphery of the storage area which is absent bulk material in order to assure that the materials do not encroach upon the boundary of the storage area and c) all altemate feedstock located outside the defined Feedstock Area are maintained within water tight containers The results of this inspection will be recorded on the Ore Storage/Sample Plant Weekly Inspection Report a copy of which is contained in Appendix A Any vanance in stored matenals from this requirement or observed leaking altemate feedstock dmms or other containers will be brought to the attention of Mill Management and rectified withm 15 days 4 MONTHLY TAILINGS INSPECTION Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from the Radiation Safety Department and recorded on the Monthly Inspection Data form an example of which IS contained in Appendix A Monthly inspections are to be performed no sooner than 14 days since the last monthly tailings inspection and can be conducted concurrently with the quarterly tailings inspection when applicable The following items are to be inspected a) Tailings Slurry Pipeline When the Mill is operating the slurry pipeline will be visually inspected at key locations to detemune pipe wear The critical points of the pipe include bends slope changes valves and junctions which are critical to dike stability These locations to be momtored will be determined by the Radiation Safety Officer or his designee from the Radiation Safety Department dunng the Mill mn b) Diversion Ditches Diversion ditches 1 2 and 3 shall be monitored monthly for sloughing erosion undesirable vegetation and obstmction of flow Diversion berm 2 should be checked N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 16 of 53 for stability and signs of distress c) Sedimentation Pond Activities around the Mill and facilities area sedimentation pond shall be summanzed for the month d) Overspray Dust Minimization The inspection shall include an evaluation of overspray minimization if applicable This entails ensuring that the overspray system is functioning properly In the event that overspray is earned more than 50 feet from the cell the overspray system should be immediately shut off e) Remarks A section is mcluded on the Monthly Inspection Data form for remarks m which recommendations can be made or observations of concem can be documented f) Summary of Daily Weekly and Quarterly Inspections The monthly inspection will also summanze the daily weekly and if applicable quarterly tailings inspections for the specific month In addition settlement monitors are typically surveyed monthly and the results reported on the Monthly Inspection Data form 5 QUARTERLY TAILINGS INSPECTION The quarterly tailings inspection is performed by the Radiation Safety Officer or his designee from the Radiation Safety Department having the training specified m Section 2 4 above once per calendar quarter A quarterly inspection should be performed no sooner than 45 days since the previous quarterly inspection was performed Each quarterly inspection shall include an Embankment Inspection an Operations/Maintenance Review a Constmction Review and a Summary as follows a) Embankment Inspection The Embankment inspection involves a visual inspection of the crest slope and toe of each dike for movement seepage severe erosion subsidence shrinkage cracks and exposed liner N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 I Page 17 of 53 b) Operations/Maintenance Review The Operations/Maintenance Review consists of reviewing Operations and Maintenance activities pertaining to the tailings area on a quarterly basis c) Construction Review The Constmction Review consists of reviewing any constmction changes or modifications made to the tailmgs area on a quarterly basis d) An estimate of the percentage of the tailings beach surface area and solution pool area is made including estimates of solutions cover areas and tailings sands for Cells 3 4Aand4B e) Summary The summary will include all major activities or observations noted around the tailmgs area on a quarterly basis If any of these conditions are noted the conditions and corrective measures taken should be documented in the Quarterly Inspection Data form An example of the Quarterly Inspection Data form IS provided in Appendix A 6 ANNUAL EVALUATIONS The following annual evaluations shall be performed 6 1 Annual Technical Evaluation An annual technical evaluation of the tailings management system is performed by a registered professional engineer (PE) who has experience and training in the area of geotechnical aspects of retention stmctures The technical evaluation includes an on site inspection of the tailings management system and a thorough review of all tailings records for the past year The Technical Evaluation also includes a review and summary of the annual movement monitor survey (see Section 5 2 below) All tailings cells and corresponding dikes will be inspected for signs of erosion subsidence shrinkage and seepage The drainage ditches will be inspected to evaluate surface water control stmctures In the event tailings capacity evaluations (as per SOP PBL 3) were performed for the receipt of altemate feed material during the year the capacity evaluation forms and associated calculation N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 Page 18 of 53 sheets will be reviewed to ensure that the maximum tailings capacity estimate is accurate The amount of tailings added to the system since the last evaluation will also be calculated to detemune the estimated capacity at the time of the evaluation Tailings inspection records will consist of daily weekly monthly and quarterly tailings inspections These inspection records will be evaluated to determine if any freeboard limits are being approached Records will also be reviewed to summarize observations of potential concem The evaluation also involves discussion with the Environmental and/or Radiation Technician and the Radiation Safety Officer regarding activities around the tailings area for the past year During the annual inspection photographs of the tailings area will be taken The traimng of individuals will be reviewed as a part of the Annual Technical Evaluation The registered engineer will obtain copies of selected tailmgs inspections along with the monthly and quarterly summaries of observations of concem and the corrective actions taken These copies will then be included in the Annual Technical Evaluation Report The Annual Technical Evaluation Report must be submitted by November 15^*^ of every year to the Executive Secretary 6 2 Movement Monitors A movement monitor survey is to be conducted by a licensed surveyor annually during the second quarter of each year The movement monitor survey consists of surveying monitors along dikes 3 S 4A W and 4A S to detect any possible settlement or movement of the dikes The data generated from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the tailings management system 6 3 Freeboard Limits The freeboard limits set out in this Section are intended to capture the Local 6 hour Probable Maximum Precipitation (PMP) event which was deternuned in the January 10 1990 Drainage Report (the Drainage Report ) for the White Mesa site to be 10 inches The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas was calculated in the Drainage Report to be 103 acre feet of water with a wave mn up factor of 0 90 feet The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas plus the adjacent drainage areas was calculated in the Drainage Report to be 123 4 acre feet of water The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage Report to be 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres) times N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 19 of 53 the PMP of 10 inches) with a wave mn up factor of 0 77 feet The flood volume from the PMP event over the Cell 4B area has been calculated to be 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 72 acres) times the PMP of 10 inches with a wave mn up factor of 0 77 feet The total pool surface area in Cell 1 is 52 9 acres in Cell 4A is 40 acres and in Cell 4B is 40 acres The top of the flexible membrane liner ( FML ) for Cell 1 is 5 618 2 FMSL for Cell 4A IS 5 598 5 FMSL and for Cell 4B is 5600 4 FMSL Based on the foregoing the freeboard limits for the Mill s tailings cells will be set as follows 63 1 Cell 1 The freeboard linut for Cell 1 will be set at 5 615 4 FMSL This will allow Cell 1 to capture all of the PMP volume associated with Cell 1 The total volume requirement for Cell 1 is 103 acre feet divided by 52 9 acres equals 1 95 feet plus the wave mn up factor of0 90 feet equals 2 85 feet The freeboard limit is then 5 618 2 FMSL minus 2 85 feet equals 5 615 4 FMSL Under Radioactive Materials License condition 10 3 this freeboard Imut is set and is not recalculated annually 632 Cell 2 The freeboard limit for Cell 2 is inapplicable since Cell 2 is filled with solids All of the PMP volume associated with Cell 2 will be attributed to Cell 4A (and/or any future tailmgs cells) 63 3 Cell 3 The freeboard liimt for Cell 3 is inapplicable since Cell 3 is close to being filled with solids and all of the PMP flood volume associated with Cell 3 will be attributed to Cell 4B (and/or any future tailmgs cells) 634 Cell 4A The freeboard limit for Cell 4A is inapplicable since all of the PMP flood volume associated with Cell 4A will be attributed to Cell 4B A spillway has been added to Cell 4A to allow overflow into Cell 4B 63 5 Cell 4B The freeboard limit for Cell 4B will be set assuming that the total PMP volume for Cells 2 3 4A and 4B of 159 4 acre feet will be accommodated m Cell 4B The procedure for calculating the freeboard limit for Cell 4B is as follows (a) When the Pool Surface Area is 40 Acres N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 20 of 53 When the pool surface area in Cell 4B is 40 acres (i e when there are no beaches) the freeboard limit for Cell 4B will be 5 594 6FMSL which is 5 7 feet below the FML This freeboard value was developed as follows PMP Flood Volume 38 1 acre feet Overflow from Cell 4A assunung no storage in Cell 3 or 4A 159 4 acre feet Sum of PMP volume and overflow volume 197 5 acre feet Depth to store PMP an overflow volume = 197 5 acre feet/40 acres 4 9 feet Wave mn up factor 0 77 feet Total required freeboard 5 7 feet (all values in the above calculation have been rounded to the nearest one tenth of afoot) (b) When the Maximum Elevation ofthe Beach Area is 5 594 FMSL or Less When the maximum elevation of the beach area m Cell 4B is 5594 FMSL or less then the freeboard limit will be 5 594 6 FMSL which is the same as in (a) above This allows for the situation where there may be beaches but these beaches are at a lower elevation than the freeboard limit established in (a) above and there is therefore ample freeboard above the beaches to hold the maximum PMP volume The maximum elevation of the beach area will be detemuned by monthly surveys performed by Mill personnel in accordance with the Mill s DMT Plan (c) When the Maximum Elevation ofthe Beach Area First Exceeds 5 594 FMSL When the maximum elevation of the beach area in Cell 4B first exceeds 5 594 FMSL then the freeboard limit for the remainder of the ensuing year (period t=0) (until the next November 1) will be calculated when that elevation is first exceeded (the Initial Calculation Date ) as follows i) The total number of dry tons of tailings that have histoncally been deposited into Cell 4B prior to the Initial Calculation Date ( To ) will be determined II) The expected number of dry tons to be deposited mto Cell 4B for the remainder of the ensuing year (up to the next November 1) based on production estimates for that period ( Ao* ) will be detemuned III) Ao* will be grossed up by a safety factor of 150% to allow for a potential underestimation of the number of tons that will be deposited in the cell during the remainder of the ensuing year This grossed up number can be referred to as the modeled tonnage for the period iv) The total design tailings solid storage capacity of Cell 4B will be accepted as 2 094 000 dry tons of tailmgs v) The available remaining space m Cell 4B for solids as at the Initial Calculation Date will be calculated as 2 094 000 dry tons minus To Vl) The reduction in the pool surface area for the remainder of the ensuing year will be assumed to be directly proportional to the reduction in the available space in Cell 4B N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mdl - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual SecUon 3 1 Page 21 of 53 for soilds That is the reduced pool surface area for period t=0 ( RPAo ) after the reduction will be calculated to be (1 - (Ao* X 1 5) / (2 094 000 To)) x 40 acres = RPAo Vll) The required freeboard for Cell 4B for the remainder of the period t=0 can be calculated in feet to be the wave mn up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAo The freeboard Imut for Cell 4B for the remainder of period t=0 would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of afoot and vill) The foregoing calculations will be performed at the Initial Calculation Date and the resulting freeboard limit will persist until the next November 1 An example of this calculation is set out m Appendix F (d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds 5 594 FMSL On November 1 of each year (the Annual Calculation Date ) the reduction m pool area for the ensuing year (referred to as period t) will be calculated by i) First calculating the Adjusted Reduced Pool Area for the previous period (ARPAt 0 to reflect actual tonnages deposited in Cell 4B for the previous period (period t 1) The RPAt 1 used for the previous penod was based on expected tonnages for period t 1 grossed up by a safety factor The ARPAt i is merely the RPA that would have been used for period t 1 had the actual tonnages for year t 1 been known at the outset of period t 1 and had the RPA been calculated based on the actual tonnages for penod t 1 This allows the freeboard calculations to be corrected each year to take into account actual tonnages deposited in the cell as of the date of the calculation The ARPAt 1 can be calculated using the following formula (1 - At 1 / (2 094 000 - Tt 0) x ARPAt i = ARPAt i Where • At 1 is the actual number of dry tons of tailmgs solids deposited in Cell 4B during period t 1 • Tt I IS the actual number of dry tons of tailings solids historically deposited in Cell 4B prior to the beginning of period t 1 and • ARPAt 2 IS the Adjusted Reduced Pool Area for penod t 2 If period t 2 started at the Initial Calculation Date then ARPAt 2 is 40 acres 11) Once the ARPAt 1 for the previous period (period t 1) has been calculated the RPA for the subject period (period t) can be calculated as follows (1 - (At* X 1 5) / (2 094 000 Tt)) x ARPAt 1 = RPAt N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 22 of 53 Where • At* IS the expected number of dry tons of tailings to be deposited into Cell 4B for the ensuing year (period t) based on production estimates for the year (as can be seen from the foregoing formula this expected number is grossed up by a safety factor of 1 5) • Tt IS the actual number of dry tons of tailings solids historically deposited m Cell 4B prior to the beginning of period t and • ARPAt 1 IS the Adjusted Reduced Pool Area for period t 1 which is the pool surface area for the previous period (period t 1) that should have applied dunng that penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the period 111) The required freeboard for period t can be calculated in feet to be the wave mn up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAt The freeboard linut for Cell 4B for period t would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of a foot and iv) The foregoing calculations will be performed at the Annual Calculation Date for period t and the resulting freeboard limit will persist until the next Annual Calculation Date for period t+1 An example of this calculation is set out in Appendix F (e) When a Spillway is Added to Cell 4B that Allows Overflow Into a New Tailings Cell When a spillway is added between Cell 4B and a new tailings cell then if an approved freeboard limit calculation method for the new cell is set to cover the entire PMP event for Cells 2 3 4A 4B and the new tailmgs cell the freeboard linut for Cell 4B will be inapplicable except for approved provisions to prevent storm water mnoff from overtopping dikes 6 3 6 Roberts Pond The freeboard limit for Roberts Pond is a liquid maximum elevation of 5 624 0 feet above mean sea level as specified in the GWDP 6 4 Annual Leak Detection Fluid Samples In the event solution has been detected in a leak detection system a sample will be collected on an annual basis This sample will be analyzed according to the conditions set forth in License Condition 11 3 C The results of the analysis will be reviewed to detemune the ongin of the solution N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 23 of 53 6 5 Annual Inspection of the Decontamination Pads a) New Decontamination Pad During the second quarter of each year the New Decontamination Pad will be taken out of service and inspected to ensure the integrity of the wash pad s exposed concrete surface If any abnormalities are identified i e cracks in the concrete with greater than 1/8 inch separation (width) or any significant deterioration or damage of the pad surface repairs will be made prior to resunung the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontanunation Pad Inspection form The inspection findings any repairs required and repairs completed shall be summarized in the 2"^* Quarter DMT Monitoring Report due September 1 of each calendar year b) Existing Decontamination Pad During the second quarter of each year the Existing Decontanunation Pad will be taken out of service and inspected to ensure the integnty of the steel tank Once the water and any sediment present is removed from the steel tank containment the walls and bottom of the tank will be visually inspected for any areas of damage cracks or bubbling indicating corrosion that may have occurred since the last inspection If any abnormalities are identified defects or damage will be reported to Mill management and repairs will be made prior to resuming the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontanunation Pad Inspection form A record of the repairs will be maintained as a part of the Annual Inspection records at the Mill site The inspection findings any repairs required and repairs completed shall be summarized in the 2nd Quarter DMT Monitoring Report due September 1 of each calendar year 7 OTHER INSPECTIONS All daily weekly monthly quarterly and annual inspections and evaluations should be performed as specified in Sections 2 3 4 5 and 6 above However additional inspections should be conducted after any significant storm or significant natural or man made event occurs 8 REPORTING REQUIREMENTS In addition to the Daily Inspection Data Weekly Tailings Inspection Monthly Inspection Data and Quarterly Inspection Data forms included as Appendix A and described m Sections 2 3 4 and 5 respectively and the Operating Foreman s Daily Inspection and Weekly Mill Inspection forms descnbed in Sections 2 and 3 respectively the following additional reports shall also be prepared 8 1 Monthlv Tailings Reports Monthly tailings reports are prepared every month and summarize the previous month s activities N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl I 4 Book 11 Environmental Protection Manual Section 3 1 Page 24 of 53 around the tailings area If not prepared by the Radiation Safety Officer the report shall be submitted to the Radiation Safety Officer for review The Mill Manager will review the report as well before the report is filed in the Mill Central File The report will contain a summary of observations of concem noted on the daily and weekly tailings inspections Corrective measures taken during the month will be documented along with the observations where appropriate All daily and weekly tailings inspection forms will be attached to the report A monthly mspection form will also be attached Quarterly inspection forms will accompany the report when applicable The report will be signed and dated by the preparer in addition to the Radiation Safety Officer and the Mill Manager 82 DMT Reports Quarterly reports of DMT monitoring activities which will include the following information will be provided to the Executive Secretary on the schedule provided in Table 5 of the GWDP a) On a quarterly basis all required information required by Part 1 F 2 of the GWDP relating to the inspections described in Section 3 1 (b) (Shmes Drain Water Level Monitoring) 3 1(d) (Tailings Wastewater Pool and Beach Area Elevation Monitoring) 3 2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3 3 (Weekly Feedstock Storage Area Inspections) b) On a quarterly basis a summary of the weekly water level (depth) inspections for the quarter for the presence of fluid in all three vertical inspection portals for each of the three chambers in the concrete settling tank system for the New Decontanunation Pad which will include a table indicating the water level measurements in each portal during the quarter c) With respect to the annual inspection of the New Decontamination Pad descnbed m Section 6 5(a) the inspection findings any repairs required and repairs completed shall be sununanzed in the 2"** Quarter report due September 1 of each calendar year d) With respect to the annual inspection of the Existing Decontamination Pad described m Section 6 5(b) the inspection findings any repairs required and repairs completed shall be summarized in the 2"^ Quarter report due September 1 of each calendar year and e) An annual summary and graph for each calendar year of the depth to wastewater in the Cell 2 shmes drain must be included in the fourth quarter report After the first year and beginning in 2008 quarterly reports shall include both the current year monthly values and a graphic comparison to the previous year N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Demsonl 1 4 Page 25 of 53 1 J N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 1 01/12 Revision Denisonll 4 Page 26 of 53 APPENDIX A FORMS L -1" N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc ^ (i-i O 1) 22 cs CJ S 5 Q < H c O c o OH > o z u o Q c c o o c/3 C3 B O (L> *^ O 1 C «J c« I o o B 3 CT' (D C o ^—< o < X 1^ O II t B M o (U CJ T3 B c 0) s 3 o o TJ c (50 o c o pe r a o. c t-H O no i > H <H re a t ne e O c/3 o o a X W Ul > o o s 03 O > o U u (D C 1—I C O ea o 3 <l> O o u c o o u cn Pui 2 o ^ I 1 eg c ^ i ^ u ? S CO ^ C> ^ OQ Csl (U c o O G O c o u c o o o tH o 2 o* ^ ^ o tj ^ -S Cl, « G O c« O ^ ^ > -3 2 o o t> 1^ ^ „ OH a a 3 CO on W) CJ C 3 - OJ - "2 l/l x> •H 3 JS I/} CO PQ o O 51 0) O OJ o ^ W O OJ (U Cl o OJ O !/J o ^ w ° 2 0 S tt > -3 S O 0 -IT; O OJ *^ cn O o OJ *^ 1/5 2^ > OJ 00 <D CJ 3 (U •o c« X) 3 C/3 ^ O a S3 2 2 u w on IH COT on o o >H >H S bO o PlH J5 00 «H ^ Q TH t« ^ o PQ 13 U < IJ U U CN U o H O u H P 3 C3- OJ CJ c 3 Q bll 3 3 E > o T3 3 cn c o Q OO 03 CU C o s «5 2 3 4) •o on (O al OJ 2 2 (U 3 O B }3 CU T3 C 2 V3 1 = 03 m ^ CQ T3 3 O CJ -a CJ bb O 3 O PQ IJ U < IJ U flj U c PE: B T3 S 3 a Q 2 S > u: B T3 OJ a S 3 a Q -3 -3-1 5 3 ^ 5 [i: T3 a E 3 a O Q s > o. E 3 a O > s > TD (U & E 3 & o o ^ s s ^ ' 2 Tailings Daily Inspection Repoit Tailings vSliiny Dischaige Location cn «n C4-1 o o cn 0) cu > 0^ cn ^ I •o on 2I 2 2 O « ^ «2 73 C 03 *^ CO I (/I B M •E § ^ CQ // MILLSITE CELL NO 1 1 n CELL NO 4B / / CELL NO 4A / N Date In^pectoi 1 White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Envu-onmental Protection Manual Section 3 1 * Page 31 of 53 APPENDIX A (CONT) DENISON MINES (USA) CORP WEEKLY TAILINGS INSPECTION Date Inspectors 1 Pond and Beach Cell 1 (a) Pond Solution Elevation elevations (msl ft) (b) FML Bottom Elevation 5597. (c) Depth of Water above FML ((a) (b)) Cell 4A (a)Pond Solution Elevation (b) FML Bottom Elevation 5555 14_ (c) Depth of Water above FML ((a) (b)) Cell4B (a)Pond Solution Elevation (b) FML Bottom Elevation 5557 50 (c) Depth of Water above FML ((a) (b)) (d) Elevation of Beach Area with Highest Elevation (monthly) Roberts Pond (a)Pond Solution Elevation (b) FML Bottom Elevation 5612 3. (c) Depth of Water above FML ((a) (b)) L 2 Shmes Dram Liquid Levels Cell 2 Pump functioning properly _Depth to Liquid pre pump .Depth to Liquid Post pump (all measurements are depth in pipe) ' Pre pump head is 37 97 Depth to Liquid Pre pump = I Post purrip head is 37 97 -Depth to Liquid Post pump = N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Denisonll 4 ^ Page 32 of 53 3 Leak Detection Systems (Same data as Daily Inspection Form Record data on daily form) Observation New Decon Pad, Portal 1 New Decon Pad. Portal 2 f New Decon Pad Portal 3 Is LDS (Portal) wet or dry*? wet drv wet drv wet drv Is LDS (Portal) wet or dry*? If wet Record liquid level Ft to Liquid Fttoi Liquid Ft to Liquid If wet Report to RSO 4 Taihngs Area Inspection (Note dispersal of blowing taihngs) 5 Control Methods Implemented 6 Remarks 7 Designated Disposal Area for Non Tailmgs Mill Waste (awaiting DRC approval) * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (solution elevation of 5556 14 amsl for Cell 4A and 5558 50 for Cell 46)*? no yes If Cell 4A leak detection system level exceeds 12 ineheSj above the lowest point on the bottom flexible membrane liner (elevation 5556 14 amsl) notify supervisor or Mill manager immediately N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 I 01/12Revision Denisonll 4 Page 33 of 53 APPENDIX A (CONT) MONTHLY INSPECTION DATA Inspector Date 1 Slurry Pipelme 2 Diversion Ditches and Diversion Berm Observation Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2 Diversion Ditches Sloughing Erosion Undesirable Vegetation Obstruction of Flow Diversion Berm Stability Issues Signs of Distress _yes_ _ycs_ _yes_ _yes_ _no _no _no no _yes_ _yes_ _yes_ _yes_ _no _no _no no _yes_ ^es_ _yes_ _yes_ _no _no _no no .yes_ _yes_ _no no Comments 3 Summary of Activities Around Sedimentation Pond N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailmgs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Denisonll 4 Page 34 of 53 4 Overspray Dust Minimization Overspray system functioning properly _yes_ Overspray camed more than 50 feet from the cell If yes was system immediately shut off? Comments no _yes_ _yes. no no 5 Remarks 6 Settlement Monitors Cell 2 Wl Cell 2 W2 Cell 2 W3 Cell 2 W4 Cell 2W7 C Cell 2 W7N Cell2W6C Cell 4A Toe Cell 3 2C Cell 3 3S CeU 3 4N Cell 3 7C Cell 3 8C Cell 2W3 S Cell 2E1 N Cell 2E1 IS Cell 2E1 2S Cell 2 East Cell 2 W7S Cell 2 W6S Cell 2 W4S Cell 3 2S _ Cell 3 3C _ Cell 3 6N _ Cell 3 7N _ Cell 3 8N Cell 3 IN _ Cell 3 IC _ Cell 3 IS _ Cell 3 2N _ Cell 2W5 N Cell 2 W6N Cell2W4N Cell 2 W5C Cell 2 W5S Cell3 3N _ Cell 3 7S _ Cell 3 8S 7 Movement Monitors (Is there visible damage to any movement monitor or to adjacent surfaces)'' 8 Summary of Daily, Weekly and Quarterly Inspections N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 1 01/12Revision Denisonll 4 Page 35 of 53 I 1 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailmgs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Denisonll 4 Page 36 of 53 APPENDIX A (CONT) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector Date 1 Embankment Inspection 2 Operations/Maintenance Review 3 Construction Activities 4 Estimated Areas Cell 3 Cell 4A Cell 4B Estimated percent of beach surface area Estimated percent of solution pool area Estimated percent of cover area Comments N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures i 01/12 Revision Denisonl I 4 Book 11 Environmental Protection Manual Section 3 1 Page 37 of 53 APPENDIX A (CONT) ORE STORAGE/SAMPLE PLANT WEEKLY INSPECTION REPORT Week of through Date of Inspection Inspector Weather conditions for the week Blowing dust conditions for the week Corrective actions needed or taken for the week Are all bulk feedstock matenals stored in the area indicated on the attached diagram yes no comments Are all altemate feedstock matenals located outside the area indicated on the attached diagram maintained within water tight containers yes no comments (e g conditions of containers) Are all sumps and low lying areas free of standing solutions'? Yes No If No how was the situation corrected supervisor contacted and conection date*? Is there free standing water or water running off of the feedstock stockpiles'? Yes No Comments N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 \ 01/12Revision Denisonll 4 Page 38 of 53 Other comments N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 39 of 53 APPENDIX A ^CONT) ANNUAL DECONTAMINATION PAD INSPECTION Date of InspecUon Inspector New Decontamination Pad Are there any cracks on the wash pad surface greater than 1/8 inch of separation*? Yes No Is there any significant detenoration or damage df the pad surface*? Yes ^No Findings i | Repair Work Required ' Existing Decontamination Pad ' Were there any observed problems with the steel tank*? Yes No Findings Repair Work Required Note For the annual inspection of the both the Existing and New Decontanunation Pads the annual inspection findings any repairs required and repairs completed along with a summary of the weekly inspections shall be discussed in the 2"f Quarter report due September 1 of each calendar year N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailmgs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 40 of 53 APPENDIX B 8 3 TAILINGS INSPECTOR TRAINING This document provides the training necessary for qualifying management designated individuals for conducting daily tailings inspections Training mformation is presented by the Radiation Safety Officer or designee from the Environmental Department Daily tailings inspections are conducted in accordance with the White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan The Radiation Safety Officer or designee from the Radiation Safety Department is responsible for performing monthly and quarterly tailings inspections Tailings inspection forms will be included in the monthly tailings inspection reports which summarize the conditions activities and areas of concem regarding the tailings areas Notifications The inspector is required to record whether all mspection items are normal (satisfactory requinng no action) or that conditions of potential concem exist (requinng action) A check mark indicates no action required If conditions of potential concem exist the inspector should mark an X m the area the condition pertains to note the condition and specify the corrective action to be taken If an observable concem is made it should be noted on the tailmgs report until the corrective action is taken and the concem is remedied The dates of all corrective actions should be noted on the reports as well Any major catastrophic events or conditions pertaining to the tailings area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) Inspections All areas of the tailings disposal system are routinely patrolled and visible observations are to be noted on a daily tailings inspection form Refer to Appendix A for an example of the daily tailings inspection form The inspection form consists of three pages and is summarized as follows 1 Tailings Slurry Transport System The slurry pipehne is to be inspected for leaks damage and sharp bends The pipeline joints are to be monitored for leaks and loose connections The pipeline supports are to be inspected for damage and loss of support Valves are also to be inspected particularly for N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailuigs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 41 of 53 leaks blocked valves and closed valves Points of discharge need to be inspected for improper location and orientation 2 Operational Systems Operating systems including water levels beach liners and covered areas are items to be inspected and noted on the daily inspection forms Sudden changes in water levels previously observed or water levels exceeding the operating level of a pond are potential areas of concern and should be noted Beach areas that are observed as having cracks severe erosion or cavities are also items that require investigation and notation on daily forms Exposed Imer or absence of cover from erosion are potential items of concem for ponds and covered areas These should also be noted on the daily inspection form Cells 1 3 4A and 4B solution levels are to be monitored closely for conditions nearing maximum operating level and for large changes in the water level since the last inspection All pumping activities affecting the water level will be documented In Cells 1 and 3 the PVC liner needs to be monitored closely for exposed liner especially after storm events It is important to cover exposed Imer immediately as exposure to sunlight will cause degradation of the PVC liner Small areas of exposed liner should be covered by hand Large sections of exposed liner will require the use of heavy equipment These conditions are considered senous and require immediate action After these conditions have been noted to the Radiation Safety Officer a work order will be written by the Radiation Safety Officer and tumed mto the Mamtenance Department All such repairs should be noted in the report and should contam the start and finish date of the repairs 3 Dikes and Embankments Inspection items include the slopes and the crests of each dike For slopes areas of concem are sloughs or sliding cracks bulges subsidence severe erosion moist areas and areas of seepage outbreak For crests areas of concem are cracks subsidence and severe erosion When any of these conditions are noted an X mark should be placed in the section marked for that dike In addition the dikes m particular dikes 4A S 4A E and4B S should be inspected closely for mice holes and more importantly for praine dog holes as the praine dogs are likely to bunow in deep possibly to the liner If any of these conditions exist the inspection report should be marked accordingly N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTadings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Denisonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 42 of 53 Flow Rates Presence of all flows in and out of the cells should be noted Flow rates are to be estimated in gallons per minute (GPM) Rates need to be detemuned for slurry lines pond retum SX tails and the spray system During non operational modes the flow rate column should be marked as 0 The same holds tme when the spray system is not utilized Physical Inspection of Slurry Line(s) A physical inspection of all slurry lines has to be made every 4 hours during operation of the null If possible the inspection should include observation of the entire discharge line and discharge spill point into the cell If fill to elevation flags are in place the tailings and build up is to be monitored and controlled so as to not cover the flags Dust Control Dusting and wind movement of tailings should be noted for Cells 2 3 4A and 4B Other observations to be noted include a brief description of present weather conditions and a record of any precipitation received Any dusting or wind movement of tailings should be documented In addition an estimate should be made for wind speed at the time of the observed dusting or wind movement of tailings The Radiation Safety Department measures precipitation on a daily basis Daily measurements should be made as near to 8 00 a m as possible every day Weekend measurements will be taken by Environmental Health and Safety personnel as close to 8 00 a m as possible All snow or ice should be melted before a reading is taken Observations of Potential Concern All observations of concem during the inspection should be noted in this section Corrective action should follow each area of concem noted All work orders issued contacts or notifications made should be noted in this section as well It is important to document all these Items in order to assure that the tailings management system records are complete and accurate Map of Tailings Cells The last section of the mspection involves drawing as accurately as possible the following Items where applicable N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 43 of 53 1 Cover area 2 Beach/tailing sands area 3 Solution as it exists 4 Pump lines 5 Activities around tailings cell (i e hauling trash to the dump liner repairs etc) 6 Slurry discharge when operating 7 Over spray system when operating 9 Safety Rules All safety mies applicable to the mill are applicable when in the tailings area These mies meet the required MSHA regulations for the tailmgs area Please pay particular notice to the following mies 1 The posted speed limit on Cell 4A and 4B dike is 5 mph and the posted speed Imut for the tailings area (other than the Cell 4A and 4B dike) is 15 mph These limits should not be exceeded 2 No food or drink is permitted in the area 3 All personnel entenng the tailings area must have access to a two way radio 4 Horseplay is not pemutted at any time 5 Only those specifically authorized may operate motor vehicles in the restncted area 6 When road conditions are muddy or slick a four wheel drive vehicle is required in the area 7 Any work performed in which there is a danger of falling or slipping in the cell will require the use of a safety belt or hamess with attended life line and an approved life jacket A portable eyewash must be present on site as well 8 Anytime the boat is used to perform any work an approved life jacket and goggles must be wom at all times There must also be an approved safety watch with a two way hand held radio on shore A portable eyewash must be present on site as well 10 Preservation of Wildlife Every effort should be made to prevent wildlife and domesticated animals from entering the tailings area All wildlife observed should be reported on the Wildlife Report Worksheet during each shift Waterfowl seen near the tailings cells should be discouraged from landing by the use of noisemakers 11 Certification Following the review of this document and on site instmction on the tailings system inspection program designated individuals will be certified to perform daily tailings inspections The Radiation Safety Officer authonzes certification Refer to the Certification N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaiUngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Denisonll 4 Page 44 of 53 Form Appendix C This form should be signed and dated only after a thorough review ofthe tailmgs information previously presented The form will then be signed by the Radiation Safety Officer and filed N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl I 4 Book 11 Environmental Protection Manual Section 3 1 Page 45 of 53 APPENDIX C CERTIFICATION FORM Date Name I have read the document titled Tailings Management System White Mesa Mill Tailmgs Inspector Training and have received on site instmction at the tailings system This instmction included documentation of daily tailings inspections analysis of potential problems (dike failures unusual flows) notification procedures and safety Signature I certify that the above named person is qualified to perform the daily inspection of the tailings system at the White Mesa Mill Radiation Safety Personnel/ Tailings System Supervisor N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc 1 White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 46 of 53 APPENDIX D r FEEDSTOCK STORAGE AREA N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc I White Mesa Mill - Standard Operating Procedures Book 11 Envu-onmental Protection Manual Section 3 I 01/12Revision Denisonll 4 Page 47 of 53 1 N I Denison Mlrtds (USA) <^ low J*"" ur rrmm ISIQI F<MMtetock 8t0f«09 Area Map F<MMtetock 8t0f«09 Area Map F<MMtetock 8t0f«09 Area Map F<MMtetock 8t0f«09 Area Map F<MMtetock 8t0f«09 Area Map H/A oe/oa/am imu^nLsoUim N VDMT PlanVDMT Plan 01 30 12 Revision 11 4\Tailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures , 01/12 Revision Denisonll 4 Book 11 Environmental Protection Manual Section 3 1 Page 48 of 53 APPENDIX E TABLES N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and.DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Demsonl 1 4 Page 49 of 53 Table lA Calculated Action leakage Rates for Various head Conditions Cell 4A White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate ( gallons / acre / day) 5 222 04 10 314 01 15 384 58 20 444 08 25 496 50 30 543 88 35 587 46 37 604 01 Table IB Calculated Action leakage Rates for Various head Conditions Cell 4B White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate ( gallons / acre / day) 5 21140 10 317 00 15 369 90 20 422 70 25 475 60 30 528 40 35 570 00 37 581 20 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaihngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 50 of 53 J N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailings Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/12 Revision Demsonl 1 4 Page 51 of 53 APPENDIX F Example of Freeboard Calculations For Cell 4B Assumptions and Factors o Total PMP volume to be stored in Cell 4A - 159 4 acre feet o Wave mnup factor for Cell 4B - 0 77 feet o Total capacity of Cell 4B - 2 094 000 dry tons o Elevation of FML of Cell 4B - 5 600 35 FMSL o Maximum pool surface area of Cell 4B - 40 acres o Total tailmgs solids deposited into Cell 4B at time beach area first exceeds 5 594 FMSL - 1 000 000 dry tons* o Date beach area first exceeds 5 594 FMSL - March 1 2012* o Expected and actual production is as set forth in the following table Time Period Expected Tailings Solids Disposition into Cell 4B Determined at the beginmng of the period (dry tons)* Expected Tailmgs Sohds Dispositio n into Cell 4B at the beginning of the period, multiplied by 150% Safety Factor (dry tons) Actual Tailings Sohds Disposition into Cell 4B determined at end of the period (dry tons)* March 1 2012 to November 1 2012 150 000 225 000 225 000 November 1 2012 to November 1 2013 300 000 450 000 275 000 November 1 2013 to November 1 2014 200 000 300 000 250 000 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTailuigs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 1 Page 52 of 53 *These expected and actual tailings and production numbers and dates are fictional and have been assumed for illustrative purposes only Based on these assumptions and factors the freeboard limits for Cell 4B would be calculated as follows 1 Prior to March L 2012 Prior to March 1 2012 the maximum elevation of the beach area in Cell 4B is less than or equal to 5 594 FMSL therefore the freeboard limit is set at 5 594 6 FMSL 2 March 1. 2012 to November 1. 2012 The pool surface area would be reduced to the following amount (1-225 000/ (2 094 000 - 1 000 000)) x 40 acres = 31 77 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 31 77 acres equals 6 22 feet When the wave mn up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 6 99 feet This means that the freeboard Imut for Cell 4B would be reduced from 5594 6 FMSL to 5592 2 FMSL (5594 6 FMSL minus 6 22 feet rounded to the nearest one tenth of a foot) This calculation would be performed at March 1 2012 and this freeboard limit would persist until November 1 2012 3 November 1, 2012 to November 1. 2013 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied during the previous period had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the period Since the actual tonnage of 225 000 dry tons was the same as the modeled tonnage of 225 000 dry tons the recalculated pool surface area is the same as the modeled pool surface area for the previous penod which is 31 77 acres Then calculate the modeled pool surface area to be used for the period (1-450 000/ (2 094 000- 1 000 000 225 000)) x 31 77 acres = 15 32 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 15 32 acres equals 12 89 feet When the wave mn up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 13 66 feet This means that the freeboard Imut for Cell 4B would be reduced from 5592 2 FMSL to 5586 7 FMSL (5600 35 FMSL minus 13 66 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2012 and this freeboard limit would persist until November 1 2013 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc White Mesa Mill - Standard Operating Procedures 01/12 Revision Demsonl 1 4 Book 11 Environmental Protection Manual Section 3 I Page 53 of 53 4 November 1. 2013 to November 1. 2014 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied during the previous period had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the period Since modeled tonnages exceeded actual tonnages the pool area was reduced too much during the previous period and must be adjusted The recalculated pool area for the previous period is (1-275 000 / (2 094 000 - 1 000 000 225 000) x 31 77 acres = 21 72 acres This recalculated pool surface area will be used as the starting point for the freeboard calculation to be performed at November 1 2013 Then calculate the modeled pool surface area to be used for the period (1-300 000 / (2 094 000 - 1 000 000 225 000 - 275 000)) x 21 72 acres 10 75 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 10 75 acres equals 18 37 feet When the wave mn up factor for Cell 4B of0 77 feet is added to this the total freeboard required is 19 14 feet This means that the freeboard limit for Cell 4B would be reduced from 5586 7 FMSL to 5581 2 FMSL (5600 4 FMSL minus 18 4 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2013 and this freeboard Imut would persist until November 1 2014 N VDMT PlanVDMT Plan 01 30 12 Revision 11 4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11 4 clean doc REDLINE f f i White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 4^ Book 11 Environmental ProtecUon Manual Section 3 1 Page 1 of 53 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN TABLE OF CONTENTS Contents 1 INTRODUCTION 3 2 DAILY TAILINGS INSPECTIONS 3 2 1 Dailv Comprehensive Tailings Inspection 3 2 2 Dailv Operations Inspection 6 2 3 Dailv Operations Patrol 6 2 4 Trammc 6 2 5 Tailings Emergencies 6 3 WEEKLY TAILINGS AND DMT INSPECTION 7 3 1 Weeklv Tailings Inspections 7 Northing 12 Easting 12 3 2 Weeklv Inspection of Solution Levels in Roberts Pond 15 3 3 Weeklv Feedstock Storage Area Inspections 15 4 MONTHLY TAILINGS INSPECTION 15 5 QUARTERLY TAILINGS INSPECTION 16 6 ANNUAL EVALUATIONS 18 6 1 Annual Technical Evaluation 18 6 2 Movement Monitors 19 6 3 Freeboard Limits 19 6 3 1 Cell I 20 6 3 2 Cell 2 20 6 3 3 CeU 3 20 6 3 4 Cell 4A 20 6 3 5 Cell 4B 20 6 3 6 Roberts Pond 23 6 4 Annual Leak Detection Fluid Samples 23 6 5 Annual Inspection of the Decontamination Pads 23 7 OTHER INSPECTIONS 24 N \DMT Plan\DMT Plan 01.30.12 Revis on 11.4\TaihnBS Ment Svstem and DMT Mon Plan January 2012 rev 11.4 redhncdocN VDMT PlanUulv 2011 DMT roviaion for pormitNToilingg Mgnt Syotem ond DMT Mon Plon July 2011 rev 11 2 rodlino doo White Mesa Mill - Standard Operating Procedures OW401/12 Revision Denisonll 4^ Book 11 Envu-onmental Protection Manual SecUon 3 1 Page 2 of 53 8 REPORTING REOUIREMENTS 24 8 1 Montfilv Tailmgs Reports 24 8 2 DMT Reoorts 25 8 3 TAILINGS INSPECTOR TRAINING 40 I INTRODUCTION i 3—DAILY TAILINGS INSPECTIONS ^ 3-1-—Daily Comprohonsive Tailings Inspection- 3-3-—Daily Opomtions Inspection 3-^—Doily Qporntionfl Patfel- 3-4-—Trainmg 3-§-—Tailings Emergencies- 3—WEEKLY TAILINGS AND DMT INSPECTION 3-1-—Weekly Tailings Inspections 7 3-1-3-—Nortfung 13 3-1-3-—Easting 13 3-3-—Weeklv Inspection of Solution Levels in Roberts W(m4 14 3-3-—Weekly Feedstock Storage Area Inspoctiens 1§ 4r-MONTHLY TAILINGS INSPECTION niTARTFRl Y TAH INn^ rM^PFPTTOM 14 1^ 6— ANNUAL EVALUATIONS 1% 6-4-—Annual Technical Evaluation 18 6-3-—Movomont Monitors 19 6-3-—Freeboard Linuts 19 6^-1— 'I Coll 1 Prll 30 XJ J 2L '•0 THI 6 3 5 Crll ilR 6^-6-Roberts Pond 33 6-4-—Annual Look Dotoction Fluid Samples 33 6-5-—Annual Inspection of the Decontanunation Pads 33 7 OTHER INSPECTIONS 34 8:—REPORTING REOUIRENffiNTS 34 8-4-—Monthly Tailings Reports 34 8 2 DMT Reports 3# ^—TAILINGS INSPECTOR TRAINING 4§ N.\DMT PlanNDMT Plan 01.30.12 Re s on 11.4\Taibne.s Mgnt Svstem and DMT Mon Plan January 2012 rev 11.4 redhne.docN \DMT PlnnMulv 2011 DMT rovioion for pormirtTiulinfia Mgnt System and DMT Mon Plan July 2011 rov 11 2 rcdlino 4e» White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Denisonl 1 4^ Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 3 of 53 1 INTRODUCTION This Tailings Management System and Discharge Minimization Technology Momtormg Plan (the Plan ) for the White Mesa Mill (the Mill ) provides procedures for momtonng of the tailings cell system as requu-ed under State of Utah Radioactive Matenals License No UTI900479 (the Radioactive Matenals License ) as well as procedures for operating and mamtenance of momtonng equipment and reportmg procedures that are adequate to demonstrate DMT compliance under State of Utah Ground Water Discharge Permit No 370004 for the MiU (the GWDP ) This Plan is designed as a systematic program for constant surveillance and documentation of the integnty of the tailings impoundment system mcluding dike stability Imer integnty and transport systems as well as momtonng of water levels in Roberts Pond and feedstock storage areas at the Mill The Plan requires dady weekly quarterly monthly and annual inspections and evaluations and monthly reporting to Mill management 2 DAILY TAILINGS INSPECTIONS The following daily tailings inspections shall be performed 2 1 Dailv Comprehensive Taihngs Inspection On a dady basis including weekends all areas connected with the evaporation cell (Cell 1) and thefivfr-four tailings cells (Cells 2. 3.4A. and 4B) will be inspected Observations will be made of the cunent condition of each cell noting any corrective action that needs to be taken The Environmental or Radiation TechnicionRadiation Safety Officer (RSO) or his designee is responsible for perfomung the daily tailmgs inspections The Radiation Safety QfficerRSO may designate other individuals with traimng as descnbed m Section 2 4 below to perform the daily tailings mspection Observations made by the inspector will be recorded on the Daily Inspection Data form (a copy of which is attached m Appendix A) The Daily Inspection Data form contains an mspection checklist which includes a tailmgs cells map and spaces to record observations especially those of immediate concem and those requinng corrective action The inspector will place a check by all mspection Items that appear to be operating properly Those items where conditions of potential concem are observed should be marked with an X A note should accompany the X specifying what the concem is and what corrective measures will resolve the problem This observation of concem should be noted on the form until the problem has been remedied The date that conective action was taken should be noted as well N.VDMT PlanNDMT Plan 01.30.12 Re son 11 4\Taihnes Ment .Svstem and DMT Mon Plan January 2012 re 11.4 redl ne.docN VDMT PlonVIulv 2011 DMT revision for pennitVToilinga Mgnt Syatom and DMT Mon Plon July 2011 rev 11 2 rodlmo doo White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Denisonll 4^ Book 11 Environmental Protection Manual SecUon 3 1 Page 4 of 53 Areas to be inspected include die following Cell I 2 3 4A and 4B Dikes 4A S 4A E and 4B S wind movement of tailings effectiveness of dust nunimization methods spray evaporation Cell 2 spillway Cell 3 spillway Cell 4A spillwav.Cell 3 Cell 4A spillway Cell 4A and 4B hquid pools and associated liquid remm equipment and cell leak detection systems Operational feamres of the tailings area are checked for conditions of potential concem The following Items require visual inspection dunng the daily tailings inspection a) Tailings slurry and SX raffinate transport systems from the Mill to the active disposal cell(s) and pool retum pipeline and pumps Daily inspections of the tailings lines are required to be performed when the Mill IS operating The lines to be inspected include the taihngs slurry hnes from CCD to the active taihngs cell SX raffinate lines that can discharge mto Cell 1 Cell 4AorCell4B the pond remm line from die tailings area to the Mill and Imes transporting pond solutions from one cell to another b) Cell 1 c) Cell 2 d) Cell 3 e) Cell 4A 0 Cell 4B g) Dike stmcmres including dikes 4A S 4A E and 4B S h) The Cell 2 spdlway Cell 3 spillway Cell 4A spillway Cell 3 Cell 4A and Cell 4B liquid pools and associated liquid remm equipment i) Presence of wildlife and/or domesticated ammals in the tailings area, including waterfowl and burrowing ammal habitations j) Spray evaporation pumps and lines k) Wind movement of tailings and dust nunimization Wind movement of tailmgs will be evaluated for conditions which may require initiation of preventative dust nunmuzation measures for cells contammg tailmgs sand Dunng tailings inspection general surface conditions will be evaluated for N.VDMT PlanVDMT Plan 01.30.12 Re i i 11.4VTailing Mgnt Sv tem and DMT M n Plan January 2012 re 11.4 redl e.docN VDMT PlonUulv 2011 DMT revision for permitVToilinga Mgnt Syatem and DMT Mon Plan July 2011 rov 11 3 rodlme^ I White Mesa Mill - Standard Operating Procedures 97/4401/12 Revision Denisonll 4* Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 5 of 53 the following I) areas of tailings subject to blowing and/or wind movement 2) liquid pool size 3) areas not subject to blowing and/or wind movement expressed as a percentage of the total cell area The evaluations will be reviewed on a weekly basis or more frequently if warranted and will be used to direct dust mimnuzation activities 1) Observation of flow and operational status of the dust control/spray evaporation system(s) m) Observations of any abnormal vanations in tailmgs pond elevations in Cells 1 3 4A and4B n) Locations of slurry and SX discharge within the active cells Slurry and SX discharge pomts need to be indicated on the tailings cells map included in the Daily Inspection Data form o) An estimate of flow for active tailings slurry and SX line(s) p) An estimate of flow m the solution retum line(s) q) Daily measurements in the leak detection system (LDS) sumps of the tailings cells will be made when warranted by changes in the solution level of the respective leak detection system The tngger for further action when evaluating the measurements m die Cell 1 and Cell 3 leak detection systems is a gam of more than 12 inches in 24 hours The solution level in Cell 4A or 4B leak detection system is not allowed to be more than 1 0 foot above the lowest point on the bottom flexible membrane liner (FML) (Cell 4A FML elevation is 5555 14 amsl and widi die addition ofthe 1 0 foot of solution the solution elevation is 5556 14 feet amsl For Cell 4B the FML elevation is 5557 50 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5558 50 feet amsl) If any of these observations are made the Mill Manager should be notified immediately and the leak detection system pump started In addition the requirement to notify the Executive Secretary m accordance widi Parts ID 6 and IG 3 of the Groundwater Discharge Permit must be adhered to when the solution level tngger for Cell 4A or 4B has been exceeded Whenever the leak detection system pump is operating and the flow meter totalizer is recording a notation of the date and the time will be recorded on the Daily Inspection Data form This data will be used in accordance with License Condition 11 3 B through 11 3 E of the Mdl s Radioactive Matenals License to N.VDMT PlanVDMT Plan 01.30.12 Revisio 11 4VTaili gs Mpit Svstem and DMT Mon Plan January 2012 rev 11.4 edh e.docN VDMT PlonVJulv 2011 DMT revision for pormitVToilings Mgnt Syatom and DMT Mon Plan July 2011 rov 11 2 rodline doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 4? Book 11 Environmental Protection Manual SecUon 3 1 Page 6 of 53 detemune whether or not the flow rate into the leak detection system is in excess of the License Conditions Items (a) (m) (n) and (o) are to be done only when the Mill is operating When the Mill is down these Items cannot be performed 2 2 Dailv Operations Inspection Durmg Mill operation the Shift Foreman or other person with the training specified m Section 2 4 below designated by the Radiation Safety Officer wdl perform an inspection of die ladings line and tailings area at least once per shift paying close attention for potential leaks and to the discharges from the pipelines Observations by the Inspector will be recorded on the appropnate line on the Operating Foreman s Daily Inspection form 2 3 Dailv Operations Patrol In addition to the inspections descnbed m Sections 2 1 and 2 2 above a Mill employee will patrol the tailings area at least twice per shift dunng Mill operations to ensure that there are no obvious safety or operational issues such as leaking pipes or unusual wildlife activity or incidences No record of these patrols need be made but the inspectors will notify the Radiation Safety Officer ^RSO-) and/or Mdl management m the event that dunng their inspection they discover that an abnormal condition or tailings emergency has occurred 24 Training All individuals performing inspections descnbed in Sections 2 1 and 2 2 above must have Tailings Management System training as set out in the Tailings Inspection Training procedure which is attached as Appendix B This training will include a training pack explaming the procedure for performing the inspection and addressing inspection items to be observed In addition each individual after reviewing the training pack will sign a certification form indicating that training has been received relative to his/her duties as an inspector 2 5 Tailings Emergencies Inspectors will notify the Radiation Safety OfficorRSQ and/or Mill management immediately if dunng their inspection they discover that an abnormal condition exists or an event has occurred that could cause a ladings emergency Until relieved by the Environmental or Radiation Technician or Radiation Safetv OfficorRSO inspectors will have the authonty to direct resources dunng tailings emergencies N.VDMTPlanVDMTPIan01.30.12Revisnnll.4VTaib gs Mgnt System and DMT Mon Plan January 2012 re 11.4tEdl e.docN VDMT PlonVJulv 2011 DMT reviaion for pormitVToilings Mgnt System ond DMT Mon Plon July 2011 rev 11 2 redlme doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 4? Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 7 of 53 Any major catastrophic events or conditions pertaining to the tailmgs area should be reported immediately to the Mill Manager or the Radiation Safetv OfficorRSO one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will dien notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) 3 WEEKLY TAILINGS AND DMT INSPECTION 3 1 Weekly Tailings Inspections Weekly tailings inspections are to be conducted by the Radiation Safety Department and include die following a) Leak Detection Systems Each ladings cell s leak detection system shall be checked weekly (as well as daily) to detemune whether it is wet or dry If marked wet the liquid levels need to be measured and reported In Cell 1 and Cell 3 the leak detection system is measured by use of a dual probe system that senses the presence of solutions in the LDS system (comparable to the systems m Cells 4A and 4B) and indicates the presence of solution with a waming light The Cell 4A and 4B leak detection systems are momtored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector The pressure transducer is calibrated for fluid with a specific gravity of 1 0 The water levels are measured every hour and the information is stored for later retneval The water levels are measured to the nearest 0 10 inch The data collector is currently programmed to store 7 days of water level information The number of days of stored data can be increased beyond 7 days if needed For Cells 1 and 3 the water level data is recorded on the Daily Taihngs Inspection Form For Cells 4A and 4B the water level data is downloaded to a laptop computer en-penodically and incorporated into the Mill s environmental monitonng data storage and into the files for weekly inspection reports of the tailings cell leak detection systems If sufficient fluid is present m the leak detection system of any cell the fluid shall be pumped from the LDS to the extent reasonably possible and record the volume of fluid recovered Any fluid pumped from an LDS shall be remmed to a disposal cell For Cells 1 and 3 if fluid is pumped from an LDS the flow rate shall be calculated by dividing the recorded volume of fluid recovered by the elapsed time since fluid was last pumped or increases m the LDS fluid levels were recorded whichever is the more recent This calculation shall be documented as part of the N.VDMT PlanVDMT Plan 01.30 12 Re so 11.4VTailings Mgnt Svstem and DMT Mon Plan January 2012 re 11.4 redbne.docN VDMT PlonVJulv 2011 DMT reviaion for pormitVTailings Mgnt System ond DMT Mon Plan July 2011 rev 11 2 redlme doo White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual Section 3 1 07/1401/12 Revision Demsonl 1 4* Page 8 of 53 weekly inspection For Cells 1 and 3 upon the initial pumping of fluid from an LDS a fluid sample shall be collected and analyzed in accordance with paragraph 11 3 C of the Radioactive Matenals License For Cell 4A and 4B under no circumstance shall fluid head in the leak detection system sump exceed a 1 foot level above the lowest point in the lower flexible membrane Imer To detemune the Maximum Allowable Daily LDS Flow Rates in the Cell 4A and 4B leak detection systems the total volume of all fluids pumped from the LDS on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145 gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1A and IB (for Cells 4A and 4B respectively) in Appendix E to determine the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A and 4B b) Shmes Drain Water Level Momtormg (i) Cell 3 is nearly full and will commence closure when filled Cell 2 is partially reclaimed with the surface covered by platform fill Each cell has a shmes drain system which aids in dewatenng the shmes and sands placed in the cell (u) Denison re graded the intenm fill on Cell 2 in order to reduce the potential for the accumulation of stormwater on the surface of Cell 2 As a result of the re grading of the intenm cover and the placement of an additional 62,000 cubic yards of fill matenal on Cell 2. the shmes drain access pipe was extended 6 97 feet The extension pipe is 6 97 feet in length, and therefore the new measunng point is 37 97 feet from the bottom of the shmes dram The measunng point on the extension pipe was surveyed bv a Utah Certified Land Survevor For the quarterlv recoverv test descnbed in section vi below, this extension has no effect on the data measurement procedures Cell 2 has a pump placed inside of the shmes drain access pipe at the bottom* of the shmes drain As taken from actual, measurements the bottom of the shmes drain is 38-37 97 feet below a water level measunng point which is a notch on the side of the Cell 2 shmes drain access pipe at the centerhne of the shmes drain access pipe at the ground surface level This means that the bottom of the shmes drain pool and the location of the pump are one foot above the lowest point of the FML m Cell Formatted Indent Left 1 No bullets or numbering N.VDMT PlanVDMT Plan 01.30.12 Revi.sio 11.4VTaili gs Mgnt System and DMT Mon Plan January 2012 re 11.4 redline.docN VDMT PlonUulv 2011 DMT revision for permitVToilings Mgnt Syatom and DMT Mon Plan July 2011 rov 11 2 redlme doc White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/1401/12 Revision Denisonl 14? Page 9 of 53 2 which based on constmction reports is at a depth of 39-^38 97 feet below the water level measunng point on the shmes drain access pipe for Cell 2 (iii) The shmes drain pump in Cell 2 is activated and deactivated by a float mechanism and water level probe system When the water level reaches the level of the float mechamsm the pump is activated Pumping then occurs until the water level reaches the lower probe which tums the pump off The lower probe is located one foot above the bottom of the shmes dram standpipe and the float valve is located at five-three feet above the bottom of the slimes drain standpipe The average wastewater head in the Cell 2 shmes drain is therefore less than §-3_feet and is below the phreatic surface of tailings Cell 2 about 30-27 feet below the water level measunng point on the shmes drain access pipe As a result there is a continuous flow of wastewater from Cell 2 into the shmes drain collection system Mill management considers that the average allowable wastewater head m the Cell 2 shmes dram resulting from pumping in this manner is satisfactory and is as low as reasonably achievable (iv) The Cell 2 shmes drain pump is checked weekly to observe that it is operating and that the water level probe and float mechamsm are working properly which is noted on the Weekly Tailings Inspection Form If at any time the pump is observed to be not working properly it will be fixed or replaced within 15 days (v) Depth to wastewater in the Cell 2 shmes drain access pipe shall be monitored and recorded weekly to detemune maximum and nunimum fluid head before and after a pumping cycle respectively The extension of the Cell 2 shmes dram access pipe did not require any changes to the measurement procedure The surveyed measunng point on the extended pipe is used as required The head measurements are calculated in the same manner, using the same procedures as those used pnor to the extension of die Cell 2 shmes drain access pipe, however, the total depth to the bottom of the pipe is now 37 97 feet as noted on the conected form in Attachment A -All head measurements must be made from the same measunng point (the* notch at the north side of the access pipe) and made to the nearest 0 01 foot The results will be recorded as depth in pipe measurements on the Weekly Tailings Inspection Form The extension of the Cell 2 shmes access pipe has not changed the method of calculation of the pre and post pump head calculations, only the constant (Cell 2 shmes dram access pipe height) used m the calculation has changed The head is calculated bv subtracting the depth to liquid from 37 97 feet rather than from the previous measurement of 38 feet The weeklv Tailings Inspection form included in Attachment A has been changed to reflect the extension height. (vi) Effective July 11 2011 on a quarterly basis the shmes dram pump will be mmed off and the wastewater in the shmes drain access pipe will be allowed to stabilize for at least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level of the wastewater will be measured and recorded as a depth in pipe measurement on -{ Formatted Not Highlight Formatted Indent Left 1 No bullets or numbering Formatted Indent Left 1 Hanging 0 5 No bullets or numbering Formatted Indent Left 0 75 No bullets or numbering N.VDMT PlanVDMT Plan 01.30.12 Re isio 11.4VTailings Mgnt Svstem and DMT Mo Plan January 2012 re 11.4 redb e.docN VDMT PlonUulv 2011 DMT rovioion for pormitVToihngs Mgnt Syatem ond DMT Mon Plan July 2011 rev 11 2 rodlino doo I White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual Secuon 3 1 Page 10 of 53 Quarterly Data form by measunng the depth to water below the water level measunng point on the shmes drain access pipe (vu) No process hquids shall be allowed to be discharged into Cell 2 (vm) If at any time the most recent average annual head in the Cell 2 shmes drain is found to have increased above the average head for the previous calendar year the Licensee will comply widi the requirements of Part IG 3 of die GWDP including die requirement to provide notification to the Executive Secretary orally withm 24 hours followed by wntten notification (ix)Because Cell 3 and Cell 4A are currentiy active no pumping from the Cell 3 or Cell 4A shmes dram is authonzed No pumping from the Cell 4B shmes drain will be authonzed once it is put into service and while it is active Pnor to initiation of tailings dewatenng operations for Cell 3 Cell 4A or Cell 4B a sinular procedure will be developed for ensunng that average head elevations in the Cell 3 and Cell 4A shmes drains are kept as low as reasonably achievable and that the Cell 3 Cell 4A and Cell 4 shmes drains are inspected and the results reported in accordance with the requirements of the pemut c) Wind Movement of Tailings An evaluation of wind movement of tailings or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements m Cells 1^4A and 4B and Roberts Pond are to be taken by survey on a weekly basis _ «id-tThe beach area in Cell 4B with the maximum elevation is to be taken by survey on a monthly basis when beaches are first observed as follows (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (u) The survey will be performed using a survey mstmment (the Survey Instmment ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a survey rod (the Survey Rod ) having a visible scale in 0 01 foot increments (iii)The Reference Points for Cells I. Cell 4A. and 4B and Roberts Pond are known points established by professional survey For Cell 1 and Roberts Pond the Reference Pomt is a wooden stake with a metal disk on it located on the southeast comer of Cell 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 3 the Roforenco Point is a piece of metal rebar located on the south dike of Cell 3 The elevation at tho top of this piece of rebar (tho Roforonce Point Elevation for Coll 3) lo at 5 607 83 FMSL For Cell 4A and 4B the Reference Point is a piece of stamped metal monument located next to the N.VDMT PlanVDMT Plan 01.30.12 Revi I 11.4VTaib g Ment Svstem and DMT M Plan January 2012 re 11.4 edb edocN VDMT PlonUulv 2011 DMT roviaion for pormitVToibngs Mgnt Syotem ond DMT Mon Plan July 2011 rov 11 2 redte^dee White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Denisonl 1 4? Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 11 of 53 transformer on die south side of Cell 4A and 4B The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A and 4B) is 5600 49 fmsl The Surveyor will set up the Survey Instmment in a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this IS typically on the road on the Cell 1 south ddce between Cell 1 and Roberts Pond approximately 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4A and Cell 4B this is typically on the south side of Cell 4A and 4B (iv) Once m location the Surveyor will ensure that the Survey Instmment is level by centenng the bubble in the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Point (on die metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by gendy rocking the rod back and forth untd die Surveyor has established a level reading (vi) The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instmment is reading above the Reference Point (vu) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the main solution pond in the Cell I Cell 4A Cell 4B or Roberts Pond or the area of the beach in Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistendy use the same locations are as follows For a newly constmcted cell when the cell is first placed into operation the solution level is typically zero feet above the FML or a nunimal elevation above the FML due to natural precipitation For newly constmcted cells solution level measurement of solution level will commence within 30 davs of authonzation for use Measurements will be conducted consistent with die procedures in this DMT Plan and consistent with current Mill health and safetv procedures The measurements will be completed using survey equipment and the appropnate length survey rod (either 25 or 45 ) not be required until the solution lovol is high enough that it can be reached isafoly by personnel with a measurmg tape along the side of tho FML Solutions levels will bo measured by this method beginmng when tho solution lovol is high enough to be reached safely as determined by the RSO Surveying of solution levels will not be required untd solution levels are high enough that thoy can effectively be measured by survey instmmont from the appropnate surveying point A Pond Surface Measurements I Cell 4A N.VDMT PlanVDMT Plan 01.30.12 Re sion 11.4VTaibngs Mpit Svstem and DMT Mo Plan January 2012 re 11.4 edb e.docN VDMT PlonUulv 2011 DMT revision for pcrmitVTaibnga Mgnt System ond DMT Mon Plon July 2011 rov 11 2 rodlino doo White Mesa Mill - Standard OperaUng Procedures Book 11 Envuonmental ProtecUon Manual SecUon 3 1 07/1401/12 Revision Denisonl 14* Page 12 of 53 The Assistant will walk down the slope m the northeast comer of Cell 4A and place the Survey Rod at the liquid level n Cell 4B The Assistant will walk down the slope in the northwest southeast comer of Cell 4B and place the Survey Rod at the liquid level m Cell 1 A mark has been painted on the north side of the ramp going to the pump platform in Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and rv Roberts Pond A mark has been painted on the railing of the pump stand in Roberts Pond The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface Based on the foregoing methods the approximate coordinate locations for the measunng points for Roberts Pond and the Cells are 34-3- Northing 3-1-^ Easting Roberts Pond 323 041 2 579 697 Cell 1 322 196 2 579 277 CeU 4A 320 300 2 579 360 Cell 4B 320 690 2 576 200 "( Formatted No bullets or numbering These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells Cell 4B Beach Elevation Beach elevations in Cell 4B will commence when beaches are first observed The Assistant will place the Survey Rod at the point on the beach area of Cell 4B that has the highest elevation If it is not clear which area of the beach has the highest elevation then multiple points on the beach area will be surveyed until the Surveyor is satisfied that the point on the CeU 4B beach area with the highest elevation has been surveyed If it is clear that all points on the Cell 4B beach area are below 5 593 FMSL then the Surveyor may rely on one survey point N.VDMT PlanVDMT Plan 01.30.12 Re i 11.4VTaib gs Ment Svst m and DMT M Plan Jan arv 2012 re 11.4 redb e.docN VDMT PlonUulv 2011 DMT revision for pormitVToibnga Mgnt Syatom ond DMT Mon Plon July 2011 rov 11 2 redlme doc I White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Envu-onmental ProtecUon Manual SecUon 3 1 Page 13 of 53 (vui) The Assistant will hold the Survey Rod vertically with one end of the Survey Rod just touching the pond surface The Assistant will ensure that the Survey Rod IS vertical by genfly rocking die rod back and forth until the Surveyor has established a level reading (ix)The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Pond Surface Reading ) which represents the number of feet the Survey Instmment is reading above the pond surface level The Surveyor will calculate the elevation of the pond surface as FSML by adding the Reference Point Reading for the Cell or Roberts Pond as the case may be to the Reference Point Elevation for the Cell or Roberts Pond and subtracting the Pond Surface Reading for die CeU or Roberts Pond and will record the number accurate to 0 01 feet ^ej Decontamination Pads (i) New Decontamination Pad The New Decontanunation Pad is located m the southeast comer of the ore pad near the Mill s scale house A In order to ensure that the pnmary containment of the New Decontanunation Pad water collection system has not been compronused and to provide an inspection capability to detect leakage from the pnmary containment vertical inspection portals have been installed between the pnmary and secondary containments B These portals will be visually observed on a weekly basis as a means of detecting any leakage from the pnmary containment into the void between the pnmary and secondary containment The depth to water in each portal will be measured weekly by physicaUy measunng the depth to water with an electncal sounding tape/device All measurements must be made from the same measunng point and be made to the nearest 0 01 foot C These inspections will be recorded on the Weekly Taihngs Inspection form D The water level shall not exceed 0 10 foot above the concrete floor in any standpipe at any time This will be determmed by subtractmg the weekly depth to water measurement from the distance from the N.VDMT PlanVDMT Plan 01.30.12 Re s on 11.4VTaih g Mgnt System and DMT Mo Plan January 2012 re 11.4 redbne.docN VDMT PlonUulv 2011 DMT revision for pormitVToibnga Mgnt System and DMT Mon Plon July 2011 rov 11 2 redlme doc White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Demsonl 143 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 14 of 53 measunng point m the standpipe to the dry concrete floor The depth to water from the top (elevation 5589 8 feet amsl) of any of the three (3) observation ports to the standing water shall be no less than 6 2 feet Depths less than 6 2 feet shall indicate more that 0 1 foot of standing water above the concrete floor (elev 5583 5 feet amsl) and shall indicate a leak in the pnmary containment E Any observation of fluid between the pnmary and secondary containments wdl be reported to the Radiation Safety Officer (RSO) F In addition to inspection of the water levels in the standpipes the New Decontamination Pad including the concrete integnty of the exposed surfaces of the pad will be inspected on a weekly basis Any sod and debns will be removed from the New Decontamination Pad immediately pnor to inspection of the concrete wash pad for cracking Observations will be made of the current condition of the New Decontamination Pad Any abnormalities relating to the pad and any damage to the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (widdi) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired (ll) Existing Decontamination Pad The Existing Decontammation Pad is located between the northwest comer of the Mdl s maintenance shop and the ore feeding gnzzly A The Existing Decontarmnation Pad will be inspected on a weekly basis Any sod and debns will be removed from the Existing Decontanunation Pad immediately pnor to inspection of the concrete wash pad for cracking Observations will be made of the current condition of the Existing Decontamination Pad including the concrete integnty of the exposed surfaces of the pad Any abnormalities relating to the pad and any damage or cracks on the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired b)f}_ Summary N.VDMT PlanVDMT Plan 01.30.12 Revision 11.4VTaihngs Mgnt Svstem and DMT Mo Plan January 2012 re 11.4 redbne.docN VDMT PlonUulv 2011 DMT revision for permitVToihngs Mgnt System and DMT Mon Plon July 2011 rov 11 2 redbne doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 4^ Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 15 of 53 In addition the weekly inspection should summanze all activities concermng the tailings area for that particular week Results ofthe weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection form An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A 3 2 Weeklv Inspection of Solution Levels in Roberts Pond On a weekly basis solution elevations are taken on Roberts Pond in accordance with the procedures set out m Section 3 1 d) above The Weekly solution level in Roberts Pond is recorded on the Weekly Tailings and DMT Inspection form Based on histoncal observations the FML at the Pond Surface Reading area for Roberts Pond is approximately six inches above the lowest point on the pond s FML If the pond solution elevation at the Pond Surface Reading area is at or below the FML for that area the pond will be recorded as being dry 3 3 Weekly Feedstock Storage Area Inspections Weekly feedstock storage area inspections will be performed by the Radiation Safety Department to confirm that a) the bulk feedstock matenals are stored and maintained within the defined area descnbed in the GWDP as indicated on the map attached hereto as Appendix D b) a 4 ft buffer is maintamed at the penphery of the storage area which is absent bulk matenal in order to assure that the matenals do not encroach upon the boundary of the storage area and c) all altemate feedstock located outside the defined Feedstock Area are maintained within water tight contamers The results ofthis inspection wdl be recorded on the Ore Storage/Sample Plant Weekly Inspection Report a copy of which is contamed m Appendix A Any vanance in stored matenals from this requirement or observed leaking altemate feedstock dmms or odier containers will be brought to the attention of Mill Management and rectified within 15 days 4 MONTHLY TAILINGS INSPECTION Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from the Radiation Safety Department and recorded on the Monthly Inspection Data form an example of which IS contained m Appendix A Monthly inspections are to be performed no sooner than 14 days since the last monthly tadmgs inspection and can be conducted concunendy with the quarterly N.VDMT PlanVDMT Plan 01.30.12 Revi i n 11.4VTaib gs Mgnt System and DMT Mon Plan January 2012 re 11.4 edlme.docN VDMT PlonUulv 2011 DMT revision for permitVTailinga Mgnt System and DMT Mon Plan July 2011 rev 11 2 redhne doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 16 of 53 tailings inspection when applicable The following items are to be inspected a) Tailings Slurry Pipeline When the Mill is operating the slurry pipeline will be visually inspected at key locations to determine pipe wear The cntical points of the pipe include bends slope changes valves and junctions which are cntical to dike stability These locations to be monitored will be detemuned by die Radiation Safety Officer or his designee from the Radiation Safety Department dunng the Mill mn b) Diversion Ditches Diversion ditches 1 2 and 3 shall be monitored monthly for sloughing erosion undesirable vegetation and obstraction of flow Diversion berm 2 should be checked for stability and signs of distress c) Sedimentation Pond Activities around the Mill and facilities area sedimentation pond shall be summanzed for the month d) Overspray Dust Minimization The inspection shall include an evaluation of overspray nunmuzation if applicable This entails ensunng that the overspray system is functioning properly In the event that overspray is camed more than 50 feet from the cell the overspray system should be immediately shut off e) Remarks A section is included on the Monthly Inspection Data form for remarks in which recommendations can be made or observations of concem can be documented /) Summary of Daily Weekly and Quarterly Inspections The monthly inspection will also summanze the daily weekly and if applicable quarterly taihngs inspections for the specific month In addition settiement monitors are typically surveyed monthly and the results reported on the Monthly Inspection Data form 5 QUARTERLY TAILINGS INSPECTION N.VDMT PlanVDMT Plan 01.30.12 Rev sion 11.4VTail es Mgnt Svstem and DMT Mo Plan January 2012 re 11.4 redb e docN VDMT PlonUulv 2011 DMT revision for permitVTaihngs Mgnt System and DMT Mon Plon July 2011 rev 11 2 redline doo White Mesa Mill - Standard Operating Procedures 07/1401/12 Revision Demsonl 143 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 17 of 53 The quarterly tailings inspection is performed by the Radiation Safety Officer or his designee from the Radiation Safety Department having the training specified in Section 2 4 above once per calendar quarter A quarterly mspection should be performed no sooner than 45 days since the previous quarterly inspection was performed Each quarterly inspection shall include an Embankment Inspection an Operations/Maintenance Review a Constraction Review and a Summary as follows a) Embankment Inspection The Embankment inspection involves a visual inspection of the crest slope and toe of each dike for movement seepage severe erosion subsidence shrmkage cracks and exposed liner b) Operations/Maintenance Review The Operations/Maintenance Review consists of reviewing Operations and Maintenance activities pertaining to the taihngs area on a quarterly basis c) Construction Review The Constraction Review consists of reviewing any constraction changes or modifications made to the tailings area on a quarterly basis d) An estimate of the percentage of the ladings beach surface area and solution pool area is made including estimates of solutions cover areas and tailings sands for Cells 3 4A and 4B N VDMT PlanVDMT Plan 01.30.12 Re sio 11.4VTaib gs Mgnt System and DMT Mon Plan January 2012 re 11.4 redbne.docN VDMT PlonUulv 2011 DMT revision for pormitVToihngs Mgnt Syatom ond DMT Mon Plon July 2011 rov 11 2 rodlino doo White Mesa Mill - Standard operating Procedures 07/1401/12 Revision Denisonll 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 18 of 53 e) Summary The summary will include all major activities or observations noted around the taihngs area on a quarterly basis If any of these conditions are noted the conditions and corrective measures taken should be documented in the Quarterly Inspection Data form An example of the Quarterly Inspection Data form IS provided in Appendix A 6 ANNUAL EVALUATIONS The followmg annual evaluations shall be performed 6 I Annual Technical Evaluation An annual techmcal evaluation of the taihngs management system is performed by a registered professional engineer (PE) who has expenence and traimng m the area of geotechnical aspects of retention stracmres The techmcal evaluation includes an on site inspection of the taihngs management system and a thorough review of all tailings records for the past year The Technical Evaluation also includes a review and summary of the annual movement monitor survey (see Section 5 2 below) All tailmgs cells and corresponding dikes will be inspected for signs of erosion subsidence shnnkage and seepage The drainage ditches will be inspected to evaluate surface water control stractures In the event taihngs capacity evaluations (as per SOP PBL 3) were performed for the receipt of altemate feed matenal dunng the year the capacity evaluation forms and associated calculation sheets will be reviewed to ensure that the maximum tailings capacity estimate is accurate The amount of tailings added to the system since the last evaluation will also be calculated to detemune the estimated capacity at the time of the evaluation Tailings inspection records wdl consist of daily weekly monthly and quarterly taihngs inspections These inspection records will be evaluated to determine if any freeboard limits are being approached Records will also be reviewed to summanze observations of potential concem The evaluation also involves discussion with the Environmental and/or Radiation Technician and the Radiation Safety Officer regarding activities around the tailings area for the past year Dunng the annual inspection photographs of the tailings area will be taken The training of individuals will be reviewed as a part of the Annual Techmcal Evaluation N.VDMT PlanVDMT Plan 01.30.12 Rev s on 11 4VTaib es Mgnt System and DMT Mon Plan January 2012 re 11.4 edb e.docN VDMT PlonUulv 2011 DMT reviaion for pemutVToibngs Mgnt System ond DMT Mon Plan July 2011 rov 11 2 redhae^ White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Demsonl 143 Book 11 Environmental Protection Manual SecUon 3 1 Page 19 of 53 The registered engineer wdl obtain copies of selected tailings inspections along with the monthly and quarterly summanes of observations of concem and the conective actions taken These copies will then be included in the Annual Techmcal Evaluation Report The Annual Technical Evaluation Report must be subrmtted by November 15* of every yearteto the Executive Secretary Directing Dam Safety Engineer State of Utah Natural Resources 1636 Woat North Tomplo Suito 220 Salt Lalco City Utah 8^1116 3156 6 2 Movement Monitors A movement monitor survey is to be conducted by a licensed surveyor annuaUy dunng the second quarter of each year The movement monitor survey consists of surveying momtors along dikes 3 S 4A W and 4A S to detect any possible settlement or movement of the dikes The data generated from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the tailings management system 6 3 Freeboard Linuts The freeboard Imuts set out in this Section are intended to capmre the Local 6 hour Probable Maximum Precipitation (PMP) event which was determined m the January 10 1990 Drainage Report (the Drainage Report ) for the White Mesa site to be 10 inches The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas was calculated in the Drainage Report to be 103 acre feet of water with a wave ran up factor of 0 90 feet The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas plus the adjacent drainage areas was calculated in the Drainage Report to be 123 4 acre feet of water The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage Report to be 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres) times the PMP of 10 mches) with a wave ran up factor of 0 77 feet The flood volume from the PMP event over the Cell 4B area has been calculated to be 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 72 acres) times the PMP of 10 inches with a wave ran up factor of 0 77 feet The total pool surface area in Cell 1 is 52 9 acres in Cell 4A is 40 acres and in Cell 4B is 40 N.VDMT PlanVDMT Plan 01.30 12 Re mn 11 4VTailings M|ini .System and DMT Mo Plan January 2012 rev 11.4 redbne.docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt System ond DMT Mon Plan July 2011 rov 11 2 nxUine-dee White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Denisonl 1 43 Book 11 Envu-onmental ProtecUon Manual Section 3 1 Page 20 of 53 acres The top of the flexible membrane liner ( FML ) for Cell 1 is 5 618 2 FMSL for Cell 4A IS 5 598 5 FMSL and for CeU 4B is 5600 4 FMSL Based on the foregoing the freeboard limits for the Mill s tailmgs cells will be set as follows 63 1 Cell 1 The freeboard limit for Cell 1 will be set at 5 615 4 FMSL This will allow Cell 1 to capmre all of the PMP volume associated with Cell 1 The total volume requirement for Cell 1 is 103 acre feet divided by 52 9 acres equals 1 95 feet plus the wave ran up factor of 0 90 feet equals 2 85 feet The freeboard limit is tfien 5 618 2 FMSL minus 2 85 feet equals 5 615 4 FMSL Under Radioactive Matenals License condition 10 3 this freeboard linut is set and is not recalculated annually 632 CeU 2 The freeboard limit for Cell 2 is inapplicable since Cell 2 is filled with solids AU of the PMP volume associated with Cell 2 wiU be attnbuted to Cell 4A (and/or any fiimre tailings cells) 633 CeU 3 The freeboard limit for Cell 3 is inapplicable since Cell 3 is close to being filled with solids and all of the PMP flood volume associated with Cell 3 wiU be attnbuted to Cell 4B (and/or any future tailings cells) 634 Cell 4A The freeboard limit for Cell 4A is inapplicable since all of the PMP flood volume associated with CeU 4A will be attnbuted to Cell 4B A spillway has been added to Cell 4A to allow overflow into CeU 4B 635 Cell 4B The freeboard linut for Cell 4B will be set assunung that the total PMP volume for CeUs 2 3 4A and 4B of 159 4 acre feet will be accommodated m Cell 4B The procedure for calculating the freeboard limit for Cell 4B is as follows (a) When the Pool Surface Area is 40 Acres When the pool surface area m Cell 4B is 40 acres (i e when diere are no beaches) the freeboard limit for Cell 4B will be 5 594 6FMSL which is 5 7 feet below the FML This freeboard value was developed as follows PMP Flood Volume 38 1 acre feet Overflow from Cell 4A assunung no storage in Cell 3 or 4A 159 4 acre feet N.VDMT PlanVDMT Plan 01 30.12 Revision 11.4VTaihngs Ment System and DMT M Plan January 2012 rev 11.4 redhne.docN VDMT PlonUulv 2011 DMT revision for pormitVToibngo Mgnt Syatom and DMT Mon Plan July 2011 rov 11 2 redhne doo I White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Envu-onmental Protection Manual Secuon 3 1 Page 21 of 53 Sum of PMP volume and overflow volume 197 5 acre feet Depth to Store PMP an overflow volume = 197 5 acre feet/40 acres 4 9 feet Wave ran up factor 0 77 feet Total required freeboard 5 7 feet (all values in the above calculation have been rounded to the nearest one tenth of afoot) (b) When the Maximum Elevation ofthe Beach Area is 5 594 FMSL or Less When the maximum elevation of the beach area in Cell 4B is 5594 FMSL or less then the freeboard limit wdl be 5 594 6 FMSL which is the same as in (a) above This allows for the situation where there may be beaches but these beaches are at a lower elevation than the freeboard limit estabhshed in (a) above and there is therefore ample freeboard above the beaches to hold the maximum PMP volume The maximum elevation of the beach area wiU be detemuned by monthly surveys performed by Mdl personnel in accordance with the Mill s DMT Plan (c) When the Maximum Elevation ofthe Beach Area First Exceeds 5 594 FMSL When the maximum elevation of the beach area in Cell 4B first exceeds 5 594 FMSL then the freeboard limit for the remainder of the ensuing year (penod t=0) (untd the next November 1) wdl be calculated when that elevation is first exceeded (the Initial Calculation Date ) as follows i) The total number of dry tons of tailings that have histoncally been deposited mto CeU 4B pnor to the Initial Calculation Date ( To ) will be determined u) The expected number of dry tons to be deposited into Cell 4B for the remainder of the ensuing year (up to the next November 1) based on production estimates for that penod ( Ao* ) will be determined Ul) Ao* wdl be grossed up by a safety factor of 150% to allow for a potential underestimation of die number of tons that wdl be deposited in the cell dunng the remainder of the ensuing year This grossed up number can be refened to as the modeled tonnage for the penod I iv) The total design tailings solid storage capacity of Cell 4AB will be accepted as 2 094 000 dry tons of ladings v) The available remaining space m Cell 4B for solids as at the Initial Calculation Date will be calculated as 2 094 000 dry tons minus To Vl) The reduction in die pool surface area for the remainder of the ensuing year will be assumed to be direcdy proportional to the reduction in the available space in Cell 4A 4B for sohds That is the reduced pool surface area for penod t=0 ( ELPAo ) after the reduction will be calculated to be (1 - (Ao* X 1 5) / (2 094 000 To)) x 40 acres = RPAo vu) The required freeboard for Cell 4A-4B for the remainder of the penod t=0 can be calculated in feet to be the wave ran up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAo The freeboard linut for Cell 4B for N.VDMT PlanVDMT Plan 01.30 12 Re i on 11.4VTaib g Mgnt Sv tem and DMT Mon Plan January 2012 re 11.4 redl e.docN VDMT PlonUulv 2011 DMT roviaion for pormitVToihngs Mgnt System and DMT Mon Plon July 2011 rov 11 2 rodlmo doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Denisonl 1 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 22 of 53 the remainder of penod t=0 would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of afoot and vill) The foregoing calculations will be performed at the Imtial Calculation Date and the resulting freeboard limit will persist until the next November 1 An example of this calculation is set out in Appendix F (d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds 5 594 FMSL On November 1 of each year (the Annual Calculation Date ) the reduction m pool area for the ensuing year (refened to as penod t) will be calculated by i) First calculating the Adjusted Reduced Pool Area for the previous penod (ARPAt i) to reflect acmal tonnages deposited in Cell 4B for the previous penod (penod t 1) The RPAt 1 used for the previous penod was based on expected tonnages for penod t 1 grossed up by a safety factor The ARPAt i is merely the RPA that would have been used for penod t 1 had the acmal tonnages for year t 1 been known at the outset of penod t 1 and had the RPA been calculated based on the actual tonnages for penod t I This allows the freeboard calculations to be corrected each year to take into account actual tonnages deposited in the cell as of the date of the calculation The ARPAt 1 can be calculated using the following formula (1 - At 1 / (2 094 000 - Tt 0) x ARPAt 2 = ARPAt 1 Where • At 1 IS the acmal number of dry tons of tailings solids deposited in Cell 4B dunng penod t 1 • Tt 1 is the acmal number of dry tons of tailings sohds histoncally deposited in Cell 4B pnor to the beginning of penod t 1 and • ARPAt 2 IS the Adjusted Reduced Pool Area for penod t 2 If penod t 2 started at the Initial Calculation Date then ARPAt 2 is 40 acres 11) Once the ARPAt 1 for the previous penod (penod t 1) has been calculated the RPA for the subject penod (penod t) can be calculated as follows (1 - (At* x 1 5) / (2 094 000 Tt)) x ARPAt 1 = RPAt Where • At* IS the expected number of dry tons of taihngs to be deposited mto Cell 4B for the ensuing year (penod t) based on production estimates for the year (as can be seen from the foregoing formula this expected number is grossed up by a safety factor of 1 5) • Tt is the acmal number of dry tons of taihngs solids histoncally deposited in Cell 4B pnor to the beginmng of penod t and N.VDMT PlanVDMT Plan 01 30.12 Re so 11 4VTail ngs Mgnt System and DMT Mo Plan January 2012 re 11.4 redb e.docN VDMT PlonUulv 2011 DMT revision for pcrmitVToibngs Mgnt Syatem and DMT Mon Plan July 2011 rov 11 2 redbne doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Envu-onmental ProtecUon Manual SecUon 3 1 Page 23 of 53 • ARPAt 1 IS the Adjusted Reduced Pool Area for penod t 1 which is the pool surface area for the previous penod (penod t 1) that should have applied dunng diat penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled acmal tonnages for the penod 111) The required freeboard for penod t can be calculated in feet to be the wave ran up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAt The freeboard linut for Cell 4A-4B for penod t would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of a foot and iv) The foregoing calculations will be performed at the Annual Calculation Date for penod t and the resulting freeboard limit will persist until the next Annual Calculation Date for penod t-i-1 An example of this calculation is set out in Appendix F (e) When a Spillway is Added to Cell 4B that Allows Overflow Into a New Tailings Cell When a spillway is added between Cell 4B and a new taihngs cell then if an approved freeboard linut calculation method for the new cell is set to cover the entire PMP event for Cells 2 3 4A 4B and the new tailings cell the freeboard limit for Cell 4B will be inapphcable except for approved provisions to prevent storm water ranoff from overtopping dikes 6 3 6 Roberts Pond The freeboard limit for Roberts Pond is a liquid maximum elevation of 5 624 0 feet above mean sea level as specified m the GWDP 6 4 Annual Leak Detection Ruid Samples In the event solution has been detected m a leak detection system a sample will be collected on an annual basis This sample will be analyzed according to the conditions set forth in License Condition 11 3 C The results of the analysis will be reviewed to detemune the ongin of the solution 6 5 Annual Inspection of the Decontanunation Pads a) New Decontamination Pad Dunng the second quarter of each year the New Decontamination Pad will be taken out of service and inspected to ensure the integnty of the wash pad s exposed concrete surface If any abnormalities are identified le cracks m the concrete with greater than 1/8 mch separation (width) or any significant detenoration or damage of the pad surface repairs will be made pnor to resunung N.VDMT PlanVDMT Plan 01 30.12 Rev ion 11.4VTaihngs Mgnt System and DMT Mo Plan January 2012 re 11.4 redhne.docN VDMT PlonUulv 2011 DMT roviaion for pormitVToihnga Mgnt System and DMT Mon Plon July 2011 rov 11 2 redbne 4»i White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 24 of 53 the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontamination Pad Inspection form The inspection findings any repairs required and repairs completed shall be summanzed m the 2 Quarter DMT Monitonng Report due September 1 of each calendar year b) Existing Decontamination Pad Dunng the second quarter of each year the Existing Decontanunation Pad will be taken out of service and inspected to ensure the integnty of the steel tank Once the water and any sediment present is removed from the steel tank containment the walls and bottom of the tank will be visually inspected for any areas of damage cracks or bubbling indicating corrosion that may have occuned since the last inspection If any abnormalities are identified defects or damage will be reported to Mill management and repairs will be made pnor to resunung the use of the facility All mspection findmgs and any repairs required shall be documented on the Annual Decontanunation Pad Inspection form A record of the repairs will be maintained as a part of the Annual Inspection records at the Mill site The inspection findings any repairs required and repairs completed shall be summanzed in the 2nd Quarter DMT Monitonng Report due September 1 of each calendar year 7 OTHER INSPECTIONS All daily weekly monthly quarterly and annual inspections and evaluations should be performed as specified in Sections 2 3 4 5 and 6 above However additional inspections should be conducted after any sigmficant storm or significant namral or man made event occurs 8 REPORTING REQUIREMENTS In addition to the Daily Inspection Data Weekly Tailings Inspection Monthly Inspection Data and Quarterly Inspection Data forms included as Appendix A and descnbed in Sections 2 3 4 and 5 respectively and the Operating Foreman s Daily Inspection and Weekly Mill Inspection forms descnbed in Sections 2 and 3 respectively the following additional reports shall also be prepared 8 1 Monthlv Tailings Reports Monthly tailings reports are prepared every month and summanze the previous month s activities around the tailings area If not prepared by the Radiation Safety Officer the report shall be subnutted to the Radiation Safety Officer for review The Mill Manager will review the report as well before the report is filed m the Mill Central File The report will contain a summary of observations of concem noted on the daily and weekly tailings inspections Corrective measures taken dunng the month will be documented along with the observations where appropnate All daily and weekly tailings inspection forms will be attached to the report A monthly inspection form will also be attached Quarterly inspection forms will accompany the report when applicable The report wiU be signed and dated by the preparer in addition to the Radiation Safety Officer and the Mill N.VDMT PlanVDMT Plan 01.30.12 Re s on 11.4VTaibngs Mgnt System and DMT Mon Plan January 2012 rev 11.4 redl e.docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt System ond DMT Mon Plon July 2011 rev 11 2 redline doo I White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 25 of 53 Manager 82 DMT Reports Quarterly reports of DMT monitonng activities which will include the following information will be provided to the Executive Secretary on the schedule provided m Table 5 of die GWDP a) On a quarterly basis aU required information required by Part 1 F 2 of the GWDP relating to the inspections descnbed in Section 3 1(b) (Shmes Drain Water Level Monitonng) 3 1(d) (Tailings Wastewater Pool and Beach Area Elevation Monitonng) 3 2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3 3 (Weekly Feedstock Storage Area Inspections) b) On a quarterly basis a summary of the weekly water level (depth) mspections for the quarter for the presence of fluid in all three vertical inspection portals for each of the three chambers in the concrete settling tank system for the New Decontamination Pad which will include a table indicatmg the water level measurements in each portal dunng the quarter c) With respect to the annual inspection of the New Decontamination Pad descnbed in Section 6 5(a) the inspection findings any repairs required and repairs completed shall be summanzed in the 2 Quarter report due September 1 of each calendar year d) With respect to the annual inspection of the Existing Decontanunation Pad descnbed in Section 6 5(b) the inspection findings any repairs required and repairs completed shall be summanzed in die 2 Quarter report due September 1 of each calendar year and e) An annual summary and graph for each calendar year of the depth to wastewater m the Cell 2 shmes dram must be included in the fourth quarter report After the first year and beginmng in 2008 quarterly reports shall include both the current year monthly values and a graphic companson to the previous year N.VDMT PlanVDMT Plan 01.30.12 Rev sio 11 4VTaibngs Mgnt System and DMT Mo Plan January 2012 rev 11.4 redl ne.docN VDMT PlonUulv 2011 DMT roviaion for permitVTaihngs Mgnt Syatem and DMT Mon Plan July 2011 rov 11 2 redbne^ White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Denison 11 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 26 of 53 APPENDIX A FORMS c N VDMT PlanVDMT Plan 01.30.12 Re s o 11.4VTaib gs Mgnt Svstem and DMT Mo Plan Jan arv 2012 rev 11 4 redb e.docN VDMT PlonUulv 2011 DMT revision for permitVTaihngs Mgnt System ond DMT Mon Plon July 2011 rev 11 2 redline doo p. e 22 c3 u S £ Q < H $1 I u-i u o CU 3 u •a c« 2 o ^ 2 l/l H-i U ^ DO < II o II 3 E O c CQ J^IW O IZl a- 3 O M O o a> o o t3 IS 1^ O M o "en -3 u o o t> •S D- 4j a c« o > -3 S ^ ^ O o o o, 8 o ^ ^ ° o t3 CL - •a 2 O cn « O I- t-> U W Pi in O z o H u as N:) U NH S ON o o Z Z. cn cn (U U JH cn -3 ^ X) ^ O u u U N:) O O u H a e > o 3 Q h m 0. 3 « C c S 2 U 3 ^ Si O 2J -a 2 S3 f i I c = 2 S > CO " T3 C O c IU O CQ U a 13 -a 11 £ T3 5 £ a £ 3 a "a a O T3 § - 8 J Q Cfl U Tailings Dail>' Inspection Report Tailms$ Sliiii^ Dischaige Location ^1 I m C<-l O o CELL NO 1 DUte 1 L ia J5 MILLSITE 1 ~^ u 2 = S <= 2 2 U 3 O B 3: o ! ^ ed [Tj c/1 P o ^ CQ CELL NO 2 Fdled CELL NO 4A Date Inspectoi N 5i ZI White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Denison 11 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 31 of 53 APPENDIX A (CONT) DENISON MINES (USA) CORP WEEKLY TAILINGS INSPECTION Date Inspectors 1 Pond and Beach Cell 1 (a) Pond SoluUon ElevaUon elevations (msl ft) (b) FML Bottom ElevaUon 5597. (c) Depth of Water above FML ((a) (b)) Cell4A (a)Pond Solution Elevation (b) FML Bottom Elevation 5555 14_ (c) Depth of Water above FML ((a) (b)) Cell 4B (a)Pond Solution Elevation (b) FML Bottom Elevation 5557 50 (c) Depth of Water above FML ((a) (b)) (d) Elevation of Beach Area with Highest ElevaUon (monthly) Roberts Pond (a)Pond Solution ElevaUon (b) FML Bottom Elevation ^5612 3. (c) Depth of Water above FML ((a) (b)) 2 Slimes Drain Liquid Levels Cell 2 Pump functioning properly. _Depth to Liquid pre pump _Depth to Liquid Post pump (all measurements are depth in pipe) Pre pump head is 38-37 97 Depth to Liquid Pre pump = Post pump head is 38-37 97 -Depth to Liquid Post pump = N VDMT PlanVDMT Plan 01.30 12 Revisio 11.4VTaib gs Mgnt Svstem and DMT Mon Plan January 2012 re 11.4redl e.docN VDMT PlonUulv 2011 DMT revision for permitVTaihngs Mgnt System and DMT Mon Plon July 2011 rov 11 2 rodlmo doo White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/4401/12 Revision Demson 11 43 Page 32 of 53 3 Leak DetecUon Systems (Same data as Daily Inspection Form Record data on daily form) Observation New Decon Pad. Portal 1 New Decon Pad. Portal 2 New Decon Pad Portal 3 Is LDS (Portal) wet or dry*^ _wet dry _wet ^dry _wet dry If wet Record hquid level Liquid Ft to Liquid Ft to Liquid Ft to If wet Report to RSO 4 Tailings Area Inspection (Note dispersal of blowing tailings) 5 Control Methods Implemented 6 Remarks 7 Contaminatod Waste DumpDesignated Disposal Area for Non Tailings Mill Waste (awaiting DRC approval) * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (solution elevaUon of 5556 14 amsl for Cell 4A and 5558 50 for Cell 4B)'^ no yes If Cell 4A leak detection system level exceeds 12 inches above the lowest point on the bottom flexible membrane liner (elevation 5556 14 amsl) notify supervisor or Mill manager immediately N.VDMT PlanVDMT Plan 01.30 12 Re sion 11.4VTail ngs Mgnt Svstem and DMT Mon Plan January 2012 re 114 redhne.docN VDMT PlonUulv 2011 DMT revision for permitVTaihngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 redbne doc White Mesa Mill - Standard OperaUng Procedures 07/4-401/12 Revision Denisonll 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 33 of 53 APPENDIX A (CONT) MONTHLY INSPECTION DATA Inspector Date 1 Slurry Pipelme 2 Diversion Ditches and Diversion Berm Observation Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2 Diversion Ditches Sloughing yes no yes no yes no Erosion yes no yes no yes no Undesirable yes no yes no yes no VegetaUon Obstmction of Flow yes no yes no yes no Diversion Berm Stability Issues yes no Signs of Distress yes no Comments 3 Summary of Activities Around Sedimentation Pond N.VDMT PlanVDMT Plan 01.30 12 Re sion 11.4VTaLhngs Mgnt Svstem and DMT Mon Plan January 2012 re 11.4redb e docN VDMT PlonUulv 2011 DMT revision for pemutVToibngs Mgnt System ond DMT Mon Plon July 2011 rev 11 2 rodlmo doc White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/4401/12 Revision Denisonll 43 Page 34 of 53 4 Overspray Dust Mmimization Overspray system functioning properly _yes_ Overspray camed more than 50 feet from the cell If yes was system immediately shut off^ Comments no J'es. _yes_ 5 Remarks 6 Setdement Momtors Cell 2 Wl Cell 2 W2 Cell 2 W3 Cell 2 W4 Cell 2W7 C Cell 2 W7N Cell 2 W6C Cell 4A Toe CeU3 2C Cell 3 3S Cell 3-4N Cell 3 7C Cell 2W3 S Cell 2E1 N Cell2El IS Cell 2E1 2S Cell 2 East Cell 2 W7S Cell 2 W6S Cell 2 W4S Cell3 2S Cell 3 3C. Cell 3 6N Cell 3 7N Cell 3 IN _ Cell 3 IC _ Cell 3 IS _ Cell 3 2N _ Cell 2W5 N Cell 2 W6N Cell 2 W4N Cell 2 W5C Cell 2 W5S Cell3 3N Cell 3 78 Cell 3 8S Cell 3 8C Cell 3 8N 7 Movement Momtors (Is there visible damage to any movement momtor or to adjacent surfaces)' 8 Summary of Dady Weekly and Quarterly Inspections N VDMT PlanVDMT Plan 01.30 12 Re sion 11.4VTaibngs Mgnt Svstem and DMT Mon Plan January 2012 re 11.4 redb e.docN VDMT PlonUulv 2011 DMT revision for pormitVToibnga Mgnt System ond DMT Mon Plon July 2011 rov 11 2 rodlino doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual Section 3 1 Page 35 of 53 N.VDMT PlanVDMT Plan 01.30.12 R onll.4VTail gs Ment System and DMT Mo Plan January 2012 re 11.4 redb e.docN VDMT PlonUulv 2011 DMT rovision for pormitVTaihnga Mgnt System and DMT Mon Plon July 2011 rov 11 2 rodlmo doo White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental Protection Manual SecUon 3 1 07/4401/12 Revision Demsonl 1 43 Page 36 of 53 APPENDIX A (CONT) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector Date 1 Embankment Inspection 2 Operations/Maintenance Review 3 Construction Activities 4 Estmiated Areas CeU 3 Cell 4A Cell 4B Estimated percent of beach surface area Estimated percent of solution pool area Estimated percent of cover area Comments NVDMTPlanVDMTPlan01.30.12Revision 11.4VTaibngsMgntSystemandDMTMo Plan January 2012 re 11.4 edh e.docN VDMT PlonUulv 2011 DMT revision for pormitVToihngs Mgnt System and DMT Mon Plan July 2011 rov 11 2 rodlmo doo I White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 37 of 53 APPENDIX A (CONT) ORE STORAGE/SAMPLE PLANT WEEKLY INSPECTION REPORT Week of through Date of Inspection Inspector Weather conditions for the week Blowing dust conditions for the week Corrective actions needed or taken for die week Are all bulk feedstock materials stored in the area indicated on the attached diagram yes no comments. Are all alternate feedstock materials located outside the area indicated on the attached diagram maintained within water tight containers yes no comments (e g conditions of containers) Are all sumps and low lying areas free of standing solutions'^ Yes No If No how was the situation corrected supervisor contacted and correction date'' Is there free standing water or water mnning off of the feedstock stockpiles'' Yes No Comments N.VDMT PlanVDMT Plan 01.30.12 Re ion 11.4VTail gs Ment Svstem and DMT Mon Plan January 2012 re 11.4 edb e.docN VDMT PlonUulv 2011 DMT rovision for permitVToihngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 rodhno doc White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual Section 3 1 Page 38 of 53 Other comments N.VDMT PlanVDMT Plan 01 30.12 Revisio 11.4VTaib e Mgnt Svstem and DMT Mon Plan January 2012 rev 11 4 edh e.docN VDMT PlonUulv 2011 DMT revision for ponmtVTaihnga Mgnt Syatem and DMT Mon Plan July 2011 rov 11 2 rodlmo doc White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 39 of 53 APPENDIX A (CONT) ANNUAL DECONTAMINATION PAD INSPECTION Date of Inspection Inspector New Decontanunation Pad Are there any cracks on the wash pad surface greater than 1/8 inch of separation'' Yes No Is there any significant deterioration or damage of the pad surface'' Yes No Findings Repair Work Required Existing Decontamination Pad Were there any observed problems with the steel tank'' Yes No Findings Repau- Work Required Note For the annual inspection of the both the Existing and New Decontamination Pads die annual inspection findings any repairs required and repairs completed along with a summary of the weekly inspections shall be discussed in the 2 Quarter report due September I of each calendar year N.VDMT PlanVDMT Plan 01.30.12 Re isio 11.4VTaib gs Mgnt Sv.siem and DMT Mon Plan January 2012 rev 11.4 redline.docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt System ond DMT Mon Plan July 2011 rov 11 2 redlme doo White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Denisonll 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 40 of 53 APPENDIX B 8 3 TAILINGS INSPECTOR TRAINING This document provides the tiaimng necessary for qualifying management designated individuals for conducting daily tailings mspections Trainmg information is presented by the Radiation Safety Officer or designee from the Environmental Department Dady tadmgs mspections are conducted m accordance with the White Mesa Mill Tadmgs Management System and Discharge Mimnuzation Technology (DMT) Monitonng Plan The Radiation Safety Officer or designee from the Radiation Safety Department is responsible for perfomung monthly and quarterly tailings inspections Tailmgs inspection forms wdl be included in the monthly tailings inspection reports which summanze the conditions activities and areas of concem regarding the tailings areas Notifications The inspector is required to record whether all inspection items are normal (satisfactory requinng no action) or that conditions of potential concem exist (requinng action) A check mark indicates no action required If conditions of potential concem exist the inspector should mark an X m the area the condition pertains to note the condition and specify the conective action to be taken If an observable concem is made it should be noted on the tailings report untd the conective action is taken and the concem is remedied The dates of all corrective actions should be noted on the reports as well Any major catastrophic events or conditions pertaining to the tailmgs area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom wdl notify Corporate Management Ifdam failure occurs notify your supervisor and the Mdl Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division ofDam Safety (801 538 7200) Inspections All areas of the tailmgs disposal system are routinely patrolled and visible observations are to be noted on a daily tailings inspection form Refer to Appendix A for an example of the daily tailmgs inspection form The inspection form consists of three pages and is summanzed as follows 1 Tailmgs Slurry Transport System The slurry pipeline is to be inspected for leaks damage and sharp bends The pipeline joints are to be monitored for leaks and loose connections The pipeline supports are to be inspected for damage and loss of support Valves are also to be inspected particularly for N.VDMT PlanVDMT Plan 01.30 12 Re sion 11.4VTaih gs Mgnt Svstem and DMT Mo Plan January 2012 re 11.4 redl e.docN VDMT PlonUulv 2011 DMT revision for pormitVToibnga Mgnt System and DMT Mon Plon July 2011 rev 11 2 rodlmo doo White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Denisonll 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 41 of 53 leaks blocked valves and closed valves Points of discharge need to be inspected for improper location and onentation Operational Systems Operating systems including water levels beach Imers and covered areas are items to be mspected and noted on the daily mspection forms Sudden changes in water levels previously observed or water levels exceeding the operating level of a pond are potential areas of concem and should be noted Beach areas that are observed as havmg cracks severe erosion or cavities are also items that require investigation and notation on daily forms Exposed liner or absence of cover from erosion are potential items of concem for ponds and covered areas These should also be noted on the daily inspection form Cells 1 3 4A and 4B solution levels are to be monitored closely for conditions neanng maximum operating level and for large changes in the water level since the last inspection All pumping activities affecting the water level will be documented In Cells I and 3 the PVC hner needs to be momtored closely for exposed liner especially after storm events It is important to cover exposed hner immediately as exposure to sunlight will cause degradation of the PVC hner Small areas of exposed hner should be covered by hand Large sections of exposed hner will require the use of heavy equipment These conditions are considered senous and require immediate action After these conditions have been noted to the Radiation Safety Officer a work order wdl be wntten by the Radiation Safety Officer and mmed into the Maintenance Department All such repairs should be noted in the report and should contain the start and finish date of the repairs Dikes and Embankments Inspection items include the slopes and the crests of each dike For slopes areas of concem are sloughs or sliding cracks bulges subsidence severe erosion moist areas and areas of seepage outbreak For crests areas of concem are cracks subsidence and severe erosion When any of these conditions are noted an X mark should be placed in die section marked for that dike In addition theddces m particular dikes 4A S 4A E and4B S should be mspected closely for mice holes and more importantly for praine dog holes as the praine dogs are likely to bunow in deep possibly to the hner If any of these conditions exist the inspection report should be marked accordingly N.VDMT PlanVDMT Plan 01.30 12 Re lo 11.4\Taih g Mgnt System and DMT Mo Plan January 2012 rev 11.4 redb e docN VDMT PlonUulv 2011 DMT roviaion for permitVToilings Mgnt Syatem and DMT Mon Plon July 2011 rov 11 2 rodhno doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 42 of 53 4 Flow Rates Presence of all flows in and out of the cells should be noted Flow rates are to be estimated in gallons per nunute (GPM) Rates need to be detemuned for slurry lines pond retum SX tails and the spray system Dunng non operational modes the flow rate colunm should be marked as 0 The same holds trae when the spray system is not utilized 5 Physical Inspection of Slurry Line(s) A physical inspection of all slurry lines has to be made every 4 hours dunng operation of the mill If possible the inspection should include observation of the entire discharge hne and discharge spill point into the cell If fill to elevation flags are in place the tailings and build up IS to be monitored and controlled so as to not cover the flags 6 Dust Control Dusting and wind movement of ladings should be noted for Cells 2 3 4A and 4B Other observations to be noted mclude a bnef descnption of present weather conditions and a record of any precipitation received Any dusting or wind movement of tailmgs should be documented In addition an estimate should be made for wind speed at the time of the observed dusting or wind movement of tailings The Radiation Safety Department measures precipitation on a daily basis Daily measurements should be made as near to 8 00 a m as possible every day Weekend measurements will be taken by Environmental Health and Safety personnel as close to 8 00 a m as possible AU snow or ice should be melted before a reading is taken 7 Observations of Potential Concern All observations of concem dunng the inspection should be noted in this section Conective action should follow each area of concem noted All work orders issued contacts or notifications made should be noted in this section as well It is important to document all these Items in order to assure that the tailmgs management system records are complete and accurate 8 Map of Tadmgs Cells The last section of the mspection involves drawing as accurately as possible the following Items where apphcable N.VDMT PlanVDMT Plan 01.30.12 Re isio 11.4VTaih g Mgnt System and DMT Mo Plan January 2012 re 11.4 edb e.docN VDMT PlonUulv 2011 DMT revision for pcrmitVTaibnga Mgnt System and DMT Mon Plan July 2011 rov 11 2 redhne doo White Mesa Mill - Standard Operating Procedures 07/1401/12 Revision Demson 11 43 Book 11 Environmental Protection Manual Section 3 1 Page 43 of 53 1 Cover area 2 Beach/tailing sands area 3 Solution as it exists 4 Pump lines 5 Activities around tailmgs cell (i e hauling trash to the dump hner repairs etc) 6 Slurry discharge when operating 7 Over spray system when operating 9 Safety Rules AU safety rales applicable to the null are applicable when in the tadmgs area These rales meet the required MSHA regulations for the tailings area Please pay particular notice to the following rales 1 The posted speed limit on Cell 4A and 4B dike is 5 mph and the posted speed limit for the tailings area (odier than the Cell 4A and 4B dike) is 15 mph These limits should not be exceeded 2 No food or dnnk is pemutted m the area 3 All personnel entenng the ladings area must have access to a two way radio 4 Horseplay is not permitted at any time 5 Only those specifically authonzed may operate motor vehicles m the restncted area 6 When road conditions are muddy or slick a four wheel dnve vehicle is required in the area 7 Any work performed in which there is a danger of falling or slipping in the cell wdl require the use of a safety belt or hamess with attended life line and an approved life jacket A portable eyewash must be present on site as well 8 Anytime the boat is used to perform any work an approved life jacket and goggles must be wom at all times There must also be an approved safety watch with a two way hand held radio on shore A portable eyewash must be present on site as well 10 Preservation of Wildlife Every effort should be made to prevent wildlife and domesticated animals from entenng the taihngs area All wildlife observed should be reported on the Wildlife Report Worksheet dunng each shift Waterfowl seen near the tailings cells should be discouraged from landing by the use of noisemakers 11 CertiHcation Following the review of this document and on site instraction on the tadmgs system inspection program designated individuals will be certified to perform daily tailings inspections The Radiation Safety Officer authonzes certification Refer to the Certification N.VDMT PlanVDMT Plan 01.30 12 Revi i 11.4VTaih a Mgnt Svstem and DMT M Plan January 2012 re 11.4 redb e docN VDMT PlonUulv 2011 DMT revision for permitVTaihngs Mgnt System and DMT Mon Plon July 2011 rev 11 2 redhne doo White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual Secuon 3 1 Page 44 of 53 Form Appendix C This form should be signed and dated only after a thorough review of die taihngs information previously presented The form will then be signed by the Radiation Safety Officer and filed N.VDMT PlanVDMT Plan 01.30.12 Re 11.4VTaibng Mgnt Sv tem and DMT Mon Plan Jan arv 2012 re 11.4 edb e docN VDMT PlonUulv 2011 DMT reviaion for pormitVToihngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 rodhne doc White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 45 of 53 APPENDIX C CERTIFICATION FORM Date Name I have read the document tided Tailings Management System White Mesa Mill Tailings Inspector Traimng and have received on site instraction at the tailings system This instraction included documentation of daily tailings inspections analysis of potential problems (dike failures unusual flows) notification procedures and safety Signamre I certify that the above named person is qualified to perform the daily inspection of the tailings system at the White Mesa Mill Radiation Safety Personnel/ Tailings System Supervisor N.VDMT PlanVDMT Plan 01.30.12 Re i 11.4VTaihng Ment Sv tem and DMT M n Plan January 2012 rev 11.4 redl e.docN VDMT PlonUulv 2011 DMT rovision for pennitVTaihnga Mgnt Syatom and DMT Mon Plan July 2011 rov 11 2 redline doc White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Demsonl 143 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 46 of 53 APPENDIX D FEEDSTOCK STORAGE AREA N VDMT PlanVDMT Plan 01.30.12 Re 11.4VTaih gs Mgnt System and DMT M Plan January 2012 rev 11.4 edh e.docN VDMT PlonUulv 2011 DMT rovision for permitVTaihngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 redlme doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/4401/12 Revision Demson 11 4^ Page 47 of 53 N VDMT PlanVDMT Plan 01.30.12 Revi o 11.4VTaibngs Ment Svstem and DMT Mon Plan January 2012 re 11.4 edl e.docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 redline doo White Mesa Mill - Standard Operating Procedures 07/4401/12 Revision Denisonll 43 Book 11 Environmental Protection Manual SecUon 3 1 Page 48 of 53 APPENDIX E TABLES N.VDMT PlanVDMT Plan 01.30.12 Revisi 11.4VTaib e Mgnt Sv tem and DMT M Plan January 2012 re 11.4 edb .docN VDMT PlonUulv 2011 DMT revision for pormitVToibnga Mgnt Systom and DMT Mon Plan July 2011 rev 11 2 rodlino doc White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/4401/12 Revision Demsonl 1 43 Page 49 of 5 3 Table lA Calculated Action leakage Rates for Vanous head Conditions Cell 4A White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate (gallons / acre / day) 5 222 04 10 31401 15 384 58 20 444 08 25 496 50 30 543 88 35 587 46 37 604 01 Table IB Calculated Action leakage Rates for Vanous head Conditions Cell 4B White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate (gallons / acre / day) 5 21140 10 317 00 15 369 90 20 422 70 25 475 60 30 528 40 35 570 00 37 58120 N.VDMT PlanVDMT Plan 01.30.12 Revisio 11 4VTail ngs Mgnt Svstem and DMT Mon Plan January 2012 rev 11.4 redbn .docN VDMT PlonUulv 2011 DMT revision for permitVToihnga Mgnt System and DMT Mon Plon July 2011 rev 11 2 redhne doo White Mesa Mill - Standard Operating Procedures 07/1101/12 Revision Demsonl 1 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 50 of 53 N.VDMT PlanVDMT Plan 01.30.12 Revi lo 11.4VTaibngs Mgnt .System and DMT Mon Plan January 2012 re 11.4redb e docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 redlme doo White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental ProtecUon Manual SecUon 3 1 07/4401/12 Revision Demson 11 43 Page 51 of 53 APPENDIX F Example of Freeboard Calculations For Cell 4B Assumptions and Factors o Total PMP volume to be stored in CeU 4A - 159 4 acre feet o Wave ranup factor for Cell 4AB - 0 77 feet o Total capacity of Cell 4B - 2 094 000 dry tons o Elevation of FML of Cell 4B - 5 600 35 FMSL o Maximum pool surface area of Cell 4A-4B - 40 acres o Total tailings solids deposited into Cell 4B at time beach area first exceeds 5 594 FMSL - 1 000 000 dry tons* o Date beach area first exceeds 5 594 FMSL - March 1 2012* o Expected and acmal production is as set forth in the following table Time Period Expected Tadmgs Solids Disposition into CeU 4B Determined at the beginmng of the penod (dry tons)* Expected Tailings Sohds Dispositio n into CeU 4B at the beginnmg ofthe penod multiplied by 150% Safety Factor (dry tons) Actual Tailmgs Sohds Disposition into Cell 4B determined at end of the penod (dry tons)* March I 2012 to November 1 2012 150 000 225 000 225 000 November 1 2012 to November 1 2013 300 000 450 000 275 000 November 1 2013 to November 1 2014 200 000 300 000 250 000 N VDMT PlanVDMT Plan 01.30.12 Re ision 11.4VTaih gs M gnt System and DMT Mon Plan January 2012 re 11 4 redh e docN VDMT PlonUulv 2011 DMT revision for pormitVToihnga Mgnt Syatom ond DMT Mon Plan July 2011 rov 11 2 redlmo doc White Mesa Mill - Standard OperaUng Procedures 07/1101/12 Revision Denisonl 1 43 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 52 of 53 *These expected and acmal tailings and production numbers and dates are fictional and have been assumed for illustrative purposes only Based on these assumptions and factors the freeboard limits for Cell 4B would be calculated as follows 1 Pnor to March 1. 2012 Pnor to March 1 2012 the maximum elevation of the beach area in Cell 4B is less than or equal to 5 594 FMSL therefore die freeboard limit is set at 5 594 6 FMSL 2 March 1. 2012 to November 1.2012 The pool surface area would be reduced to the following amount (1-225 000/ (2 094 000 - 1 000 000)) x 40 acres = 31 77 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 31 77 acres equals 6 22 feet When die wave ran up factor for Cell 4B of0 77 feet is added to this die total freeboard required is 6 99 feet This means that the freeboard limit for Cell 4B would be reduced from 5594 6 FMSL to 5592 2 FMSL (5594 6 FMSL nunus 6 22 feet rounded to the nearest one tenth of a foot) This calculation would be performed at March 1 2012 and this freeboard limit would persist until November 1 2012 3 November 1. 2012 to November 1.2013 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since the acmal tonnage of 225 000 dry tons was the same as the modeled tonnage of 225 000 dry tons the recalculated pool surface area is the same as the modeled pool surface area for the previous penod which is 31 77 acres Then calculate the modeled pool surface area to be used for the penod (1-450 000/ (2 094 000 - 1 000 000 225 000)) x 31 77 acres = 15 32 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 15 32 acres equals 12 89 feet When the wave ran up factor for Cell 4B of0 77 feet is added to this the total freeboard required is 13 66 feet This means that the freeboard limit for Cell 4B would be reduced from 5592 2 FMSL to 5586 7 FMSL (5600 35 FMSL minus 13 66 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2012 and this freeboard limit would persist until November 1 2013 N.VDMT PlanVDMT Plan 01.30.12 Re sion 11.4VTaih gs Mgnt Svstem and DMT Mon Plan January 2012 re 11.4 redh e.docN VDMT PlonUulv 2011 DMT roviaion for pormitVToihngs Mgnt System ond DMT Mon Plon July 2011 rov 11 2 redbne doo White Mesa Mill - Standard OperaUng Procedures 07/4401/12 Revision Demsonl 143 Book 11 Environmental ProtecUon Manual Section 3 1 Page 53 of 53 4 November I. 2013 to November I. 2014 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since modeled tonnages exceeded acmal tonnages the pool area was reduced too much dunng the previous penod and must be adjusted The recalculated pool area for the previous penod is (1-275 000/ (2 094 000 - 1 000 000 225 000) x 31 77 acres = 21 72 acres This recalculated pool surface area will be used as the starting point for the freeboard calculation to be performed at November I 2013 Then calculate the modeled pool surface area to be used for the penod (I - 300 000 / (2 094 000 - I 000 000 225 000 - 275 000)) x 21 72 acres •• 10 75 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 10 75 acres equals 18 37 feet When the wave ran up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 19 14 feet This means that the freeboard limit for CeU 4B would be reduced from 5586 7 FMSL to 5581 2 FMSL (5600 4 FMSL nunus 18 4 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November I 2013 and this freeboard limit would persist until November 1 2014 N.VDMT PlanVDMT Plan 01.30.12 Rev sion 11.4VTaihngs Mgnt .System and DMT Mo Plan January 2012 re 11.4 edb e docN VDMT PlonUulv 2011 DMT revision for pormitVToibngs Mgnt Syatem and DMT Mon Plon July 2011 rov 11 2 rodlmo doc Page 1 of 1 Dave Rupp RE Re request for Response From Jo Ann Tischler <jtisch]er(2)denisonmines com> To Dave Rupp <DRUPP@utah gov> Date 12/12/2011 12 33 PM Subject RE Re request for Response CC Harold Roberts <HRoberts@denisonmines com> Kathy Weinel <KWeinel ©denisonmines com> David Frydenlund <DFry den lund ©denisonmines com> Dave You are correct that we owe you the revisions of the revised DMT Plan and other items Even though we responded to the NOED we stilt have not responded to the Corrective Action Letter that preceded it I apologize for the oversight We will respond within 30 days of receiving the new RFI letter from Rusty as you requested Jo Ann Jo Ann Tischler Direr ct C hi ^-^ ll " f 9 PVt' "O t 303 389 4132 I f 303 389 4125 1050 17th Street Suite 950 Denver CO US 80265 DENISON MINES (USA) CORP v/vww denisonmines com Th s e ma I s nte ded for the e clus e use the of person(s) mentioned as the ec p ent(s) Th s message and any attached f les with it are conf dent al and may contain pr leged o propr etary nfo mat on If you are not the ntended ecipient(s) please delete th s message and ot fy the sende You may not use d stribute pr nt or copy th s message f you a e not the ntended rec p ent(s) From Dave Rupp [mailto DRUPP@utah gov] Sent Monday December 12 2011 11 52 AM To Jo Ann Tischler Cc Harold Roberts Subject Re request for Response Jo Ann Please see the attached draft letter on the subject I am requesting a response time for DUSA on this per the last paragraph of the letter Due to the response time nearly being expired on the original RFI letter I have suggested a 30 day response time Please respond to the above request for your response time prior to 5 00 p m December 13, 2011 The final version of this letter should not change significantly from this draft If you have questions on this particular item please contact me David A Rupp P E Utah Division of Radiation Control P 0 Box 144850 Salt Lake City UT 84114 4850 Telephone (801) 536 4023 Fax (801) 533 4097 Email drupp@utah gov file //C \Documents and Settings\drupp\Local Settings\Temp\XPgrpwise\4EE5F4AFEQD 12/1 V20\ DENISON MINES Demson Mines (USA) Corp 1050 17th Street Suite 950 Denver CO 80265 USA Tel 303 628 7798 Fax 303 389^125 www denisonmines com Junes 2011 VIA E MAIL AND OVERNIGHT DELIVERY Rusty Lundberg Co Executive Secretary Utah Water Quality Board Utah Department of Environmental Quality 195 North 1950 West PO Box 144810 SaltLakeCity UT84114 4810 Re State of Utah Ground Water Discharge Permit No UGW370004 White Mesa Uranium Mill - Notice Pursuant to Part I G 3 ofthe Permit and UAC R317 6 6 16(C) Dear Mr Lundberg Please take notice pursuant to Part I G 3 of the White Mesa Mill s (the Mill s ) State of Utah Groundwater Discharge Permit No UGW370004 (the Permit) and Utah Administrative Code ( UAC ) R313 6 6 16(C) that Demson Mines (USA) Corp ( Demson ) as operator of the Mill and holder of the Permit failed to meet the Best Available technology (BAT) standards in Part ID 13d) of the Permit by not measunng weekly wastewater levels on newly approved Cell 4B until May 31 2011 as descnbed in more detail below This exceedance was discovered on Tuesday May 31 2011 Initial notice of this failure to maintain BAT was given by telephone to Mr David Rupp of the Utah Department of Environmental Quality at 3 45pm on Wednesday June 1 2011 at 801 536 4023 (within 24 hours of the discovery) 1 Facts and Background Information a) DRC provided authorization for use of Cell 48 on January 27 2011 b) Section 3 Id) of the Mills DMT Momtonng Plan requires that Solution elevation measurement in Cells 4A 4B and Roberts Pond are to be taken by survey on a weekly basis c) Denison began transfernng solutions to Cell 4B (by siphon) on February 1 2011 d) Until May 31 2011 the solution level in Cell 4B was too low to be measured safely either by survey instrument or by measunng tape along the sidewall (dike) e) Unlike the other tailings cells constructed at 3 to 1 sideslopes the sidewall (dike) of Cell 4B constructed at 2 to 1 sideslope is too steep to allow a worker to be lowered by harness safely until the solution level reached approximately 25 feet N \Notices\06 06 11 Notice to RLundberg Cell 48 signed doc Letter to Mr Rusty Lundberg Junes 2011 ^ Page 2 f) Denison began measuring solution level in Cell 4B on May 31 2011 by dropping a tape along the sidewall of the dike This was the first date on which the solution level could safely be reached by measunng tape At that time the solution level was 5581 10 feet that is approximately 23 6 feet of solution That means over 19 feet of freeboard remained g) At the time of this nohce the solution level is still too low to be measured by survey instrument h) Denison notified UDEQ by phone call at 3 45pm on Wednesday June 1 2011 that the Cell 4B liquid level could be reached by tape from the sidewall that the weekly measurements by tape had begun and that the liquid level still could not be measured by survey instrument 0 The Mill has been running on a 10 day on and 4 day off operating cycle 2 Action Taken Upon receipt of the initial survey results the Mill s Environmental Coordinator notified the Mill Manager at 3 45pm that day The following plan of action was immediately put mto place in accordance with section 5 1 ofthe Mill s Contingency Plan a) The Cell 4B solution level was measured the first day that the solution could be reached by tape along the side wall b) Mill personnel have been instructed to continue solution level measurements by tape until such time as the solution level is high enough to be read by survey instrument c) Verbal notification was given to the DRC at 3 45pm on June 1 2011 within 24 hours of discovery This verbal notification was followed by this written notification within five days of discovery 3 Root Cause The root cause analysis is as follows a) The DMT Plan does not address measurement of cell solution level dunng cell startup conditions that IS when solution level is too low to be safely measured by survey instrument and too low to be safely reached by suspending a worker by cable to take a tape measurement in circumstances when the solution level is nowhere near the freeboard limit for Cell 4B b) Denison made the judgment not to nsk the safety of a worker by requinng them to be suspended along the steep bank above the Cell 4B solutions in order to collect an environmental measurement 4 Actions That Will be Taken to Prevent a Reoccurrence of this Incident The following actions will be taken to prevent a reoccurrence of this incident a) The Cell 4B solution has reached a level that can be accessed safely by measunng tape DENISON MINES Letter to Mr Rusty Lundberg Junes 2011 Page 3 b) Measurements by tape have commenced and will continue until the solution level can be measured by survey instrument c) Demson will propose revisions to the DMT Plan to address the cell startup (low solution level) situation 5 Affirmative Defense Demson believes that the affimnative defense in Part I G 3 c) of the Permit should be applicable to this incident for the following reasons a) Notification By virtue of the initial oral notification given to UDEQ at 3 45 PM on Wednesday June 1 2011 (within 24 hours ofthe discovery) and this written notice Denison has submitted notification according to UAC R317 6 6 13 b) Failure was not Intentional or Caused by the Permittee s Negligence The failure to survey the water level in Cell 4B was not caused by Denison s negligence either in action or in failure to act The Mill made a judgment not to nsk the safety of an employee in order to take an environmentai measurement particularly when the solution level in Cell 4B is obviously lower than the freeboard limit The DMT Plan does not address the low solution level situation adequately c) The Permittee has Taken Adequate Measures to Meet Permit Conditions Denison has measured the Cell 4B solution level as soon as a tape measurement could safely be performed Based on the solution measurement taken on May 31 2011 the freeboard level was significantly lower (met) the requirement for the entire penod from cell startup on February 1 2011 through May 31 2011 All other required measurements in Part 1D 13 have been made and recorded since cell startup Based on the solution levei measurement made on May 31 2011 and the calculated action leakage rates from table 1B of the BAT 08iM Plan Cell 4B has not exceeded the maximum allowable average daily leakage rate during the penod d) Demson has taken adequate measures to meet Permit conditions in a timely manner The provisions of the Permit were implemented immediately UDEQ was notified within 24 hours of discovery of the solution measurement information Measurements of cell solution level began as soon as measurement could safely be achieved e) The Provisions of UCA 19 5 107 Have Not Been Violated The provisions of Utah Code 19 5 107 have not been violated There has been no discharge of a pollutant into waters of the state Demson has not caused pollution which conshtutes a menace to public health and welfare or is harmful to wildlife fish or aquatic life or impairs domestic agncultural industrial recreational or other beneficial uses of water nor has Denison placed or caused to be placed any waste in a location where there is probable cause to believe it will cause pollution i There was no discharge of solutions from the Mill s tailings impoundments DENISONO MINES Letter to Mr Rusty Lundberg Junes 2011 Page 4 Please contact the undersigned if you have any questions or require any further information Yours very truly '\ \ DENISON MINES (USA) CORP -Mo Jo Ann Tischler Director Compliance and Permitting cc Rich Bartlett David C Frydenlund Harold R Roberts David E Turk Central files r 1 ; DENISON MINES ! i "aNn lauM iV n«J 'ssauttv NunllUWrA . iH01«3Hi»13J»13AN3d«Jtii¥U3>(0liS30>nd SENDER: COMPLETE THIS SECTION Complete Items 1 2 and 3 Also complete Item 4 if Restncted Delivery is desired Print your name and address on the reverse so that we can return the card to you Attach this card to the back of the mailpiece or on the front if space permits 1 Article Addressed to |ved by (Pnnted Name) RE 3/12/12 approval of smt plan DR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 , / D Is delivery address >d CJ)^e of Qehvery cal closeout / Service J. • Certify9!^ail •B^nesd'Mkil • Registd(e^ •, Returh Receipt foj^ • Insured M^x» • C O D w v/ 2 Article Number (Transfer from service label) , ^ ,11 - ) 2 Article Number (Transfer from service label) 17011 DllD aODl 7T51'. OaflE 1 \ PS Form 3811 February 2004 Domestic Return Receipt — ;i. 102595-02 M 1540 \ J I / \ CO ' CD ) LTJ i-=i • a a I C3 HI O r-q O U.S. Postal ServiceiM CERTIFIED MAIL™ RECEIPT (D0mestic Mail Only; N» Insurance Coverage Pr9viM) F»r ^eliverv information visit our website at vww.us|is.c«m«, OFFICIAL USE Postage $ Certified Fee DR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265^^^ FS F«rm 3»M. Ausust 2M6 See Reverse (ar Instructions State of Utah GARY R HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Smith Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director ^0 / March 12 2012 Certified Mail (Retum Receipt Requested) Ms Jo Ann Tischler Director Compliance and Permitting Denison Mines (USA) Corp (DUSA) 1050 17* Street Suite 950 Denver CO 80265 DRC-2012-001274 Dear Ms Tischler SUBJECT February 29 2012 DUSA Transmittal of Revised White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan February 15 2012 DRC Letter September 13 2011 DRC Confirmatory Action Letter (CAL) Approval of DMT Plan and CAL Closeout We received the subject February 29 2012 DUSA transmittal letter and the corresponding DMT Plan version 2/12 Revision Denison 115 We have reviewed this plan and it is hereby approved Approval ofthis DMT Plan is the final action necessary to complete the requirements ofthe subject CAL Therefore these CAL requirements are hereby closed out We remind you of the condition specified in our letter of February 15 2012 that we expect the additional requirements specified in our December 20 2011 letter to be completed and provided to the DRC withm 30 days UTAH WATER QUALITY BOARD Rusty Lundberg Co Executive Secretary RL/DAR Cc Harold R Roberts DUSA Russell Topham DRC F \DUSA\NOVs & SCAsXCell 4B WLMeas Omissions \DMT Plan Approval 3 12 12 docx 195 North 1950 West Salt Lake City UT Mailing Address POBox 144850 Salt Lake City UT 84114-4850 Telephone (801) 536 4250 Fax (801) 533-4097 TDD (801)536-4414 i T <7 i I go Pn ted 100/ e ycl dp p State of Utah GARYR HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Snuth Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director February 15 2012 Certified Mail (Retum Receipt Requested) Ms Jo Ann Tischler Director Compliance and Permitting Denison Mines (USA) Corp (DUSA) 1050 17* Street Suite 950 Denver CO 80265 Dear Ms Tischler nj o u^ IT i-=i a CD o o HI a HI CD U.S. Postal Service™ CERTIFIED MAILM RECEIPT (Domestic Mail Only; Nm Insurance Cmverage FrmviM) F»r delivery information visit our website at www.us^s.comf} OFFICIAL USE Postage Certified Fee $ P tmark Postage Certified Fee P tmark Postage Certified Fee P tmark RE 1/30/12 response to CAL DMT RFI/dar Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 PS Form 3tM. August 2Me See Reverse f»r Instructions SUBJECT January 30 2012 DUSA Letter Response to Confirmatory Action Letter (CAL) and Transmittal of Revised Discharge Minimization Technology (DMT) Momtonng Plan December 22 2011 DRC Letter September 13 2011 DRC Confirmatory Action Letter (CAL) Request for Information We have reviewed the subject January 30 2012 letter from DUSA and the transmitted DMT Monitonng Plan We have reviewed this information and have the following comments The comment shown immediately below corresponds to comment number three (3) in the subject September 13 2011 DRC CAL 3 DUSA states that Denison has developed other means to accurately measure cell solution level elevations pnor to construction of any walkways However the DRC CAL states that The procedures for this method to measure the water level elevation will be submitted by DUSA for approval in a revised DMT Plan Please propose the other means to measure the water level as discussed above It is not apparent in the DMT plan what the other means to measure the solution elevation are The comment numbers below correspond to the comment numbers m the subject December 22 2011 DRC Letter 3 Part ID 3(b)(3) of the Permit states that Annual Slimes Dram Compliance - shall be achieved when the average annual wastewater recovery elevation in the slimes dram access pipe as determined pursuant to the currently approved DMT Monitonng Plan 195 North 1950 West Salt Lake City UT Mailing Address PO Box 144850 SaltLakeCity UT 84114 4850 Telephone(801)536 4250 Fax (801)533 4097 TDD (801)536-4414 wwd q t hg Pnnt d on 100% recycl d paper Page 2 meets the conditions in Equation 1 below Thus the DMT Plan needs to state how the slimes drain recovery elevations are to be calculated A DUSA letter dated January 27 2012* shows DUSA s current method of calculating the slimes drain recovery elevation as well as the annual average slimes drain recovery elevation This method is clanfied m the second full paragraph on page 2 of that letter One may call the current DUSA method of calculating recovery elevations a relative elevation method Although this method is valid for companson purposes it appears correct elevations with respect to the tme elevation above mean sea level (fmsl) are not being used As mentioned in the January 27 2012 letter the standpipe elevation was re surveyed m 2011 which indicated that the elevation of the measurement point of 5614 83 fmsl reported to date was 3 07 feet higher than the 2011 survey result of 5611 76 fmsl To avoid the complex adjustments to calculate relative elevations and to avoid future errors DUSA must convert to using actual fmsl elevations not relative elevations in all of Its shmes drain recovery elevation determinations and calculations DUSA s method to do this must be stated in the DMT Plan Notwithstanding the above the DMT Plan needs to state how the shmes drain recovery elevations are to be calculated 5 In Appendix F of the DMT Plan additionally the first bullet line should refer to Cell 4B instead of Cell 4A Please make this correction 6 The previous comment was Paragraph 6 2 needs to be revised due to the construction of Cell 4B It needs to be corrected to refer to the current extenor dikes required to have movement monitonng However DUSA s response that 'The text corrections have been made as requested is incorrect as no changes were made It appears dikes 4A E 4A S and 4B S are the current exposed extenor dikes subject to movement monitonng Please indicate such in this paragraph of the plan 7 See Appendix A page 28 Table III Since the freeboard in Cell 1 is always exposed and the water level is often changing all the dike/embankments in Cell 1 become visible from time to time Columns need to be made available so inspection entnes can be made for all the dikes of Cell 1 Similarly all the dikes of Cells 4A and 4B need to be included in the table January 27 2012 DUSA response letter on Failure to Meet Affirmative Defense Requirements on Cell 2 Slimes Drain Recovery Elevation Page 3 We request that DUSA review and respond m wnting to the above This response must include all appropnate adjustments in a new version of the DMT Plan with a unique version number Per your telephone conversation with Messrs Rupp and Goble on Febmary 14 2012 on this subject you agreed that DUSA will fully respond to this letter by March 1 2012 In our letter to you dated December 20 2011 we documented a commitment from you to provide additional refinements to the DMT Plan by March 1 2012 In light of the above paragraph we now will expect the additional requirements specified in our December 20 2011 letter to be completed and provided to the DRC within 30 days of our approval of the revisions requested herein Inasmuch as this letter is the DRC comments on your response to the subject CAL your response to this letter is subject to enforcement If you have any questions on the above please contact Mr Rupp at 801 536-4023 UTAH WATER QUALITY BOARD Rusty Lundberg Co Executive Secretary RL/RT/DAR Cc Harold R Roberts DUSA Russell Topham DRC F \DUSA\NOVs & SCAsXCell 4B WLMeas Omissions \RFI DMT Plan&CAL response02 12 docx SENDER: COMFLE' COMPLETE THIS SECTION ON DELIVERY Complete items 1 2 and 3 Also complete Item 4 if Restricted Delivery is desired Print your name and address on the reverse so that we can return the card to you Attach this card to the back of the mailpiece or on the front if space permits 1 Article Addressed to^ • Agen • Addf e i, B Receiv^ by (Pnpted Name) C Dale of Delivt v ID Is delivery addi^^fS^pt-ton item 1'> • Ye 11 ^^E^_.^er delivery aiwrfs^elow • No RE 12/22/11 ^combined comments / D^R/W ^'^i Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 3 iS^iceType •[Certifled^M^II • Express / • R^ist^d ^ O Fteturn ReicSlpt for Merchandist • Inured Mail • C 0 D \^ Restncted Deliverj^^jExfr^be/ • Yes 2 Article Number (Transfer from service label) 7011 DUO DOOl 7T51 0103 I PS Form 3811 Febmary 2004 Domestic Return Receipt 1025g5-02-M 1540 -J r 1 IS Hi |ir 1^ (a CD CD I a I ° HI Hi O U.S. Postal Service™ GERTIFIED MAIL™ RECEIPT (Dmmestic Mail Only; Nm Insurance Cmverage PrmviM) For ilelivery information Visit our website at www.us»s com. Postage Cert fed Fee $ n — Postage Cert fed Fee n — RE 12/22/11 combined comments/DARf Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 PS F«rm 3«M. August 2tti See Reverse f»r Instructions State of Utah GARYR HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Smith Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director December 22 2011 CERTIFIED MAIL (Retum Receipt Requested) Ms Jo Ann Tischler Director Compliance and Permitting Denison Mines (USA) Corp (DUSA) 1050 17* Street Suite 950 Denver CO 80265 Dear Ms Tischler SUBJECT July 11 2011 DUSA Letter Transmittal of Revised Discharge Minimization Technology (DMT) and Cell 4A and 4B Best Available Technology (BAT O&M) Plans July 14 2011 DUSA Ground Water Discharge Permit UGW370004 June 23 2011 DUSA Letter Transmitting a Proposed DMT Plan December 14 2011 DRC Request for Information on a Confirmatory Action Letter Combined Comments on Proposed DMT Plan Versions This letter provides combined comments by the Division of Radiation Control (DRC) on two separately proposed White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitonng Plan (DMT Plan) versions submitted by DUSA The two separate DMT Plans proposed are referenced below A White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan (DMT Plan) version 06/11 Revision Denison 112 transmitted by a DUSA June 23 2011 letter B DMT Plan version 07/11 Revision Denison 11 3 transmitted by a DUSA July 11 2011 letter Reference (A) was provided but DRC review was deferred by DRC letter dated October 17 2011 An earlier DRC comment letter of June 13 2011 requested additions to the DMT Plan monthly inspection form for the specific inspection of the movement monitors After review it appears the proposed changes to the monthly movement monitor inspection form are adequate Reference (B) was provided in response to Part IH 7 of DUSA s July 14 2011 Ground Water Discharge Permit The Permit required modifications to the DMT Plan and the Cell 4A and Cell 4B BAT O&M Plan (BAT O&M Plan) be submitted for Executive Secretary approval A separate letter from DRC addresses the proposed BAT O&M Plan changes 195 North 1950 West Salt Lake City UT Mailing Address POBox 144850 Salt Lake City UT 84114 4850 Telephone (801) 536 4250 Fax (801) 533 4097 TDD (801) 536 4414 www d q t h g Pr t d 1009' re y 1 d p pe Ms Jo Ann Tischler ) ^ \ Page 2 I Our comments below are provided for the reference (B) DMT Plan ^ DMT Plan Changes Required, from the Ground Water Discharge Permit Part IH 7 1 Permit Part ID 3(b) paragraphs ii and iii now that the shmes drain access pipe has been extended the corresponding measurements in the DMT Plan need to be corrected ' 2 Part IE 7(b) paragraph (2) a professional survey of the new measurement point needs to be made 3 Now that the Cell 2 slimes drain access pipe has been extended in height DUSA must state in the DMT Plan how the measurements to the water surface will be taken now and how DUSA will correlate these measurements conectly to earlier measurements Other Comments on the DMT Plan^ (reference (B) ' 4 On page 4 m the first sentence the items Cell 3 Cell 4A spillway should be reversed m their order m the sentence to be clearer in meaning > ^ ^ 5 In paragraph 6 3 5 there are several references to Cell 4A that apparently should refer to Cell 4B instead This occurs m paragraphs (c) iv vi vii and paragraph (d)iii In Appendix F of the DMT Plan this misreference appears to occur on page 56 in the second and fifth bullet line Please correct \_ 6 Paragraph 6 2 needs to be revised due to the constmction of Cell 4B It needs to be corrected to refer to the current extenor dikes required to have movement monitoring ( 7 Page 29 Table III Column under Dike 3 If there is visible embankment on the south dike of Cell 3 please adjust the form as appropnate ^ ^ / ^8 On page 36 paragraph 7 refers to a Contaminated Waste Dump awaiting DRC approval We are uncertain as to what this is Please clanfy 9 Due to the installation of additional platform fill on Cell 2 slimes drain recovery elevation measurement related items in the DMT Plan need to be changed On^the DMT Plan inspection form p 34 (paragraph 2 the 38 foot figure appears to need adjustment V State of Utah GARY R HERBERT Governoi GREG BELL - . Ueutenant Governor December 22 2011 , Department of Environmental Quality ^ Amanda Smith Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg I Dvectoi \ \ CERTIFIED MAIL (Retum Receipt Requested) \ \ Ms Jo Ann Tischler Director Compliance and Permitting \ Denison Mines (USA) Corp (DUSA) \ 1050 n'^ Street Suite 950 \ Denver CO 80265 Dear Ms Tischler \ SUBJECT July 11 2011 DUSA Letter Transmittal ^f^evised Discharge Minimization Technology (DMT) and Cell 4A and 4B Best Available T^chnoIog^AT O&l^) Plans July 14 2011 DUSA Ground Waler Discharge Permit UGW3700p4 June 23 2011 DUSA Letter Transmitting a Proposed DMT Plan December 1^011 DRC Request for Information on a Confirmatory Action Letter Combined Comrnems on Proposed DMT Plan Versions This letter provides combined comments by the Divisionpf Radiation Control (DRC) on two separately proposed White Mesa Mill Tailings Management Syst^ and Discharge Minimization Technology (DMT) ' Momtormg Plan (DMT Plan) versions submitted by/DUSA The two separat^^pMT Plans proposed are referenced below / ^ ( / / A White Mesa Mill Tailings Manageipent System and Discharge Minimization Technology (DMT) Monitoring Plan (DMT Plan) version 06/11 Revision Denison 11 2 transmitted by a DUSA'June 23 2011 letter y""" ) > B DMT Plan version OT^M Revision Denison 11 3\transm]tted by a DUSA July^ll letter Reference (A) was provided but DRC review was deferred by DRC letter dated October 17 201 l\An earlier DRC comment letter of June 13 2011 requested additions to the DMT Plan monthly inspection form for the specific inspection of the movement monitors After review it appears the proposed changes to the monthly movement monitor inspection form are adequate , i \ Reference (^B) was provided m response to Part 1H 7 of DUSA s July 14 20M Ground Water Discharge Permit The Permit required modifications to the DMT Plan and the Cell 4A and Cell 4B BAT O&M Plan (BAT O&M Plan) be submitted for Executive Secretary approval A separate letter from DRC addresses the proposed BAT O&M Plan changes \ 195 North 1950 West Salt Lake City UT Mailing Address PO Box 144850 SaltLakeCity UT 84114 4850 ^ Telephone (801) 536 4250 Fax (801) 533-4097 TDD (801)5 6-44147 el q t hg \ Pr ted 100% c> I d p per ' 1^ Ms Jo Ann Tischler Page 3 DUSA is concurrently prepanng to submit a new DMT Plan in response to a separate DRC Letter dated December 14 2011 DUSA s response to the DRC December 14 2011 letter also requires other information and commitments from DUSA separate from the DMT Plan We request that DUSA review and respond in wnting to the above including m that response a full response to the DRC letter of December 14 2011 This response must include all appropriate adjustments in a new version of the DMT Plan with a unique version number In your telephone conversation with Mr Rupp on December 21 2011 on this subject you agreed that DUSA will fully respond to this letter on or before January 30 2012 The original deadline for DUSA s response to the DRC December 14 2011 letter is also hereby extended to that date If you have any questions on the above please contact Mr Rupp UTAH RADIATION CONTROL BOARD Rusty Lundberg Executive Secretary ^ RL/DAR Cc Harold R Roberts DUSA Russell Topham DRC F\DUSA\ GWDPermit\DMT Plan HistoryXDMT Plan Progress on RevisCmtsl2 2011 docx State of Utah GARY R HERBERT Go\ ernoi GREG BELL Lie ute lant G nein i Department of Environmental Quality Amanda Smith Exeuani Due(U i DIVISION OFRADIAT Rusty Lundt Dtiedn . LT) m a CD HI LO ir FILE SR U.S. Postal ServiceTM CERTIFIED MAIL™ RECEIPT (Dmmestic Mail Only; Nm Insurance Cmverage PrmviM) For delivery information visit our website at www.us|is.com# Certified Mail (Retum Receipt Requested) December 14 2011 Ms Jo Ann Tischler Director Compliance and Permitting CD CD CD CD HI HI CD Retur (End me Rest cted [ (E dorsem Total Post RE 12/14/11 NOED9/13 RFI/DAR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 Demson Mines (USA) Corp (DUSA) HI Se tTo 1050 17'*'Street Suite 950 r-l CD Steet Apt No Denver CO 80265 P-PO Box No Cty State ZIP 4 Dear Ms Tischler PS F»rm 3St«. Auflust 2Mfi See Reverse f«r Instructions SUBJECT October 27 2011 DRC letter Notice of Enforcement Discretion (NOED) September J 3 2011 DRC Confirmatory Action Letter -Pertaining to the Non Measurement ofthe Water Level in Cell 4B Request for Information DRC sent DUSA a September 13 2011 Confirmatory Action Letter with a request for information pertaining to the non measuiement ofthe water levels in Cell 4B Subsequently DRC issued an NOED on the same subject October 27 2011 Due to this action it appears DUSA did not lespond to the Confirmatory Action Lettei However this information is still needed by DRC Therefore we lequest a full response to the subject Confirmatory Action Letter Per your email dated December 12 2011 you agreed that DUSA will fully respond to the above in writing making the pecessary commitments and changes to the DMT Plan withm 30 calendar days of receipt of this letter If you have any questions please contact Mr Dave Rupp at (801) 536 4023 UTAH RADIATION CONTROL BOARD Rusty Lundberg Executive Secretary RL/PG/DAR CC David Turk DUSA Blanding UT F \d pp\Dl S \\N0\ V 1 I t CAL doc I )-» Nonh I ;50 Wesl Sail Like C il\ Ul Miilin Addrc b PO li( \ 144850 Salt Lake Cit\ I I K4I 14 48 0 Telephone (801)-. ( 4^i0 Fix (801) 5 3 4097 TDD (801)^ ( 4414 fi q t I c Pll 100 I d M State of Utah GARY R HERBERT Governor GRE|n Lieutenah] Department of Environmental Quality ^ Ln Amanda Smith Executive Director DIVISION OF RADIATION CONTROL ^ Rusty Lundberg Director u;s. Postal Service in CERTIFIED MAIL , RECEIPT (Dmmestic Mail Only; Nf Insurance Cmverage PrmviM) October 27 2011 Fomelivery mformation visil our website at www.us^s.comfi, ' U r r • 1 C 1 A i Postage $ Certified Fee P tm k Here Reium Receipt Fee P tm k Here RE DRC FINDINGS CONF ACTION & NOED/RT David C Frydenlund Vice President & General Counsel Denison Mines (USA) Corp (DUSA) 1050 17th ST STE 950 Denver CO 80265 PS Fbrm 3fit0. Alienist 2i»6 See Reveise lor lnslriicti»iis CERTIFIED MAIL RETURN RECEIPT REOUESTED Mr David C Frydenlund Vice President and General Counsel Denison Mines (USA) Corp (DUSA) 1050 Seventeenth St Suite 950 Denver, Colorado 80265 Subject 2"*^ (garter 2011 DUSA DMT Performance Standards Momtonng Report and Cell 4A and Cell 4B Performance Standards Momtormg Report (Dated August 31 2011) Ground Water Quahty Discharge Permit UGW370004 DRC Findings, Confirmatory Action and Nodce of Enforcement Discretion DearMr Frydenlund On September 1 2011 the Utah Division of Radiation Control (DRC) received the 2"^ (garter 2011 DMT Performance Standards Momtormg Report and Cell 4A and Cell 4B Performance Standards Momtonng Report (dated August 31 2011) for the DUSA While Mesa Mill near Blanding Utah After review of the referenced report several issues were identified as discussed below These items were discussed with you dunng a teleconference on October 26 2011 This letter summanzes the outcome of our staff review of the Report and the agreements made dunng the teleconference The DRC findmgs were as follows 1 Part 3 1 (b)(v) of the GWDP requires DUSA to momtor and record weekly the depth to wastewater in the Cell 2 slimes dram access pipe to determme maximum and minimum head before and after a pumping cycle respectively This information was not included m the Report 2 Appendix A to the Report presents weekly water surface elevations m the tailmgs cells and Roberts Pond Data for the week of Apnl 29 2011 does not appear in the referenced Attachment A 3 DUSA began diverting tailmgs to Cell 4B on Febmary 1 2011 No solution pool elevation measurements were taken until May 31 2011 This is m violation of Part 3 1(a) of the BAT Plan DRC previously noted this violation durmg its review letter for the (Quarter Report dated August 31 2011 Durmg the 2"'' Quarter of 2011 DUSA discovered this violation and rettimed to compliance 4 Part 3 1 (d) of the DMT/BAT requires DUSA measure the size and maximum elevation of the tailmgs beach in Cells 4A and 4B monthly This information does not appear m the Report 195 North 1950 West Salt Lake City UT Maihng Address POBox 144850 Salt Uke City UT 84114-4850 Telephone(801) 536-4250 Fax(801)533^097 TDD (801)536^14 wvnv d q tah g P t d 100/ y Icdp p David C Frydenlund Page 2 October 27 2011 5 Part 3 1 (a) of the DMT Plan requires DUSA to momtor the leak detection system for Cells 1 and 3 weekly The Plan requires DUSA to report the leak detection system as dry or to report the fluid level m the system Detectmg fluid tnggers a requirement to extract the fluid measure the extracted volume and compute a leakage rate for the cell The 2"*" Quarter DMT Performance Standards Momtonng Report contains no data for either the Cell 1 or Cell 3 leak detection systems 6 Part I D 6(b) ofthe GWDP specifies a head dependent allowable leakage rate through the Cell 4 A flexible membrane Imer Part 3 1(a) ofthe BAT Plan reiterates this requirement In light ofthe spillway between Cell 4A and Cell 4B the DRC removed the requirement to measure the Cell 4A solution pool elevation to demonstrate compliance with freeboard requirements for the cell When DUSA placed Cell 4B mto service on Febmary 1 2011 measurement of the solution pool elevation in Cell 4A ceased The result of termmating the Cell 4A momtonng was a lack ofdata to use to calculate the allowable leakage rate through the flexible membrane Imer This failure to momtor persisted through the end of the 2 Quarter of 2011 DRC addressed this issue m conjunction with the review ofthe 1"' Quarter Report DUSA has now retumed to compliance with respect to this monitonng requirement 7 Part 1 E 8(a)( 1) of the GWDP requires DUSA to provide continuous operation of the Cell 4A LDS pumpmg and momtonng equipment and to make such equipment operational within 24 hours of discovery of a failure of such equipment On June 27 2011 Mill personnel discovered that the LDS momtonng datalogger had ceased to record on June 7 2011 Plant personnel rebooted the system and observed resumption of data logging Plant personnel checked the logger more frequently following the reboot, and repeated the system reboot on July 1 2011 Upon discovery that rebooting the system did not conect the failure DUSA consulted with the equipment manufacturer for trouble shootmg and repair advice DUSA has restored the data loggmg equipment to compliant operation mcludmg installation of an upgraded version of the data management software durmg July 2011 Failure to repau- a failed system and bnng it to ftill operation within 24 hours constimtes a violation of Part 1 G 3 ofthe GWDP Confirmatory Actions During the October 26 2011 conference call DUSA committed to do the followmg on or before November 14 2011 1 DUSA will provide the weekly inspection sheets and a data table summanzmg the weekly maximum and mimmum fluid level m the Cell 2 Slimes Dram for the 2 quarter of 2011 to the DRC as an addendum to the 2"^ Quarter DMT Performance Standards Momtonng Report All future DUSA DMT Performance Standards Momtormg Reports will include weekly inspection sheets and a data table presenting the weekly maximum and nunimum fluid level m the Cell 2 Slimes Dram 2 DUSA will provide a revised Attachment A to the report that includes the weekly water surface elevations m the tailings cells and Roberts Pond for the week of Apnl 29 2011 3 DUSA will provide the monthly survey data and a data table summanzmg the tailings beach area and maximum elevation for each month of the 2"** quarter of 2011 All future DUSA DMT Performance Standards Momtonng Reports will include monthly survey data and a data table presenting the taihngs beach area and maximum elevation for each month David C Frydenlund Page 3 October 27, 2011 4 DUSA will provide the leak detection system momtonng resuhs for Cells 1 and 3 m a table for each week of the 2""^ quarter of 2011 All ftiture DUSA DMT Performance Standards Momtonng Reports will include leak detection system monitonng results for Cells 1 and 3 m a table for each week ofthe monitonng penod Notice of Enforcement Discretion Although DUSA failed to momtor the solution pool elevation m Cell 4B for the first two months of the 2""* (Quarter of 2011 the Executive Secretary has determined to use enforcement discretion m this matter based on 1 This violation was a continuation of an issue addressed m a previous DRC action specifically the referenced letter of August 31 2011 and 2 DUSA has as of May 31 2011 returned to compliance Although DUSA failed to monitor the solution pool elevation m Cell 4A from Febmary 1 through June 30 2011 the Executive Secretary has determmed to use enforcement discretion in this matter based on 1 This violation was a continuation of an issue addressed m a previous DRC action specifically the letter of August 31 2011 transmitting findmgs of DRC review of the I''' Quarter Report and 2 DUSA has as of July 2011 retumed to compliance and 3 Quantities of fluid pumped from the leak detection system were well below the lowest rate presented in Table 1A Appendix E to the BAT Plan which table relates solution head to maximum allowable leakage rate Thus the cell was operated m compliance with the leakage rate requirement even though a numencal proof of that compliance is lacking Although DUSA failed to retum the Cell 4A leak detection system data logging equipment to full functionality withm 24 hours of discovenng a failure of the product the Executive Secretary has determmed to use enforcement discretion in this matter based on 1 DUSA personnel made reasonable efforts to troubleshoot and repair the data logger 2 DUSA continued to manually collect daily measurement from the process controller This redundant data set provided data of sufficient quality and quantity effectively to perform as a surrogate for the data logger 3 The product failure and protracted trouble shooting did not result in a violation of the performance standards for the leak detection system or result in failure to detect a liner breach David C Frydenlund Page 4 October 27 2011 1 Please respond m wntmg within seven calendar days of receipt of this letter if you disagree with the above agreed upon resolution or compliance scheclule^ i ^ " ' Thank you for your contmued cooperatton UTAH WATER QUALITY BOARD Rusty Lundberg \ Co Executive Secretary RL/RJT ijt 1 V / ft - •) 'H:. Department of Environmental Quality Amanda Smith Executive Directoi DIVISION OF RADIATION CONTROL Rusty Lundbere Diredoi I H)i> ^ State of Utah GARYR HERBERT Governor GREG BELL Lieutenant Governor Certified Mail (Retum Receipt Requested) September 13 2011 Ms Jo Ann Tischler Director Compliance and Permitting Denison Mines (USA) Corp (DUSA) 1050 17* Street Suite 950 Denver CO 80265 Dear Ms Tischler SUBJECT Confirmatory Action Letter -Pertaining to the Non Measurement of the Water Level in CelUB White Mesa Uranium Mill License #UT0900480 Request for Information References a June 6 2011 DUSA letter on the subject b DMT Plan paragraph 3 1(d) c Ibid paragraph 3 1 (d)vii A(II) d Cell 4A and Cell 4B BAT Monitoring Operations and Maintenance Plan paragraph 4 4 e DUSA Letter of June 23 2011 Transmittal of Revised DMT Plan etc On August 31 2011 Messrs Phillip Goble and David Rupp of the Division of Radiation Control (DRC) held a telephone enforcement conference with you and Mr David Turk of DUSA This enforcement conference was under authority of UAC R313 14 15(5)(b) In this discussion DUSA made the following commitments 1 DUSA will provide the DRC the appropriate Mine Safety and Health Administration (MSHA) rule quotation(s) and citing(s) that require the use of walkways with handrails when egressing active tailings cells According to our discussion these requirements precluded DUSA from making water level elevation measurements in Cell 4B 2 DUSA will commit to a penod of time to construct walkways for new tailmgs cells after receiving authorization for use of any new tailings cell from the Executive Secretary This time period must be submitted for approval m a revised DMT Plan 3 DUSA will acquire a steel surveyor s tape(s) of adequate le ngth or develop other approved means to accurately measure water level elevations pnor to construction of the walkway discussed in the two numbered items immediately above The procedure s for this method to measure the water level elevation will be submitted by DUSA for approval ir a revised DMT Plan 195 North 1950 West Salt Lake City UT Mailing Address POBox 144850 SaltLakeCity UT 84114 4850 Telephone (801) 536 4250 Fax (801) 53J 4097 TDD (801)536-4414 d q t hg P t d 1009" ycl d p p Page 2 4 DUSA will revise the DMT Plan reference (c) so the point designated for the water level measurement m Cell 4B will be the southeast comer rather than the current required location 5 DUSA must acquire a longer survey elevation rod e g a 45 rod in order to survey the water level in the subject cell at lowest depths DUSA will revise the DMT Plan to include procedures for use of this longer survey rod 6 A revised DMT Plan proposed in reference (e) contains a new paragraph on page 10 As discussed this specific proposed new verbiage is not acceptable The DMT Plan must be revised in accordance with the above commitments and requirements 7 A new revised DMT Plan containing all the necessary verbiage changes from the items above will be submitted for approval In your email dated September 13 2011 you agreed that DUSA will fully respond to the above m writing making the necessary commitments and changes to the DMT Plan within 45 calendar days of receipt of this letter If you have any questions on the above please contact Mr Dave Rupp at (801) 536 4023 UTAH RADIATION CONTROL BOARD Rusty Lundberg Executive Secretary DAR dr CC David Turk DUSA Blanding UT F\dr pp\DUSA\NOVs\CAL C4BWL Me sur me ts doc n- !^ HI Ln cr CD o i CD CD HI HI CD HI HI U.S. Postal Service™ CERTIFIED MAIL™ RECEIPT (Dmmestic Mail Only; Nm Insurance Cmverage Frmviiletl) For delivery Information visit our website at www.usjis.com. %j r f i A i i P 1 i #*% mm %J -^w Postage Certified Fee $ P stm rk Postage Certified Fee RE 8/13/11 Confirmatory action letter/DR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 i Denver Co 80265 PS F»rm 3«M. August 2»9i See Reverse f«r Instructions i i SENDER: COMPLETE THIS SECTION Complete items 1 2 and 3 Also complete Item 4 if Restncted Delivery is desired Print your name and address on the reverse so that we can return the card to you Attach this card to the back of the mailpiece .or on the front if space permits COMPLETE THIS SECTION 9N BELIVERY 1 Article Addressed to etoed by, ( Printed Name) • Agent [ • Addressee h C Pelte dl.DelD TJ D Is delivery address different from Hern 1 • Yes enter delivery address below D No RE 8/T3/n Confirmatory action letter / DR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 3 SefvlceType ^Certified Mail • Registered • Insured Mail • Express Mall • Retum Receipt fbr Merchandise i • COD ( 4 Restncted Delivery? (Extra Fee) • Yes 2 Article Number T (Transfer from service label/i 7011 0110-oofii—y^si-ii?^ I PS Form 3811 February 2004 Domestic Return Receipt 102595-02 M 1540 / V ^- <, • .1** ^^^^^ < , 1 ^ ^-i-oo0«^5«<?^09^03UU9^09 J fy^-««^5»<5yv-«-5W+95U-|fo^)aodo 1=9 [:0Jiuu0 f+0oooo$i fuja^loafq^Ol • t State of Utah GARY R HERBERT Governor GREG BELL Liei tenant Go e iio> Department of Environmental Quality Amanda Smilh Exec utl e Di ecin DIVISION OF RADIATION CONTROL Rusty Lundber D led )r August 31 2011 CERTIFIED MAIL (Retum Receipl Requested) Ms Jo Ann Tischler Director Compliance and Permitting Denison Mines (USA) Corp (DUSA) 1050 17*^ Street Suite 950 Denver CO 80265 Dear Ms Tischler SUBJECT May 31 2011 White Mesa MiU Discharge Mmimization Technology (DMT) Performance Standard Monitoring Report (DMT Report) and Cell 4A BAT Perfonnance Standards Momtormg Report (Cell 4A BAT Report) for the 1st Quarter 2011 Submitted as a Single Volume Findings and Closeout Letter We received the subject combmed DMT and Cell 4A BAT Reports for the 1 ' Quarter 2011 dated May 31 2011 These two reports were submitted as a combined single bound volume under one title as descnbed in the subject block above An electronic copy of the volume was also submitted on compact disk We have reviewed this information and recognize the following items 1 Weekly tailings wastewater pool elevations for Cell 4B were not taken dunng the T' Quarter of 2011 This deficiency was reported by DUSA in a letter lo DRC dated June 6 2011 This will be addressed by DRC outside this report review under separate cover 2 In Section 3 0 of the subject volume m the sixth and last paragraphs waler surface measurements for Cell 4A are discussed These paragraphs reference the DRC letter of March 15 2011 While it is correct that water surface measurements for Cell 3 are no longer required by the latest DMT and BAT O&M Plans weekly water surface measurements for Cell 4A are still required by the plans (See DMT Plan Section 3 1 d and BAT O&M Plan p 12 paragraph under Solution Elevation ) Measurements for Cell 4A are necessary to determine the allowable leakage for Cell 4A dunng each quarter The last sentences in both the sixth and last paragraph of Section 3 0 need to be conected They should stale that water level elevation survey measurements for Cell 4A still need lo be conducted rather than the current that elevation survey measurements m Cell 4A are no longer required or conducted These statements in these paragraphs must be conected in the upcoming 2011 2 ^ Quarter Report 3 In Attachment A of the subject volume a table titled Tailings Pond Elevations I ' Quarter 195 No ih 1950 Wesi Salt Lake C ty UT Mai! ng Addr ss P O Bo 144850 Salt Lake City UT 84114 4850 Telephone (80! ) 53( 4250 Fax (801) 533 4097 TDD (801)5 6 4414 d q hf; P d 100/ y led p pe Page 2 Elevations 2011 is provided In the column underlined Cell 4A no solution elevations are provided for the weeks of 3/11/2011 through 4/1/2011 and the verbiage No Longer Required is shown These readings must be reinstated and the No Longer Required verbiage removed from the table m the upcoming 2011 2^ Quarter Report 4 In section 6 0 of the report it is noted that dunng the week of March 20 2011 the road grader hit 4 drums of KF Altemate Feed that is stored in steel drums on the Ore Pad The four drums were placed m steel over pack drums and placed back into the stockpile 5 Section 7 0 of the report discusses Imer repairs underway for the Cell 1 hner as a result of discovery of leakage m the Cell 1 Leak Detection System (LDS) on June 2 2010 and later on August 7 2010 As approved m a DRC Confirmatory Action Letter (CAL) dated September 22 2010 DUSA has committed to complete repair of these leaks by July 31 2012 and submittal of the required repair report by December i 2012 6 No leakage is noted each week of the Quarter m the LDS inspections for the New Decontamination Pad (NDP) Sedimentation Tank at the mill The report notes that repairs to observed cracks m the pad were completed although the cracks were less than 1/8 mch m width DRC authonzed use of the NDP on February 1 2011 7 LDS Momtonng Section 9 1 of the subject report states that during the quarter there were no failures of any LDS pumping or monitonng equipment not made operational within 24 hours of discovery However for reference by letter dated July 6 2011 DUSA informed DRC that the Cell 4A LDS electronic log has had a penod of non operation from June 3 2011 through June 27 2011 This will be addressed by DRC outside this report review under separate cover Cell 4A had a lotal collected leakage for the quarter of 3 160 gallons compared to allowable leakage of 23 955 gallons per day The allowable leakage rate for Cell 4B was 460 8 gallons per acre day (based on the table in the BAT O&M Plan) or 18 432 gallons per day for 40 acres with the maximum height of water in the cell at 5581 10 fmsl as measured May 31 2011 New Cell 4B had a total collected leakage and collected condensate volume of 310 433 gallons or 4 927 gallons per day for the 63 days the cell was m operation The leakage rale m Cell 4B was well below the maximum limit We have no further commenls on the subject volume Therefore our review of this item is hereby closed out If you have any questions regardmg the above please contact Mr Dave Rupp of my staff UTAH WATER QUALITY BOARD Rusty Lundberg ^""^^ Co Executive Secretary DAR dr Cc Philhp Goble DRC F \dnipp\Dl)SA\GWDPrel t d doc \DMT\2011 1 t Qtr F d g & CI o t Lett doc ^010 4th Qu-Repo tRefere ce DRC 2011 002214 m IT J] H» tr ru ir a CD CD a HI tr a a li0JSS?io#il :^S-ervice^ ||||i||j;|a|IV^ 0 FFICI AL USE Postage $ CerbfedFee RE 8/31/11 5/31/11 findings closeout / DR Jo Ann Tischler Denison Mines (USA) Corp 1050 Seventeenth ST STE 950 Denver Co 80265 .Soc:ilpvefse:fdr,lnstrLictiii"n's-J State of Utah GARYR HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Smith Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director MEMORANDUM Phil Goble and Rusty Lundberg Dave Rupp • ANDUM / / TO FROM DATE August 18 2011 SUBJECT DUSA Cell 4B Violation of Part ID 13 and DMT Plan DUSA Failed to Measure Weekly Water Level in Cell 4B References a DUSA Letter June 6 2011 Notice for Affirmative Defense DUSA did not measure the weekly wastewater level in Cell 4B from startup on February 1 2011 until May 31 2011 b Ground Water Discharge Permit Part ID 13(d) Maximum weekly wastewater level under no circumstance shall the freeboard be less than 3 feet m Cell 4B as measured from the top of the upper FML c DMT Plan Paragraph 3 1(d) Solution elevation measurements in Cell 4A 4B and Roberts Pond are to be taken by survey on a weekly basis The plan goes on to detail a prescnptive method of surveying by use of a survey rod d Ibid paragraph 3 1 (d)vii A(II) The Assistant will walk down the slope in the northwest comer of Cell 4B and place the survey rod at the liquid level e Cell 4A and Cell 4B BAT Monitonng Operations and Maintenance Plan paragraph 4 4 3 foot Minimum Vertical Freeboard Cnteria Said measurements shall be made to the nearest 0 1 foot f Interview with Mr Ryan Palmer of DUSA August 9 2011 g Geosyntec Drawing DUSA Cell 4B White Mesa Mill sheet 3 of 8 Cell 4B Base Grading Plan As Built Drawing submitted to DRC November 30 2011 DRC 2010 006190 h Copies of advertisements for long leveling rods and surveyors tape taken from Intemet advertisements of Survey Supply Inc and Perfect Measuring Tape Company 1 DUSA letter June 23 2011 Transmittal of Revised Standard Operating Procedures Regarding Movement Monitonng SOP [and Revised DMT Plan] DRC 2011 006671 Pomayed in reference (a) DUSA states it has had problems safely measuring the water level m Cell 4B as Until May 31 2011 the solution level in Cell 4B was too low to be measured safely either by survey instmment or by measuring tape along the sidewall (dike) It is impossible to argue against safety and we should not compromise anyone s safety to force any permit or plan requirements However it appears the main problem DUSA had is it did not have the nght equipment to do the work and it did not know where the measurements were supposed to be taken Apparently DUSA felt safety was compromised if the individual doing measurements had to be harnessed travel part way down the embankment measure using a 25 or so long hand tape to the water surface note 195 North 1950 West Salt Lake City UT Maihng Address PO Box 144850 SaltLakeCity UT 84114 4850 Telephone (801) 536 4250 Fax (801) 533-4097 TDD (801)536-4414 tv H' deq t h g Pr t d o 1009' cy 1 d p pe Page 2 the end point of that measurement travel up the embankment and finally measure from that end point to the top of the dike Per reference (a) DUSA s mam argument for affirmative defense for this omission centers on the safety of personnel trying to do measurements Some specific points follow below 1 Individuals familiar with using a long surveyor s steel tape know that a long steel surveyor s tape could easily be snaked down from the top of the embankment to the water level to make a measurement The depth of the water could then be determined using mathematics This depth may be made to nearest 0 1 foot as required per reference (e) 2 References (c) and (d) show that the water depth measurements in Cell 4B are prescnbed m the DMT Plan to be made by a survey rod (not by measurement tape) Per reference (f) DUSA has a survey rod of about 25 height This rod is too short to read the depth of the pond at shallow depths when the height of the survey level is above the height of the survey rod Per reference (a) paragraph 1 g At the time of this notice [June 6 2011] the solution level is still too low to be measured by a survey instmment Individuals familiar with using surveyor level rods know that these rods are available in longer lengths such as 35 and 45 foot standard lengths as shown m reference (h) By using a longer survey rod the depth of the water could be determined complying with the requirements of the existing DMT Plan per reference (d) It appears DUSA s case for affirmative defense is weak m that the decisions made by DUSA seem to have been made by individuals ignorant of surveying techniques and equipment available to eliminate these problems 3 Per reference (a) paragraph 1 e DUSA states the sidewall (dike) of Cell 4B constructed at 2 to 1 sideslope is too steep to allow a worker to be lowered by hamess safely until the solution level reached approximately 25 feet We note that the required point for measurement per reference (d) is the northwest comer of Cell 4B The northwest embankment of Cell 4B is at a 2 1 slope per reference (g) In accordance with the referenced drawing (g) m the northwest comer of Cell 4B the vertical elevation from the top of the cell liner to the cell bottom is 33 04 feet Due to the fact that the sideslope at the requued point of measurement is 3 1 DUSA s statement of too steep a slope for required measurements appears invalid Measurements apparently are being taken at the wrong location where the sideslope is steep at 2 1 rather than at the required location where the sideslope IS gentler at 3 1 4 Per reference (a) paragraph 1 f Denison began measunng solution level m Cell 4B on May 31 2011 by dropping a tape along the sidewall of the dike This is the first date on which the solutton level could safely be reach by a measunng tape At that time the solution level was 5581 10 feet lhat IS approximately 23 6 feet of solution That means over 19 feet of freeboard remained Analyzing these measurements reveals that the bottom of the cell at this location is 5557 50 feet and the top over 5600 10 feet for a total depth of over 42 6 feet As noted m the paragraph numbered 3 and 4 above the identifying elevation differences for the required point of measurement and the actual pomt of measurement are different as used by DUSA This shows that DUSA IS taking the measurements m the wrong location It should be noted that the location where the measurements are being taken has an elevation difference greater than the required point of measurement making their short survey rod useless at lower water depths Measurements apparently are Page 3 being taken at a location where the sideslope is steep at 2 1 rather than at the requued location where the sideslope is gentler at 3 1 5 Per reference (a) paragraph 4 c Denison will propose revisions to the DMT Plan to address the cell startup (low solution level) situation These revisions were sent via reference (i) The change to the DMT Plan proposed is as follows For a newly constructed cell when the cell is first placed into operation the solutton level IS typically zero feet above the FML or a minimal elevation above the FML due to natural precipitation For newly constmcted cells solution level measurement will not be required until the solution level is high enough that it can be reached safely by personnel with a measunng tape along the side of the FML Solutions levels will be measured by this method beginning when the solution level is high enough to be reached safely as determined by the RSO Surveying of solution levels will not be required until solution levels are high enough that they can effectively be measured by survey insttument from the appropnate surveying point This change to the DMT Plan is not appropnate or necessary as the nsk to safety is not high as DUSA mistakenly envisioned it and the required measurements can be made usmg a longer surveyor s rod as required by the DMT Plan DUSA recently built a walkway (for a future pump platform) m the southeast comer of Cell 4B The completion of the walkway may coincide with the date when DUSA began making water level measurements on May 31 2011 DUSA may wish to make changes to the DMT Plan to allow use of a surveyor s tape as described above in the paragraph numbered as 1 prior to constmction of an access walkway Once a walkway is complete the measurements could be done by survey level and rod methods This would help avert falling risk to employees from walking on an HDPE liner to perform survey measurements Recommendations Reference (a) states This exceedance was discovered on Tuesday May 31 2011 DUSA management may have not known the staff was not taking the measurements during the four month period February 1 2011 to May 31 2011 The staff mayn t have known this was a violation of the Permit and DMT Plan requuements However clearly DUSA staff violated the requirements by not taking measurements Also they did not take measurements due to mistakenly believing they had to be taken on a steep embankment Rebuttal to Affirmative Defense Reference G W P Part I G 3 c I It appears this failure was not intentional but was caused by the Permittee s negligence m failure to act on the conditions given See items following paragraphs numbered 2 3 and 4 above II The Permittee has not proposed an adequate plan for meeting Permit conditions See items following paragraph numbered 5 above Reference G W P Part IG 4 d III Where it is infeasible to reestablish DMT or BAT as defined m the Permit the Permittee may propose an alternative DMT or BAT for approval by the Executtve Secretary Recommend this alternative (revisions to the DMT Plan) not be approved as it appears to be based m enor See items following paragraphs numbered 1 through 5 above Depending on DRC enforcement history in this regard I suggest we issue an NOED or NOV END R f re ( ) diro gh ( ) ttached I V V. DENISO MINES Denison Mines (USA) Corp 105017th Street Suite 950 Denver CO 80265 USA Tel 3Q3 628 7798 Fax 303 389-4125 www denisonmines com Junes 2011 VIA E MAIL AND OVERNIGHT DELIVERY Rusty Lundberg Co-Executive Secretary Utah Water Quality Board Utah Department of Environmental Quality 195 North 1950 West PO Box 144810 Salt Lake City UT 84114 4810 Re state of Utah Ground Water Discharge Permit No UGW370004 White Mesa Uranium Mill - Notice Pursuant to Part I G 3 ofthe Permit and UAC R317 6 6 16(C) DearMr Lundberg Please take notice pursuant to Part I G 3 of the White Mesa Mill s (the Mill s ) State of Utah Groundvi/ater Discharge Permit No UGW370004 (the Permit) and Utah Administrative Code ( UAC ) R313 6 6 16(0) that Demson Mines (USA) Corp ( Denison ) as operator of the Mill and holder of the Permit failed to meet the Best Available technology (BAT) standards in Part ID 13d) of the Permit by not measuring weekly wastewater levels on newly approved Cell 4B until May 31 2011 as described in more detail below This exceedance was discovered on Tuesday May 31 2011 Initial notice of this failure to maintain BAT was given by telephone to Mr David Rupp of the Utah Department of Environmental Quality at 3 45pm on Wednesday June 1 2011 at 801 536 4023 (withm 24 hours ofthe discovery) 1 Facts and Background Information a) DRC provided authorization for use of Cell 4B on January 27 2011 b) Section 3 Id) of the Mills DMT Monitoring Plan requires that Solution elevation measurement in Cells 4A 4B and Roberts Pond are to be taken by survey on a weekly basis /v}d^4fcl^ "to Denison began transferring solutions to Cell 4B (by siphon) on February 1 2011 Until May 31 2011 the solution level in Cell 4B was too low to be measured safely either by survey instrument or by measunng tape along the sidewall (dike) / 1^ e) Unlike the other tailings ceils constructed at 3 to 1 sideslopes the sidewall (dike) of Cell 4B constructed at 2 to 1 sideslope is too steep to allow a worker to be lowered by harness safely until the solutton level reached approximately 25 feet ^7 N \Notices\06 06 11 Notice to RLundberg Cell 48 signed doc Letter to Mr Rusty Lundberg June 6 2011 Page 2 ^ a f) Demson began measuring solution level in Cell 4B on May 31 2011 by dropping a tape along the sidewall of the dike This was the first date on which the solution level could safely be reached by J. I measunng tape At that time the solution level was 5581 10 feet that is approximately 23 6/feet of tJ solution That means over 19 feet of freeboard remaine^^* 5* ^^Lp<vtf*f^ *^ , g) At the time of this notice the solution level is still too low to be measured by survey instrument h) Denison notified UDEQ by phone call at 3 45pm on Wednesday June 1 2011 that the Cell 4B liquid level could be reached by tape from the sidewall that the weekly measurements by tape had begun and that the liquid level still could not be measured by survey instrument i) The Mill has been running on a 10 day on and 4 day off operating cycle 2 Action Taken Upon receipt of the initial survey results the Mill s Environmental Coordmator notified the Mill Manager at 3 45pm that day The following plan of action was immediately put into place in accordance with section 5 1 ofthe Mill s Contingency Plan UMA t'^^ly a) The Cell 4B solution level was measured thejirst dav that the solution could be reached bv tajje A t^i^ ^along the side wall I^MI^* b) Mill personnel have been instructed to continue solution level measurements by tape until such time y Jr as the solution level is high enough to be read by survey instrument c) Verbal notification was given to the DRC at 3 45pm on June 1 2011 withm 24 hours This verbal notification was followed by this written notification within five days of discovp 3 Root Cause The root cause analysis is as follows \ ^llM^ address measurement of cell solution level dunng cell startup conditions that cl L solution level is too low to be safely measured by survey instrument and too low to be safely y V reached by suspending ¥ worker by cable to take a tape measurement in circumstances when the / ^JA solution level is nowhere near the freeboard limit for Cell 4B \^ ^ X Denison made the judgment not to risk the safety of a worker by requiring them to be suspended ^ \ along the steep bank above the Cell 4B solutions in order to collect an environmental measurement 4 Actions That Will be Taken to Prevent a Reoccurrence of this Incident The followmg actions will be taken to prevent a reoccurrence of this incident a) The Cell 4B solution has reached a level that can be accessed safely by measunng tape DENISO MINES Letter to Mr Rusty Lundberg June 6 2011 Page 3 b) Measurements by tape have commenced and will continue until the solutton level can be measured by survey instrument Q c) Demson will propose revisions to the DMT Plan to address the cell startup (low solution level) situation^ 5 Affirmative Defense Denison believes that the affimnative defense in Part I G 3 c) of the Permit should be applicable to this incident for the following reasons ^ a) Notification „ By virtue of the initial oral notification given to UDEQ at 3 45 PM on Wednesday June 1 2011 (within 24 vW hours of the discovery) and this written notice Denison has submitted notification according to UAC R317 6 / 6 13 b) Failure was not Intentional or Caused by the Permittee s Negligence >^ i^ ^ , The failure to survey the water level in Cell 4B was not caused by Denison s negligence either m action or in •^^•'^ ^ A^\/ failure to act The Mill made a judgment not to nsk the safetv of an employee m order to take an yo*^ \^'^ t^*'^ eriv'^'onmental measuremenfTparticuiariy when the solution level in Cell 4B is obviously lower than the ^ ^ pe» it* ^ Treeboard limit I he DMT Plan does not address the low solution level situation adequately y^^'' U ^ c) The Permittee has Taken Adequate Measures to Meet Permit Conditions Denison has measured the Cell 4B solution level as soon as a tape measurement could safely be performed-^ ^O^t Based on the solution measurement taken on May 31 2011 the freeboard level was significantly lower (met) the requirement for the entire penod from cell startup on February 1 2011 through May 31 2011 All other required measurements m Part 1D 13 have been made and recorded since celt startup Based on the solution level measurement made on May 31 2011 and the calculated action leakage rates from table IB ofthe BAT O&M Plan Cell 4B has not exceeded the maximum allowable average daily leakage rate during the penod d) Demson has taken adequate measures to meet Permit conditions in a timely manner yfaf*' "^^^ provisions of the Permit were implemented immediately UDEQ was notified Within 24 hours of discovery ^ J ^ of the solution measurement information Measurements of cell solution level bejj^an as soon as c^i>^ yM^^ y measurement could safely be achieved _ . fVJ*'^^ e) The Provisions of UCA 19 5 107 Have Not Been Violated vl ^0 The provisions of Utah Code 19 5 107 have not been violated There has been no discharge of a pollutant ^ I waters of the state Denison has not caused pollution which constitutes a menace to public health and ^'^ , «^ welfare or is harmful to wildlife fish or aquatic life or impairs domestic agricultural industrial recreational or / * y^'^^ ''^"sf'cial uses of water nor has Denison placed or caused to be placed any waste in a location where I V^* 1 Ibere is probable cause to believe it will cause pollution 'h' ^t\^ ,vi*i ^b'^ r'^ There was no discharge of solutions from the Mill s tailings impoundments DENISoJO< MINES Letter to Mr Rusty Lundberg June 6 2011 Page 4 Please contact the undersigned if you have an^^ questions or require any further infonnation Yours very truly / ^ / ) - > i - ^ J DENISON MINES (USA) CORP ' Jo Ann Tischler Director Compliance and Permitting cc ^ Rich Bartlett David C Frydenlund Harold R Roberts David E Turk Central files 0 ''( K J DENISO MINES Part ID Pennit No UGW370004 fabnc installed within it at its midsection set atop a cushion geotextile placed directly over the pnmary FML in a 4 foot deep trapezoidal channel A 100-foot wide 60 mil HDPE membrane splash pad will be installed beneath the emergency spillway No other spillway or overflow stmcture will be constmcted at Cell 4B All stormwater mnoff and tailings wastewaters not retained in Cells 2 and 3 and 4A will be managed and contamed in Cell 4B including the Probable Maximum Precipitation and flood event 13 BAT Performance Standards for Tailings Cell 4B - the Permittee shall operate and maintain Tailings Cell 4B so as to prevent release of wastewater to groundwater and the environment in accordance with the cunently approved Cell 4B BAT Momtonng Operations and Maintenance Plan Any failure to achieve or maintain the required BAT performance standards shall constitute a violation of the Permit and shall be reported to the Executive Secretary in accordance with Part IG 3 Perfonnance standards for Tailmgs Cell 4B shall include the following a) Leak Detection System (LDS) Maximum Allowable Daily Head the fluid head m the LDS shall not exceed 1 foot above the lowest point on the lower flexible membrane liner on the cell floor At all times the Permittee shall operate the LDS pump and transducer m a honzontal position at the lowest pomt of the LDS sump floor b) LDS Maximum Allowable Daily Leak Rate - shall not exceed 26 145 gallons/day c) Slimes Dram Annual Average Recovery Head Cntena after the Permittee initiates pumping conditions m the slimes dram layer m Cell 4B the Permittee will provide 1) continuous declining fluid heads in the slimes drain layer in a manner equivalent to the requirements found m Part ID 3(b) and 2) a maximum head of 1 0 feet in the tailmgs (as measured from the lowesLpoint nfjmngr flexible membrane liner) in 5 5 years or less d) Maximum Weekly Wastewater Level - under no circumstance shall the freeboard be less then 3 feet m Cell 4B as measured from the top of the upper FML men 5 leet m cell 413 as measured irom the top oi the upper rML J 14 BAT>RrfnrnTanf^ fm MiKiCg^nprnntflminafiniTPaA^e Perrmttee-tAiA]] li[)Sf^e and mamtain the New Decontamination Pad (NDP) to prevent release of wastewater to groundwater and the environment in accordance with the currently approved DMT Monitonng Plan Any failure to achieve or maintain the required BAT performance standards shall constitute a violation of the Permit and shall be reported to the Executive Secretary m accordance with Part IG 3 Performance standards for the NDP shall include but are not limited to the following a) NDP LDS Access Pipes - the water level shall not exceed 0 10 foot above the concrete floor in arty LDS access pipe at any time Compliance will be defined as a depth to standing water present in any of the LDS access pipes of more than or equal to 6 2 feet as measured from the water measunng point (top of access pipe) b) Soil and debns will be removed from the wash pad of the NDP m accordance with the cunently approved DMT Monitonng Plan Cracks in the wash pad greater than 1/8 inch (width) will be repaired within five working days of discovery 19 Part ID Pemut No UGW370004 4) Geosynthetic Clay Lmer consisting of a manufactured geosynthetic clay liner (GCL) composed of 0 2 inch of low permeability bentonite clay centered and stitched between two layers of geotextile Pnor to disposal of any wastewater in Cell 4B the Permittee shall demonstrate that the GCL has achieved a moisture content of at least 50% by weight e) Shmes Dram Collection System - including a two part system of stnp drains and perforated collection pipes both installed immediately above the pnmary FML as follows 1) Honzontal Stnp Dram System is installed in a hemngbone pattem across the floor of Cell 4B that dram to a backbone of perforated collection pipes These stnp drams are made of a prefabncated two part geo composite drain matenal (solid polymer drainage stnp) core sunounded by an envelope of non woven geotextile filter fabnc The stnp drains are placed immediately over the pnmary FML on 50- foot centers where they conduct fluids downgradient in a southwesterly direction to a physical and hydraulic connection to the perforated shmes dram collection pipe A senes of continuous sand bags filled with filter sand cover the stnp drams The sand bags are composed of a woven polyester fabnc filled with well graded filter sand to protect the drainage system from plugging 2) Honzontal Slimes Dram Collection Pipe System includes a backbone piping system of 4 inch ID Schedule 40 perforated PVC slimes dram collection (SDC) pipe found at the downgradient end of the stnp dram lines This pipe is m tum overlain by a berm of gravel that runs the entire diagonal length of the cell sunounded by a geotextile fabnc cushion in immediate contact with the pnmary FML In tum the gravel is overlam by a layer of non woven geotextile to serve as an additional filter matenal This perforated collection pipe serves as the backbone to the shmes dram system and mns from the far northwest comer downhill to the far southeast comer of Cell 4B where it joins the slimes drain access pipe 3) Shmes Dram Access Pipe consisting of an 18-inch ID Schedule 40 PVC pipe placed down the mside slope of Cell 4B at the southeast comer above the pnmary FML Said pipe then merges with another honzontal pipe of equivalent diameter and matenal where it is enveloped by gravel and woven geotextile that serves as a cushion to protect the pnmary FML A reducer connects the horizontal 18 inch pipe with the 4 inch SDC pipe At some future time a pump will be set in this 18-inch pipe and used to remove taihngs wastewaters for purposes of de-watenng the taihngs cell f) Cell 4B North and East Dike Splash Pads Nine 20-foot wide splash pads will be constmcted on the north and east dikes to protect the pnmary FML from abrasion and scounng by tailings slurry These pads will consist of an extra layer of 60 mil HDPE membrane that will be installed m the anchor trench and placed down the inside slope of Cell 4B from the top of the dike under the inlet pipe and down the mside slope to a point at least 5 feet onto the Cell 4B floor beyond the toe of the slope g) Cell 4B Emergency Spillway a concrete lined spillway will be constmcted near the southeastem comer of the east dike to allow emergency mnoff from Cell 4A into Cell 4B This spillway will be limited to a 6 inch reinforced concrete slab with a welded wire 18 White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 1 of 49 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN 1 INTRODUCTION This Tailings Management System and Discharge Minimization Technology Monitonng Plan (the Plan ) for the White Mesa Mill (the Mill ) provides procedures for monitonng of the tailings cell system as required under State of Utah Radioactive Matenals License No UT1900479 (the Radioactive Matenals License ) as well as procedures for operating and maintenance of monitonng equipment and reporting procedures that are adequate to demonstrate DMT compliance under State of Utah Ground Water Discharge Permit No 370004 for the Mill (the GWDP) This Plan is designed as a systematic program for constant surveillance and documentation of the mtegnty of the tailings impoundment system includmg dike stability liner integnty and transport systems as well as monitonng of water levels m Roberts Pond and feedstock storage areas at the Mill The Plan requires daily weekly quarterly monthly and annual inspections and evaluations and monthly reporting to Mill management 2 DAILY TAILINGS INSPECTIONS The followmg daily tailings inspections shall be performed 2 1 Daily Comprehensive Tailmgs Inspection On a daily basis including weekends all areas connected with the four tailmgs cells will be inspected Observations will be made of the cunent condition of each cell noting any corrective action that needs to be taken The Environmental or Radiation Technician is responsible for performing the daily tailings inspections The Radiation Safety Officer may designate other individuals with training as descnbed in Section 2 4 below to perfonn the daily tailmgs inspection Observations made by the inspector will be recorded on the Daily Inspection Data form (a copy of which IS attached in Appendix A) The Daily Inspection Data form contains an inspection checklist which includes a tailings cells map and spaces to record observations especially those of immediate F \W P\Dt IS on ot Ridiati in C ontn I\Dcnison Mine . Dl S \\(_\VDl Rclat d ItcmsVDMT & BAT Docs\DMT I hn Histor \Appio\(-d DMT Phn Nc\ 010 R Hi lean docN \( ell ^B^Januai> "^Ol I SuhmiUjii. and Revision-, for Cell 4B\DMT Plan 01 10 i i\Tjjlin"t. M"nt Svi.tem and DMT Mon Plan No^ "^010 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 2 of 49 concern and those requinng corrective action The inspector will place a check by all inspection Items that appear to be operating properly Those items where conditions of potential concem are observed should be marked with an X A note should accompany the X specifying what the concem is and what corrective measures will resolve the problem This observation of concem should be noted on the form until the problem has been remedied The date that corrective action was taken should be noted as well Areas to be inspected include the following Cell 1 2 3 4Aand4B Dikes 1 2 3 4A S 4A W 4B S and 4B W wind movement of tailings effectiveness of dust minimization methods spray evaporation Cell 2 spillway Cell 3 spillway Cell 3 4A and 4B liquid pools and associated liquid retum equipment cell leak detection systems and the wildlife ponds Operational features of the tailmgs area are checked for conditions of potential concem The following Items require visual inspection dunng the daily tailings inspection a) Tailings slurry and SX raffinate transport systems from the Mill to the active disposal cell(s) and pool retum pipelme and pumps Daily inspections of the tailmgs lines are required to be performed when the Mill IS operating The lines to be inspected include the tailmgs slurry lines from CCD to the active tailmgs cell SX raffinate lines that can discharge into Cell 1 Cell 3 Cell 4A or Cell 4B the pond retum Ime from the tailings area to the Mill and lines transporting pond solutions from one cell to another b) Cell 1 c) Cell 2 d) Cell 3 e) Cell 4A f) Cell 4B g) Dike stmctures including dikes 1 2 3 4A S 4A W 4B S and 4B W h) The Cell 2 spillway Cell 3 spillway Cell 3 Cell 4A and Cell 4B liquid pools and associated liquid retum equipment i) Presence of wildlife and/or domesticated animals m the tailings area including waterfowl and burrowing animal habitations F\WP\Di ision of Ridiati )n C ontrcMXnison Mmes, Dl SA\C WPP Rclat d ItcmsXDMT & BAT Docs\DMT 1 hn Histor \Aopioved DMT Phn Nov 2010 Rv 11 1 lean UocN \(, eil dBVJanuaP, 2011 Suhmittali. .ind Rtni'.mn., for Coll IB\DMT Plan 01 10 1 IMuilm-c. Mgnt S'ibtom and DMT Mon Plan Nov ^OlOR'i 11 1 Redline dot. White Mesa Mill - Standard OperaUng Procedures Ol/l 1 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 3 of 49 j) Spray evaporation pumps and lines k) Wind movement of tailings and dust minimization Wind movement of tailings will be evaluated for conditions which may require initiation of preventative dust minimization measures for cells containing tailings sand Dunng tailings inspection general surface conditions will be evaluated for the following 1) areas of failings subject to blowing and/or wind movement 2) liquid pool size 3) areas not subject to blowing and/or wind movement expressed as a percentage of the total cell area The evaluations will be reviewed on a weekly basis or more frequently if warranted and will be used to direct dust minimization activities 1) Observation of flow and operational status of the dust control/spray evaporation system(s) m) Observations of any abnormal vanations in tailings pond elevations in Cells 1 3 4A and4B n) Locations of slurry and SX discharge withm the active cells Slurry and SX discharge points need to be indicated on the tailings cells map included in the Daily Inspection Data form o) An estimate of flow for active tailings slurry and SX line(s) p) An estimate of flow m the solution retum line(s) q) Daily measurements m the leak detection system (LDS) sumps of the tailings cells will be made when warranted by changes m the solution level of the respective leak detection system The tngger for further action when evaluating the measurements in the Cell 1 and Cell 3 leak detection systems is a gam of more than 12 inches in 24 hours The solution level in Cell 4A or 4B leak detection system is not allowed to be more than 1 0 foot above the lowest point on the bottom flexible membrane liner (Cell 4A FML elevation is 5555 14 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5556 14 feet amsl For Cell 4B the FML elevation is 5557 50 amsl and with the addition of the 1 0 foot of solution the solution elevation is 5558 50 feet amsl) If any of these observations are made the Mill Manager should be notified immediately and the leak detection system pump started In addition the requirement to notify the Executive Secretary in accordance with Parts ID 6 and IG 3 of the Groundwater Discharge Permit must F\WI Dl IS -)n ot RidiJUon ( ontrolMXnison Mines. Dl SWC WPP Rclat d ltems\DMT & BAT Docs\DMT 1 Ian Histor\\ADpro ed DMT Phn No\20lOR 11 1 lean docWCi'lUBVl.inuar',''Oil Suhmittal!. and ReviMons for Cell IB\DMTliun01 10 11\foibn"', Mgnt SNutom and DM1 Mon Plan Nov ''OiO R\ 11 I Redlmo doc White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 4 of 49 be adhered to when the solution level tngger for Cell 4A or 4B has been exceeded Whenever the leak detection system pump is operating and the flow meter totalizer is recording a notation of the date and the time will be recorded on the Daily Inspection Data form This data will be used in accordance with License Condition 11 3 B through 11 3 E of the Mill s Radioactive Matenals License to determine whether or not the flow rate into the leak detection system is in excess of the License Conditions r) An estimate of the percentage of the tailmgs beach surface area and solution pool area is made mcluding estimates of solutions cover areas and tailings sands for Cells 3 4Aand4B Items (a) (m) (n) and (o) are to be done only when the Mill is operating When the Mill is down these Items cannot be performed 2 2 Dailv Operations Inspection Dunng Mill operation the Shift Foreman or other person with the training specified m Section 2 4 below designated by the Radiation Safety Officer will perform an inspection of the failings line and tailings area at least once per shift paying close attention for potential leaks and to the discharges from the pipelines Observations by the Inspector will be recorded on the appropnate line on the Operating Foreman s Daily Inspection form 2 3 Daily Operations Patrol In addition to the inspections descnbed in Sections 2 1 and 2 2 above a Mill employee will patrol the tailings area at least twice per shift dunng Mill operations to ensure that there are no obvioussafety or operational issues such as leaking pipes or unusual wildlife activity or incidences No record of these patrols need be made but the inspectors will notify the Radiation Safety Officer and/or Mill management m the event that dunng their inspection they discover that an abnormal condition or failings emergency has occurred 2 4 Training All individuals performing inspections descnbed in Sections 2 1 and 2 2 above must have Tailings Management System training as set out m the Tailmgs Inspection Training procedure which is attached as Appendix B This training will include a training pack explaining the procedure for performing the inspection and addressing inspection items to be observed In addition each individual after reviewing the training pack will sign a certification form indicating that training r\WP\Di isnn ot Radiau )n ( intrclMXnison Mines. Dl SWC WDl Rclat d ltemb\DMT& BAT Docs\DMT 1 Ian HistorvUpp o cd DMT Phn Ncv ^010 Rill lean docN \C oil ^BVIanuarv 2011 Snhmiii.ilf. .md R.>vi..inn.. fnr Tnll m\nMT Pl.in 01 101 i\Tailin-". M.^nt Sv.tem and PMT Mon Plan Nov ^010 Rv 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 I Page 5 of 49 has been received relative to his/her duties as an inspector 2 5 Tailmgs Emergencies Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if dunng their inspection they discover that an abnormal condition exists or an event has occuned that could cause a tailings emergency Until relieved by the Environmental or Radiation Technician or Radiation Safety Officer inspectors will have the authonty to direct resources dunng tailmgs emergencies Any major catastrophic events or conditions pertaining to the failings area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division ofDam Safety (801 538 7200) 3 WEEKLY TAILINGS AND DMT INSPECTION 3 1 Weekly Tailings Inspections Weekly tailings inspections are to be conducted by the Radiation Safety Department and include the following a) Leak Detection Systems Each tailmgs cell s leak detection system shall be checked weekly to determine whether it is wet or dry If marked wet the liquid levels need to be measured and reported In Cell 1 and Cell 3 the leak detection system is measured by use of a pipe that is removed from the system which will indicate the presence of solutions in the LDS system The Cell 4A and 4B leak detection systems are monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector The pressure transducer is calibrated for fluid with a specific gravity of 1 0 The water levels are measured every hour and the information is stored for later retneval The water levels are measured to the nearest 0 10 mch The data collector is currently programmed to store 7 days of water level mformation The number of days of stored data can be increased beyond 7 days if needed The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill s environmental monitonng data base and into the files for weekly inspection reports of the failings cell leak detection systems F\Wl\Pi ision olRiduunnC ontrolMXnison Mines. Dl SA\C WPI Rclat d ltcms\PMT & BAT Dxs\PMTPhn Histor Worn cd DMT Phn Nc\ 010 R 111 lean docN \C ell ^BVIanuarv "iQl I Submittal!, and RoviMon', for Cell IB\DMr Plan 01 10 1 t\1aihn"o Munt Sy.tem and DM1 Mon I Ian Nov "^010 Rv 11 1 Redline dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 I 01/11 Revision Denisonll 1 Page 6 of 49 If sufficient fluid is present m the leak detection system of any cell the fluid shall be pumped from the LDS to the extent reasonably possible and record the volume of fluid recovered Any fluid pumped from an LDS shall be retumed to a disposal cell If fluid IS pumped from an LDS the flow rate shall be calculated by dividing the recorded volume of fluid recovered by the elapsed time since fluid was last pumped or increases in the LDS fluid levels were recorded whichever is the more recent This calculation shall be documented as part of the weekly inspection Upon the initial pumping of fluid from an LDS a fluid sample shall be collected and analyzed in accordance with paragraph 11 3 C of the Radioactive Matenals License For Cell 4A and 4B under no circumstance shall fluid head m the leak detection system sump exceed a 1 foot level above the lowest point m the lower flexible membrane liner To determine the Maximum Allowable Daily LDS Flow Rates m the Cell 4A and 4B leak detection systems the total volume of all fluids pumped from the LDS on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1A and IB (for Cells 4A and 4B respectively) in Appendix E to detemune the maximum daily allowable LDS flow volume for varying head conditions in Cell 4Aand4B b) Slimes Drain Water Level Monitonng (i) Cell 3 IS nearly full and will commence closure when filled Cell 2 is partially reclaimed with the surface covered by platform fill Each cell has a slimes dram system which aids in dewatenng the slimes and sands placed in the cell (ll) Cell 2 has a pump placed mside of the shmes drain access pipe at the bottom of the shmes drain As taken from actual measurements the bottom of the shmes dram is 38 feet below a water level measunng point at the centerhne of the shmes dram access pipe at the ground surface level This means that the bottom of the shmes dram pool and the location of the pump are one foot above the lowest point of the F\WP\Pi IS on ot Ridiauon ( ontrolMXnison Mine . Pl S WC WPP Rclat d ltcms\PMT &. BAT Docs\PMT 1 Ian Histor\\App o cd DMT Phn Ntv DIOR 11 I lean docWrulUBVlaniiarv 201 1 Siitimitl,il..;^nriR,iviMnn.. fnr r>>ll IR\nM F F l.in 01 10 n\Tnilin'". Ment Sv.lftm ami PMT Mon Plan Nov ^010 Rv 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 7 of 49 FML m Cell 2 which based on constmction reports is at a depth of 39 feet below the water level measunng point on the slimes dram access pipe for Cell 2 (iii) The shmes dram pump m Cell 2 is activated and deactivated by a float mechanism and water level probe system When the water level reaches the level of the float mechanism the pump is activated Pumping then occurs until the water level reaches the lower probe which tums the pump off The lower probe is located one foot above the bottom of the slimes dram standpipe and the float valve is located at five feet above the bottom of the slimes drain standpipe The average wastewater head m the Cell 2 shmes drain is therefore less than 5 feet and is below the phreatic surface of tailings Cell 2 about 20 feet below the water level measunng point on the slimes dram access pipe As a result there is a continuous flow of wastewater from Cell 2 into the slimes dram collection system Mill management considers that the average allowable wastewater head m the Cell 2 shmes drain resulting from pumping m this manner is satisfactory and is as low as reasonably achievable (iv) The Cell 2 slimes drain pump is checked weekly to observe that it is operating and that the water level probe and float mechanism are working properly which is noted on the Weekly Tailings Inspection Form If at any time the pump is observed to be not working properly it will be fixed or replaced withm 15 days (v) Depth to wastewater in the Cell 2 shmes dram access pipe shall be monitored and recorded weekly to determine maximum and nunimum fluid head before and after a pumping cycle respectively All head measurements must be made from the same measunng point (the notch at the north side of the access pipe) and made to the nearest 0 01 foot The results will be recorded as depth m pipe measurements on the Weekly Tailings Inspection Form (vi) On a monthly basis the slimes dram pump will be tumed off and the wastewater in the shmes dram access pipe will be allowed to stabilize for at least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level of the wastewater will be measured and recorded as a depth in pipe measurement on the Monthly Inspection Data form by measunng the depth to water below the water level measunng point on the shmes dram access pipe (vn) No process liquids shall be allowed to be discharged into Cell 2 (vill) If at any time the most recent average annual head m the Cell 2 slimes dram is found to have increased above the average head for the previous calendar year the Licensee will comply with the requirements of Part IG 3 of the GWDP including the requirement to provide notification to the Executive Secretary orally withm 24 hours followed by wntten notification (ix)Because Cell 3 and Cell 4A are currently active no pumping from the Cell 3 or Cell 4A shmes dram is authonzed No pumping from the Cell 4B shmes dram will be authonzed once it is put into service and while it is active Pnor to initiation of tailmgs dewatenng operations for Cell 3 Cell 4A or Cell 4B a similar procedure will be developed for ensunng that average head elevations in the Cell 3 and Cell 4A F \W P\Dnision M Ridiation ( ontn IMXnison Mines. Pl SAXCAVPI Rclat i ltcms\PMT & BAT Docs\DMT 1 i m Hislorv\Appio ed DMT Phn Nov 2010 Rv H t ckan doc\ \Cell ^BManuarv 2011 Suhmitial'. and ReviMon', for Cell IBNDMF Plan 0110 1 l\Tailnv^!, M^nt System and PMT Mon Plan Nov ^010 RH 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 8 of 49 slimes drains are kept as low as reasonably achievable and that the Cell 3 Cell 4A and Cell 4 shmes drains are inspected and the results reported in accordance with the requirements of the permit c) Wind Movement of Tailings An evaluation of wind movement of tailmgs or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 14A and 4B and Roberts Pond are to be taken by survey on a weekly basis and the beach area in Cell 4A and 4B with the maximum elevation is to be taken by survey on a monthly basis as follows f (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (ll) The survey will be performed using a survey instmment (the Survey Instmment ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a survey rod (the Survey Rod ) havmg a visible scale in 0 01 foot increments (iii) The reference Points (the Reference Points ) for Cells 14A and 4B and Roberts Pond are known points established by professional survey For Cell 1 and Roberts Pond the Reference Point is a wooden stake with a metal disk on it located on the southeast comer of Cell 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 3 Cell 4A and Cell 4B the Reference Point is a piece of metal rebar located on the south dike of Cell 3 The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A and 4B) is at 5 607 83 FMSL The Surveyor will set up the Survey Instmment in a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this is typically on the road on the Cell 1 south dike between Cell 1 and Roberts Pond approximately 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4A and Cell 4B this is typically on the road on the Cell 3 dike approximately 100 feet east of the Cell 3 Reference Point (iv) Once in location the Surveyor will ensure that the Survey Instmment is level by centenng the bubble in the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor has established a level reading F \W P\Pi IS )n ol Ridiation ( ontrolVPenison Mines. Pl S W( WPP Rtlat d ltems\PMT & BAT Docs\DMT Plan Histor \APDIO cd DMT Plm Ncv 010 R 111 lean do N \C ell ^BVJanuarv 201 I SiihmillaK and R^-viMon.. fnr ( <>n IRxPMT Plan 01 101 l\Tailin'T-. M-tnl Sv.lom and PMT Mon I Ian Nov ''OlO Rv 11 I Redlmo dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 Ol/l 1 Revision Denisonll 1 Page 9 of 49 (vi) The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instmment is reading above the Reference Point (vn) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the mam solution pond m the Cell 1 Cell 4A Cell 4B or Roberts Pond or the area of the beach m Cell 4A or Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistently use the same locations are as follows A Pond Surface Measurements I Cell 4A The Assistant will walk down the slope in the northeast comer of Cell 4A and place the Survey Rod at the liquid level n Cell 4B The Assistant will walk down the slope in the northwest comer of Cell 4B and place the Survey Rod at the liquid level m Cell 1 A mark has been painted on the north side of the ramp going to the pump platform in Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and Roberts Pond A mark has been painted on the railing of the pump stand m Roberts Pond The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface Based on the foregoing methods the approximate coordinate locations for the measunng points for Roberts Pond and the Cells are Northing Easting Roberts Pond 323 041 2 579 697 Cell 1 322 196 2 579 277 Cell 4A 320 300 2 579 360 Cell 4B 320 690 2 576 200 F \W P\Pi ISI in ot K-idi \i on C introlXDenison Mines. PL SA\C W Pt Relat d Itcms\DMT & B AT D xs\PMT Phn HistorvNApDiovcd DMT Phn Nov 2010 R III kan doc\ \Cell 4B\Januarv 2011 Suhmittai!, and ReviMon-. for Cell IBM)MT Plan 01 101 t\Tailin"Q Mgnt System and PMT Mon 1 Ian Nov ^010 Rs 11 1 Redlme doc White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 10 of 49 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells B Cell 4B Beach Elevation The Assistant will place the Survey Rod at the point on the beach area of Cell 4B that has the highest elevation If it is not clear which area of the beach has the highest elevation then multiple points on the beach area will be surveyed until the Surveyor is satisfied that the point on the Cell 4B beach area with the highest elevation has been surveyed If it is clear that all points on the Cell 4B beach area are below 5 593 FMSL then the Surveyor may rely on one survey point (vill) The Assistant will hold the Survey Rod vertically with one end of the Survey Rod just touching the pond surface The Assistant will ensure that the Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor has established a level reading (ix)The Surveyor will focus the cross hairs of the Survey Instmment on the scale on the Survey Rod and record the number (the Pond Surface Reading ) which represents the number of feet the Survey Instmment is reading above the pond surface level The Surveyor will calculate the elevation of the pond surface as FSML by adding the Reference Point Reading for the Cell or Roberts Pond as the case may be to the Reference Point Elevation for the Cell or Roberts Pond and subtracting the Pond Surface Reading for the Cell or Roberts Pond and will record the number accurate to 0 01 feet e) Decontamination Pads (i) New Decontamination Pad The New Decontamination Pad is located in the southeast comer of the ore pad near the Mill s scale house A In order to ensure that the pnmary containment of the New Decontamination Pad water collection system has not been compromised and to provide an inspection capability to detect leakage from the pnmary containment vertical inspection portals have been installed between the pnmary and secondary containments B These portals will be visually observed on a weekly basis as a means of detecting any leakage from the pnmary containment into the void F\WP\Pi isnn it R idiation C onirol\Dcnison Mines. Pl SA\C WPP Rclat d ItemsMIMT BAT Dix:s\PMT Plan Histor\\ApDiovcd PMT Plan Nov '>0I0 R 11! lean docN \Cell IBMonuarv 2011 Submittal!, and Rovii.inn-, for C oil IB\DMT I Ian 01 10 1 t\Tailin"!, Mgnt System and PMT Mon Plan Nov ^010 Rv 11 1 Rodlino dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 11 of 49 between the pnmary and secondary containment The depth to water m each portal will be measured weekly by physically measunng the depth to water with an electrical sounding tape/device All measurements must be made from the same measunng point and be made to the nearest 0 01 foot C These inspections will be recorded on the Weekly Tailings Inspection form D The water level shall not exceed 0 10 foot above the concrete floor m any standpipe at any time This will be determined by subtracting the weekly depth to water measurement from the distance from the measunng point in the standpipe to the dry concrete floor The depth to water from the top (elevation 5589 8 feet amsl) of any of the three (3) observation ports to the standing water shall be no less than 6 2 feet Depths less than 6 2 feet shall indicate more that 0 1 foot of standing water above the concrete floor (elev 5583 5 feet amsl) and shall indicate a leak in the pnmary containment E Any observation of fluid between the pnmary and secondary containments will be reported to the Radiation Safety Officer (RSO) F In addition to inspection of the water levels m the standpipes the New Decontamination Pad including the concrete integnty of the exposed surfaces of the pad will be inspected on a weekly basis Any soil and debns will be removed from the New Decontamination Pad immediately pnor to inspection of the concrete wash pad for cracking Observations will be made of the cunent condition of the New Decontamination Pad Any abnormalities relating to the pad and any damage to the concrete wash surface of the pad will be noted on the Weekly Tailings Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired (ll) Existing Decontamination Pad The Existing Decontamination Pad is located between the northwest comer of the Mill s maintenance shop and the ore feeding gnzzly A The Existing Decontamination Pad will be inspected on a weekly r\WP\Pivisnn ol Rtdituon C ontrol\Denison Mines. Pl SA\C WPP Relai d ItcmsMIMT jiL BAT Pics\PMT 1 Ian HistorvUppio cd PMT Phn Ncv ''010 Rv 11 i lean docN \C ell IBVIanuarv 2011 Suhmittai'. and RoviMon-. for C ell IHvPMT I hn 01 10 1 IXTailni"!, M^^nt Sv!.tom and PM I Mon 1 hn Nov ^010 Rv 11 1 Redlme dot White Mesa Mill - Standard OperaUng Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 I Page 12 of 49 basis Any soil and debns will be removed from the Existing Decontammation Pad immediately pnor to inspection ofthe concrete wash pad for cracking Observations will be made of the cunent condition of the Existing Decontamination Pad including the concrete integnty of the exposed surfaces of the pad Any abnormalities relating to the pad and any damage or cracks on the concrete wash surface of the pad will be noted on the Weekly Tailmgs Inspection form If there are any cracks greater than 1/8 inch separation (width) the RSO must be contacted The RSO will have the responsibility to cease activities and have the cracks repaired f) Summary In addition the weekly inspection should summanze all activities conceming the tailings area for that particular week Results of the weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection form An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A 3 2 Weeklv Inspection of Solution Levels in Roberts Pond On a weekly basis solution elevations are taken on Roberts Pond in accordance with the procedures set out in Section 3 1 d) above The Weekly solution level m Roberts Pond is recorded on the Weekly Tailings and DMT Inspection form Based on histoncal observations the FML at the Pond Surface Reading area for Roberts Pond is approximately six inches above the lowest point on the pond s FML If the pond solution elevation at the Pond Surface Reading area is at or below the FML for that area the pond will be recorded as being dry 3 3 Weeklv Feedstock Storage Area Inspections Weekly feedstock storage area inspections will be performed by the Radiation Safety Department to confirm that a) the bulk feedstock matenals are stored and maintained within the defined area descnbed m the GWDP as indicated on the map attached hereto as Appendix D b) a 4 ft buffer is maintained at the penphery of the storage area which is absent bulk matenal in order to assure that the matenals do not encroach upon the boundary of the storage area and c) all altemate feedstock located outside the defined Feedstock Area are maintained withm water tight containers FWVRPi isnn >1 Ridijtnn ( ontrclUXn son Mines. Pl SWC WPP Rclat d Itc msM')MT (S. BAT Dx:sM>MT I hn Histor\\Appioved DMT Phn Ncn "^010 R HI lean docN VCell ^BVJanuarv 2011 Suhmiital!. .ind R^'viMon., for C nil IB\PMT Plan 01 10 1 l\Tailin"!. Mgnt Sv!.tem and PM F Mon I Ian Nov ^010 Rs 11 1 Redlmo dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 13 of 49 The results of this inspection will be recorded on the Ore Storage/Sample Plant Weekly Inspection Report a copy of which is contained m Appendix A Any vanance in stored matenals from this requirement or observed leaking altemate feedstock dmms or other containers will be brought to the attention of Mill Management and rectified withm 15 days 4 MONTHLY TAILINGS INSPECTION Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from the Radiation Safety Department and recorded on the Monthly Inspection Data form an example of which IS contained m Appendix A Monthly inspections are to be performed no sooner than 14 days since the last monthly tailings inspection and can be conducted concunently with the quarterly tailings inspection when applicable The following items are to be inspected a) Tailings Slurry Pipeline When the Mill is operating the slurry pipeline will be inspected at key locations to determine pipe wear Pipe thickness will be measured using an ultrasonic device by either the radiation safety staff or other trained designees The cntical points of the pipe include bends slope changes valves and junctions which are cntical to dike stability These locations to be monitored will be determined by the Radiation Safety Officer or his designee from the Radiation Safety Department dunng the Mill mn b) Diversion Ditches Diversion ditches 1 2 and 3 shall be monitored monthly for sloughing erosion undesirable vegetation and obstmction of flow Diversion berm 2 should be checked for stability and signs of distress c) Sedimentation Pond Activities around the Mill and facilities area sedimentation pond shall be summanzed for the month d) Overspray Dust Minimization The inspection shall include an evaluation of overspray minimization if applicable This entails ensunng that the overspray system is functioning properly In the event that overspray is camed more than 50 feet from the cell the overspray system should be immediately shut off F WV P\Pi ision of R^dlatlon ( introl\Denison Mines. Dl SA\C VV Dt Rclat d ltcms\PMT & BAT Docs\DMT 1 hn Histc r \AOD T cd DMT Phn Nov 010 Rv 11 1 lean dot\ \C oil 'IBNJanu.in. 2011 Submittal!, and R^jviMon', for ( cll IB\DM1 Plan 01 10 1 i\Tailin'". M'^nt Sv!.lem and PMT Mon 1 hn Nov ^010 Rs 11 1 Rodlino doc White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 14 of 49 e) Remarks A section is included on the Monthly Inspection Data form for remarks m which recommendations can be made or observations of concem can be documented f) Summary of Daily Weekly and Quarterly Inspections The monthly inspection will also summanze the daily weekly and if applicable quarterly tailings inspections for the specific month In addition settlement monitors are typically surveyed monthly and the results reported on the Monthly Inspection Data form 5 QUARTERLY TAILINGS INSPECTION The quarterly tailings inspection is performed by the Radiation Safety Officer or his designee from the Radiation Safety Department having the training specified m Section 2 4 above once per calendar quarter A quarterly inspection should be performed no sooner than 45 days since the previous quarterly mspection was performed Each quarterly inspection shall include an Embankment Inspection an Operations/Maintenance Review a Constmction Review and a Summary as follows a) Embankment Inspection The Embankment inspection involves a visual inspection of the crest slope and toe of each dike for movement seepage severe erosion subsidence shnnkage cracks and exposed liner b) Operations/Maintenance Review The Operations/Maintenance Review consists of reviewing Operations and Maintenance activities pertaining to the tailings area on a quarterly basis c) Construction Review The Constmction Review consists of reviewing any constmction changes or modifications made to the tailings area on a quarterly basis r wv P\Pi IS on ot Ridiati in C ontrol\Pcn son Mines. Pl SA\C W PI Rclat d ltcms\PMT & B \T Docs\PMT 1 Ian HistorvXAppi i cd DMT Pl ui Nov 010 R lit lean d(x\ \Colt IBManuarv 2011 Submiltal'. and Rnvi'ann-, fnr Cell IBsPMT Plan 01 101 INTailm"!. Mgnt Sv!.tom and PMT Mon 1 Ian Nov -^010 Rv 11 1 Redhne dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental ProtecUon Manual Section 3 1 Page 15 of 49 d) Summary The summary will include all major activities or observations noted around the tailmgs area on a quarterly basis If any of these conditions are noted the conditions and corrective measures taken should be documented m the Quarterly Inspection Data form An example of the Quarterly Inspection Data form IS provided m Appendix A 6 ANNUAL EVALUATIONS The following annual evaluations shall be performed 6 1 Annual Technical Evaluation An annual technical evaluation of the tailings management system is performed by a registered professional engineer (PE) who has expenence and training m the area of geotechnical aspects of retention stmctures The technical evaluation includes an on site inspection of the tailings management system and a thorough review of all tailings records for the past year The Technical Evaluation also includes a review and summary of the annual movement monitor survey (see Section 5 2 below) All failings cells and conesponding dikes will be inspected for signs of erosion subsidence shnnkage and seepage The drainage ditches will be inspected to evaluate surface water control stmctures In the event tailings capacity evaluations (as per SOP PBL 3) were performed for the receipt of altemate feed matenal dunng the year the capacity evaluation forms and associated calculation sheets will be reviewed to ensure that the maximum tailings capacity estimate is accurate The amount of tailings added to the system since the last evaluation will also be calculated to determine the estimated capacity at the time of the evaluation Tailings inspection records will consist of daily weekly monthly and quarterly tailings inspections These inspection records will be evaluated to detemune if any freeboard limits are being approached Records will also be reviewed to summanze observations of potential concem The evaluation also involves discussion with the Environmental and/or Radiation Technician and the Radiation Safety Officer regarding activities around the tailings area for the past year Dunng the annual inspection photographs of the tailings area will be taken The training of individuals will be reviewed as a part of the Annual Technical Evaluation r WVP\Pivisnn ol Radiau in ( ontrol\Dcnison M ncs. Pl SA\C WPP Rclat d ltcms\PMT & BAT lX>csM')MT 1 Ian HistorvWppioved DMT Phn Nov 2010 Rv 11 t -clean docWCell 4B\Januarv 2011 Submiiial-. and ReviMons for Cell IRMJMTPhn 01 10 1 IMailm-T!. Mgnt Svotemand PMT Mon Plan Nov ^010 Rs 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 I Page 16 of 49 The registered engineer will obtain copies of selected tailings inspections along with the monthly and quarterly summanes of observations of concem and the corrective actions taken These copies will then be included in the Annual Technical Evaluation Report The Annual Technical Evaluation Report must be submitted by November 15* of every year to Directing Dam Safety Engineer State of Utah Natural Resources 1636 West North Temple Suite 220 Sah Lake City Utah 84116 3156 6 2 Movement Monitors A movement monitor survey is to be conducted by a licensed surveyor annually dunng the second quarter of each year The movement monitor survey consists of surveying monitors along dikes 3 S 4A W and 4A S to detect any possible settlement or movement of the dikes The data generated from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the tailings management system 6 3 Freeboard Limits The freeboard linuts set out in this Section are intended to capture the Local 6 hour Probable Maximum Precipitation (PMP) event which was detennined in the January 10 1990 Drainage Report (the Drainage Report ) for the White Mesa site to be 10 inches The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas was calculated in the Drainage Report to be 103 acre feet of water with a wave mn up factor of 0 90 feet The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas plus the adjacent drainage areas was calculated m the Drainage Report to be 123 4 acre feet of water The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage Report to be 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres) times the PMP of 10 inches) with a wave mn up factor of 0 77 feet The flood volume from the PMP event over the Cell 4B area has been calculated to be 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 72 acres) times the PMP of 10 inches with a wave mn up factor of 0 77 feet The total pool surface area m Cell 1 is 52 9 acres in Cell 4A is 40 acres and in Cell 4B is 40 acres The top of the flexible membrane liner ( FML ) for Cell 1 is 5 618 2 FMSL for Cell 4A r \W I \Pi isi in ol Ridiatiin ( introlXPcn son Mines. Pl SA\C WPP Related llcmsXPMT &. BAT Pocs\PMT Plan Histor \Appio cd DMT Phn Ncv ^010 R 11 I lean docN \C eti 4B\Januar\ 2011 Submittal!, and Rrivi-ann-. fnr ( ell 4BsPMT I Ian 01 10 1 INTailm"!. Mjint System and DMT Mon Phn Nov ^010 Rv 11 1 Redline dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 17 of 49 IS 5 598 5 FMSL and for Cell 4B is 5600 4 FMSL Based on the foregoing the freeboard limits for the Mill s tailings cells will be set as follows 63 1 Cell 1 The freeboard linut for Cell 1 will be set at 5 615 4 FMSL This will allow Cell 1 to capture all of the PMP volume associated with Cell 1 The total volume requirement for Cell 1 is 103 acre feet divided by 52 9 acres equals 1 95 feet plus the wave mn up factor of 0 90 feet equals 2 85 feet The freeboard limit is then 5 618 2 FMSL minus 2 85 feet equals 5 615 4 FMSL Under Radioactive Matenals License condition 10 3 this freeboard limit is set and is not recalculated annually 632 Cell 2 The freeboard limit for Cell 2 is inapplicable since Cell 2 is filled with solids All of the PMP volume associated with Cell 2 will be attnbuted to Cell 4A (and/or any future tailings cells) 633 Cell 3 The freeboard hmit for Cell 3 is inapplicable since Cell 3 is close to being filled with solids and all of the PMP flood volume associated with Cell 3 will be attnbuted to Cell 4B (and/or any future tailings cells) 634 Cell 4A The freeboard limit for Cell 4A is inapplicable since all of the PMP flood volume associated with Cell 4A will be attnbuted to Cell 4B A spillway has been added to Cell 4A to allow overflow mto Cell 4B 635 Cell 4B The freeboard lirmt for Cell 4B will be set assuming that the total PMP volume for Cells 2 3 4A and 4B of 159 4 acre feet will be accommodated in Cell 4B The procedure for calculating the freeboard limit for Cell 4B is as follows (a) When the Pool Surface Area is 40 Acres When the pool surface area m Cell 4B is 40 acres (i e when there are no beaches) the freeboard linut for Cell 4B will be 5 594 6FMSL which is 5 7 feet below the IML This freeboard value was developed as follows PMP Flood Volume 38 1 acre feet Overflow from Cell 4A assuming no storage m Cell 3 or 4A 159 4 acre feet Sum of PMP volume and overflow volume 197 5 acre feet F WVP\Pmsiin it Rid at on C ontrol^Dcnison Mines. Dl SA\C WDl Rclat d ItcmsMlMT &. BAT Dx-sXDMT 11 in Histor \Appioved DMT Phn Nov 2010 Rv 11 1 kan docN \Ceil 4B\Januar> 2011 Submiltjl!, and ReviMon-, for Cell -IBNDMT Plan 01 10 1 !\Tailin"', Mgnt Sv!.tem and DMT Mon Plan Nov ^010 Rv 11 1 Redlmo dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 18 of 49 Depth to store PMP an overflow volume = 197 5 acre feet/40 acres 4 9 feet Wave mn up factor 0 77 feet Total required freeboard 5 7 feet (all values in the above calculation have been rounded to the nearest one tenth of afoot) (b) When the Maximum Elevation ofthe Beach Area is 5 594 FMSL or Less When the maximum elevation of the beach area in Cell 4B is 5594 FMSL or less then the freeboard limit will be 5 594 6 FMSL which is the same as m (a) above This allows for the situation where there may be beaches but these beaches are at a lower elevation than the freeboard liimt established m (a) above and there is therefore ample freeboard above the beaches to hold the maximum FMP volume The maximum elevation of the beach area will be determined by monthly surveys performed by Mill personnel in accordance with the Mill s DMT Plan (c) When the Maximum Elevation ofthe Beach Area First Exceeds 5 594 FMSL When the maximum elevation of the beach area m Cell 4B first exceeds 5 594 FMSL then the freeboard limit for the remainder of the ensuing year (penod t=0) (until the next November 1) will be calculated when that elevation is first exceeded (the Initial Calculation Date ) as follows i) The total number of dry tons of tailings that have histoncally been deposited into Cell 4B pnor to the Initial Calculation Date ( 'TQ ) will be determined II) The expected number of dry tons to be deposited into Cell 4B for the remainder of the ensuing year (up to the next November 1) based on production estimates for that penod ( AQ* ) will be detemuned III) AQ* will be grossed up by a safety factor of 150% to allow for a potential underestimation of the number of tons that will be deposited in the cell dunng the remainder of the ensuing year This grossed up number can be referred to as the modeled tonnage for the penod iv) The total design tailmgs solid storage capacity of Cell 4A will be accepted as 2 094 000 dry tons of tailmgs v) The available remaining space in Cell 4B for solids as at the Initial Calculation Date will be calculated as 2 094 000 dry tons minus TQ VI) The reduction in the pool surface area for the remainder of the ensuing year will be assumed to be directly proportional to the reduction m the available space m Cell 4A for solids That is the reduced pool surface area for penod t=0 ( RPAQ ) after the reduction will be calculated to be (1 - (Ao* X 1 5) / (2 094 000 To)) x 40 acres = RPAo VII) The required freeboard for Cell 4A for the remainder of the penod t=0 can be calculated m feet to be the wave mn up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAo The freeboard limit for Cell 4B for the remainder of penod t=0 would then be the elevation of the FML for Cell 4B of F \W P\Pivis in ot R-id at on C mtn 1 Pen son Mines. Dl SA\C WDl Relat d ItcmsXDMT & B \T Docs\DMT 1 Ian Histor \Appiovcd DMT Phn Nov ?0t0 R 111 lean docN VCeil IBUanuarv 2011 Siihmittalf. and R.n.i..inn.. rnrColl IRsPMT Plan 01 10 11XTailm-v. Mgnt Svitem and PMT Mon Plan Nov ''OlO Rs 11 I Redlmo dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual SecUon 3 1 Page 19 of 49 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of afoot and vill) The foregoing calculations will be performed at the Initial Calculation Date and the resulting freeboard limit will persist until the next November 1 An example of this calculation is set out in Appendix F (d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds 5 594 FMSL On November 1 of each year (the Annual Calculation Date ) the reduction in pool area for the ensuing year (refened to as penod t) will be calculated by i) First calculating the Adjusted Reduced Pool Area for the previous penod (ARPAt i) to reflect actual tonnages deposited m Cell 4B for the previous penod (penod t 1) The RPAt 1 used for the previous penod was based on expected tonnages for penod t 1 grossed up by a safety factor The ARPAt i is merely the RPA that would have been used for penod t 1 had the actual tonnages for year t 1 been known at the outset of penod t 1 and had the RPA been calculated based on the actual tonnages for penod t 1 This allows the freeboard calculations to be conected each year to take into account actual tonnages deposited m the cell as of the date of the calculation The ARPAt 1 can be calculated using the followmg formula (1 - At 1 / (2 094 000 - Tt 0) x ARPAt i = ARPAt i Where • At 1 is the actual number of dry tons of tailings solids deposited in Cell 4B dunng penodt 1 • Tt 1 is the actual number of dry tons of tailings solids histoncally deposited in Cell 4B pnor to the beginning of penod t 1 and • ARPAt 2 IS the Adjusted Reduced Pool Area for penod t 2 If penod t 2 started at the Initial Calculation Date then ARPAt i is 40 acres ll) Once the ARPAt i for the previous penod (penod t 1) has been calculated the RPA for the subject penod (penod t) can be calculated as follows (1 - (At* X 1 5) / (2 094 000 Tt)) x ARPAt i = RPAt Where • At* IS the expected number of dry tons of tailings to be deposited into Cell 4B for the ensuing year (penod t) based on production estimates for the year (as can be seen from the foregoing formula this expected number is grossed up by a safety factor of 1 5) • Tt IS the actual number of dry tons of tailings solids histoncally deposited in Cell 4B pnor to the beginning of penod t and r \W P\Pivision )t Ridiati in C mtn l\Dcn son Mines. Dl SA\C W DP Rclat d ItemsXPMT ^ B \T Pocs\DMT Plan Historv\Atipio cd DMT Pl in Nc V 2010 R 111 lean docN \C eil IBVJanuarv 20] | Submittalr. and RfviMon-, for Cell 4B\PMT I lan 01101 INTailm"!. Mgnt Sv!,tom and PMT Mon Plan Nov -^010 Rs 11 1 Redlmo dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 20 of 49 • ARPAt 1 IS the Adjusted Reduced Pool Area for penod t 1 which is the pool surface area for the previous penod (penod t 1) that should have applied dunng that penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod in) The required freeboard for penod t can be calculated m feet to be the wave mn up factor for Cell 4B of 0 77 feet plus the quotient of 197 5 acre feet divided by the RPAt The freeboard limit for Cell 4A for penod t would then be the elevation of the FML for Cell 4B of 5594 0 FMSL less this required freeboard amount rounded to the nearest one tenth of a foot and iv) The foregoing calculations will be perfonned at the Annual Calculation Date for penod t and the resulting freeboard limit will persist until the next Annual Calculation Date for penod t+1 An example of this calculation is set out in Appendix F (e) When a Spillway is Added to Cell 4B that Allows Overflow Into a New Tailings Cell When a spillway is added between Cell 4B and a new tailings cell then if an approved freeboard limit calculation method for the new cell is set to cover the entire PMP event for Cells 2 3 4A 4B and the new tailings cell the freeboard limit for Cell 4B will be inapplicable except for approved provisions to prevent storm water mnoff from overtopping dikes 6 3 6 Roberts Pond The freeboard limit for Roberts Pond is a liquid maximum elevation of 5 624 0 feet above mean sea level as specified m the GWDP 6 4 Annual Leak Detection Fluid Samples In the event solution has been detected in a leak detection system a sample will be collected on an annual basis This sample will be analyzed according to the conditions set forth in License Condition 11 3 C The results of the analysis will be reviewed to detemune the ongin of the solution 6 5 Annual Inspection of the Decontamination Pads a) New Decontamination Pad Dunng the second quarter of each year the New Decontamination Pad will be taken out of service and inspected to ensure the integnty of the wash pad s exposed concrete surface If any abnormalities are identified i e cracks m the concrete with greater than 1/8 inch separation (width) or any significant detenoration or damage of the pad surface repairs will be made pnor to resuming r\WPMli ision if Ridiatim C ontrolMXnison Mines. Dl SA\C WPP Related ltcmsM>MT& BAT PocsM^MT Phn Histor\\Appio\ed DMT Phn Nov ''010 Rill kan docN \CelI IBXJanuarv '>0I I Submitlal!. and ReviMon., fnr Coll IB\PMT I hn 01 10 1 IXTailm"!, Mgnt SvAcm and PMT Mon Plan Nov ''OlO Rv 11 1 Redlme dot White Mesa Mill - Standard OperaUng Procedures 01/11 Revision Demsonl I 1 Book 11 Environmental Protection Manual Section 3 1 Page 2 lof 49 the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontamination Pad Inspection form The inspection findings any repairs required and repairs completed shall be summanzed in the 2"*^ Quarter DMT Monitonng Report due September 1 of each calendar year b) Existing Decontamination Pad Dunng the second quarter of each year the Existing Decontamination Pad will be taken out of service and inspected to ensure the integnty of the steel tank Once the water and any sediment present is removed from the steel tank containment the walls and bottom of the tank will be visually inspected for any areas of damage cracks or bubbling indicating corrosion that may have occuned since the last inspection If any abnormalities are identified defects or damage will be reported to Mill management and repairs will be made pnor to resuming the use of the facility All inspection findings and any repairs required shall be documented on the Annual Decontammation Pad Inspection form A record of the repairs will be maintained as a part of the Annual Inspection records at the Mill site The inspection findings any repairs required and repairs completed shall be summanzed m the 2nd Quarter DMT Monitonng Report due September 1 of each calendar year 7 OTHER INSPECTIONS All daily weekly monthly quarterly and annual inspections and evaluations should be performed as specified in Sections 2 3 4 5 and 6 above However additional inspections should be conducted after any significant storm or significant natural or man made event occurs 8 REPORTING REQUIREMENTS In addition to the Daily Inspection Data Weekly Tailings Inspection Monthly Inspection Data and Quarterly Inspection Data forms included as Appendix A and descnbed in Sections 2 3 4 and 5 respectively and the Operating Foreman s Daily Inspection and Weekly Mill Inspection forms descnbed in Sections 2 and 3 respectively the following additional reports shall also be prepared 8 1 Monthly Tailmgs Reports Monthly tailings reports are prepared every month and summanze the previous month s activities around the tailings area If not prepared by the Radiation Safety Officer the report shall be submitted to the Radiation Safety Officer for review The Mill Manager will review the report as well before the report is filed m the Mill Central File The report will contain a summary of observations of concem noted on the daily and weekly tailings inspections Conective measures taken dunng the month will be documented along with the observations where appropnate All daily and weekly taihngs inspection forms will be attached to the report A monthly inspection form will also be attached Quarterly inspection forms will accqmpany the report when applicable The report will be signed and dated by the preparer m addition to the Radiation Safety Officer and the Mill FWVlAPi isimofRidiatiinCintrol\PemsonMmcs. Pl SWC WPI Related Item \PMT JiL BAT PocsM)MT Plan Histor \ App i ed PMT 1 hn Ncn 010 R 111 -clean doc\ VC ell 4B\Januan 2011 Submittal!, and Rfvi-.ion', for Cell IB\PMT I hn 01 101 IXTailin"!. Mpii Sv!,lem and PM F Mon 1 lan Nov ^010 Rs 11 1 Redline dot ' I White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental ProtecUon Manual Section 3 I Page 22 of 49 Manager 82 DMT Reports Quarterly reports of DMT monitonng activities which will include the following information will be provided to the Executive Secretary on the schedule provided m Table 5 of the GWDP a) On a quarterly basis all required information required by Part 1 F 2 of the GWDP relating to the inspections descnbed m Section 3 1(b) (Slimes Dram Water Level Monitonng) 3 1(d) (Tailings Wastewater Pool and Beach Area Elevation Monitonng) 3 2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3 3 (Weekly Feedstock Storage Area Inspections) b) On a quarterly basis a summary of the weekly water level (depth) inspections for the quarter for the presence of fluid m all three vertical inspection portals for each of the three chambers in the concrete settling tank system for the New Decontamination Pad which will include a table indicating the water level measurements m each portal dunng the quarter c) With respect to the annual inspection of the New Decontamination Pad descnbed in Section 6 5(a) the inspection findings any repairs required and repairs completed shall be summanzed in the 2"^^ Quarter report due September 1 of each calendar year d) With respect to the annual inspection of the Existing Decontamination Pad descnbed m Section 6 5(b) the inspection findings any repairs required and repairs completed shall be summanzed m the 2^^ Quarter report due September 1 of each calendar year and e) An annual summary and graph for each calendar year of the depth to wastewater in the Cell 2 slimes dram must be included in the fourth quarter report After the first year and beginning m 2008 quarterly reports shall include both the cunent year monthly values and a graphic companson to the previous year FWVP\Pi IS mot R-idiU m Contrc IMXnison Mmes. Pl SA\C WPP Related ItcmsM^MT & BAT DocsXPMT Plin HistorvUppiovcd DMT Phn Ncv ^010 R Hi lean doc\ \Cell 1BVlanu.irv 2011 Submiltal'. and R.^v.i..inn.. fnr Poll IRXPMT Phn 01 10 1 l\T.nlin"-. Mgnt Svr.tom and DMT Mon 1 hn Nov ''OlO Rs 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 I 01/11 Revision I)enisonll 1 Page 23 of 49 APPENDIX A FORMS FWVP\Pivisiin ot Ridiation C ontrol\Pcnison Mines. Pl SA\C WPI Related ltcms\DMT.S. B\T DocsM^MT 1 hn Histor \Appio cd DMT Phn Ncv ^010 Rv 11 t kan docN \C ell IBUanuarv >011 Suhmiiial'. and Roviiaon', forCell IB\PMT Plan 01 10 1 IVTailin'-'!, Mgnt Sv!,tem and PMT Mon Phn Nov '^{)\{) Rv 11 1 Redlmo dot s CJ H H < O Q o S; C/5 3 <o T3 'ZI S 2 o I f3 c c/3 «J m t/3 ^ CQ TJ cr c o -4—> u < II X O Xi o C e 3 O o T3 JD 3 o o c S HH c TJ c CQ n s 04 a Q c o >—J D C c^ Cu o a & 3 CO o H-l s O a a 3 CO (U c CM c c3 o o >H <D S o CO Q x: U fiuO > w) 2 S o &l HH O M § 2 f=5 > §3 a CO o X 6 Q 3 O > o U T3 C cd Ul D 3 51 < • c o c u Q c o > CN PL, (D 2 o OH ^ b- c/3 HH s =: B ^ o ^ CQ CO 0) 3 o 3 O •4—» 1—4 -a 3 O U o 3 o U 3 O o CO o 3 (D T3 Tl +-> CO -3 t« 5? CO P5 W 3 o c5^ CM a> i cd" ;H cor CO CZ) >^ P< Pi to o ;z: o H iz; u >^ s Pk o o :z; :^ 3 S w) Ox Xi 5d Q -3 o 3 a. u 3 O 4—> •3 3 O U Id o 5b o 3 o -H 4-. c o c Q c o > pi, so 60 m c 3 •O c/3 11 2 I O B CO c ed m c/3 (U s =: o ^ OQ 13 U 13 U CN 13 U U X u o H u H >^ NN Q > JJ T3 a S 3 O (L) > ';:H —' s " S > £ ^: ia 13 s 3 D. p > ii 3 S > 5 ia T3 I 3 Id o Q > ia 3 S > £ fc ia T3 I 3 & "cd o T3 O Q 2 £ > fc ia a S 3 a ^ u B t> ed -ni to 2> H-l Q CO U ^ 0^ -X 5+- c o O cs > OH •5 CO a> 2 § 53 c CO I c (1> £ c 3; o ^ t" 2 i ed m < w < CO O S d < fc O OH White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 28 of 49 APPENDIX A (CONT) DENISON MINES (USA) CORP WEEKLY TAILINGS INSPECTION Date Inspectors 1 Pond and Beach Cell 1 (a) Pond Solution ElevaUon elevations (msl ft) (b) FML Bottom Elevation 5597. (c) Depth of Water above FML ((a) (b)) Cell 4A (a)Pond SoluUon Elevation (b) FML Bottom ElevaUon 5555 14_ (c) Depth of Water above FML ((a) (b)) Cell 4B (a)Pond Solution ElevaUon (b) FML Bottom ElevaUon 5557 50 (c) Depth of Water above FML ((a) (b)) (d)Elevation of Beach Area with Highest ElevaUon (monthly) Roberts Pond (a)Pond Solution Elevation (b) FML Bottom ElevaUon 5612 3. (c) Depth of Water above FML ((a) (b)) 2 Shmes Dram Liquid Levels Cell 2 Pump funcUoning properly _Depth to Liquid pre pump _Depth to Liquid Post pump (all measurements are depth m pipe) Pre pump head is 38 Depth to Liquid Pre pump = Post pump head is 38 -Depth to Liquid Post pump = FWVl\Pi IS n ol Ridimon C ontrol\Dcn son Mmes. Dl SA\C WDl Related ItemsM^MT &. BAT Docs\DMT 1 hn Historv\Appi i ed DMT Phn Ncv 2010 R 111 kan docN \( oil IBVIanuarv 201 I Siihmillal'. and R..vi..inn., for Cnll IR\PMT 1 lan 01 10 1 UTailm"!, Mgnl Sv!.lem and DMT Mon Phn Nov ''OlO Rs II 1 Redlme dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 I 01/11 Revision Denisonll 1 Page 29 of 49 3 Leak Detection Systems Observation Cell 1 Cell 2 Cell 3 Cell 4A Cell 4B Is LDS wet or dry'? wet wet wet wet wet Is LDS wet or dry'? dry drv dry dry drv If wet Record liquid level Ft to Ft to Ft to Ft to Ft to If wet Record liquid level Liquid Liquid Liquid Liquid Liquid ^ If sufficient fluid IS present record volume of fluid pumped and flow rate Volume Volume Volume Volume Volume If sufficient fluid IS present record volume of fluid pumped and flow rate Flow Rate Flow Rate Flow Rate Flow Rate Flow Rate If sufficient fluid IS present record volume of fluid pumped and flow rate Was fluid sample collected'? ves no ves no ves no ves no ves no Observation New Decon Pad, Portal 1 New Decon Pad, Portal 2 New Decon Pad Portal 3 Is LDS (Portal) wet or dry*? .wet dry _wet dry _wet ^dry If wet Record liquid level Liquid Ft to Liquid Ft to Ft to Liquid If wet Report to RSO 4 Tailings Area Inspection (Note dispersal of blowing tailmgs) 5 Control Methods Implemented 6 Remarks rWVP\Divis in ot Ridiatnn Contrc i\Dcnison Mine . Pl SA\C WPP Rclat d ItcmsXDMT BAT DticsM^MT Phn Historv\Appio cd DMT Phn Nov 2010 Rv II 1 ckan docN \Cell1B\Janu.irv 2011 Submitlal!. and RaviMon-, for Cell It^\DMri*lan 01 10 1 INTaitm'-'', Mgnt Sv!,tem and PMT Mon Phn Nov -^010 Rv 11 1 Redline dot White Mesa Mill - Standard Operating Procedures \ Book 11 Environmental ProtecUon Manual SecUon 3 1 01/11 Revision Denisonll 1 Page 30 of 49 7 Contaminated Waste Dump * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (soluUon elevation of 5556 14 amsl for Cell 4A and 5558 50 for Cell 4B)'? no yes If Cell 4A leak detection system level exceeds 12 inches above the lowest pomt on the bottom flexible membrane liner (elevation 5556 14 amsl) notify supervisor or Mill manager immediately J • r FWVIAPmsim ofRidiu mC intrclM)cnison Mmes. PLSWC WPP Related lkmsM)MT& BATDx:s\DMT Phn Histor \App o ed DMT Phn Ncv2010Rv II 1 lean docN\Ce'lMBVlanu.irv 2011 Suhmilt.il!. .ind Ri-.vi'ann., fnr Coll IRM)MTH.in01 10 1 hFailin"!. Mfinl Sv!,tcm and PMT Mon Phn Nov ^010 Rs 11 1 Redline dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demkonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 31 of 49 APPENDIX A (CONT) MONTHLY INSPECTION DATA Inspector Date 1 Slurry Pipelme Pipe Thickness (To be measured only dunng penods when the Mill is operating) 2 Diversion Ditches and Diversion Berm Observation Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2 Diversion Ditches Sloughing yes no yes no yes no Erosion yes no yes no yes no Undesu-able yes no yes no yes no Vegetation Obstmction of Flow yes no yes ^no yes no Diversion Berm Stability Issues yes no Signs of Distress yes no Comments 3 Summary of Activities Around Sedimentation Pond F WVP\Pivision of RidiationControlM3enison Mines. Pl SA\C WPP Relat dltcms\PMT& BAT Dics\DMT Plan Histor \Appi i cd DMT Phn Nov •>010 Rv 11 1 lean docN \C ell 4BVI.muarv 2011 Suhmitial'. and Rrivision., for C oil .IR\PMT Phn 01 10 11\1 .iilin"'. Mgnt Sv.tem and PMT Mon Plan Nov ^010 Rv 11 1 Redlme dot White Mesa Mill - Standard OperaUng Procedures " j Book 11 Environmental Protection Manual Section 3 1 01/11 Revision Denisonll 1 Page 32 of 49 4 Overspray Dust Minimization Overspray system functioning properly .yes. no V Overspray camed more than 50 feet from the cell If yes was system immediately shut off? .yes_ _yes_ no no Comments 5 Remarks 6 Settlement Momtors Cell 2 Wl Cell 2 W2 Cell 2 W3 Cell 2 W4 Cell 2W7 C Cell 2 W7N Cell 2 W6C Cell 4A Toe Cell 3 2C Cell 2W3 S Cell 2E1 N Cell 2E1 IS Cell 2E1 2S Cell 2 East Cell 2 W7S Cell 2 W6S Cell 2 W4S Cell 3 2S Cell 3 IN _ Cell 3 IC _ Cell 3 IS _ Cell 3 2N _ Cell 2W5 N Cell 2 W6N Cell 2 W4N Cell 2 W5C Cell 2 W5S 7 Summary of Daily, Weekly and Quarterly Inspections 8 Monthly Shmes Dram Static Head Measurement for Cell 2 (Depth in Pipe Water Level Reading) 9 Monthly Shmes Drain Static Head Measurement for Cell 3 (Depth in Pipe Water level) (after Cell 3 is closed) F\WP\Pi isiin ot Rndiatiin C mtrolMXnison Mines. Pl SA\C WPP Related Item \PMT& B\T IXics\DMT Phn Histor \Appi i ed DMT Phn Ncv •>0t0 R 11 1 -clean docN \C ell 'IBVJanu.irv -'011 Suhmillal'. and Rovi'.ion., for ( o.ll IB\DMT Plan 01 101 W \iL\\m"b Mgnt Sv!,tom and PMT Mon 1 hn Nov ''OIO Rv 11 I Redlme dot White Mesa Mill - Standard OperaUng Procedures Ol/l 1 Revision Demsonl I 1 Book 11 Environmental Protection Manual Section 3 I Page 33 of 49 APPENDIX A (CONT) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector Date 1 Embankment Inspection 2 Operations/Maintenance Review 3 Construction Activities 4 Summary FWVP\Pi isnn ot Ridnion C ontrol\Denison Mines. Pl SAK WPI Related ItemsMIMT .S. BAT DOCSM:)MT Plan Historv\Appioved DMT Phn Ncv 010 R lit lean doc\ \Cell IBVIanuarv 2011 Submittal!, .md Revi'.ion'. for Coll 48\DMT 1 lan 01 10 11Mailin"!, Mgnt S>!,tcm and DMT Mon 1 lan Nov ^010 Rv 11 1 Redhne dot White Mesa Mill - Standard Operating Procedures Ol/l I Revision Denisonl 1 1 Book 11 Environmental Protection Manual SecUon 3 1 Page 34 of 49 APPENDIX A (CONT) ORE STORAGE/SAMPLE PLANT AVEEKLY INSPECTION REPORT Week of through Date of Inspection . Inspector Weather condiUons for the week Blowing dust conditions for the week Corrective actions needed or taken for the week Are all bulk feedstock matenals stored in the area indicated on the attached diagram yes no comments Are all altemate feedstock matenals located outside the area indicated on the attached diagram maintained within water tight containers yes no comments (e g conditions of contamers) Are all sumps and low lying areas free of standing solutions'? Yes No If No how was the situation corrected supervisor contacted and correction date"? Is there free standing water or water mnning off of the feedstock stockpiles'? Yes No Comments F\WP,Di ision it R idiat n C )ntn IVDenison Mmes. Pl SANC WPP Related ltcms\PMT & BAT Docs\PMT Phn Histor \Appio cd PMT Phn Nc "^010 Rv I I I lean docN \C ell 1BU.inuarv ''011 Suhmitt.i]-. .ind Revv.ion., for roll 1B\DMT Plan 01 10 1 l\Tailin"!3 Mgni Sv!,toin and PMT Mon Phn Nov -XllO Rs 11 I Redlme dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/11 Revision Denisonll 1 Page 35 of 49 1- Other comments rWVlM^i IS mol Ridiatiin C ontrolMXnison Mines. Dl SA\C WDP Relat d ltems\DMT& B AT Dies\PMT 1 hn HistorvUppio cd PMT Phn Ncv ^010 R 11 t IcandocN VCell 1B'vl.inu.irv 2011 Submitul-, .md Revv.ion', for Cell IBsPMT Plan 01 10 1 l\Tadin"'^ Mgnt Sv-itom and DMT Mon Phn Nov 2010 Rv 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures ^ 01/11 Revision Demsonl 1 1 Book 11 Environmental ProtecUon Manual SecUon 3 1 Page 36 of 49 \ APPENDIX A (CONT) ANNUAL DECONTAMINATION PAD INSPECTION Date of Inspection " i Inspector New Decontamination Pad Are there any cracks on the wash pad surface greater than 1/8 inch of separation*? Yes No Is there any significant detenoration or damage of the pad surface"? Yes No Fmdings Repair Work Required Existing DecontanunaUon Pad Were there any observed problems with the steel tank*? ^Yes No Findings — "T f LepaiTWork Required Note For the annual inspection of the both the Existing and New Decontamination Pads the annual mspecUon findings any repairs required and repairs completed along with a summary of the weekly inspections shall be discussed m the 2^^ Quarter report due September 1 of each calendar year FWVI\Pi isi in ol Ridiatim C mtrol\Pcnison Mines. Dl SA\C WDl Relat d ltemsM:)MT .S. BAT Dtx:s\DMT I lan Histor\\Appio ed DMT Plan Ncn 010 Rv 11 I kan docN \Cell 1R\J.mu.uv 2011 Submittal', and R>iv.ii,»>n.. fnr Cell IR\I)MT Pi.in 01 10 11NT.ulin"!. Mgnt Sv!,tem and PMT Mon Phn Nov -'OIO Rv 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental ProtecUon Manual Section 3 1 Page 37 of 49 APPENDIX B TAILINGS INSPECTOR TRAINING This document provides the training necessary for qualifying management designated individuals for conducting daily tailings inspections Training information is presented by the Radiation Safety Officer or designee from the Environmental Department Daily tailmgs inspections are conducted in accordance with the White Mesa Mill Tailmgs Management System and Discharge Minimization Technology (DMT) Momtonng Plan The Radiation Safety Officer or designee from the Radiation Safety Department is responsible for performing monthly and quarterly tailmgs inspections Tailings inspection forms will be included in the monthly tailings mspection reports which summanze the conditions activities and areas of concem regarding the tailings areas Notifications The inspector is required to record whether all inspection items are normal (satisfactory requinng no action) or that conditions of potential concem exist (requinng action) A check mark indicates no action required If conditions of potential concem exist the inspector should mark an X m the area the condition pertains to note the condition and specify the corrective action to be taken If an observable concem is made it should be noted on the tailings report until the conective action is taken and the concem is remedied The dates of all corrective actions should be noted on the reports as well Any major catastrophic events or conditions pertaining to the tailings area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Divisionof Dam Safety (801 538 7200) Inspections All areas of the tailings disposal system are routinely patrolled and visible observations are to be noted on a daily failings inspection form Refer to Appendix A for an example of the daily tailings inspection form The inspection form consists of three pages and is summanzed as follows 1 Tailings Slurry Transport System The slurry pipeline is to be inspected for leaks damage and sharp bends The pipeline joints are to be monitored for leaks and loose connections The pipeline supports are to be F\WP\Pi ision ot Ridiation C ontrolVDcnison Mines. Dl SA\C WDl Relat d Items\PMT & BAT Docs\PMT 1 lan Historv\Appio cd DMT Phn Ncv ''010 Rill lean docN \Cell 4B\Januarv 2011 Submittal', .md ReviL.ion-, for Coll IBNDMF I hn 01 1011'sTailm"!. Mgnt Sv!,tem and PMT Mon Phn Nov ''010 Rv 11 1 Redlme dot White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl I 1 Book 11 Environmental Protection Manual SecUon 3 1 Page 38 of 49 inspected for damage and loss of support Valves are also to be inspected particularly for leaks blocked valves and closed valves Points of discharge need to be inspected for improper location and onentation Operational Systems Operating systems including water levels beach liners and covered areas are items to be inspected and noted on the daily inspection forms Sudden changes in water levels previously observed or water levels exceeding the operating level of a pond are potential areas of concem and should be noted Beach areas that are observed as having cracks severe erosion or cavities are also items that require investigation and notation on daily forms Exposed liner or absence of cover from erosion are potential items of concem for ponds and covered areas These should also be noted on the daily inspection form Cells 1 3 4A and 4B solution levels are to be monitored closely for conditions neanng maximum operating level and for large changes in the water level since the last inspection All pumping activities affecting the water level will be documented In Cells 1 and 3 the PVC liner needs to be monitored closely for exposed hner especially after storm events It is important to cover exposed liner immediately as exposure to sunlight will cause degradation of the PVC liner Small areas of exposed liner should be covered by hand Large sections of exposed liner will require the use of heavy equipment These conditions are considered senous and require immechate action After these conditions have been noted to the Radiation Safety Officer a work order will be wntten by the Radiation Safety Officer and tumed into the Maintenance Department All such repairs should be noted in the report and should contain the start and finish date of the repairs Dikes and Embankments Inspection items include the slopes and the crests of each dike For slopes areas of concem are sloughs or sliding cracks bulges subsidence severe erosion moist areas and areas of seepage outbreak For crests areas of concem are cracks subsidence and severe erosion When any of these conditions are noted an X mark should be placed m the section marked for that dike In addition the dikes m particular dikes 3 4A S 4A W 4B S and 4B W should be inspected closely for mice holes and more importandy for praine dog holes as the praine dogs are likely to bunow in deep possibly to the liner If any of these conditions exist the inspection report should be marked accordingly F \W P\Pi 1 in ol Ridiatiin C ontrol\Dcnison Mines. Pl SA\C WPP Rclat d ltems\PMT B \T Pocs\PMT Plan Histor\\Appi i cd DMT Phn Ncv OIO R 11 1 lean docN \Cell 4B\Janu.irv ^011 Submittal!, and Revv.ion-, for Cell 4B\PMT I lan 01 10 1 IVTailm'^!, Mgnt Sv!,tem and PMT Mon I lan Nov ^010 Rv 11 1 Redlmo doe White Mesa Mill - Standard OperaUng Procedures 01/11 Revision Denisonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 39 of 49 4 Flow Rates Presence of all flows in and out of the cells should be noted Flow rates are to be estimated m gallons per minute (GPM) Rates need to be determined for slurry lines pond retum SX tails and the spray system Dunng non operational modes the flow rate column should be marked as 0 The same holds true when the spray system is not utilized 5 Physical Inspection of Slurry Line(s) A physical inspection of all slurry lines has to be made every 4 hours dunng operation of the mill If possible the inspection should include observation of the entire discharge line and discharge spill point mto the cell If fill to elevation flags are m place the tailings and build up IS to be monitored and controlled so as to not cover the flags 6 Dust Control Dusting and wind movement of tailings should be noted for Cells 2 3 4A and 4B Other observations to be noted include a bnef descnption of present weather conditions and a record of any precipitation received Any dusting or wind movement of tailings should be documented In addition an estimate should be made for wind speed at the time of the observed dusting or wind movement of tailings The Radiation Safety Department measures precipitation on a daily basis Daily measurements should be made as near to 8 00 a m as possible every day Weekend measurements will be taken by the Shifter as close to 8 00 a m as possible All snow or ice should be melted before a reading is taken 7 Observations of Potential Concern All observations of concem dunng the inspection should be noted in this section Conective action should follow each area of concem noted All work orders issued contacts or notifications made should be noted m this section as well It is important to document all these Items m order to assure that the tailings management system records are complete and accurate 8 Map of Taihngs Cells The last section of the inspection involves drawing as accurately as possible the followmg Items where applicable FwvP\Pivision of Rid anm C introl\Penison Mines. Pl SA\C WPI Relat d Items PMT& BAT Dics\DMT I lan Histor Wppn ed PMT Phn Nov 2010 R 111 lean docN ell -IBVJanuarv ''Ol 1 Submmal!. and Rflvi'.ion', for Col! -IBNDMT PKin 01 10 1 INTadiii'^'. M'^nt Sv!.tem and DMT Mon Plan Nov ^010 Rs 11 1 Rodlmo doc White Mesa Mill - Standard Operating Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental Protection Manual Section 3 1 Page 40 of 49 1 Cover area 2 Beach/tailing sands area 3 Solution as it exists 4 Pump lines 5 Activities around tailings cell (i e hauling trash to the dump liner repairs etc ) 6 Slurry discharge when operating 7 Over spray system when operating 9 Safety Rules All safety mies applicable to the mill are applicable when in the tailings area These mies meet the required MSHA regulations for the failings area Please pay particular notice to the following mies 1 The posted speed limit for the tailmgs area is 15 mph and should not be exceeded 2 No food or dnnk is permitted m the area 3 All personnel entenng the tailings area must have access to a two way radio 4 Horseplay is not permitted at any time 5 Only those specifically authonzed may operate motor vehicles in the restncted area 6 When road conditions are muddy or slick a four wheel dnve vehicle is required m the area 7 Any work performed in which there is a danger of falling or slipping m the cell will require the use of a safety belt or hamess with attended life line and an approved life jacket A portable eyewash must be present on site as well 8 Anytime the boat is used to perform any work an approved life jacket and goggles must be wom at all times There must also be an approved safety watch with a two way hand held radio on shore A portable eyewash must be present on site as well 10 Preservation of Wildlife Every effort should be made to prevent wildlife and domesticated animals from entenng the tailmgs area All wildlife observed should be reported on the Wildlife Report Worksheet dunng each shift Waterfowl seen near the failings cells should be discouraged from landing by the use of noisemakers 11 Certification Following the review of this document and on site instruction on the tailings system inspection program designated individuals will be certified to perform daily tailmgs inspections The Radiation Safety Officer authonzes certification Refer to the Certification Form Appendix C This form should be signed and dated only after a thorough review of the tailings information previously presented The form will then be signed by the Radiation F \W P\Di IS in ot Ridiation ( introl\Dcn son Mmes. Dl SA\C W DP Rclat d ltcms\DMT & B \T POCSM:)MT Plan Historv\ Appi i cd PMT Pl m Ncv ^010 R Hi -clean doc\ \( ell '1B\Janu.irv 2011 Suhmiii.il'. .nnd R.ivi'.inn.. fnr Coll IR\PMT Phn 01 10 1 l\Tnilin'v. Mgnt Sv!-.tem and PM I Mon 1 hn Nov ''OIO Rs 11 1 Rodline dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section'3 1 01/11 Revision Denisonll 1 Page 41 of 49 Safety Officer and filed V V F\WP\Dtvision of Radiatnn C ontn IMXnison Mines. Dl SA\C WDP Related ItcmsVDMTiS. BAT Docs\DMT Phn Histor Wppio cd PMT Phn Nov 2010 Rv 11 I clean docN \Ceil 'IBVIanuarv 2011 Siibminal.. .md R.nL.inn.. fnr C nW ,IR\nMT Pl.in 01 111 1 l\Tnil,n.T. M^^nt Sy ,..m ,n,i p^j Mon Plan Nov '^010 Rv 11 1 Rcdiinc dot White Mesa Mill - Standard Operating Procedures Book 11 Environmental ProtecUon Manual Section 3 1 01/11 Revision Denisonll 1 Page 42 of 49 APPENDIX C CERTIFICATION FORM Date . Name ( > I have read the document titled Tailmgs Management System White Mesa Mill Tailmgs Inspector Training and have received^on site instmction at the tailings system This instmction included documentation of daily tailings inspections analysis of potential problems (dike failures unusual flows) notification procedures and safety Signature I certify that the above named person is qualified to perform the daily inspection of the tailings system at the White Mesa Mill Radiation Safety Personnel/ Tailmgs System Supervisor F \W P\Pi ision ot Ridiat in C mtto!\Penison Mmes. PLSA\C WPP Relat d Item PMT & BAT Pocs\PMT 1 lan Historv\Appi i cd DMT Phn Ncv ''010 Rill lean docN .( ell IRvJanuarv 2011 Submittal!, .md RoviMon'. fnr C oil IB\PMT Plan 01 10 1 UTailnv^!, M'^nt S\!.tem and DMT Mon Phn Nov "'010 Rv 11 1 Redlme dot i ' A ^7 V ^ White Mesa Mill - Standard pperating Procedures Book 11 Environmental Protection Manual Section 3 1 01/11 Revision Denisonll 1 Page 43 of 49 APPENDIX D 1 FEEDlSTOCK STORAGE AREA 1 " < ^ 1 s f ) 1 1 \ A . 4 - 1 ' J 1 1 F \W P\Pi ision ot Ridiation C introm')cnison\Mincs. Pl S WC W Pl Rclat d ltcms\DMT & B \T P ics\PMT Plan Histor \ Appi ov cd DMT Phn V Nov 2010 Rv 11 1 lean d(xN \Cell '1 BUanu.irv 2011 Submm.il!. .md Rovii.ion', for Coll IB\DMT Plan 01 10 1 UTailni'^!, Mgnt Sy.tem and PMT ( Mon I hn Nov ^010 Rv 11 1 Rodline dot J y r V i White Mesa Mill - Standard Operating Procedures 01/11 Revision Denisonll 1 ^ Book 11 Environmental Protection Manual Section 3 1 ' Page 44 of 49 APPENDIX E TABLES FWVP\PiMS m of Ridiaam C mtrolMXnison Mines. Pl SWC WPI Related ItcmsXDMT & BAT Dics\DMT I hn Histor \Appioved DMT Plan Ncv 010 Rv 11 I ckan docN \Cell 4B\Janu.ir\ 2011 Submittal', and Revisions fnr Cell 4B\PM F I hn 01 10 1 UTailuv^!. Mgnt Sv')tem and DMT Mon Phn Nov ''OIO Rv 11 1 Redline doe White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 01/11 Revision Denisonll 1 Page'4!5 of 49 Table lA Calculated Action leakage Rates for Vanous head Conditions Cell 4A White mesa Mill Blanding Utah Head above Lmer System (feet) Calculated Action leakage Rate ^ ^ ^ ( gallons / acre A day) 5 222 04 V /V ; 10 314 01 ^ - 15) 384 58 20 444 08 25 496 50 30 543 88 35 587 46 37 604 01 / H i I Table IB Calculated Action leakage Rates for Vanous head Conditions Cell 4B White mesa Mill Blanding Utah Head above Liner System (feet) Calculated Action leakage Rate ( gallons / acre / day) \ " 5 21140 ^ / 1 10 317 00 > 15 369 90 ' 1 20 422 70 - ^ 25 475 60 30 528 40 • ' 35 ' 570 00 ^ 37 581 20 ' r-. FWVP\Division ol Ridutti m C ontrolVDcnison Mines. Dl SA\C WPP Rclat d ltemsM:>MT& BAT DocsVPMT I hn Historv\Appi i cd PMT Phn Ncv 010 R 11 1 -clean doe\ \C ell 4B\Januarv 2011 Submiltal'. .ind Rovvaon'. for Coll .IB\DMT Phn 01 10 1 t\Tailm'^'. M^mt S>!,tom and DMT Mon Phn Nov ''OiO Rv 11 1 Redline dot White Mesa Mill - Standard OperaUng Procedures Book 11 Environmental Protection Manual Section 3 1 01/11 Revision Denisonll 1 Page 48 of 49 *These expected and actual tailings and production numbers and dates are fictional and have been assumed for illustrative purposes only Based on these assunlptions and factors the freeboard limits for Cell 4B would be calculated as follows 1 Pnor to March 1, 2012 Pnor to March 1 2012 the maximum elevation of the beach area m Cell 4B is less than or equal to 5 594 FMSL therefore the freeboard limit is set at 5 594 6 FMSL 2 March 1, 2012 to November 1, 2012 The pool surface area would be reduced to the following amount (1 - 225 000/ (2 094 000 - 1 000 000)) x 40 acres = 31 77 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 31 77 acres equals 6 22 feet When the wave mn up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 6 99 feet This means that the freeboard limit for Cell 4B would be reduced from 5594 6 FMSL to 5592 2 FMSL (5594 6 FMSL minus 6 22 feet rounded to the nearest one tenth of a foot) This calculation would be performed at March 1 2012 and this freeboard limit would persist until November 1 2012 3 November 1, 2012 to November 1, 2013 The pool surface area would be reduced to the following amount First recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since the actual tonnage of 225 000 dry tons was the same as the modeled tonnage of 225 000 dry tons the recalculated pool surface area is the same as the modeled pool surface area for the previous penod which is 31 77 acres Then calculate the modeled pool surface area to be used for the penod (1-450 000 / (2 094 000 - 1 000 000 225 000)) x 31 77 acres =15 32 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 15 32 acres equals 12 89 feet When the wave mn up factor for Cell 4B of0 77 feet is added to this the total freeboard required is 13 66 feet This means that the freeboard limit for Cell 4B would be reduced from 5592 2 FMSL to 5586 7 FMSL (5600 35 FMSL minus 13 66 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2012 and this freeboard hmit would persist until November 1 2013 r WVP\Pi ision ol Ridial in ( introi\Dcnison Mines. Dl SA\C WDP Related ItcmsXDMT & BAT Dx:s\DMT Plan Histor \Appio cd PMT t hn Ncv 010 R 11! lean d(xN \C ell 4B\Januarv 2011 SubmiU.il!. and Rovvaon'. for Coll IBXPMI I lan 01 10 1 UTailm"'^ Mgnt Sy.dum and PMT Mon 1 hn Nov '^(m) Rs 11 1 Redlme doe 1 ft White Mesa Mill - Standard OperaUng Procedures 01/11 Revision Demsonl 1 1 Book 11 Environmental ProtecUon Manual Section 3 1 Page 49 of 49 4 November 1, 2013 to November 1, 2014 The pool surface area would be reduced to the following amount First, recalculate the pool surface area that should have applied dunng the previous penod had modeled tonnages (i e expected tonnages grossed up by the 150% safety factor) equaled actual tonnages for the penod Since modeled tonnages exceeded actual tonnages the pool area was reduced too much dunng the previous penod and must be adjusted The recalculated pool area for the previous penod is (1 - 275 000/ (2 094 000 - 1 000 000 225 000) x 31 77 acres = 21 72 acres This recalculated pool surface area will be used as the starting point for the freeboard calculation to be performed at November 1 2013 Then calculate the modeled pool surface area to be used for the penod (1-300 000/ (2 094 000 - 1 000 000 225 000 - 275 000)) x 21 72 acres 10 75 acres Based on this reduced pool area the amount of freeboard would be 197 5 acre feet divided by 10 75 acres equals 18 37 feet When the wave mn up factor for Cell 4B of 0 77 feet is added to this the total freeboard required is 19 14 feet This means that the freeboard linut for Cell 4B would be reduced from 5586 7 FMSL to 5581 2 FMSL (5600 4 FMSL minus 18 4 feet rounded to the nearest one tenth of a foot) This calculation would be performed at November 1 2013 and this freeboard limit would persist until November 1 2014 F\WP\Pivision ot Ridiat on C mtrolXPcnison Mines. Pl SA\C WPI Rclat d ItcmsXDMT & BAT DocsXDMT 1 lan Histor Anni i ed DMT Phn Ncv 2010 Rv 11 1 lean d(xN \Cell IBXJanuarv ''011 Submiltal!. .md Revi-aon-. for Cell IBXDMT Plan 01 10 1 l\T.iiIin'^'. M'^iit S^!,tom and PMT Mon Plan Nov ''OIO Rv 11 I Redlmo dot :5 t \ 1 -.1 1 1' mmW/2011 Revision Denison 2 -1-3^ Cell 4A and 4B BAT Monitoring, Operations and Mamtenance Plan IABLE Ol^ CONTENTS 10 Introduction 2 2 0 Cell Design 2 2 1 Cell 4A Design 2 2 2 CelUB Design 5 3 0 Cell Operation 8 3 1 Solution Discharge to Cell 4A 8 3 2 Solution Discharge to Cell 4B 99§ 3 3 Initial Solids Discharge mto Cell 4A 9 3 4 Initial Solids Discharge mto Cell 4B 10 3 5 Equipment Access to Cell 4A and Cell 4B 10 3 6 Reclaim Water System at Cell 4A 11-1440 3 7 Reclaim Water System at Cell 4B 114-140 3 8 Intenm Solids Discharge to Cell 4A 11 3 9 Intenm Solids Discharge to Cell 4B 11 3 10 Lmer Maintenance and QA/QC for Cell 4A 11 3 11 Lmer Mamtenance and QA/QC for Cell 4B 12^4- 4 0 BAT Performance Standards for Tailings Cell 4A and 4B 124^ 5 0 Routine Maintenance and Monitonng 13 5 1 Solution Elevation 13 5 2 Leak Detection System 13 5 3 Shmes Drain System 15 6 0 Tailmgs Emergencies 16 7 0 Solution Freeboard Calculations 174^4^ 8 0 List of Attachments 19 C \DOCUME~l\DriippXLOCALS~l\remD\XPgiT>\Mse\Celi 4A md 4B O M Plui Rev 2 2 uly 2011 redline docC \Ui;erb\itii,chler\De'.ktopVlul> 2011 BAT O and M Rc\u,ion toi pcrnutXCeli 4A and O M Plan Rc-v^ ledline docN \Ccll ^Bygniiarv 2011 Submittal', and RcviMon', for Cell iBXO&M Plan 01 10 I l\Coll IA and 1B O M Plan Rov 2 1 Rodlino docC \DOCLME~l\DrutiD\LOCALS~lXTemt3\XPgip\Mse\Cell 4A nnd 4B O M Plan Rev 2 2 ulv 20! 1 redline doc4ALi.ei-!,\Uibohler\DobktonVlulv 2011 BAT O aiid M Rcvit.ion lor peiTnitXCell and IB O-Vl Plan Rev 2 2 redlme doc Page 1 mUQUlOl I Revision Demson 2 -i32 10 Introduction Construction of Cell 4A was authonzed by the Utah Department of Environmental Quality Division of Radiation Control ( DRC) on June 25 2007 The constmction authonzation provided that Cell 4A shall not be in operation until after a BAT Monitonng Operations and Maintenance Plan is submitted for Executive Secretary review and approval The Plan shall mclude requirements in Pait IF 3 of the Groundwater Discharge Permit No UGW370004 ( GWDP ) and fulfill the requirements of Parts ID 6 IE 8 and IF 9 of the GWDP Construction of Cell 4B was authonzed by DRC on June 21 2010 The constmction i authorization provided that Cell 4B shall not be in operation until after a BAT Monitonng Operations and Mamtenance Plan is submitted for Executive Secretary review and approval The Plan shall include requirements m Part IF 3 of the GWDP and fulfill the requirements of Parts ID 12 IE 12 and IF 9 of the GWDP 20 Cell Design 2 1 Cell 4A Design y Tailings Cell 4A consists of the followmg major elements a) Dikes - consisting of earthen embankments of compacted soil constmcted between 1989 1990 and composed of four dikes each mcluding a 15 foot wide road at the top (minimum) On the north east and south margins these dikes have slopes of 3H to IV The west dike has an intenor slope of 2H to IV \ Width of these dikes vanes each has a minimum crest width of at least 15 feet to support an access road Base width also vanes from 89 feet on the east dike (with no extenor embankment) to 211 feet at the west dike b) Foundation - mcludmg subgrade soils over bedrock matenals Foundation preparation included excavation and removal of contaminated soils compaction of imported soils to a maximum dry density of 90% Floor of Cell 4A has an average slope of 1% that grades from the northeast to the southwest comers c) Tailings Capacity - the floor and inside slopes of Cell 4A encompass about 40 acres and have a maximum capacity of about 1 6 million cubic yards of tailings matenal storage (as measured below the required 3 foot freeboard) d) Lmer and Leak Detection Systems - including the following layers m C \D0CliMfc~l\Drupp\LQCALS~l\Temp\XPgi-p\Mse\Cel1 4A and 4B O \1 Plan Rev 2 2 ulv 2011 redline docC \Ui.crt.\itii.chlerVDeL.ktop\Juh 2011 BAT O and M RcviMon foi pern-utXCej) IA and IB O M Plan Rc?^^ redhne docN \Coll IBVIanuarv 3011 Submittal', and Revision', for Cell ^BXCmM Plan 01 10 1 iXColl IA and IB O M Plan Rev 2 1 Rodlmo docC XDOCLME~l\DruppXLOCALS-lXTemp\XPgip\viseXCell 4A and 4B O M Plan Rev 2 2 uh 2011 icdlme docC XLberG\iiibchlci\PebktopV(ulv 2011 BAT O and M Rovi^iun for permitXCcll IA and IB 0 M Plan Rev 2 2 redline doc Page 2 <W24-07/2011 Revision Denison 2 4-32 descenchng order 1) Pnmary Flexible Membrane Liner (FML) - consisting of impermeable 60 mil high density polyethylene (HDPE) membrane that extends across both the entire cell floor and the inside side slopes and is anchored in a trench at the top of the dikes on all four sides The pnmary FML will be in direct physical contact with the taihngs matenal over most of the Cell 4A floor area In other locations the pnmary FML will be m contact with the shmes drain collection system (discussed below) C \DOCUME~l\DRiDp\LOCALS~lXremp\XPgrp\MseXCel] 4A and 4B O M Plan Rev 2 2 ulv 2011 redlme docC \Useri.\itii,cli]er\DtbktopVlulv 2011 BAT O and M Revi'.ion toi pciniit\Cell IA and 4B O M Plan RL-^^^ redlme docN \Cell 4BVIanuarv 2011 Submittal!, and Rcvisionj, for Cell ^BX0&^4 Plan 01 10 1 l\Cell <\\and IB O M Plan Rev 2 1 Rediino docC \DOCLME~l\Drupp\LOCALS~i\Temp\XPgipvMse\Lell 4A and 4B O M Plan Rev 2 2 ul\ 2011 ledlmc docG-Mj-.eroXuibchlnXDobkiopVlulv 2011 BAT O and M Revi!.ion for ptrmitXCcll 4A and IB O M Plan Rev 2 2 redlme doc Page 3 Cell 4A BAT Momtormg Operations and Maintenance Plan 014-/21/2010 Revision Denison 2 Z-t 2) Leak Detection System - includes a permeable HDPE geonet fabnc that extends across the entire area under the pnmary FML m Cell 4A and drains to a leak detection sump in the southwest comer Access to the leak detection sump is via an 18 inch inside diameter (ID) PVC pipe placed down the mside slope located between the pnmary and secondary FML liners At its base this pipe will be sunounded with a gravel filter set m the leak detection sump having dimensions of 10 feet by 10 feet by 2 feet deep In tum the gravel filter layer will be enclosed in an envelope of geotextile fabnc The purpose of both the gravel and geotextile fabnc is to serve as a filter 3) Secondary FML - consisting of an impermeable 60 mil HDPE membrane found immediately below the leak detection geonet Said FML also extends across the entire Cell 4A floor up the inside side slopes and is also anchored in a trench at the top of all four dikes 4) Geosynthetic Clay Liner - consisting of a manufactured geosynthetic clay liner (GCL) composed of 0 2 inch of low permeability bentonite clay centered and stitched between two layers of geotextile Pnor to disposal of any wastewater in Cell 4A the Permittee shall demonstrate that the GCL has achieved a moisture content of at least 50% by weight This Item IS a revised requirement per DRC letter to DUSA dated September 28 2007 e) Slimes Drain Collection System - including a two part system of stnp drains and perforated collection pipes both installed immediately above the pnmary FML as follows 1) Honzontal Stnp Drain System - is installed m a hemngbone pattem across the floor of Cell 4A that drain to a backbone of perforated collection pipes These stnp drains are made of a prefabncated two part geo composite dram matenal (solid polymer drainage stnp) core sunounded by an envelope of non woven geotextile filter fabnc The stnp drains are placed immediately over the pnmary FML on 50 foot centers where they conduct fluids downgradient m a southwesterly direction to a physical and hydraulic connection to the perforated slimes dram collection pipe A senes of continuous sand bags filled with filter sand cover the stnp drains The sand bags are composed of a woven polyester fabnc filled with well graded filter sand to protect the drainage system from plugging 2) Honzontal Slimes Drain Collection Pipe System - includes a backbone piping system of 4 inch ID Schedule 40 perforated PVC shmes dram collection (SDC) pipe found at the downgradient end of the stnp dram lines This pipe is m tum overlain by a berm of gravel that runs the entire diagonal length of the cell sunounded by a geotextile fabnc cushion in C \DOCUME~l\Drunp\LOCALS~l\remp\XPgrp\\ise\Cell 4A ^nd 4B O M Plin Rev 2 2 uly 2011 redline doc€ \U{;on.\itisLhlcr\DebktopV)uh 2011 BAT O and M Rev ii^ion foi pcrmit\Ccll 1A and IB O M Plan Rev 2^ ledlmo docN XCcll 'IBVIanuarv 2011 Submittal', and Revi'.ioni, for Cell 1B\0&M Plan 01 10 1 IXCell IA and IB O M Plan Rev 2 1 Redlino docC \DOCLME~l\Dmpp\LOCALS~l\Temp\XPgip\vise\Cell 4A and 4B O M Plan Rev 2 2 UIN 2011 redline docGALt.eri.Xiti'.chlerVDebktop^Julv 2011 BAT O and M Rcvu,ion for pemntXCell IA and IB Q-M Plan Rev 2 2 redline doc Page 4 Cell 4A BAT Monitonng Operations and Maintenance Plan 014-/21/2010 Revision Denison 2 24 immediate contact with the pnmary FML The non woven geotextile material is overlain at the surface by a woven geotextile fabnc which is ballasted laterally by sandbags on each side of the backbone of the berm In tum the gravel is overlain by a layer of non woven geotextile to serve as an additional filter matenal This perforated collection pipe serves as the backbone to the slimes drain system and runs from the far northeast comer downhill to the far southwest comer of Cell 4A where it joins the shmes drain access pipe 3) Shmes Drain Access Pipe - consisting of an 18 inch ID Schedule 40 PVC pipe placed down the inside slope of Cell 4A at the southwest comer above the primary FML Said pipe then merges with another horizontal pipe of equivalent diameter and matenal where it is enveloped by gravel and nonwoven geotextile that serves as a cushion to protect the pnmary FML The non woven geotextile matenal is overlain at the surface by a woven geotextile fabnc which is ballasted by sandbags A reducer connects the honzontal 18 inch pipe with the 4 inch SDC pipe At some future time a pump will be set m this 18 inch pipe and used to remove tailings wastewaters for purposes of de watenng the failings cell f) Dike Splash Pads - A minimum of eight (8) 20 foot wide splash pads are installed on the intenor dike slopes to protect the pnmary FML from abrasion and scounng by tailings slurry These pads consist of an extra layer of 60 mil HDPE membrane that is placed down the inside slope of Cell 4A from the top of the dike and down the inside slope The pads extend to a point 5 feet beyond the toe of the slope to protect the liner bottom dunng initial startup of the Cell The exact location of the splash pads is detailed on the As Built Plans and Specifications g) Rub Protection Sheets - In addition to the splash pads descnbed in f) above mb sheets are installed beneath all piping entenng or exiting Cell 4A that is not located directly on the splash pads h) Emergency Spillway - a concrete lined spillway constructed near the westem comer of the north dike to allow emergency mnoff from Cell 3 into Cell 4A This spillway will be limited to a 6 inch reinforced concrete slab set directly over the pnmary FML m a 4 foot deep trapezoidal channel A second spillway has been constmcted in the southwest comer of Cell 4A to allow emergency runoff from Cell 4A into Cell 4B All stormwater mnoff and tailings wastewaters not retained m Cells 3 and 4A will be managed and contained m Cell 4B including the Probable Maximum Precipitation and flood event 2 2 Cell 4B Design Tailings Cell 4B consists of the following major elements C XD0CUME~l\DRipp\L0CALS~l\1emp\XPgrp\vise\Ce!l 4A tnd 4B O M Plan Rev 2 2 uly 2011 redline docC \Ui.crs\itii3chlcr\Dei,ktopV)uh 2011 BAT O and M Revibion foi pcrmit\Ceil M and 4B Q M Plan Rev 2^ lodline docN XCcll 4BVIanuarv 2011 Submittal', and ReviMon!, for Cell iB\0&M Plan 01 10 1 IVCcll IA and IB O M Plan Rev 2 1 Redline docC XDOCLME~l\Drupp\LOCALS~l\Temp\XPgipvMse\Cell 4A and 4B O M Plan Rev 2 2 uK 2011 redline docGAbt.er^.Xitit.chlerXDebkiopXJulv 2011 BAT O and M Revi!.ion for pennitXCell ^ A and IB 0-N4 Plan Rev 2 2 redline doc Page 5 Cell 4A BAT Monitoring Operations and Maintenance Plan 014/21/2010 Revision Denison 2 21- a) Dike - consisting of a newly constmcted dike on the south side of the cell with a 15 foot wide road at the top (minimum) to support an access road The grading plan for the Cell 4B excavation includes intenor slopes of 2H to IV The extenor slope of the southem dike will have the typical slopes of 3H to IV Limited portions of the Cell 4B intenor sideslopes in the northwest comer and southeast comer of the cell (where the shmes dram and leak detection sump will be located) will also have a slope of 3H to IV The base width of the southem dike vanes from approximately 100 feet at the westem end to approximately 190 feet at the eastem end of the dike with no extenor embankment present on any other side of the cell b) Foundation - including subgrade soils over bedrock matenals Foundation preparation included 6 inch over excavation of rock and placement and compaction of imported soils to a maximum dry density of 90% at a moisture content between +3% and 3% of optimum moisture content as determined by ASTM D 1557 The floor of Cell 4B has an average slope of 1% that grades from the northwest comer to the southeast comer c) Tailings Capacity - the floor and inside slopes of Cell 4B encompass about 45 acres and the cell will have a water surface area of 40 acres and a maximum capacity of about 1 9 million cubic yards of failings matenal storage (as measured below the required 3 foot freeboard) d) Liner and Leak Detection Systems - including the following layers in descending order 1) Pnmary Flexible Membrane Liner (FML) - consisting of 60 mil high density polyethylene (HDPE) membrane that extends across both the entire cell floor and the inside side slopes and is anchored m a trench at the top of the dikes on all four sides The pnmary FML will be m direct physical contact with the tailings matenal over most of the Cell 4B floor area In other locations the pnmary FML will be in contact with the shmes drain collection system (discussed below) 2) Leak Detection System - includes a permeable HDPE geonet fabnc that extends across the entire area under the pnmary FML in Cell 4B and drains to a leak detection sump in the southeast comer Access to the leak detection sump is via an 2 toot-18 inch mside diameter (ID) PVC pipe placed down the inside slope located between the pnmary and secondary FML liners At its base this pipe will be sunounded with a gravel filter set in the leak detection sump havmg dimensions of 10 feet by 10 feet by 2 feet deep In tum the gravel filter layer will be enclosed m an envelope of geotextile fabnc The purpose of both the gravel and geotextile fabnc is to serve as a filter 3) Secondary FML - consisting of a 60 mil HDPE membrane found immediately below the leak detection geonet Said FML also extends C XPOCUMh--l\DruppXLOCALS~l\Temp\XPgrpvMse\Cell 4A md 4B O M Plan Rev 2 2 uly 2011 redhne doeC \U',eR.XitibLhler\Dci,ktopV)uh 201 i BAT O and M Revision foi permitVCell 4A and 'IB O M Plan Rev-3^ lodhne docN XCell IBVIanuarv 2011 Submittal, and Revi'aim', for Cell 4BX()&M Plan 01 10 1 IXC ell \A and IB O M Plan Rov 2 1 Rodlino docC XDOCLME-lXDruppVLOCALS-IXTempXXPgipvviseXCel] 4A and 4B O M Plan Rev 2 2 ul\ 2011 redline doeGALbcrAitisehlerVDobktopVlulv 2011 BAT O and M Revi^,ion for permitXCcll 4A and 'IB C4-M Plan Rev 2 2 lediine doc Page 6 Cell 4A BAT Monitoring OperaUons and Maintenance Plan 01+/21/2010 Revision Denison 2 24 across the entire Cell 4B floor up the mside side slopes and is also anchored in a trench at the top of all four dikes 4) Geosynthetic Clay Lmer - consisting of a manufactured geosynthetic clay liner (GCL) composed of 0 2 mch of low permeability bentonite clay centered and stitched between two layers of geotextile Pnor to disposal of any wastewater in Cell 4B the Permittee shall demonstrate that the GCL has achieved a moisture content of at least 50% by weight e) Shmes Drain Collection System - including a two part system of stnp drains and perforated collection pipes both installed immediately above the pnmary FML as follows 1) Honzontal Stnp Dram System - is installed m a hemngbone pattem across the floor of Cell 4B that dram to a backbone of perforated collection pipes These stnp drams are made of a prefabncated two part geo composite dram matenal (solid polymer drainage stnp) core sunounded by an envelope of non woven geotextile filter fabnc The stnp drains are placed immediately over the pnmary FML on 50 foot centers where they conduct fluids downgradient in a southeasterly direction to a physical and hydraulic connection to the perforated shmes dram collection pipe A senes of continuous sand bags filled with filter sand cover the stnp drains The sand bags are composed of a woven polyester fabnc filled with well graded filter sand to protect the drainage system from plugging^ 2) Honzontal Shmes Dram Collection Pipe System - mcludes a backbone piping system of 4 inch ID Schedule 40 perforated PVC shmes dram collection (SDC) pipe found at the downgradient end of the stnp dram lines This pipe is m tum overlain by a berm of gravel that runs the entire diagonal length of the cell surrounded by a geotextile fabnc cushion in immediate contact with the pnmary FML In tum the gravel is overlain by a layer of non woven geotextile to serve as an additional filter matenal The non woven geotextile matenal is overlam at the surface by a woven geotextile fabnc which is ballasted by sandbags This perforated collection pipe serves as the backbone to the shmes dram system and runs from the far northwest comer downhill to the far southeast comer of Cell 4B where it joins the slimes dram access pipe 3) Shmes Drain Access Pipe - consisting of an 18 inch ID Schedule 40 PVC pipe placed down the mside slope of Cell 4B at the southeast comer above the pnmary FML Said pipe then merges with another honzontal pipe of equivalent diameter and matenal where it is enveloped by gravel and non woven geotextile that serves as a cushion to protect the pnmary FML The non woven geotextile matenal is overlain at the surface by a woven geotextile fabnc which is ballasted laterally by sandbags on each C \DOCUME~l\DruppXLOCALS~lxremp\XPgrpvMse\C ell 4A and 4B O M Plan Rev 2 2 uly 2011 redline docC \U!.crs\itii.ehler\Dei.ktopVJulv 2011 BAT O and M Rcvii,ion foi permit\Ccll 4A and 4B O M Plan Rev 2 2 redlmo doeM XC oil 'IB^Januarv 201 I Submittal', and R(-vi',ion', for Coll 4BXQ&M Plan 01 10 1 IXC ell 4A and 1B C:> M Plan Rov 2 1 Rodlino docC XDQCLME- l\Drupp\LOCALS~ l\Temp\XPgip\Mse\Cell 4A and 4B O M Plan Rev 2 2 uK 2011 redlme doeC:ALt.er.oXiLiOLhlcrXPeskioiAlulv 2011 BAT O and M Revision for permitXCell 1 \ and IB Q-M Plan Rev 2 2 rodlmo doe Page 7 Cell 4A BAT Monitoring OperaUons and Maintenance Plan 014-/21/2010 Revision Denison 2 24 Side of the backbone of the berm A reducer connects the honzontal 18 mch pipe with the 4 mch SDC pipe At some future time a pump will be set in this 18 mch pipe and used to remove tailings wastewaters for purposes of de watenng the tailings cell f) Cell 4B North and East Dike Splash Pads Nine 20 foot wide splash pads will be constructed on the north and east dikes to protect the pnmary FML from abrasion and scounng by tailings sluny These pads will consist of an extra layer of textured 60 mil HDPE membrane that will be installed m the anchor trench and placed down the inside slope of Cell 4B from the top of the dike under the inlet pipe and down the inside slope to a pomt at least 5 feet onto the Cell 4B floor beyond the toe of the slope g) Rub Protection Sheets - In addition to the splash pads descnbed m f) above rub sheets are installed beneath all piping entenng or exiting Cell 4B that IS not located directly on the splash pads h) Emergency Spillway - a concrete lined spillway constmcted near the southem comer of the east dike to allow emergency mnoff from Cell 4A into Cell 4B This spillway will be limited to a 6 mch reinforced concrete slab with a welded wire fabnc mstalled within its midsection set atop a cushion geotextile placed directly over the pnmary FML m a 4 foot deep trapezoidal channel A 100 foot wide 60 mil HDPE geomembrane splash pad will be installed beneath the emergency spillway No other spillway or overflow structure will be constmcted at Cell 4B All stormwater mnoff and tailings wastewaters not retained m Cells 2 3 and 4A will be managed and contained m Cell 4B mcluding the Probable Maximum Precipitation and flood event 3 0 Cell Operation I 3 1 Solution Discharge to Cell 4A Cell 4A will initially be used for storage and evaporation of process solutions from the Mill operations These process solutions will be from the uranium/vanadium solvent extraction circuit or transfened from Cell 1 evaporation pond or the free water surface from Cell 3 or transferred from Cell 2 tailmgs dewatenng operations The solution will be pumped to Cell 4A through 6 mch or 8 mch diameter HDPEappropnalely sized pipelines The initial solution discharge will be in the southwest comer of the Cell The solution will be discharged m the bottom of the Cell away from any sand bags or other installation on the top of the FML Buildmg the solution pool from the low end of the Cell will allow the solution pool to gradually nse around the shmes dram stnps eliminating any damage to the stnp drams or the sand bag cover due to solution flowing past the drainage stnps The solution will eventually be C XDOCliME~l\DriippXLOCALS~l\[emp\XPgrpwise\Cell 4A md 4B O M Plan Rev 2 2 uly 2011 redhne doeC XU'.ersXitischlcrXDcsktopVIuly 2011 BAT O and M Rev I'.ion foi permit\Ccll IA and IB O M Plan Re\^ ledhnc doeN XCell 4BVIanuarv 2011 Submittals and Revisions for Cell IBXOfcM Plan 01 10 1 IXCell d A and 1B O M Plan Rev 2 1 Rodlino docC XDOCLME~l\Dmpp\LOCALS~ IX rempXXPgi pwiseXCell 4A and 4B O M Plan Rev 2 2 ul\ 2011 1 dime docC XLsersXiiisehlerXPesktopVIuly 2011 BAT O and M Revision for pernutXCcll iA and IB-O-M Plan Rev 2 2 ledline doc Page 8 Cell 4A BAT Monitoring Operations and Maintenance Plan 014-/21/2010 Revision Denison 2 24 discharged along the dike between Cell 3 and Cell 4A utilizing the Splash Pads descnbed above The subsequent discharge of process solutions will be near the floor of the pond through a discharge header designed to discharge through multiple pomts thereby reducing the potential to damage the Splash Pads or the Shmes Drain system At no time subsequent to initial filling will the solution be discharged mto less than 2 feet of solution As the cell begins to fill with solution the discharge point will be pulled back up the Splash Pad and allowed to continue discharging at or near the solution level 3 2 Solution Discharge to Cell 4B Cell 4B will initially be used for storage and evaporation of process solutions from the Mill operations These process solutions will be from the uranium/vanadium solvent extraction circuit or transferred from Cell 1 evaporation pond or the free water surface from Cell 3 or Cell 4A or transferred from Cell 2 dewatenng operations The solution will be pumped to Cell 4B through 6 inch or 8 inch diametei HDPEdppropnate sized pipelines pipelines The initial solution discharge will be in the southeast comer of the Cell The discharge pipe will be routed down the Splash Pad provided m the southeast comer of the Cell at the spillway to protect the pnmary FML The solution will be discharged m the bottom of the Cell away from any sand bags or other installation on the top of the FML Building the solution pool from the low end of the Cell will allow the solution pool to gradually nse around the slimes dram stnps elinunating any damage to the stnp drains or the sand bag cover due to solution flowing past the drainage stnps The solution will eventually be discharged along the dike between Cell 3 and Cell 4B utilizing the Splash Pads descnbed above The subsequent discharge of process solutions will be near the floor of the pond through a discharge header designed to discharge through multiple points thereby reducing the potenUal to damage the Splash Pads or the Shmes Drain system At no time subsequent to initial filling will the solution be discharged mto less than 2 feet of solution As the cell begins to fill with solution the discharge point will be pulled back up the Splash Pad and allowed to continue discharging at or near the solution level 3 3 Initial Solids Discharge mto Cell 4A Once Cell 4A is needed for storage for tailings solids the slurry discharge from No 8 CCD thickener will be pumped to the cell through 6 inch or 8 mch diameter HDPEappiopndtely sized pipelines The pipelines will be routed along the dike between Cell 3 and Cell 4A with discharge valves and drop pipes extending down the Splash Pads to the solution level One or all of the discharge pomts can be used depending on operational considerations Solids will settle into a cone or mound of matenal under the solution level with the courser fraction settling out closer to the discharge pomt The initial discharge locations are shown on Figure C \DOCUME~lXPnipp\LOCALS~lxremp\XPgrp\vise\Cell 4A and 4B O M Plan Rev 2 2 uly 2011 redline docC \UserG\nisLhkr\PesKtopV)ulv 2011 BAT O and M Revision foi permitXCell 4y\ and <\B O M Plan redline doeN XCell IBVIanuarv 2011 Submiitak, and Revisions for Cell 4BX0A:M Plan 01 10 I l\Cel1 4A and 1B O M Plan Rov 2 1 Rodlino docC \POCLME~l\PntppVLOCALS~l\Temp\XPgrpvMse\Cell 4A and 4B O M Plan Rev 2 2 ulv 2011 redlme docCAUsersXitischlerXPesktopVlulv 2011 BAT O and M Revision for pcnnitXColl 4A and 'IB O-M Plan Rev 2 2 tedlme doc Page 9 Cell 4A BAT Monitoring Operations and Maintenance Plan 014-/21/2010 Revision Denison 2 24 lA Figure 2A illustrates the general location of the solution and slurry discharge pipelines and control valve locations The valves are 6 or 8 stainless steel knife gate valves The initial discharge of slurry will be at or near the toe of the Cell slope and then gradually moved up the slope continuing to discharge at or near the water surface This is illustrated m Section A A on Figure 2A Because of the depth of Cell 4A each of the discharge points will be utilized for an extended penod of time before the cone of matenal is above the maximum level of the solution The discharge location will then be moved further to the intenor of the cell allowing for additional volume of solids to be placed under the solution level The solution level in the cell will vary depending on the operating schedule of the Mill and the seasonal evaporation rates The tailmgs slurry will not be allowed to discharge directly on to the Splash Pads m order to further protect the FML The tailings sluny will discharge directly in to the solution contamed in the Cell onto an additional protective sheet or on to previously deposited tailmgs sand 3 4 Initial Solids Discharge into Cell 4B Once Cell 4B is needed for storage for tailings solids the sluny discharge from No 8 CCD thickener will be pumped to the cell through 6 mch or 8 inch diametci H^PEappropridtciy sized pipelines The pipelines will be routed along the dike between Cell 3 and Cell 4B with discharge valves and drop pipes extending down the Splash Pads to the solution level One or all of the discharge pomts can be used depending on operational considerations Solids will settle mto a cone or mound of matenal under the solution level with the courser fraction settling out closer to the discharge point The initial discharge locations are shown on Figure IB Figure 2B illustrates the general location of the solution and sluny discharge pipelines and control valve locations The valves are 6 or 8 stainless steel knife gate valves The initial chscharge of slurry will be at or near the toe of the Cell slope and then gradually moved up the slope continuing to discharge at or near the water surface This is illustrated m Section A A on Figure 2B Because of the depth of Cell 4B each of the discharge points will be utilized for an extended penod of time before the cone of material is above the maximum level of the solution The discharge location will then be moved further to the intenor of the cell allowing for additional volume of solids to be placed under the solution level The solution level in the cell will vary depending on the operating schedule of the Mill and the seasonal evaporation rates The tailings sluny will not be allowed to discharge directly on to the Splash Pads in order to further protect the FML The tailings slurry will discharge directly in to the solution contained in the Cell onto an additional protective sheet or on to previously deposited tailings sand C XPOCUIVlh~{\PrunpXLOCALS~lXremp\XPgrpv\ise\Cell 4A and 4B 0 M Plan Rev 2 2 uly 2011 redhne doeC XLiscrsXitischlcrXPesktopVIuly 2011 BAT O and M Rovision for pemntNCell 4A and 'IB O M Plan Rev 2 2 lediinc docN XCell IBVIanuarv 201 1 Submittal!, and Rfivismns fnr Coll 4BXO&M Plan 01 10 1 IXCell 'IA and 1B O M Plan Rev 2 1 Rodlmo docC \POCLME~lXPmppXLOCALS~lXTempXXPgip\MseXCell 4A and 4B Q M Plan Rev 2 2 ulv 2011 redline doeCALsersXitisehloiXPeskiopVluly 2011 BAT O and M Revision for pcrmitXCell '1 \ and \B O-M Plan Rev 2 2 redline doc Page 10 Cell 4A BAT Monitoring Operations and Maintenance Plan 014-/21/2010 Revision Denison 2 24 I 3 5 Equipment Access to Cell 4A and Cell 4B Access will be restncted to the mtenor portion of the cells due to the potential to damage the flexible membrane Imers Only low pressure mbber tired all tenam vehicles or foot traffic will be allowed on the flexible membrane liners Personnel are also cautioned on the potential damage to the flexible membrane liners through the use and handling of hand tools and maintenance matenals I 3 6 Reclaim Water System at Cell 4A A pump barge and solution recovery system is operating in the southwest comer of the cell to pump solution from the cell for water balance purposes or for re use m the Mill process Figure 3A illustrates the routing of the solution retum pipeline and the location of the pump barge The pump barge will be constmcted and maintained to ensure that the flexible membrane liner is not damaged dunng the initial filling of the cell or subsequent operation and mamtenance activities The condition of the pump barge and access walkway will be noted durmg the weekly Cell inspections I 3 7 Reclaim Water System at Cell 4B A pump barge and solution recovery system will be mstalled m the southeast comer of the cell to pump solution from the cell for water balance purposes or for re use in the Mill process Figure 3B illustrates the routing of the solution retum pipeline and the location of the pump barge The pump barge will be constmcted and maintained to ensure that the flexible membrane liner is not damaged dunng the initial filling of the cell or subsequent operation and maintenance activities The condition of the pump barge and access walkway will be noted dunng the weekly Cell inspections I 3 8 Intenm Solids Discharge to Cell 4A Figure 4A illustrates the progression of the slurry discharge points around the north and east sides of Cell 4A Once the failings solids have been deposited along the north and east sides of the Cell the discharges points will subsequently be moved to the sand beaches which will eliminate any potential for damage to the lmer system 3 9 Intenm Solids Discharge to Cell 4B Figure 4B illustrates the progression of the slurry discharge pomts around the north and east sides of Cell 4B Once the tailings sohds have been deposited along the north and east sides of the Cell the discharges pomts will subsequently be moved to the sand beaches which will eliminate any potential for damage to the lmer system C XPOCUME~l\PrttppXLOCALS~IXIeinp\XPu-p\Mse\Cell 4A and 4B O M Plan Rev 2 2 uly 2011 redhne doeC \Users\itischlcrXPesktopVluh 2011 BAT O and M Revision foi permitXCcll IA and IB O M Plan Rcv^ redlme dotN XCtll 4BVIanuar\ 2011 Submittal', and Rcvi!,ions for Cell 4BX0&M Plan 01 10 1 IXColl '^lA and 1B O M Plan Rev 2 1 Redlino docC \POCLME~l\PruppXLOCALS~l\TempVX:Pgin\Mse\Cell 4A and 4B O M Plan Rev 2 2 ulv 2011 redlme doc€ XUsersXuisehltAPeskiopVlulv 2011 BAT O and M Revision for permitXCcll 4A and 'IB C^ Plan Rev 2 2 redlme doc Page 11 Cell 4A BAT Monitoring OperaUons and Maintenance Plan Ql-lr/21/2010 Revision Denison 2 24 3 10 Lmer Maintenance and QA/QC for Cell 4A Any construction defects or operational damage discovered dunng observation of the flexible membrane lmer will be repaired tested and documented according to the procedures detailed in the approved Revised Construction Quality Assurance Plan for the Construction of the Cell 4A Lining System, May 2007, by GeoSyntec Consultants 3 11 Liner Mamtenance and QA/QC for Cell 4B Any construction defects or operational damage discovered dunng observation of the flexible membrane liner will be repaired tested and documented according to the procedures detailed in the approved Construction Quality Assurance Plan for the Construction of the Cell 4B Lining System, October 2009, by Geosyntec Consultants 40 BAT Performance Standards for Tailings Cell 4A and 4B DUSA will operate and maintam Tailings Cell 4A and 4B so as to prevent release of wastewater to groundwater and the environment in accordance with this BAT Monitonng Operations and Maintenance Plan pursuant to Part IH 8 of the GWDP These performance standards shall mclude 1) Leak Detection System Pumping and Monitonng Equipment - the leak detection system pumping and monitonng equipment in each cell includes a submersible pump pump controller water level indicator (head monitonng) and flow meter with volume totalizer The pump controller is set to maintain the maximum level in the leak detection system in each cell at no more than 1 foot above the lowest level of the secondary flexible membrane not including the sump A second leak detection pump with pressure transducer flow meter and manufacturer recommended spare parts for the pump controller and water level data collector is maintamed m the Mill warehouse to ensure that the pump and controller can be replaced and operational withm 24 hours of detection of a failure of the pumpmg system The root cause of the equipment failure will be documented m a report to Mill management with recommendations for prevention of a re occurrence 2) Maximum Allowable Head - the Permittee shall measure the fluid head above the lowest point on the secondary flexible membrane m each cell C \PQCUME--l\Prupp\L0CALS~lX1emp\XPgm\Mse\Cell 4A xnd 4B O M Plan Rev 2 2 uly 2011 redline doeC XUsersXitischlerXPosktopVlulv 2011 BAT O and M Revision foi perniitXCetl 1A and IB Q VI Plan-Rev^ redline docN XC oil IBVIanuarv 2011 Submittals and Rnvnaon', for Cell 4RXOA.LM Plan 01 10 I IXC.L4I 'IA and IB O M Plan Rov 2 1 Redline docC XPOCLME-lXPruppXLOCALS-lXTempXXPgipvMseXCell 4A and 4B O M Plan Rev 2 2 ulv 2011 redline doeC^XUsei'-,Xiiisehlei\PesktopXJulv 2011 BAT O and M Revision for permitXCcll 4'\ and'IB-0-A4 Plan Rev 2 2 redline doc Page 12 Cell 4A BAT Momtormg Operations and Maintenance Plan 01-4/21/2010 Revision Demson 2 2A by the use of procedures and equipment specified in the White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan, 10/10 Revision Denison 10 2, or the currently approved DMT Plan Under no circumstance shall fluid head m the leak detection system sump exceed a 1 foot level above the lowest pomt in the lower flexible membrane liner not including the sump 3) Maximum Allowable Daily LDS Flow Rates the Permittee shall measure the volume of all fluids pumped from each LDS on a weekly basis and use that mformation to calculate an average volume pumped per day Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day for Cell 4A or 26 145 gallons/day for Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Table lA or IB for Cells 4A or 4B respectively to determme the maximum daily allowable LDS flow volume for varying head conditions in the cell 4) 3 foot Mmimum Vertical Freeboard Cntena - the Permittee shall operate and mamtam wastewater levels to provide a 3 foot Minimum of vertical freeboard in Tailings Cell 4A and Cell 4B Said measurements shall be made to the nearest 0 1 foot 5) Shmes Drain Recovery Head Monitonng - immediately after the Permittee initiates pumping conditions m the Tailmgs Cell 4A or Cell 4B shmes dram system monthly qutirteih recovery head tests and fluid level measurements will be made in accordance with a plan approved by the DRC Executive Secretary The slimes dram system pumpmg and monitonng equipment includes a submersible pump pump controller water level indicator (head monitonng) and flow meter with volume totalizer 5 0 Routme Maintenance and Monitoring Trained personnel inspect the White Mesa tailmgs system on a once per day basis Any abnormal occunences or changes m the system will be immediately reported to Mill management and mamtenance personnel The inspectors are trained to look for events involving the routme placement of tailmgs matenal as well as events that could affect the integnty of the tailings cell dikes or lining systems The daily inspection reports are summanzed on a monthly basis and reviewed and signed by the Mill Manager and RSO 5 1 Solution Elevation C \PQCUME~lXPrtipp\LOCALS~IXTemp\XPgrpvvise\Cell 4A md 4B O M Plan Rev 2 2 uly 2011 redline docC \Uscrs\itischlcrXPesktopVluh 2011 BAT O and M Revision foi permitXCcll IA and 4B O M Plan Rev 2 2 redlmo docN XCcll IBVIanuarv 2011 Submittals and RLvif.ions for Coll ^BXO&M Plan 01 10 1 IXC ell 4 A and IB O M Plan Rev 2 1 Rodlino docC XPOCLME~1\PRIPP\LOCALS~ l\Temp\XPgipwise\Cell 4A and 4B O M Plan Rev 2 2 ul\ 2011 redline doe€ALsersXitisthltrXPesktopV)u{y 2011 BAT O and M Revision for permitXColl 4 \ and 'IB O-M Plan Rev 2 2 ledline-dee Page 13 Cell 4A BAT Monitoring Operations and Maintenance Plan 01-1-/21/2010 Revision Denison 2 24 Measurements of solution elevation in Cell 4A and Cell 4B are to be taken by survey on a weekly basis and measurements of the beach area in Cell 4A and Cell 4B with the highest elevation are to be taken by survey on a monthly basis by the use of the procedures and equipment specified in the latest approved edition of the DMT Plan I 2 Leak Detection System The Leak Detection System m Cell 4A and Cell 4B is monitored on a continuous basis by use of a pressure transducer that feeds water level mformation to an electronic data collector The water levels are measured every hour and the mformation is stored for later retneval The water levels are measured to the nearest 0 10 mch The data collector is currently programmed to store 7 days of water level information The number of days of stored data can be increased beyond 7 days if needed The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill s environmental monitonng data base and into the files for weekly mspection reports of the tailmgs cell leak detection systems Withm 24 hours after collection of the weekly water level data the information will be evaluated to ensure that 1) the water level in the Cell 4A and Cell 4B leak detection sumps did not exceed the allowable level (5556 14 feet amsl m the Cell 4A LDS sump and 5558 5 feet amsl in the Cell 4B sump) and 2) the average daily flow rate from the LDS did not exceed the maximum daily allowable flow rate at any time dunng the reportmg penod For Cell 4A and Cell 4B under no circumstance shall fluid head m the leak detection system sump exceed a 1 foot level above the lowest point m the lower flexible membrane liner not includmg the sump To determine the Maximum Allowable Daily LDS Flow Rates in the Cell 4A and Cell 4B leak detection system the total volume of all fluids pumped from the LDS of each cell on a weekly basis shall be recovered from the data collector and that information will be used to calculate an average volume pumped per day for each cell Under no circumstances shall the daily LDS flow volume exceed 24 160 gallons/day from Cell 4A or 26 145 gallons/day from Cell 4B The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Tables lA and IB to determine the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A and Cell 4B Any abnormal or out of compliance water levels must be immediately reported to Mill management The data collector on each cell is also equipped with an audible alannvisuil strobe light that flashes on the control pmel thtrt Gound.G if the water level in the leak detection sump exceeds the allowable level (5556 14 feet amsl m the Cell 4A LDS sump and 5558 5 feet amsl in C \PQCUME~l\PaippXLOCALS~IXTemp\XPgm\\ise\Cell 4A and 4B O M Plan Rev 2 2 uly 2011 redline docC \Users\itischler\PcsktopVlul> 2011 BAT O and M RcMSion for permitXCell IA and IB O M Plan Rev 2 2 redjinedoeN XCell IBVIanuary 2011 Submittal', and Revisions for Coll iBXO&M Plan 01 10 1 IXCell 'lA and IB O M Plan Rev 2 1 Rodlino docC \PQCLME-l\Prupp\LOCALS~lXTemp\XPgipwiseXCell 4A and 4B O M Plan Rev 2 2 ulv 2011 redlme doeC XUsersXitisehlerXPosktopVIulv 2011 BAT Q and M Revision for permitXCcll 4A and 'IB O-M Plan Rev 2 2 redhne doc Page 14 Cell 4A BAT Monitoring OperaUons and Maintenance Plan 014-/21/2010 Revision Denison 2 21^ the Cell 4B sump) The cunent water level is displayed at all times on each data collector and available for recording on the daily inspection form Each leak detection system is also equipped with a leak detection pump EPS Model # 25S05 3 stainless steel or equal Each pump is capable of pumpmg m excess of 25 gallons per minute at a total dynamic head of 50 feet Each pump has a 1 5 mch diameter discharge and operates on 460 volt 3 phase power Each pump is equipped with a pressure sensing transducer to start the pump once the level of solution in the leak detection sump is approximately 2 25 feet (elevation 5555 89 in the Cell 4A LDS sump and 5557 69 feet amsl m the Cell 4B sump) above the lowest level of the leak detection sump (9 inches [0 1"^ ieeij above the lowest pomt on the lower flexible membrane liner for Cell 4A and 2_l/4^ mches 10 19 feetl for Cell 4B) to ensure the allowable 1 0 foot (5556 14 feet amsl in the Cell 4A LDS sump and 5558 5 feet amsl m the Cell 4B sump) above the lowest point on the lower flexible membrane lmer is not exceeded) The attached Figures 6A and 6B (Cell 4A and 4B respectively) Leak Detection Sump Operating Elevations illustrates the relationship between the sump elevation the lowest pomt on the lower flexible membrane liner and the pump on solution elevation for the leak detection pump The pump also has manual start and stop controls The pump will operate until the solution is drawn down to the lowest level possible expected to be approximately 4 inches above the lowest level of the sump (approximate elevation 5554 0 and 5555 77 ft amsl for Cells 4A and 4B respectively) The pump discharge is equipped with a 1 5 mch flow meter EPS Paddle Wheel Flowsensor or equal that reads the pump discharge in gallons per mmute and records total gallons pumped The flow rate and total gallons are recorded by the Inspector on the weekly inspection form The leak detection pump is installed m the honzontal section of the 18 mch perforated section of the PVC collection pipe The distance from the top flange face at the collection pipe invert to the centerhne of the 22 5 degree elbow is 133 4 feet m Cell 4A and 135 6 feet m Cell 4B and the vertical height is approximately 45 feet m Cell 4A and approximately 42 5 feet m Cell 4B The pump is installed at least 2 feet beyond the centerhne of the elbow The bottom of the pump will be installed m the leak detection sump at least 135 4 feet in Cell 4A and 137 6 feet m Cell 4B or more from the top of the flange invert A pressure transducer mstalled withm the pump continuously measures the solution head and is programmed to start and stop the pump within the ranges specified above The attached Figure 5 illustrates the general configuration of the pump installation A spare leak detection pump with pressure transducer flow meter and manufacturer recommended spare parts for the pump controller and water level data collector will be maintained m the Mill warehouse to ensure that C \POCUME~l\PruppXLOCALS~l\Temp\XPgTP\Mse\Cell 4A and 4B O M Plm Rev 2 2 ulv 2011 redhne docC \Uscrs\itisehlcr\PtsktopVluh 2011 BAT O and M Revision foi permitVCcll <IA and IB O M Plan Rev-3^ redlme docN \Cell IBVIanuarv 2011 Submittals and Revisions for ( oil ^BXO&M Plan 01 10 1 ]\Cell IA and IB O M Plan Rov 2 1 Rodhno docC \POCLME~l\Pnipp\LOCALS~lXTemp\XPgipv\ise\Cell 4A and 4B O M Plan Rev 2 2 ul\ 2011 redhne doe€-\LscrsXitisehlei\PeskiopVlulv 2011 BAT O and M Revision for permitXCell 'IA and 'IB O-M Plan Rev 2 2 redline-dee Page 15 Cell 4A BAT Monitoring Operations and Maintenance Plan 014/21/2010 Revision Denison 2 24 the pump and controller on either cell can be replaced and operational within 24 hours of detection of a failure of the pumping system The root cause of the equipment failure will be documented m a report to Mill management with recommendations for prevention of a re occunence I 5 3 Shmes Dram System (i) A pump Tsurumi Model # KTZ23 7 62 stainless steel or equal will be placed inside of the slimes dram access nser pipe of each cell and a near as possible to the bottom of the shmes drain sump The bottom of the shmes drain sump m Cell 4A and Cell 4B are 38 and 35 9 feet below a water level measunng point respectively at the centerhne of the slimes dram access pipe near the ground surface level Each pump discharge will be equipped with a 2 mch flow meter E/H Model #33 or equal that reads the pump discharge m gallons per minute and records total gallons pumped The flow rate and total gallons will be recorded by the Inspector on the weekly mspection form (ll) The slimes dram pumps will be on adjustable probes that allow the pumps to be set to start and stop on intervals determined by Mill management (iii) The Cell 4A and Cell 4B shmes dram pumps will be checked weekly to observe that they are operating and that the level probes are set properly which is noted on the Weekly Tailings Inspection Form If at any time either pump is observed to be not working properly it will be repaired or replaced within 15 days (iv) Depth to wastewater m the Cell 4A and Cell 4B slimes dram access nser pipes shall be monitored and recorded weekly to determine maximum and rmnimum fluid head before and after a pumping cycle respectively All head measurements must be made from the same measunng point to the nearest 0 01 foot The results will be recorded as depth in pipe measurements on the Weekly Taihngs Inspection Form (v) After initntion ot pumpmg conditions m Tailings Cell 4A oi 4B, On a monthly qu irtcrly basis each slimes dram pump will be tumed off and the wastewater in the slimes dram access pipe will be allowed to stabilize for at least 90 hours Once the water level has stabilized (based on no change in water level for three (3) successive readings taken no less than one (1) hour apart) the water level of the wastewater will be measured and recorded as a depth in pipe measurement on the Monthlya Oiiaiterlv Inapection Data form by measunng the depth to water below the water level measunng pomt on the shmes dram access pipe The slimes drain pumps for each cell will not be operated until Mill management has detennined that no additional process solutions will be discharged to that cell and the cell has been partially covered with the first phase of the reclamation cap C \POCliMfc~l\Prupp\LCX ALS~l\femp\XPgipv\ise\Ceil 4A and 4B O M Plan Rev 2 2 uly 2011 redlme doeC \Usors\itiSLhlcr\PcsktopVlul> 2011 BAT O and M Revision foi permitXCcll 1A and 4B Q M Plan Rev 2 2 ledlme docN XCell 4BVjanuap/ 2011 Submittalo and Revisions foi Cell 4BXO&M Plan 01 10 1 l\Celt 'IA and 1B O M Plan Rev 2 1 Rodlino docC XPOCLME~l\Pmpp\LOCALS~lXTemp\XPgipvvise\Cell 4A and 4B O M Plan Rev 2 2 ulv 2011 redhne doeC XbsersXlt^sehlerXPesktop^Julv 2011 BAT O and M Revi?,ion for permitXCcll 'IA and '1^-O-M Plan Rev 2 2 redlme doc Page 16 Cell 4A BAT Monitoring Operations and Maintenance Plan 014/21/2010 Revision Denison 2 24 The long term effectiveness and performance of the shmes drain dewatenng will be evaluated on the same basis as the currently operating shmes drain system for Cell 2 6 0 Tailings Emergencies Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if dunng their inspection they discover that an abnormal condition exists or an event has occuned that could cause a tailmgs emergency Until relieved by the Environmental or Radiation Technician or Radiation Safety Officer inspectors will have the authonty to direct resources dunng tailings emergencies Any major catastrophic events or conditions pertaining to the tailmgs area should be reported immediately to the Mill Manager or the Radiation Safety Officer one of whom will notify Corporate Management If dam failure occurs notify your supervisor and the Mill Manager immediately The Mill Manager will then notify Corporate Management MSHA (303 231 5465) and the State of Utah Division of Dam Safety (801 538 7200) 7 0 ^II-4A^Solution Freeboard Calculations The maximum tailmgs cell pond wastewater levels in Cell 1 Cell 2 Cell 3 Cell 4A and Cell 4B are regulated by condition 10 3 of the White Mesa Mill 1 le (2) Matenals License Howevei, fretboaid limits are no longer applic ible to Coll 2, Cell 3 and Cell 4A as discussed below Condition 10 3 states that Freeboard limits stormwater and wastewater management for the tailings cells shall be detemuned as follows A The freeboard limit for Cell 1 shall be set annually in accordance with the procedures set out in Section 3 0 to Appendix E of the previously approved NRC license application includmg the January 10 1990 Drainage Report Discharge of any surface water or wastewater from Cell 1 is expressly prohibited B The freeboard limit for Celk 3 IA and ^B shall be recalculated annually in accordance with the procedures established by the Executive Secretary Said calculations for freeboard limits shall be submitted as part of the Annual Technical Evaluation Report (ATER) as descnbed in Condition 12 3 below [of the licesnse and not included herein] Based on tppro\cd icvisions to the DMT Phn dated January 2011 the freeboard limit is no longer C XPOCliMb~l\PruppXLOCALS~l\remp\XPMT>\Mse\Cell 4A md 4B O M Plan Rev 2 2 uly 2011 redline doeC \Users\itisehler\PcsktopVlul> 2011 BAT O and M Revision foi permitXCcll 4A and IB O M Plaivjtev^ lodhne dotN XCell IBVIanuarv 2011 Submittals and Revisions for Cell ^BXO&M Plan 0110 1 l\Coll IA and IB O M Plan Rev 2 1 Rodlino docC VPOCLME-l\Prupp\LOCALS~l\Tenip\XPgipwiseXCell 4A and 4B O M Plan Rev 2 2 ulv 2011 ledhnc doeGALsersXitischlerXPesktop^Julv 2011 BAT O and M Revision for pormuXCell IA and 'IB O M Plan Rev 2 2 redline doc Page 17 Cell 4A BAT Momioring Operations and Mamtenance Plan 014/21/2010 Revision Denison 2 24 applic ible to Cells 2, 3 and 4A C The discharge of any surface water stormwater or wastewater from Cells 3 4A and 4B shall only be through an Executive Secretary authonzed spillway stmcture [Applicable NRC Amendment 16] [Applicable UDRC Amendment 3] [Applicable UDRC Amendment 4] The freeboard limits set out in Section 6 3 of the DMT Plan are intended to capture the Local 6 hour Probable Maximum Precipitation (PMP) event which was determmed in the January 10 1990 Drainage Report for the White Mesa site to be 10 inches Based on the PMP storm event the freeboard requirement for Cell 1 is a maximum operating water level of 5615 4 feet above mean sea level (amsl) The Cell 1 freeboard limit IS not affected by operations or conditions m Cells 2 3 4A or 4B Cells 2 and 3 have no freeboard Iirmt because those Cells are full or near full of tailmgs solids Cell 4A has no freeboard limit because it is assumed that all precipitation falling on Cell 4A will overflow to Cell 4B All precipitation falling on Cell 2 3 and 4A and the adjacent drainage areas must be contained in Cell 4B The flood volume from the PMP event over the Cell 2 3 and Cell 4A pond areas plus the adjacent drainage areas which must be contamed in Cell 4B is 159 4 acre feet of water The flood volume from the PMP event over the Cell 4A area is 36 acre feet of water (40 acres plus the adjacent drainage area of 3 25 acres times the PMP of 10 inches) For the purposes of establishing the freeboard in Cell 4B it is assumed Cell 4A has no freeboard linut and all of the flood volume from the PMP event will be contained m Cell 4B The flood volume from the PMP event over the Cell 4B area is 38 1 acre feet of water (40 acres plus the adjacent drainage area of 5 7 acres times the PMP of 10 inches) This would result in a total flood volume of 197 5 acre feet includmg the 123 4 acre feet of solution from Cells 2 and 3 and 36 acre feet of solution from Cells 2 3 and 4A that must be contained in Cell 4B The procedure for calculating the freeboard limit for Cell 4B is set out in the DMT Plan The Groundwater Quality Discharge Permit No UGW370004 for the White Mesa Mill requires that the mmimum freeboard be no less than 3 0 feet for Cells 1 4A and 4B but based on License condition 10 3 and the procedure set out in the DMT Plan the freeboard limits for Cells 1 4A and 4B will be at least three feet Figure 7 Hydraulic Profile Schematic shows the relationship between the Cells and the relative elevations of the solution pools and the spillway elevations The required freeboard for Celk 4 \ dmV4B will be recalculated annually C \POCl'Mfc-{\Prunp\LOCALS~i\Temp\XPgrpvMse\Cen 4A and 4B O VI Plan Rev 2 2 uly 2011 redhne docC \Uscrs\itisehler\Pc',KtopVlul> 2011 BAT Q and M Rovi',ion toi permitXCcll 1A and 'IB 0 M Plan Rev-3^ redhne doeN XCell 4B\January 2011 Submittals and Rtnision', for C ell 4RXOfcM Plan 01 10 1 IXCell IA and 1B () M Plan Rev 2 1 Rodlino docC XPOCLME~l\PruppXLOCALS~lXTemp\XPgipvMse\CeH 4A and 4B O M Plan Rev 2 2 ulv 2011 icdhnc doeC4LsersXitisehler\PesktopVlulv 2011 BAT O and M Revision for pormitXCell 4A and 'IB O-M Plan Rev 2 2 i edl ine doc Page 18 Cell 4A BAT Monitoring Operations and Maintenance Plan 014/21/2010 Revision Denison 2 2 t 8 0 List of Attachments 1) Figures 1A and IB Initial Filling Plan Geosyntec Consultants 2) Figure 2A and 2B Initial Filling Plan Details and Sections Geosyntec Consultants 3) Figure 3A and 3B Initial Filling Plan Solution and Sluny Pipelme Routes Geosyntec Consultants 4) Figure 4A and 4B Intenm Filling Plan Geosyntec Consultants 5) Figure 5 Leak Detection System Sumps for Cell 4A and 4B Geosyntec Consultants 6) Figure 6A and 6B Leak Detection Sump Operating Elevations Geosyntec Consultants 7) Figure 7 Hydraulic Profile Schematic 8) Cell 4A and Cell 4B Freeboard Calculations 9) Table lA Calculated Action leakage Rates for Vanous Head Conditions Cell 4A White Mesa Mill Blanding Utah Geosyntec Consultants 10) Table IB Calculated Action leakage Rates for Vanous Head Conditions Cell 4B White Mesa Mill Blanding Utah Geosyntec Consultants 11) White Mesa Mill Tailings Management System and Discharge Minmuzation Technology (DMT) Monitonng Plan C XPOCUME-l\Prtipp\LOCALS-lxrempXXPgrp\\iseXCell 4A md 4B O M Plan Rev 2 2 uly 2011 redline doeC VUsersNitischlcrVPcsktopVluh 2011 BAT O and M Revision foi porniitXCcll 1A and ^BO M Plan Rev 2^ redlme docN XCell <lBVIanuar> 2011 Submittals and Revisions for Cell 4BX0&M Plan 01 10 1 UCell IA and 1B O M Plan Rov 2 1 Redlino docC \POCLME~l\PruppXLOCALS~lXTempVXPgipwiseXCell 4A and 4B O M Plan Rev 2 2 ulv 2011 redhne doeCAt^sersXitisehleiXPesktopVlulv 2011 BAT O and M Revision for permitXCell -IA and '1B O M Plan Rev 2 2 redlme doc Page 19 CQ^J^ i 25 r /yPnu5)y ifc veAi (b^ l^^l j^lzsy^^^-^ ^Jh!!:, l^v^^jK ^ "^^^^ 1^^*^ ^'^y 6^ As -J>^^- 'JL'^^JL Y-^--^-^^^^ ^^^-^ tj>-^i:jt^_j^-i^&.±__3kG±>^^^^ I I i Oz si i i g 8 QJ O imm. f £5 \ I ' -7- V 1 I \ > V i °^ It is r p-3 igi 8 IS] 8 ' ' S lg; S ljs:8! h s LR-PRO 45' lOths (#90026) - Survey Supply LR PRO 45 lOths (#90026) Survey Supply Page 1 of 1 " Cart Total $0 00 j Mv Account Searcfi our Online Store Home Delivery Links Contact Us Jobs Categories Automatic Levels Bags & Cases Batteries & Chargers Calculators Direct Reading Rods Estimating/Take Off Tools Field Supplies GPS Accessories Hand & Field Tools Hand Levels Laser Measurers Lasers Leveling Rods Cram Levels & Transit Levels Magnetic Locators Measuring Rulers Measuring Tapes Measuring Wheels Pnsm Poles Prisms & Accessories Property Markers Robotics Accessories Safety Utility Vests Scanner Accessories Surveying Bipods Surveying Tripods Theodolites Tota! 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Contact us fo all your p. ci ity v holesale and promotional tape n-e s i F i eed http //perfecttape com/wholesale/surveyors-tapes/senes-j 10 8/16/2011 White Mesa Mill - Standard Operating Procedures Book 11 Environmental Protection Manual Section 3 1 0+01/11 Revision Demsonl 1 _4 Page 10 of 56 the Cell 4A and 4B Reference Point The Assistant will ensure that the Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor has estabhshed a level reading (vi) The Surveyor will focus the cross hairs of the Survey Instrument on the scale on the Survey Rod and record the number (the Reference Point Reading ) which represents the number of feet the Survey Instrument is reading above the Reference Point <Mi) The Assistant will then move to a designated location where the Survey Rod can be placed on the surface of the main solution pond m the Cell 1 Cell 4 A Cell 4B or Roberts Pond or the area of the beach m Cell 4 A oi Cell 4B with the highest elevation as the case may be These designated locations and the methods to be used by the Assistant to consistently use the same locations are as follows fvrt^ Foi g newly constiueted cell, v^hcn the cell is tnst placed into opeiation. the sokition level IS typically zero fect above the VML or a minimil elevation above the h\il due lo natural precipitation For nevsh constructed cells, solution level measuiement w ill not he required until the solution level is hiuh enough that it can be rc ichcd safely by peisonnel with a measunng tape aloniL. the side of the PML Solutions levels will be measured by this method beginning w hen tht solution le\e] is high enough to be reached safely, as determmed b\ the RSO Sui\eying of solution levels will not be lequned until solution levels are hi Jt enough that th \ can eftcctneh b mea tiied by suncy instrument from the appropiidtc suivcynu point Formatted No b liets or n mbe ng A _Pond Surface Measurements Ar I Coll ^A Formatted number ng Indent Left 1 54 No b Nets o The Asbistant VMII walk down the 'jlope m the nottheast comet of Cell 4A and place the Survey Rod at the liquid level H-l Cell 4B The Assistant will walk down the slope in the northwest comer of Cell 4B and place the Survey Rod at the liquid level M4-n _Cell 1 A mark has been painted on the north side of the ramp going to the pump platform m Cell 1 The Assistant will place the Survey Rod against that mark and hold the rod vertically with one end just touching the liquid surface and IV Roberts Pond w t SOP d Tm 1 0( 2 U 0( I M RH M Formatted Indent Left 1 5 Tab stops 15 Left + Not at 1 13 \1 M 1 I We. ISN t d PVl 1 VI 11 J , torCelMB DM I Plan 01 10 1 M jilini'n Mg.u • land DM1 Mon 1 lai -^H -44-1 KojIii'cd.H I White Mesa Mill - Standard Operating Procedures O+OL/l 1 Revision Denisonl 1 2+ Book 11 Environmental Protection Manual Section'^S 1 Page 9 of 56 and Cell 4 slimes drains are mspected and the results reported m accordance with the requirements of the permit c) Wind Movement of Tailings \ , An evaluation of wind movement of tailings or dusting and control measures shall be taken if needed d) Tailings Wastewater Pool Elevation Monitoring j Solution elevation measurements in Cells 14 A and 4B and Roberts Pond are to be taken by survey on a weekly basis and the beach area in Cell 4 A and 4B with the maximum elevation is to be taken by survey on a monthly basis as follows (i) The survey will be performed by the Mill s Radiation Safety Officer or designee (the Surveyor ) with the assistance of another Mill worker (the Assistant ) (ll) The survey will be performed usmg a survey instrument (the Survey ^ Instrument ) accurate to 0 01 feet such as a Sokkai No B21 or equivalent together with a survey rod (the Survey Rod ) having a visible scale in 0 01 foot increments ^ (ill) The Rj-eference Points (the JReferonco Pomts )for Cells 14A- and 4B and Roberts Pond are known points established by professional survey For ^ Cell 1 and Roberts Pond the Reference Point is a wooden stake with a metal disk on it located on the southeast comer of Cell 1 The elevation of the metal disk (the Reference Point Elevation ) for Cell 1 and Roberts Pond is at 5 623 14 feet above mean sea level ( FMSL ) For Cell 3 Coll IA and Coll 1B the Reference Pomt IS a piece of metal rebar located on the south dike of Cell 3 The elevation at the top of this piece of rebar (the Reference Pomt Elevation for Cell 4A and 4B2) is at 5 607 83 FMSL Foi C cll 4 A and 4B the Retcrenee Point is a piece ot Stamped metal monument located next to the transformer on the south side of Cell 4A and 4B The elevation at th top of this piece of tcbar (the Retcrenee Point Llev ation toi C ell 4 A and 4B) is S600 49 fm 1 The Surveyor will set up the Survey Instmment in a location where both the applicable Reference Point and pond surface are visible For Cell 1 and Roberts Pond this is typically on the road on the Cell 1 south dike between Cell 1 and Roberts Pond approximately \ 100 feet east of the Cell 1/Roberts Pond Reference Point For Cell 4 A and Cell 4B this is typically on the load on the Cell 3 diko appio\imatol> 100 feet east of the Cell 3 Reference Pointsouth side of Cell 4A and 4B (iv) Once in location the Surveyor will ensure that the Survey Instmment is level by centering the bubble m the level gauge on the Survey Instmment (v) The Assistant will place the Survey Rod vertically on the Reference Pomt (on the metal disk on the Cell 1/Roberts Pond Reference Point on the top of the rebar on 0( 1 II Rt 1 \1 m SOP 6 J i Rl A _VL M T_l M Si J DMT M Pl I 11 I i d N C oil lij4-^mie<^ Or 1Wr\^^ '^^^L pavW<j t^' ^^^^^ B^r ^-^is ar^^:cp,a/^^ 1^ 5^ ^ , mecis -J .Tibir. ' r» ^— Mill Ptf^i^'^^ H t'*'**^ 2.^ 3^ ri- fli> tfN V^ei. erf f-iru ^itfjf?^ t?^^T/ j^ftT f^lW' go(r Si>(»^ l^^t^ f ¥ X r-' vj. A ^ ii ^ I Y o TP ^ (Ty^ /U^]pYAc\iaX ^J&lciA3 W^jk <^ \&:^.t ^frW ^rj^)^ tr 44- f 1 Feb ^, IZo/fi- i) ^.4&'. Mau SiPJ/ leir&/of Sir face, WxlZ^ d, f^c/f s^fc rywyo.':unifie^^ (?j Ape,. ^24^ yxJjyJ^ /TiMjfiAjtfyjtA ^ ^/>/g£^y Lbs 1