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HomeMy WebLinkAboutDRC-2010-002643 - 0901a06880176a9aD£6-.5oii^-oO'^W5 DENISOhn/i MINES March 22, 2010 VIA PDF AND FEDERAL EXPRESS Mr. Dane L. Finerfrock, Executive Secretary, Utah Radiation Control Board, Utah Department of Environmental Quality, Division of Radiation Control 168 North 1950 West Salt Lake City, Utah 84114-4850 Dear Mr. Finerfrock: Denison Mines (USA) Corp. 1050 17th Street, Suite 950 Denver, CO 80265 USA Tel : 303 628-7798 Fax:303 389-4125 www.denisonmines.coni Re: White Mesa Mill - January 12, 2010 DUSA Response Letter; November 25, 2009 DRC Request for Information (RFI) on Engineering Inspection Module 75E; February 3, 2010 Response Review and Request for Information In response to your letter of February 3, 2010, which Denison received on or about February 5, 2010, enclosed please find the following documents for final review and approval: a) 3/10 Revision: Denison-7 of the White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan (the "DMT Plan"); b) Redline comparing version 3/10 Revision: Denison-7 of the DMT Plan to the currently approved version 9/08 Revision: Denison-6 ofthe DMT Plan; c) 3/10 Revision Denison 1.4 of the White Mesa Mill Cell 4A BAT Monitoring, Operations and Maintenance Plan (the "Cell 4A BAT Plan"); and d) Redline comparing version 3/10 Revision Denison 1.4 of the Cell 4A BAT Plan to the currently approved version 09/08 Revision 1.3 ofthe Cell 4A BAT Plan. If you have any questions or require any further information, please contact the undersigned at (303) 389-4130 or Ms. Jo Ann Tischler at (303) 389-4132. Yours very tnijfy, David C. Frydenlund Vice President, Regulatory Affairs and Counsel cc Ron F. Hochstein Harold R. Roberts Jo Ann S. Tischler David E. Turk DENISO MINES ,Di 3/1 0 Revision Denison 1.4 Cell 4A BAT Monitoring, Operations and Maintenance Plan. Introduction Construction of Cell 4A was authorized by the Utah Department of Environmental Quality, Division of Radiation Control ("DRC) on June 25,2007. The construction authorization provided that Cell 4A shall not be in operation until after a BAT Monitoring, Operations and Maintenance Plan is submitted for Executive Secretary review and approval. The Plan shall include requirements in Part F.3 of the Groundwater Discharge Permit No. UGW370004 ("GWDP") and full fill the requirements of Parts l.D.6, l.E.8, and l.F.8 of the GWDP. Cell Design Tailings Cell 4A consists of the following major elements: a) Dikes -consisting of earthen embankments of compacted soil, constructed between 1989-1990, and composed of four dikes, each including a IS-foot wide road at the top (minimum). On the north, east, and south margins these dikes have slopes of 3H to 1 V. The west dike has a interior slope of 2H to 1 V. Width of these dikes varies; each has a minimum crest width of at least 15 feet to support an access road. Base width also varies from 89-feet on the east dike (with no exterior embankment), to 211-feet at the west dike. b) Foundation -including sub grade soils over bedrock materials. 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 I % that grades from the northeast to the southwest corners. 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 material storage (as measured below the required 3-foot freeboard). d) Liner and Leak Detection Systems -including the following layers, in descending order: 1) Primary 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 primary FML will be in direct physical contact with the tailings material over most of the Cell 4A floor area. In other locations, the primary FML will be in contact with the slimes drain collection system (discussed below). Page 1 Cell 4A BAT Monitoring, Operations and Maintenance Plan 311 0 Revision Denison 1.4 2) Leak Detection System -includes a permeable HOPE geonet fabric that extends across the entire area under the primary FML in Cell 4A, and drains to a leak detection sump in the southwest corner. Access to the leak detection sump is via an IS-inch inside diameter (10) PVC pipe placed down the inside slope, located between the primary and secondary FML liners. At its base this pipe will be surrounded with a gravel filter set in the leak detection sump, having dimensions of 10 feet by 10 feet by 2 feet deep. In turn, the gravel filter layer will be enclosed in an envelope of geotextile fabric. The purpose of both the gravel and geotextile fabric is to serve as a filter. 3) Secondary FML -consisting of an impermeable 60-mil HOPE 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. Prior 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 strip drains and perforated collection pipes both installed immediatcly above the primary FML, as follows: 1) Horizontal Strip Drain System -is installed in a herringbone pattern across the floor of Cell 4A that drain to a "backbone" of perforated collection pipes. These strip drains are made of a prefabricated two-part geo-composite drain material (solid polymer drainage strip) core surrounded by an envelope of non-woven geotextile filter fabric. The strip drains are placed immediately over the primary FML on 50-foot centers, where they conduct fluids downgradient in a southwesterly direction to a physical and hydraulic connection to the perforated slimes drain collection pipe. A series of continuous sand bags, filled with filter sand cover the strip drains. The sand bags are composed of a woven polyester fabric filled with well graded filter sand to protect the drainage system from plugging. 2) Horizontal Slimes Drain Collection Pipe System -includes a "backbone" piping system of 4-inch 10 Schedule 40 perforated PVC slimes drain collection (SOC) pipe found at the downgradient end of the strip drain lines. This pipe is in turn overlain by a berm of gravel that runs the entire diagonal length of the cell, surrounded by a geotextile fabric cushion in immediate contact with the primary FML. In turn, the gravel is overlain Page 2 Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/1 0 Revision Denison 1.4 by a layer of non-woven geotextile to serve as an additional filter materiaL This perforated collcction pipe serves as the "backbone" to the slimes drain system and runs from the far northeast corner downhill to the far southwest corner of Cell 4A where it joins the slimes drain access pipe, 3) Slimes Drain Access Pipe -consisting of an I8-inch ID Schedule 40 PVC pipe placed down the inside slope of Cell 4A at the southwest corner, above the primary FML. Said pipe then merges with another horizontal pipe of equivalent diameter and material, where it is enveloped by gravel and woven geotextile that serves as a cushion to protect the primary 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 IS-inch pipe and used to remove tailings wastewaters for purposes of de-watering the tailings celL f) Dike Splash Pads - A minimum of eight (8) 10-foot wide splash pads are installed on the interior dike slopes to protect the primary FML from abrasion and scouring by tailings slurry. These pads will consist of an extra layer of 60 mil HDPE membrane that will be placed down the inside slope of Cell 4A, from the top of the dike and down the inside slope. The pads on the north side of the Cell will extend to a point 5-feet beyond the toe of the slope to protect the liner bottom during 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 described in f) above, rub sheets are installed beneath all piping entering or exiting Cell 4A that is not located directly on the splash pads. h) Emergency Spillway - a concrete lined spillway constructed near the western corner of the north dike to allow emergency runoff from Cell 3 into Cell 4A. This spillway will be limited to a 6-inch reinforced concrete slab set directly over the primary FML in a 4-foot deep trapezoidal channel. No other spillway or overflow structure will be constructed at Cell 4A. All stormwater runoff and tailings wastewaters not retained in Cells 2 and 3, will be managed and contained in Cell 4A, including the Probable Maximum Precipitation and flood event. Cell Operation Solution Discharge 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 transferred from Cell I evaporation pond or the free water surface from Cell 3. The solution will be pumped to Cell 4A through 6 inch or 8 inch diameter HDPE pipelines. The initial solution discharge will be in the southwest corner of the Cell. The discharge pipe will be routed down the Splash Pad provided in the corner of the Cell to protect Page 3 Cell4A BAT Monitoring, Operations and Maintenance Plan 311 () Revision Denison 1.4 the pipeline running from the solution reclaim barge. The solution will be discharged in 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 rise around the slimes drain strips, eliminating any damage to the strip drains or the sand bag cover due to solution flowing past the drainage strips. The solution will eventually be discharged along the dike between Cell 3 and Cell 4A, utilizing the Splash Pads described 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 potential to damage the Splash Pads or the Slimes Drain system. At no time will the solution be discharged into less than 2 feet of solution. As the cell begin to fill with solution the discharge point will be pull back up the Splash Pad and allowed to continue discharging at or near the solution level. Initial Solids Discharge 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 inch diameter HOPE 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 points can be used depending on operational considerations. Solids will settle into a cone, or mound, of material under the solution level, with the courser fraction settling out closer to the discharge point. The initial discharge locations are shown on Figure I. Figure 2 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 ncar 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 in Section A-A on Figure 2. Because of the depth of Cell 4A, each of the discharge points will be utilized for an extended period of time before the cone of material is above the maximum level of the solution. The discharge location will then moved further to the interior 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 slurry 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. Equipment Access Access will be restricted to the interior portion of the cell due to the potential to damage the flexible membrane liner. Only rubber tired all terrain vehicles or foot traffic will be allowed on the flexible membrane liner. Personnel are also Page 4 Cell 4A BAT Monitoring, Operations and Maintenance Plan 311 0 Revision Denison 1.4 cautioned on the potential damage to the flexible membrane liner through the use and handling of hand tools and maintenance materials. Reclaim Water System A pump barge and solution recovery system will be installed in the southwest corner of the cell to pump solution from the cell for water balance purposes or for re-use in the Mill process. Figure 3 illustrates the routing of the solution return pipeline and the location of the pump barge. The pump barge will be constructed and maintained to ensure that the flexible membrane liner is not damaged during the initial filling of the cell or subsequent operation and maintenance activities. The condition of the pump barge and access walkway will be noted during the weekly Cell inspections. Interim Solids Discharge Figure 4 illustrates the progression of the slurry discharge points around the east side of Cell 4A. Once the tailings 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 liner system. Liner Maintenance and QAIQC Any construction defects or operational damage discovered during observation of the flexible membrane liner 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. BAT Performance Standards for Tailings Cell4A DUSA will operate and maintain Tailings Cell 4A so as to prevent release of wastewater to groundwater and the environment in accordance with this BAT Monitoring Operations and Maintenance Plan, pursuant to Part I.H.19 of the GWDP. These performance standards shall include: 1) Leak Detection System Pumping and Monitoring Equipment -the leak detection system pumping and monitoring equipment, includes a submersible pump, pump controller, water level indicator (head monitoring), and flow meter with volume totalizer. The pump controller is set to maintain the maximum level in the leak detection system at no more than 1 foot above the lowest level of the secondary flexible menbrane. A second leak detection pump with pressure transducer, flow Page 5 Cel14A BAT Monitoring, Operations and Maintenance Plan 311 0 Revision Denison 1.4 meter, and manufacturer recommended spare parts for the pump controller and water level data collector is maintained in the Mill warehouse to ensure that the pump and controller 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 in a report to Mill management with recommendations for prevention of are-occurrence. 2) Maximum Allowable Head -the Permittee shall measure the fluid head above the lowest point on the secondary flexible membrane by the use of procedures and equipment specified in the White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) monitoring Plan, 3/07 Revision: Denison-3, or the currently approved DMT Plan. Under no circumstance shall fluid head in the leak detection system sump exceed a I-foot level above the lowest point in the lower flexible membrane liner. 3) Maximum Allowable Daily LDS Flow Rates -the Permittee shall measure the volume of all fluids pumped from the LDS on a weekly basis, and use that information to calculate an average volume pumped per day. Under no circumstances shall the daily LDS flow volume exceed 24,160 gallons/day. The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Table I to determine the maximum daily allowable LDS flow volume for varying head conditions in the cell .. 4) 3-foot Minimum Vertical Freeboard Criteria -the Permittee shall operate and maintain wastewater levels to provide a 3-foot Minimum of vertical freeboard in Tailings Cell 4A. Said measurements shall be made to the nearest 0.1 foot. 5) Slimes Drain Recovery Head Monitoring -immediately after the Permittee initiates pumping conditions in the Tailings Cell 4A slimes drain system, monthly recovery head tests and fluid level measurements will be made in accordance with a plan approved by the DRC Executive Secretary. The slimes drain system will pumping and monitoring equipment, includes a submersible pump, pump controller, water level indicator (head monitoring), and flow meter with volume totalizer. Routine Maintenance and Monitoring Trained personnel inspect the White Mesa tailings system on a once per day basis. Any abnormal occurrences or changes in the system will be immediately reported to Mill management and maintenance personnel. The inspectors are trained to look for events involving the routine placement of tailings material as well as events that could affect the integrity of the tailings cell dikes or lining systems. The daily inspection reports are Page 6 Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/1 0 Revision Denison 1.4 summarized on a monthly basis and reviewed and signed by the Mill Manager. Solution Elevation Measurements in Ce1l4A are to be taken by survey on a weekly 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"); (ii) The survey will be performed using a survey instrument (the "Survey Instrument") accurate to 0.0 I feet, such as a Sokkai No. B21, or equivalent, together with a survey rod (the "Survey Rod") having a visible scale in 0.0 I foot increments; (iii)The reference Points (the "Reference Points") for Cells 4A are known points established by Registered Land Surveyor. For Cell 4A, the Reference Point is a piece of metal rebar located on the dike between Cell 3 and Cell 4A. The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell 4A is at 5,607.83 feet above mean sea level ("amsl"); (iv) The Surveyor will set up the Survey Instrument in a location where both the applicable Reference Point and pond surface are visible. For Cell 4A, this is typically on the road between Cell 3 and Ce1l4A, approximately 100 feet east of the Cell 4A Reference Point; (v) Once in location, the Surveyor will ensure that the Survey Instrument is level by centering the bubble in the level gauge on the Survey Instrument; (vi)The Assistant will place the Survey Rod vertically on the Ce1l4A Reference Point. The Assistant will ensure that the Survey Rod is vertical by gentl y rocking the rod back and forth until the Surveyor has established a level reading; (vii) 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; 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 Cell 4A. The designated location for Cell 4A is in the northeast corner of the Cell where the side slope allows for safe access to the solution surface. The approximate coordinate locations for the measuring points for Cell 4A is 2,579,360 east, and 320,300 north. These coordinate locations may vary somewhat depending on solution elevations in the Cell. 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; Page 7 Cell 4A BAT Monitoring, Operations and Maintenance Plan 311 0 Revision Denison 1.4 (viii) The Surveyor will focus the cross hairs of the Survey Instrument on the scale on the Survey Rod, and record the number (the "Pond Surface Reading"), which represents the number of feet the Survey Instrument is reading above the pond surface level. The Surveyor will calculate the elevation of the pond surface in feet amsl by adding the Reference Point Reading for the Cell and subtracting the Pond Surface Reading for the Cell, and will record the number accurate to 0.01 feet. Leak Detection System The Leak detection system is monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector. 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. The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill's environmental monitoring data base, and into the files for weekly inspection reports of the tailings cell leak detection systems. Within 24 hours after collection of the weekly water level data, the information will be evaluated to ensure that: 1) the water level in the leak detection sump did not exceed the allowable level (5556.14 feet amsl), and 2) the average daily flow rate from the LDS did not exceed the maximum daily allowable flow rate at any time during the reporting period. For Cell 4A, under no circumstance shall fluid head in the leak detection system sump exceed a I -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 leak detection system, 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. The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Table 1, to determine the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A. Any abnormal or out of compliance water levels must be immediately reported to Mill management. The data collector is also equipped with an audible alarm that sounds if the water level in the leak detection sump exceeds the allowable level (5556.14 feet amsl). The current water level is displayed at all times on the data collector and available for recording on the daily inspection form. The Page 8 Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/1 0 Revision Denison 1.4 leak detection system is also equipped with a leak detection pump, EPS Model # 25S05-3 stainless steel, or equal. The pump is capable of pumping in excess of 25 gallons per minute at a total dynamic head of 50 feet. The pump has a L5 inch diameter discharge, and operates on 460 volt 3 phase power. The 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) above the lowest level of the leak detection sump (9 inches above the lowest point on the lower flexible membrane liner, to ensure the allowable LO foot (5556.14 feet amsl) above the lowest point on the lower flexible membrane liner is not exceeded). The attached Figure 6, Leak Detection Sump Operating Elevations, illustrates the relationship between the sump elevation, the lowest point 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). The pump discharge is equipped with a 1.5 inch flow meter, EPS Paddle Wheel Flowsensor, or equal, that reads the pump discharge in gallons per minute, and records total gallons pumped. The flow rate and total gallons is recorded by the Inspector on the weekly inspection form. The leak detection pump is installed in the horizontal section of the 18 inch, horizontal, perforated section of the PVC collection pipe. The distance from the top flange face, at the collection pipe invert, to the centerline of the 22.5 degree elbow is 133.4 feet, and the vertical height is approximately 45 feet. The pump is installed at least 2 feet beyond the centerline of the elbow. The bottom of the pump will be installed in the leak detection sump at least 135.4 feet or more from the top of the flange invert. A pressure transducer installed with 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 second 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 in the Mill warehouse to ensure that the pump and controller 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 in a report to MiIlmanagement with recommendations for prevention of are-occurrence. Slimes Drain System (i) A pump, Tsurumi Model # KTZ23.7-62 stainless steel, or equal, will be Page 9 Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/1 0 Revision Denison 1.4 placed inside of the slimes drain access riser pipe and a near as possible to the bottom of the slimes drain snmp. The bottom of the slimes drain sump is 38 feet below a water level measuring point at the centerline of the slimes drain access pipe, ncar the ground surface level. The pump discharge will be equipped with a 2 inch flow meter, E/H Model #33, or equal, that reads the pump discharge in gallons per minute, and records total gallons pumped. The flow rate and total gallons will be recorded by the Inspector on the weekly inspection form. (ii) The slimes drain pump will be on adjustable probes that allows the pump to be set to start and stop on intervals determined by Mill management. (iii)The Cell 4A slimes drain pump will be checked weekly to observe that it is operating and that the level probes are set 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 repaired or replaced within 15 days; (iv)Depth to wastewater in the Cell 4A slimes drain access riser pipe shall be monitored and recorded weekly to determine maximum and minimum fluid head before and after a pumping cycle, respectively. All head measurements must be made from the same measuring point, to the nearest 0.01 foot. The results will be recorded as depth-in-pipe measurements on the Weekly Tailings Inspection Form; (v) On a monthly basis, the slimes drain pump will be turned off and the wastewater in the slimes 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 (I) 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 measuring the depth to water below the water level measuring point on the slimes drain access pipe; The slimes drain pump will not be operated until Mill management has determined that no additional process solutions will be discharged to Cell 4A, and the Cell has been partially covered with the first phase of the reclamation cap. The long term effectiveness and performance of the slimes drain dewatering will be evaluated on the same basis as the currently operating slimes drain system for Cell 2. Tailings Emergencies Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if, during 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 Radiation Technician or Radiation Safety Officer, inspectors will have the authority to direct resources during tailings emergencies. Page 10 Cell 4A BAT Moniloring, Operalions and Maimenance Plan 311 0 Revision Denison 1.4 Any major catastrophic cvents 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). Cell 4A Solutiou Freeboard Calculation The maximum tailings cell pond wastewater levels in Cells I-I, Cell 2, Cell 3 and Cell 4A are regulated by condition 10.3 of the White Mesa Milllle.(2) Materials License. Condition 10.3 states that "Freeboard limits for Cells 1·1, and 3, shall be set periodically in accordance with the procedures set out in Section 3.0 to Appendix E of the previously approved NRC license application, including the October 13, 1999 revisions made to the January 10, 1990 Drainage Report. The freeboard limit for Cell 3 shall be recalculated annually in accordance with the procedures set in the October 13, 1999 revision to the Drainage Report." The 1990 Drainage Report uses the Local 6-hour Probable Maximum Precipitation (PMP) event for calculating the freeboard requirements for each of the tailings cells. The PMP for the White Mesa site is 10 inches. Based on the PMP storm event, the freeboard requirement for Cell I is a maximum operating water level of 5615.4 feet above mean sea level (amsl). The Cell I freeboard limit is not affected by operations or conditions in Cells 2, 3 or 4A. Cell 2 has no freeboard limit because the Cell is 99% full of tailings solids and all precipitation falling on Cell 2 and the adjacent drainage area must be contained in Cell 3. The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas, plus the adjacent drainage areas, is 123.4 acre-feet of water. According to the freeboard calculation procedures, this volume currently must be contained in thc existing 24-acre pool area in Cell 3. This results in a maximum operating water level in Cell 3 of 5601.6 feet amsl. The Ce1l4A design includes a concrete spillway between Cell 3 and Ce1l4A with the invert elevation 4 feet below the top of the Cell 3 dike, at an elevation of 5604.5 feet amsl. Once Cell 4A is placed in operation, the cell would be available for emergency overflows from Cell 3, but as long as the freeboard limit in Cell 3 is maintained at 5601.6 it is extremely unlikely that Ce1l4A would see any overflow water from Cell 3 unless the full PMP event were to occur. Should Cell 3 receive the full PMP volume of 123.4 acre feet of water, approximately 62 acre feet of that volume would flow through the spillway into Cell 4A. 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). This would result in a total flood volume of 98 acre-feet, including the 62 acre-feet of solution Page II Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/10 Revision Denison 1.4 from Cell 3. The freeboard depth required for Ce1l4A from the PMP event would be 2.44 feet, plus a wave run-up depth of 0.77 feet (from the 1990 Drainage Report), for a total freeboard requirement of 3.2 feet. This calculation is illustrated on Attachment 4. The Groundwater Quality Discharge Permit, No. UGW370004, for the White Mesa Mill requires that the minimum freeboard be no less than 3.0 feet for any of the existing Cell construction, but based on the above calculation the freeboard would be set 3.2 feet below the top of liner. The freeboard for CeIl4A would therefore be 5595.3 amsl (top of liner 5598.5 -3.2 feet). Figure 7, Hydraulic Profilc Schematic, shows the relationship between the Cells, and the relative elevations of the solution pools and the spillway elevations. If Cell 4A were required to store the entire PMP event for Cell 2, Cell 3 and Cell 4A, the required storage volume would be approximately 160 acre-feet of solution. This would increase the necessary freeboard to 4.77 feet. The required freeboard for Ce1l4A will be recalculated annually along with the re- calculation of the Cell 3 freeboard requirement. A calculation of the current freeboard calculation for both Cells is attached to this Plan. Page 12 Cell 4A BAT Monitoring, Operations and Maintenance Plan 3/1 0 Revision Denison 1.4 Attachments 1) Figure 1, Initial Filling Plan, GeoSyntec Consultants 2) Figure 2, Initial Filling Plan, Details and Sections, GeoSyntec Consultants 3) Figure 3, Initial Filling Plan, Solution and Slurry Pipeline Routes, GeoSyntec Consultants 4) Figure 4, Interim Filling Plan, GeoSyntec Consultants 5) Figure 5, Leak Detection System Sump, GeoSyntec Consultants 6) Figure 6, Leak Detection Sump Operating Elevations 7) Figure 7, Hydraulic Profile Schematic 8) Cell 3 and Cell 4A Freeboard Calculation 9) Table 1, Calculated Action leakage Rates for Various Head Conditions, Ce1l4A, White Mesa Mill, Blanding, Utah, GeoSyntec Consultants 10) White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan, 3/07 Revision: DUSA-2, 32 pages, or currently approved version of the DMT Page 13 \ (' i, -------4 + -" ~'.-. '0 o N o 1-,-ro m o • o ~ N 0 U m -h.,y """-''''I;J M"r, '''L.I~-8'~~~' \IO',!CI"""'IOi,r,foY.:,:"iiilT:i\"[;;,:..:r., va2\'~ ;.: ;'.; // ,--" \. ./\ , (" ,/ I , ; / ( > ( ) "-, " o N " o o ~-, ,"" N / /~ 'i';~ ,: I. ~ ~" ~ _______ ,-_r /'_ , ( <';: ,. ;:,:;.;.~:;;. / r/ ,/ / ( / /,j "::.-·W:: SOLUTION RETURN 8" HOPE PIPELINE SLUi~RY OR SOLUTION ~N'~ o 100' 2CO' .... : SCALE IN FEET INITIAL FILLING .t:lLAN Ce_l 4A :.!.~;:'-;;:~\'~ 3 I ; ,.-'---. / \. I ( I ( ( , -----•• 44"··7- 00 m o ~ o '0 N 8 ," if> Z 'l tl ~ 8, ::;; Jl ~I i ~I ~; 0, ~i :7., • < \8" ~ SCl-IrOU'..£; ~Cl PVC ns ruew 60 >.<IL ~O~E Ge:OMwaRAN!: (SI.<oon-1) OCOJtT CU~!O\I CE01'EXTILE ~01t I fPl'l€PAAEO SlJSGR"-OC..-/ .:/.':;;~ . l.J)S PUMP ff\ SECTION W LEAK DElEC'TlONSYSTEMSUl.lf> ~~ ::;'Y;:i", 18"X(;" REU'J:DUCE:R su: S£CllON / CllOlJSYSWJ --/'ffi":~~",,,,,,,, : / /"""~. II 50:::; 4() PW; , CU,y UNER MIL HoPE GtOJ,lEM'8RANO: (SMOOlll) CUs>!IQ'" ~OT'EXTll.£ LEAK DETECl1QN SySTEM SUMP CELL 4A WHIl'E MESA MIlLS BLANDING, UTAH Geosyntec r--0".' JULY 2008 con.sulwnt;; PROJfiCTNO. SC034-9 ---.-----.:,~.;;f:!;~~:. "," : ::::~~::.,: . FIGURE 5 Maximum Solution Elevation -5556.14 feet amsl '--'--'--'--'--'--'--'--'--'--'--'--'--'--'--'- Pump-on level 5555.89 feet omsl Leak Detection Sump Elevation -5553.64 feet amst Lowest level on Secondary Liner -5555.14 feet amsl Proloo' White Mesa Mill REVISIONS County: Son Juan Col,lntv I State: ur Dale Bv LocaUl>n: white Mesa Mill AuthOr: HRR Figure 6 Leak Detection Sump Operating Levels I Dalo: 09/1008 I fillur" 6.dwg I 01uftrid By: 8M t'i: .-----. t PMP PMP Volume, 123.4 ac-ft Volume, 61.6 ac-ft overflows to 36 ac-ft. Cell4A plus 61.6 I ac-ft from Cell 2 and Cell 3. -" --------' Ce112 Svillway -E1ev. 5611.0 Cell 2 Closed Cell4A Cell 3 Freeboard Limit Freeboard Limit 5595.3 ms! 5601.9msl Figure 7 Hydraulic Profile Schematic Not to Scale .'; . ;!;!~'r. :'.<, . ,".".;.,-. -;i.;·-:~:" :'::.'.' Cell 3 Cell 4A Freeboard Calculation Radioactive Materials License UT1900479, License Condition 10.3 Annual Recalculation Annual Calculation Variables ~ Cella PS MDT Cell 3 Pool Surface, from most recent survey or aerial photograph (acres) (August 24, 2003) Estimated Maximum dry tons of Tailings to be generated during next 12 momhs ( October I, 2005 • September 30. 2007 ) 24.0 70,000 Definitions, Constant Factors and Calculations· CeJl3 PMP ARF WRU DC SWE MMP RPA PfJlPFL TRF Fl.(3) AS(3) OFV(3) PMP ROOd Volume Requirement (acre-feel) Area Reducl10n Factor from January 10, 1990 Drainage Report (dry tons per acre) Wave Run Up facter, from January 10, 1990 Drainage Aepo:1 (feel) Top of Liner {Dike Crest}, Cell 3 (feel above mean sea Jevel) Spillway Invert Elevaflon (feet above mean sea Jevel) Maximum Mill PrOduction (dl}' tons) Reduced Pool Arsa (acres) PMP Freeboard Level (feet) Total Required Freeboard (fee!) Freeboard Un-oil (feel above mean sea level) 123.4 39,146 0.78 5608.5 5604,5 1.5 x MDT PS " (MMP I ARF) PMP/RPA P:v,PFL '" WAU DC • TRF Available Slorage Cel! 3 (acre-feel) PMp· «SWE -Fl{3)) x PSI Overflow Voluma to Cell 4A (acre.jaG!) PMp· AS(S) Maximum Freeboard Limit from GWDP is 5605.5 feel msl Maximum Freeboard limit from runoff calculation Is 5603.0 feetfT'lSl If the calculated Fl is greater than 5603.0 fect msl, then the FL is 5603.0 rr.sl .~:" .. ~, ;;' .: .. :~." : 1.5 , 70,000 105,000 dry tons 24.0 -( 105,000 39,146 21.3 acres 123.4 21.3 5.8 feet 5.8 + 0.78 6.6leel 5608.5 6.6 5601.9 feet msl 123.4· 5604.5 5601.9 } , 24.0 6'1.8 iicre·feel 123.4 61.8 61.6 ... :;-; ~T.'. ., '::3" .".',;:;:' _.0' Cell 3 Cell 4A Freeboard Calculation Radioaclive Materials License UT1900479, License Condition 10.3 Annual Recalculation Annual Calculation Variables. Cell4A PS{4) Cell 4A Pool Surface, from most tecertt survey or aerial photograph (acres) MDT(4) Estimated MaXimum dry tons of Tailings to be deposited in Cell4A during next 12 monthS ( July 1,2006 -June 30, 2009) ATS(4) Area of Tailings So~d$ above elevation 5593 (acres) Definitions, Constant Factors and Calculations· Cell 4A PMP(4) PMP Flood Volume Requirement (acre-Ieet) ARF NUl Reduction Facior from January 10, 1990 Drainage Report (dry tons per acre) WRU(4) Wave' Run Up factor, from January 10, 1990 Drainage Report (teet) DC(4) Top of liner (Dike Crest), CeIl4A(fee\ above mean sea level) 40.0 70,000 0.0 36.0 3,9,146 0.77 5598.5 PS(4) -ATS(4) 40.0· RPA{4) Reduced Poof Area (acres) PMPFl.(4) PMP Freeboard level (feet) mF Total Required Freeboard (feet) PMP(4) ... OFV(3) f RPA(4) 36.0 + PMPFl(4) + WRU(4) Fl(4) :-~ . Freeboard Lirr.it (feet above mean sea fevel) DC(4) -TRF(4) Maximum Freeboard limit from GWDP is 5595.5 feet msl MaxImum Freebo<lrd limit from runoff calculation is 5595.3 feet msl If lhe calcu!ated FL(4) is greater than 5595.5 feet msl. Ihen the FL(4) Is 5595.3 msf :f,:?;'-. ... ,~-.-':, , .,i.: . 40.0 acres 61.6 40.0 2.44 (eel 2.44 + 0.77 3.2 fee! 5598.5 3.2 5595,3 feet msl '. ~::: ;;." , ;'-. :"!:.:r;:;::· ;.;" ,~;: i;~;;: Table 1 Calculated Action Leakage Rates for Various Head Conditions Cell 4A White Mesa Mill Blanding, Utah , Head AbO~~e~:~er RatP~"fion Z!2.O; 0 3' 4.0 5 3114.51 20 444:58 21 496. 3( 3. 31 17. 37 i4Jf GeoSyntec Consultants :~ ~)9"J/OglQ Revision Denison 1 Cell 4A BAT Monitoring, Operations and Maintenance Plan. Introduction Construction of Cell 4A was authorized by the Utah Department of Environmental Quality, Division of Radiation Control ("DRC) on June 25,2007. The construction authorization provided that Cell 4A shall not be in operation until after a BAT Monitoring, Operations and Maintenance Plan is submitted for Executive Secretary review and approval. The Plan shall include requirements in Part F.3 of the Groundwater Discharge Permit No. UGW370004 ("GWDP") and full fill the requirements of Parts LD.6, LE.8, and LF.8 of the GWDP. Cell Design Tailings Cell 4A consists of the following major elements: a) Dikes -consisting of earthen embankments of compacted soil, constructed between 1989-1990, and composed of four dikes, each including a IS-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 a interior slope of 2H to 1 V. Width of these dikes varies; each has a minimum crest width of at least 15 feet to support an access road. Base width also varies from 89-feet on the east dike (with no exterior embankment), to 211-feet at the west dike. b) Foundation -including subgrade soils over bedrock materials. 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 corners. c) Tailings Capacity -the floor and inside slopes of Cell4A encompass about 40 acres and have a maximum capacity of about 1.6 million cubic yards of tailings material storage (as measured below the required 3-foot freeboard). d) Liner and Leak Detection Systems -including the following layers, III descending order: 1) Primary 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 primary FML will be in direct physical contact with the tailings material over most of the Cell 4A floor area. In other locations, the primary FML will be in contact with the slimes drain collection system (discussed below). Page 1 I Cell 4A BAT Monitoring, Operations and Maintenance Plan OO}/{).glQ Revision Denison I 2) Leak Detection System -includes a permeable HDPE geonet fabric that extends across the entire area under the primary FML in Cell 4A, and drains to a leak detection sump in the southwest corner. Access to the leak detection sump is via an 18-inch inside diameter (ID) PVC pipe placed down the inside slope, located between the primary and secondary FML liners. At its base this pipe will be surrounded with a gravel filter set in the leak detection sump, having dimensions of 10 feet by 10 feet by 2 feet deep. In turn, the gravel filter layer will be enclosed in an envelope of geotextile fabric. The purpose of both the gravel and geotextile fabric 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. Prior 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 strip drains and perforated collection pipes both installed immediately above the primary FML, as follows: 1) Horizontal Strip Drain System -is installed in a herringbone pattern across the floor of Cell 4A that drain to a "backbone" of perforated collection pipes. These strip drains are made of a prefabricated two-part geo-composite drain material (solid polymer drainage strip) core surrounded by an envelope of non-woven geotextile filter fabric. The strip drains are placed immediately over the primary FML on 50-foot centers, where they conduct fluids downgradient in a southwesterly direction to a physical and hydraulic connection to the perforated slimes drain collection pipe. A series of continuous sand bags, filled with filter sand cover the strip drains. The sand bags are composed of a woven polyester fabric filled with well graded filter sand to protect the drainage system from plugging. 2) Horizontal Slimes Drain Collection Pipe System -includes a "backbone" piping system of 4-inch ID Schedule 40 perforated PVC slimes drain collection (SDC) pipe found at the downgradient end of the strip drain lines. This pipe is in turn overlain by a berm of gravel that runs the entire diagonal length of the cell, surrounded by a geotextile fabric cushion in Page 2 I Cell4A BAT Monitoring, Operations and Maintenance Plan Q9J1G&l.Q Revision Denison 1.J1 immediate contact with the primary FML. In turn, the gravel is overlain by a layer of non-woven geotextile to serve as an additional filter material. This perforated collection pipe serves as the "backbone" to the slimes drain system and runs from the far northeast corner downhill to the far southwest corner of Cell 4A where it joins the slimes drain access pipe. 3) Slimes Drain Access Pipe -consisting of an I8-inch ID Schedule 40 PVC pipe placed down the inside slope of Cell 4A at the southwest corner, above the primary FML. Said pipe then merges with another horizontal pipe of equivalent diameter and material, where it is enveloped by gravel and woven geotextile that serves as a cushion to protect the primary FML. A reducer connects the horizontal I8-inch pipe with the 4-inch SDC pipe. At some future time, a pump will be set in this I8-inch pipe and used to remove tailings wastewaters for purposes of de-watering the tailings cell. f) Dike Splash Pads - A minimum of eight (8) lO-foot wide splash pads are installed on the interior dike slopes to protect the primary FML from abrasion and scouring by tailings slurry. These pads will consist of an extra layer of 60 mil HDPE membrane that will be placed down the inside slope of Cell 4A, from the top of the dike and down the inside slope. The pads on the north side of the Cell will extend to a point 5-feet beyond the toe of the slope to protect the liner bottom during initial startup of the Cell. The exact location of the splash pads is detailed on the As-Built Plans and Specifications. Bg)Rub Protection Sheets -In addition to the splash pads described in f) above, rub sheets are installed beneath all piping entering or exiting Cell 4A that is not located directly on the splash pads. gjhl-Emergency Spillway - a concrete lined spillway constructed near the western corner of the north dike to allow emergency runoff from Cell 3 into Ce1l4A. This spillway will be limited to a 6-inch reinforced concrete slab set directly over the primary FML in a 4-foot deep trapezoidal channel. No other spillway or overflow structure will be constructed at Cell 4A. All stormwater runoff and tailings wastewaters not retained in Cells 2 and 3, will be managed and contained in Cell 4A, including the Probable Maximum Precipitation and flood event. Cell Operation Solution Discharge 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 transferred from Cell 1 evaporation pond or the free water surface from Cell 3. The solution will be pumped to Cell4A through 6 inch or 8 inch diameter HDPE pipelines. The initial Page 3 I CeIl4A BAT Monitoring, Operations and Maintenance Plan Revision Denison I solution discharge will be in the southwest corner of the Cell. The discharge pipe will be routed down the Splash Pad provided in the corner of the Cell to protect the pipeline running from the solution reclaim barge. The solution will be discharged in 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 rise around the slimes drain strips, eliminating any damage to the strip drains or the sand bag cover due to solution flowing past the drainage strips. The solution will eventually be discharged along the dike between Cell 3 and Cell 4A, utilizing the Splash Pads described 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 potential to damage the Splash Pads or the Slimes Drain system. At no time will the solution be discharged into less than 2 feet of solution. As the cell begin to fill with solution the discharge point will be pull back up the Splash Pad and allowed to continue discharging at or near the solution level. Initial Solids Discharge 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 inch diameter HDPE 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 points can be used depending on operational considerations. Solids will settle into a cone, or mound, of material under the solution level, with the courser fraction settling out closer to the discharge point. The initial discharge locations are shown on Figure 1. Figure 2 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 in Section A-A on Figure 2. Because of the depth of Cell 4A, each of the discharge points will be utilized for an extended period of time before the cone of material is above the maximum level of the solution. The discharge location will then moved further to the interior 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 slurry 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. Equipment Access Access will be restricted to the interior portion of the cell due to the potential to Page 4 I Cell 4A BAT Monitoring, Operations and Maintenance Plan Revision Denison 1 damage the flexible membrane liner. Only rubber tired all terrain vehicles or foot traffic will be allowed on the flexible membrane liner. Personnel are also cautioned on the potential damage to the flexible membrane liner through the use and handling of hand tools and maintenance materials. Reclaim Water System A pump barge and solution recovery system will be installed in the southwest corner of the cell to pump solution from the cell for water balance purposes or for re-use in the Mill process. Figure 3 illustrates the routing of the solution return pipeline and the location of the pump barge. The pump barge will be constructed and maintained to ensure that the flexible membrane liner is not damaged during the initial filling of the cell or subsequent operation and maintenance activities. The condition of the pump barge and access walkway will be noted during the weekly Cell inspections. Interim Solids Discharge Figure 4 illustrates the progression of the slurry discharge points around the east side of Cell 4A. Once the tailings 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 liner system. Liner Maintenance and QAlQC Any construction defects or operational damage discovered during observation of the flexible membrane liner 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. BAT Performance Standards for Tailings Cell 4A DUSA will operate and maintain Tailings Ce1l4A so as to prevent release of wastewater to groundwater and the environment in accordance with this BAT Monitoring Operations and Maintenance Plan, pursuant to Part LH.19 of the GWDP. These performance standards shall include: 1) Leak Detection System Pumping and Monitoring Equipment -the leak detection system pumping and monitoring equipment, includes a submersible pump, pump controller, water level indicator (head monitoring), and flow meter with volume totalizer. The pump controller Page 5 I Ce1l4A BAT Monitoring, Operations and Maintenance Plan Revision Denison I is set to maintain the maximum level in the leak detection system at no more than 1 foot above the lowest level of the secondary flexible menbrane. 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 maintained in the Mill warehouse to ensure that the pump and controller 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 in a report to Mill management with recommendations for prevention of are-occurrence. 2) Maximum Allowable Head -the Permittee shall measure the fluid head above the lowest point on the secondary flexible membrane by the use of procedures and equipment specified in the White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) monitoring Plan, 3/07 Revision: Denison-3, or the currently approved DMT Plan. Under no circumstance shall fluid head in the leak detection system sump exceed a I-foot level above the lowest point in the lower flexible membrane liner. 3) Maximum Allowable Daily LDS Flow Rates -the Permittee shall measure the volume of all fluids pumped from the LDS on a weekly basis, and use that information to calculate an average volume pumped per day. Under no circumstances shall the daily LDS flow volume exceed 24,160 gallons/day. The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Table 1 to determine the maximum daily allowable LDS flow volume for varying head conditions in the cell. . 4) 3-foot Minimum Vertical Freeboard Criteria -the Permittee shall operate and maintain wastewater levels to provide a 3-foot Minimum of vertical freeboard in Tailings Ce1l4A. Said measurements shall be made to the nearest 0.1 foot. 5) Slimes Drain Recovery Head Monitoring -immediately after the Permittee initiates pumping conditions in the Tailings Cell4A slimes drain system, monthly recovery head tests and fluid level measurements will be made in accordance with a plan approved by the DRC Executive Secretary. The slimes drain system will pumping and monitoring equipment, includes a submersible pump, pump controller, water level indicator (head monitoring), and flow meter with volume totalizer. Routine Maintenance and Monitoring Trained personnel inspect the White Mesa tailings system on a once per day basis. Any Page 6 I Cell 4A BAT Monitoring, Operations and Maintenance Plan Revision Denison 1 abnormal occurrences or changes in the system will be immediately reported to Mill management and maintenance personnel. The inspectors are trained to look for events involving the routine placement of tailings material as well as events that could affect the integrity of the tailings cell dikes or lining systems. The daily inspection reports are summarized on a monthly basis and reviewed and signed by the Mill Manager. Solution Elevation Measurements in Cell 4A are to be taken by survey on a weekly 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"); (ii) The survey will be performed using 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; (iii)The reference Points (the "Reference Points") for Cells 4A are known points established by Registered Land Surveyor. For Cell 4A, the Reference Point is a piece of metal rebar located on the dike between Cell 3 and Cell 4A. The elevation at the top of this piece of rebar (the Reference Point Elevation for Cell4A is at 5,607.83 feet above mean sea level ("amsl"); (iv) The Surveyor will set up the Survey Instrument in a location where both the applicable Reference Point and pond surface are visible. For Cell 4A, this is typically on the road between Cell 3 and CeIl4A, approximately 100 feet east of the Cell 4A Reference Point; (v) Once in location, the Surveyor will ensure that the Survey Instrument is level by centering the bubble in the level gauge on the Survey Instrument; (vi)The Assistant will place the Survey Rod vertically on the Cell4A 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; (vii) 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; 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 Cell 4A. The designated location for Cell 4A is in the northeast corner of the Cell where the side slope allows for safe access to the solution surface. The approximate coordinate locations for the measuring points for Cell 4A is 2,579,360 east, and 320,300 north. These coordinate locations may vary somewhat depending on solution elevations in the Cell. Page 7 I Cell 4A BAT Monitoring, Operations and Maintenance Plan {l9-J/{h'd,LQ Revision Denison I 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; (viii) The Surveyor will focus the cross hairs of the Survey Instrument on the· scale on the Survey Rod, and record the number (the "Pond Surface Reading"), which represents the number of feet the Survey Instrument is reading above the pond surface level. The Surveyor will calculate the elevation of the pond surface in feet amsl by adding the Reference Point Reading for the Cell and subtracting the Pond Surface Reading for the Cell, and will record the number accurate to 0.01 feet. Leak Detection System The Leak detection system is monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector. 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. The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill's environmental monitoring data base, and into the files for weekly inspection reports of the tailings cell leak detection systems. Within 24 hours after collection of the weekly water level data, the information will be evaluated to ensure that: 1) the water level in the leak detection sump did not exceed the allowable level (5556.14 feet amsl), and 2) the average daily flow rate from the LDS did not exceed the maximum daily allowable flow rate at any time during the reporting period. For Cell 4A, under no circumstance shall fluid head in the leak detection system sump exceed a I-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 leak detection system, 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. The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on the attached Table 1, to determine the maximum daily allowable LDS flow volume for varying Page 8 I Cell 4A BAT Monitoring, Operations and Maintenance Plan Revision Denison 1 head conditions in Cell 4A. Any abnormal or out of compliance water levels must be immediately reported to Mill management. The data collector is also equipped with an audible alarm that sounds if the water level in the leak detection sump exceeds the allowable level (5556.14 feet amsl). The current water level is displayed at all times on the data collector and available for recording on the daily inspection form. The leak detection system is also equipped with a leak detection pump, EPS Model # 25S05-3 stainless steel, or equal. The pump is capable of pumping in excess of 25 gallons per minute at a total dynamic head of 50 feet. The pump has a 1.5 inch diameter discharge, and operates on 460 volt 3 phase power. The 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) above the lowest level of the leak detection sump (9 inches above the lowest point on the lower flexible membrane liner, to ensure the allowable 1.0 foot (5556.14 feet amsl) above the lowest point on the lower flexible membrane liner is not exceeded). The attached Figure 6, Leak Detection Sump Operating Elevations, illustrates the relationship between the sump elevation, the lowest point 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). The pump discharge is equipped with a 1.5 inch flow meter, EPS Paddle Wheel Flowsensor, or equal, that reads the pump discharge in gallons per minute, and records total gallons pumped. The flow rate and total gallons is recorded by the Inspector on the weekly inspection form. The leak detection pump is installed in the horizontal section of the 18 inch, horizontal, perforated section of the PVC collection pipe. The distance from the top flange face, at the collection pipe invert, to the centerline of the 22.5 degree elbow is 133.4 feet, and the vertical height is approximately 45 feet. The pump is installed at least 2 feet beyond the centerline of the elbow. The bottom of the pump will be installed in the leak detection sump at least 135.4 feet or more from the top of the flange invert. A pressure transducer installed with 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 second 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 in the Mill warehouse to ensure that the pump and controller can be replaced and operational within 24 hours of detection of a failure of the pumping system. The root cause of the Page 9 I Ce1l4A BAT Monitoring, Operations and Maintenance Plan Revision Denison I equipment failure will be documented in a report to Mill management with recommendations for prevention of are-occurrence. Slimes Drain System (i) A pump, Tsurumi Model # KTZ23.7-62 stainless steel, or equal, will be placed inside of the slimes drain access riser pipe and a near as possible to the bottom of the slimes drain sump. The bottom of the slimes drain sump is 38 feet below a water level measuring point at the centerline of the slimes drain access pipe, near the ground surface level. The pump discharge will be equipped with a 2 inch flow meter, E/H Model #33, or equal, that reads the pump discharge in gallons per minute, and records total gallons pumped. The flow rate and total gallons will be recorded by the Inspector on the weekly inspection form. (ii) The slimes drain pump will be on adjustable probes that allows the pump to be set to start and stop on intervals determined by Mill management. (iii)The Cell 4A slimes drain pump will be checked weekly to observe that it is operating and that the level probes are set 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 repaired or replaced within 15 days; (iv)Depth to wastewater in the Cell 4A slimes drain access riser pipe shall be monitored and recorded weekly to determine maximum and minimum fluid head before and after a pumping cycle, respectively. All head measurements must be made from the same measuring point, to the nearest 0.01 foot. The results will be recorded as depth-in-pipe measurements on the Weekly Tailings Inspection Form; (v) On a monthly basis, the slimes drain pump will be turned off and the wastewater in the slimes 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 the Monthly Inspection Data form, by measuring the depth to water below the water level measuring point on the slimes drain access pipe; The slimes drain pump will not be operated until Mill management has determined that no additional process solutions will be discharged to Cell 4A, and the Cell has been partially covered with the first phase of the reclamation cap. The long term effectiveness and performance of the slimes drain dewatering will be evaluated on the same basis as the currently operating slimes drain system for Cell 2. Page 10 I Cell 4A BAT Monitoring, Operations and Maintenance Plan Tailings Emergencies Revision Denison I Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if, during 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 Radiation Technician or Radiation Safety Officer, 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 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). Cell 4A Solution Freeboard Calculation The maximum tailings cell pond wastewater levels in Cells 1-1, Cell 2, Cell 3 and Cell4A are regulated by condition 10.3 of the White Mesa Mill lle.(2) Materials License. Condition 10.3 states that "Freeboard limits for Cells 1-1, and 3, shall be set periodically in accordance with the procedures set out in Section 3.0 to Appendix E of the previously approved NRC license application, including the October 13, 1999 revisions made to the January 10, 1990 Drainage Report. The freeboard limit for Cell 3 shall be recalculated annually in accordance with the procedures set in the October 13, 1999 revision to the Drainage Report." The 1990 Drainage Report uses the Local 6-hour Probable Maximum Precipitation (PMP) event for calculating the freeboard requirements for each of the tailings cells. The PMP for the White Mesa site is 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 in Cells 2, 3 or 4A. Cell 2 has no freeboard limit because the Cell is 99% full of tailings solids and all precipitation falling on Cell 2 and the adjacent drainage area must be contained in Cell 3. The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas, plus the adjacent drainage areas, is 123.4 acre-feet of water. According to the freeboard calculation procedures, this volume currently must be contained in the existing 24-acre pool area in Cell 3. This results in a maximum operating water level in Cell 3 of 5601.6 feet amsl. The Cell 4A design includes a concrete spillway between Cell 3 and Cell 4A with the invert elevation 4 feet below the top of the Cell 3 dike, at an elevation of 5604.5 feet Page 11 I Ce1l4A BAT Monitoring, Operations and Maintenance Plan Revision Denison I amsl. Once Cell 4A is placed in operation, the cell would be available for emergency overflows from Cell 3, but as long as the freeboard limit in Cell 3 is maintained at 5601.6 it is extremely unlikely that Ce1l4A would see any overflow water from Cell 3 unless the full PMP event were to occur. Should Cell 3 receive the full PMP volume of 123.4 acre feet of water, approximately 62 acre feet of that volume would flow through the spillway into Ce1l4A. The flood volume from the PMP event over the Ce1l4A area is 36 acre-feet of water (40 acres, plus the adjacent drainage area of 3.25 acres, times the PMP of 10 inches). This would result in a total flood volume of 98 acre-feet, including the 62 acre-feet of solution from Cell 3. The freeboard depth required for Ce1l4A from the PMP event would be 2.44 feet, plus a wave run-up depth of 0.77 feet (from the 1990 Drainage Report), for a total freeboard requirement of 3.2 feet. This calculation is illustrated on Attachment 4. The Groundwater Quality Discharge Permit, No. UGW370004, for the White Mesa Mill requires that the minimum freeboard be no less than 3.0 feet for any of the existing Cell construction, but based on the above calculation the freeboard would be set 3.2 feet below the top of liner. The freeboard for Ce1l4A would therefore be 5595.3 amsl (top of liner 5598.5 -3.2 feet). Figure 7, Hydraulic Profile Schematic, shows the relationship between the Cells, and the relative elevations of the solution pools and the spillway elevations. If Cell 4A were required to store the entire PMP event for Cell 2, Cell 3 and Cell 4A, the required storage volume would be approximately 160 acre-feet of solution. This would increase the necessary freeboard to 4.77 feet. The required freeboard for Ce1l4A will be recalculated annually along with the re- calculation of the Cell 3 freeboard requirement. A calculation of the current freeboard calculation for both Cells is attached to this Plan. Page 12 I Cell 4A BAT Monitoring, Operations and Maintenance Plan Attachments 1) Figure 1, Initial Filling Plan, GeoSyntec Consultants Revision Denison I 2) Figure 2, Initial Filling Plan, Details and Sections, GeoSyntec Consultants 3) Figure 3, Initial Filling Plan, Solution and Slurry Pipeline Routes, GeoSyntec Consultants 4) Figure 4, Interim Filling Plan, GeoSyntec Consultants 5) Figure 5, Leak Detection System Sump, GeoSyntec Consultants 6) Figure 6, Leak Detection Sump Operating Elevations 7) Figure 7, Hydraulic Profile Schematic 8) Cell 3 and Cell 4A Freeboard Calculation 9) Table 1, Calculated Action leakage Rates for Various Head Conditions, CeIl4A, White Mesa Mill, Blanding, Utah, GeoSyntec Consultants 10) White Mesa Mill Tailings Management System and Discharge Minimization Technology (DMT) Monitoring Plan, 3/07 Revision: DUSA-2, 32 pages, or currently approved version of the DMT Page 13 -------' sa: 7-------.- <0 o o N / / \. I ------...... za.:-1~ o o N (:, o o co (J> o " o t') N 0 U W If) Z :::J -, " , ~ ~ 51 ;\ ~ ,< .. ~ ~ g il ~ ,3 ~ ~ " \\ [ \ \\ \', ~ \'h ~1 '(~ , \ " \"-. \ \ \ \ '~'-----~'-"'/,'': / I <' /// ( --------. ~- \ , ~'\)~i~; . ~; .. . ~ :,·:;:·:r~;·· (/ /.1 , ,. ; j /.~ .... - /// / ......... i ,/' /" -/ " .i ,. ! i ( / 8" HDPE PIPELINE SLURRY OR SOLUTION \ \ \ ~'-'-,~ ~~ o 100' 200' ~' I SCALE IN FEET INITIAL FILLING PLAN CELL 4A BLANDING. UTAH Geosyntec f> DATE: JUNE 2008 I'IGURE 3 consultants PROJECT NO, SC0349 . ~: ,: i;.f.;·;; , ;, ~;" ;'~, :.(;r:;;J·.:~; "'J :::.J (~~ :.:'.: ;:...-:: : '.~; ;.~j ~~~ .;: p \:)~.)\S::;C<lc·J\~: . .l,'JD\)f.OJ-19',rnl~(m-hjt/OI\':C03B_fl'"''tJI'" 1 lflt~"'''X~!l".i."",---________________________________ , L 0 CD 0 0 o CIl ~~ ;:;,.... '" CD ~ () 'V ~ !D -l '" r ;0 ~O~ ~~i2 GO r . ~Z C:l>Cl -j WI~ l -U r » 8 ~ z ~ g " ~~ m \\ I '\ ',",'I '\ ''''''j <.. I ", / ./ ~~ '{f(,"'-~cce}IIIHllff 1I11/, __ ~/~"=~,,,",;1 II ___ ,,/ r '" '" ~ ~ ~~~)Ir I/J )r\~~t~\C~'\':',,>~)!\0\ .. / ( a ~~£~~~v. 1, \\~~~\\\~.~'.\ ~~),;r~. ~ .. ':;J '\ \'/' I. .,. 0 0, ~~~17F" ...... ____ __ I '.",,- / ( '\ , / /' f / " ! :i II J ~I c il .. ;~:!;' .. :;}'j ~, 18"' CII SCt-!ECULE -!-O PVC LOS PUMP ff\ SECTION ~~6JlI=Al<-DETEC'TlOl""I SYSTEM SUMP ~ [fL " -. ::~~;?~:;:;~,: : 18"X6" REDUCER s·x ... REDUCER SEE SECTION --------/" ll:AK OETEC110N SYSID.< I I ... " " SCHEDULE 40 PVC : : 4-I! SCHEDULe 40 PVC I I I I ,1" _ .. -_._------;;?!:;-- GE:OS~THe:nc etA Y UNER 60 MIL HOPE GEOMEMBRANE (slAOOno CUSt-lION CE'OTEXTlLE LEAK DETECilON SYSTEM SUMP CELL 4A WHITE MESA MILLS 8LANDING. UTAH Geosyntec r::-DATE, JULY 2008 con.,uiwnts PROJECT NO, SC0349 ) ;~.;-, ;;~~::," : ; ::.?~: .. ~.: FIGURE 5 . ,:<,?~:'i Pump-on level 5555.89 feet amsl Leak Detection Sump Elevation· 5553.64 feet amsl Maximum Solution Elevation -5556.14 feet amsl Lowest Level on Secondary Liner· 5555.14 feet amsl Denison Mines (USA) Corp. Project White Mesa Mill REVISIONS County: Son Juon Ceun!!:. 1 Slate: UT Date By Location: While Mesa Mill Figure 6 Leak Detection Sump Operating Levels ~ENISONI)14 MINES Scale: N/A 1 Date: 09/2008 [figure 6.dwg Author: HRR lOraftedBY; 8M ;< Not to Scale ~ ,;,- ~-------, PMP Volume, 36 ac-ft. plus 61.6 ac-ft from Cell 2 and Cell 3. , ; _' ____ ----.-i Ce1l4A Freeboard Limit 5595.3 ms1 ::~~:tH~·. . . :~~/< PMP Volume, 123.4 ac-ft. 61.6 ac-ft overflows to Ce1l4A Cell 3 Freeboard Limit 5601.9 ms1 Ce112Svillwav -EJev. 5611.0 Cell 2 Closed ~ Figure 7 Hydraulic Profile Schematic :::-.;.~.:.; . . :~r,·· :<~·.i -: . Cell 3 Cell 4A Freeboard Calculation Radioactive Materials License UT1900479, License Condition 10.3 Annual Recalculation Annual Calculation Variables. Cell 3 PS MDT Cell 3 Pool Surface. from most recent survey or aerial photograph (acres) (August 24. 2003) Estimated Maximum dry tons of Tailings to be generated during next 12 months ( Oclober I, 2006 -September 30. 2007 ) Definitions, Constant Factors and Calculations· Cell 3 PMP ARF WRU DC SWE MMP RPA PMPFL TRF FL(3) PMP Rood Volume Requirement (acre-feet) Area Reduction Factor from January 10, 1990 Drainage Report (dry tons per acre) Wave Run Up factor, from January 10.1990 Drainage Report (feet) Top of Liner (Dike Crest), Cell 3 (feet above mean sea level) Spillway Invert Elevation (feet above mean sea level) Maximum Mill Production (dry tons) Reduced Pool Area (acres) PMP Freeboard Level (feel) Total Required Freeboard (feet) Freeboard Umit (feet above mean sea level) 24.0 70,000 123.4 39,146 0.78 5608.5 5604.5 1.5 x MDT 1.5 x 70.000 105,000 drylons PS -(MMP I ARF) 24.0· ( 105,000 39.146 21.3 acres PMP/RPA 123.4 21.3 5.8 feel PMPFL + WRU 5.8 + 0.78 6.6 feet DC· TRF 5608.5 6.6 5601.9 feet msl AS(3) Avallable Storage Cell 3 (acre-feet) PMP • «SWE ·FL(3)) x PS) 123.4 • 5604.5 5601.9 ) x 24.0 61.8 acre-feet OFV(3) Overflow Volume to Cell 4A (acre·feet) PMP· AS(S) 123.4 61.8 61.6 Maximum Freeboard Limit from GWDP is 5605.5 feet msl Maximum Freeboard Limit from runoff calculation Is 5603.0 fGet msl If the calculated Fl is greater than 5603.0 feet msl, then the FL is 560S.0 msl ;..:; ;"';. "'::" -:. :,: ~~";::' .::. ~ < ~ ".-;; :.r " ;: ).: .--;.{~ .. .".-~,~:):,~ ; .. ;', Cell 3 Cell 4A Freeboard Calculation Radioactive Materials License UT1900479, License Condition 10.3 Annual Recalculation Annual Calculation Variables· Cell 4A PS(4) Cell 4A Pool Surface, from most recent survey or aerial photograph (acres) MDT(4) Estimated Maximum dry tons of Tailings to be deposited in Cell 4A during next 12 months ( July 1, 2008 -June 30, 2009 ) ATS(4) Area of Tailings Solids above elevation 5593 (acres) Definitions, Constant Factors and Calculations· Cell4A PMP(4) PMP Flood Volume Requirement (acre-Ieet) ARF Area Reduction Factor from January 10,1990 Drainage Report (dry tons per acre) WRU(4) Wave Run Up factor, from January 10,1990 Drainage Report (feot) DC(4) Top of Uner (Dike Crest), Cell 4A (feet above mean sea level) 40.0 70,000 0.0 36_0 3.9,146 0_77 5598_5 PS(4) -ATS(4) 40.0 -RPA(4) Reduced Pool Area (acres) PMPFL(4) PMP Freeboard Level (feet) mF Total Required Freeboard (feel) PMP(4) + OFV(3) I RPA(4) 36.0 + PMPFL(4) + WRU(4) Fl(4) ,;;" Freebcard Limit (feet above mean sea level) DC(4) -TRF(4) Maximum Freeboard Umit from GWDP is 5595.5 feet msl Maximum Freeboard limit from runoff calculation is 5595.3 feet msl If the calculated FL(4) is greater than 5595_5 feet msl, then the FL(4) Is 5595_3 msl ~ (~pr' .r~,: . : ;";', 40.0 acres 61.6 40.0 2.44 feel 2.44 + 0.77 3.2 feet 5598.5 3.2 5595.3 feet msl . <:' ";;>': : l·~~.::·~.;;::·;;: . ·','::;7·~:.' I· i. Table 1 Calculated Action Leakage Rates for Various Head Conditions Cell 4A White Mesa Mill Blanding, ~tah Head Above Liner Calculated Action Leakage System (feet) Rate laallons/acre/davl 5 222.04 10 314.01 15 384.58 20 444.08 25 496.50 30 543.88 35 587.46 37 604.01 GeoSyntec Consultants :.~ ~ . -. :'~ : ~.'. White Mesa Mill -Standard Operating Procedures Book 1 I: Environmental Protection Manual, Section 3. I 3/1 0 Revision: Denison-? Page I of37 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN 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. UTl900479 (the "Radioactive Materials License"), as well as procedures for operating and maintenance of monitoring 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 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 four tailings cells will be inspected. Observations will be made of the current 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, except on weekends when the Shift Foreman will perform the weekend tailings inspections. The Radiation Safety Officer 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, White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 3/1 0 Revision: Denison-7 Page 2 of 37 which includes a tailings cells map, and spaces to record observations, especially those of immediate concern 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 concern is and what corrective measures will resolve the problem. This observation of concern 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: CellI, 2, 3, and 4A, Dikes 1,2,3, 4A-S, and 4A-W, wind movement of tailings, effectiveness of dust minimization methods, spray evaporation, Cell 2 spillway, Cell 3 spillway, Cell 3 and 4A liquid pools and associated liquid return equipment, cell leak detection systems, and the wildlife ponds. Operational features of the tailings area are checked for conditions of potential concern. 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 return 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 CellI, Cell 3 or Cell 4A; the pond return line from the tailings area to the Mill; and, lines transporting pond solutions from one cell to another. b) CellI. c) Cell 2. d) Cell 3. e) Ce1l4A. f) Dike structures including dikes 1,2,3, 4A-S, and 4A-W. g) The Cell 2 spillway, Cell 3 spillway, Cell 3 and Cell 4A liquid pools and associated liquid return equipment. h) Presence of wildlife and/or domesticated animals in the tailings area, including waterfowl and burrowing animal habitations. i) Spray evaporation pumps and lines. White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3, I 3110 Revision: Denison-7 Page 3 0[37 j) 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. During tailings inspection, general surface conditions will be evaluated for the following: 1) 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 minimization activities. k) Observation of flow and operational status of the dust control/spray evaporation system(s). I) Observations of any abnormal variations in tailings pond elevations in Cells 1,3, and4A. m) 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 Impection Data form. n) An estimate of flow for active tailings slurry and SX line(s). 0) An estimate of flow in the solution return line(s). p) Daily measurements in the leak detection system (LOS) 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 CellI and Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours. The solution level in Cell 4A leak detection is not allowed to be more than 1.0 foot above the lowest point on the bottom flexible membrane liner (elevation 5556.14 feet musl). If any of these observation 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 1.0.6 and I.G.3 of the Groundwater Discharge Permit must be adhered to when the solution level trigger for Cell 4A has been exceeded. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 3/1 0 Revision: Dcnison-7 Page 4 of 37 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 Impection 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 of the License Conditions. q) 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 and 4A. Items (a), (m), (n), and (0) are to be done only when the Mill is operating. When the Mill is down, these items cannot be performed. 2.2. Daily 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 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. 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 during 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 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 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. While Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 2.5. Tailings Emergencies 3/1 0 Revision: Denison-7 Page 5 of37 Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if, during 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 Radiation Technician or Radiation Safety Officer, inspectors will have the authority to direct resources during tailings emergencICs. 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). 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 tailings 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 Ce1l4A leak detection system is 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. The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill's environmental monitoring data base, and into the files for weekly inspection reports of the tailings cell leak detection systems White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 3/10 Revision: Denison-7 Page 6 of 37 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 LDA 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 lcvels were recorded, whichever is the more recent. This calculation shalI be documented as part of the weekly inspection. Upon the initial pumping of fluid from an LDS, a fluid sample shalI be colIeeted and analyzed in accordance with paragraph 11.3 C. of the Radioactive Materials License. For CelI 4A, under no circumstance shall fluid head in the leak detection system sump exceed a I-foot level above the lowest point in the lower flexible membrane liner. To determine the Maximum AlIowable Daily LDS Flow Rates in the Cell 4A leak detection system, the total volume of alI fluids pumped from the LDS on a weekly basis shalI be recovered from the data colIector, and that information will be used to calculate an average volume pumped per day. Under no circumstances shalI the daily LDS flow volume exceed 24,160 galIons/day. The maximum daily LDS flow volumc wilI be compared against the measured celI solution levels detailed on Table I in Appendix E, to determine the maximum daily alIowable LDS flow volume for varying head conditions in CelI 4A. b) Slimes Drain Water Level Monitoring (i) CelI 3 is an active tailings celI while CelI 2 is partialIy reclaimed with approximately 90% of the surface covered by platform fill. Each celI has a slimes drain system which aids in dewatering the slimes and sands placed in the celI; (ii) Cell 2 has a pump placed inside of the slimes drain access pipe at the bottom of the slimes drain. As taken from actual measurements, the bottom of the slimes drain is 38 feet below a water level measuring point at the centerline of the slimes drain access pipe, at the ground surface level. 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 CelI 2, which, based on construction reports, is at a depth of 39 feet below the water level measuring point on the slimes drain access pipe for CelI 2; White Mesa Mill-Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 311 0 Revision: Denison-7 Page 7 of 37 (iii)The slimes drain pump in Cell 2 is on a timed system, under which it pumps for IS minutes each hour, thereby allowing the slimes wastewater to recharge for 45 minutes before being pumped again. Based on measurements taken in August 2006, the water level in the Cell 2 slimes drain recharges to a depth of about 28.50 feet before each pumping and is pumped to a depth of 3 8 feet after each pumping, in each case measured below the water level measuring point on the slimes drain access pipe. The average wastewater head in the Cell 2 slimes drain is therefore about 5 feet. The depth to water of about 28.50 feet after recharge is below the phreatic surface of tailings Cell 2, which is at a depth of about 20 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 at these intervals is satisfactory and is as low as reasonably achievable. Based on past experience, cycling the pump more than IS minutes every hour can result in more replacement costs for pumps and more resulting system downtime; (iv)The Cell 2 slimes drain pump is checked weekly to observe that it is operating and that the timer is set 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 IS 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. 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; (vi)On a monthly basis, the slimes drain pump will be turned off and the wastewater in the slimes 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 the Monthly Inspection Data form, by measuring the depth to water below the water level measuring point on the slimes drain access pipe; (vii) No process liquids shall be allowed to be discharged into Cell 2; (viii) 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 I.G.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 Ce1l4A are currently active, no pumping from the Cell 3 or Cell 4A slimes drain is authorized. Prior to initiation of tailings dewatering operations for Cell 3 or Cell 4A, a similar procedure will be developed for ensuring that average White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 3/ I 0 Revision: Denison-7 Page 8 of 37 head elevations in the Cell 3 and Ce1l4A slimes drains are kept as low as reasonably achievable, and that the Cell 3 and Ce1l4A 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 tailings or dusting and control measures shall be taken if needed. d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 1, 3 and 4A and Roberts Pond are to be taken by survey on a weekly 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"); (ii) The survey will be performed using 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; (iii)The reference Points (the "Reference Points") for Cells 1,3 and 4A, 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 CellI and Roberts Pond is at 5,623.14 feet above mean sea level ("FMSL"). For Cell 3 and cell4A, 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 3 and cell 4A) is at 5,607.83 FMSL; (iv) The Surveyor will set up the Survey Instrument 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 CellllRoberts Pond Reference Point. For Cell 3 and Cell 4A, this is typically on the road on the Cell 3 dike approximately 100 feet east of the Cell 3 Reference Point; (v) Once in location, the Surveyor will ensure that the Survey Instrument is level by centering the bubble in the level gauge on the Survey Instrument; (vi)The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell lIRoberts Pond Reference Point and on the top of the rebar on the Cell 3 and cell 4A 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; (vii) 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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 3/10 Revision: Denison-7 Page 9 of37 represents the number of feet the Survey Instrument is reading above the Reference Point; (viii) 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 or Roberts Pond, 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: I. Cell 3 A stake has been place in the central area of the south dike of Cell 3. The Assistant will walk perpendicular to the dike from the stake to the nearest point on the liquid surface of Cell 3 and place the Survey Rod at that location; B. Cell4A The Assistant will walk down the slope in the northeast corner of Cell 4A and place the Survey Rod at the liquid level. C. CellI A mark has been painted on the north side of the ramp going to the pump platform in Cell I. The Assistant will place the Survey Rod against that mark and hold the rod vertically, with one end just touching the liquid surface; and D 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 I 322,196 2,579,277 Cell 3 320,508 2,577,760 Cell4A 320,300 2,579,360 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells; White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 3110 Revision: Denison-7 Page 10 of37 (ix)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; (x) The Surveyor will focus the cross hairs of the Survey Instrument on the scale on the Survey Rod, and record the number (the "Pond Surface Reading"), which represents the number of feet the Survey Instrument 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) Summary In addition, the weekly inspection should summarize all activities concerning 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 ({nd DMT Inspection form is provided in Appendix A. 3.2. Weekly 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 ({nd 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 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 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 White Mesa Mill -Standard Operating Procedures Book J 1: Environmental Protection Manual, Section 3, I 3/10 Revision: Denison-7 Page 11 of37 c) all alternate 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 variance in stored materials from this requirement or observed leaking alternate feedstock drums 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 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 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 critical points of the pipe include bends, slope changes, valves, and junctions, which are critical to dike stability. These locations to be monitored will be determined by the Radiation Safety Officer or his designee from the Radiation Safety Department during the Mill run. b) Diversion Ditches Diversion ditches 1, 2 and 3 shall be monitored monthly for sloughing, erosion, undesirable vegetation, and obstruction 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 summarized for the month. d) Overl>pray Dust Minimization The inspection shall include an evaluation of overs pray minimization, if applicable. This entails ensuring that the overs pray system is functioning properly. In the event that overs pray is carried more than 50 feet from the cell, the overs pray system should While Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 be immediately shut-off. e) Remarks 3/10 Revision: Denison-7 Page 1201'37 A section is included on the Monthly Inspection Data form for remarks in which recommendations can be made or observations of concern can bc documented . .f) Summary ot'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 In.llJection 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 Review, a Construction Review and a Summary, as follows: a) Embankment In.1l)ection 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. 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 Construction Review consists of reviewing any construction changes or modifications made to the tailings area on a quarterly basis. White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 d) Summary 3110 Revision: Denisnn-7 Page 13 of37 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 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 structures. 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 structures. In the event tailings capacity evaluations (as per SOP PBL-3) were performed for the receipt of alternate 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 summarize observations of potential concern. 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. White Mesa Mill -Standard Operating Procedures Book 1 I: Environmental Protection Manual, Section 3.1 311 0 Revision: Denison-7 Page 14 of 37 The registered engineer will obtain copies of selected tailings inspections, along with the monthly and quarterly summaries of observations of concern 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 September 1 $I of every year to: Directing Dam Safety Engineer State of Utah, Natural Resources 1636 West North Temple, Suite 220 Salt Lake City, Utah 84116-3156 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 a) Tailings Cells 1 and 4A The freeboard limits are as per January 10, 1990 Drainage Reportfor Cells] and 4A and are stated below: (i) A liquid maximum elevation of 5,615.4 feet mean sea level in CellI. (ii) A liquid maximum elevation of 5,596.4 feet mean sea level in Ce1l4A. b) Tailings Cell 3 The freeboard limit for Cell 3 is determined annually using the following procedure: (i) From a survey of Cell 3, the pool surface will be determined. (ii) An estimate of the maximum tons of dry tailings to be generated during the next 12 months will be made. This estimate is multiplied by 1.5, a factor of safety, to yield the Maximum Mill Production. (iii) The Maximum Mill Production is divided by the number of tons required White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 3/10 Revision: Denison-7 Page 15 of 37 to reduce the pool size by one acre and then subtracted from the pool surface (determined in Step i), yielding the Reduced Pool Area. (iv) The PMP Flood Volume Requirement, as per the January 10, 1990 Drainage Report, is 123.4 acre feet. The PMP Flood Volume Requirement is divided by the Reduced Pool Area to determine the PMP Freeboard Level. (v) The Wave Run Up of 0.78 feet (as specified in the January 10, 1990 Drainage Report) is added to the PMP Freeboard Level to determine the Total Required Freeboard. The calculation of the Total Required Freeboard for Cell 3 will be calculated annually and the calculation sheet filed in the Mill Central File. c) Tailings Ce1l4A The freeboard limit for Cell 4A is determined annually using the following procedure: The Ce1l4A design includes a concrete spillway between Cell 3 and Ce1l4A, with the invert elevation 4 feet below the top of the Cell 3 dike, at an elevation of 5604.5 feet amsl. Should Cell 3 receive the full PMP volume of 123.4 acre feet of water, approximately 62 acre feet of that volume would flow through the spillway into Cell 4A. 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 of3.25 acres, times the PMP of 10 inches). This would result in a total flood volume of 98 acre-feet, including the 62 acre-feet of solution from Cell 3. The freeboard depth required for Cell 4A from the PMP event would be 2.44 feet, plus a wave run-up depth of 0.77 feet (from the 1990 Drainage Report), for a total freeboard requirement of 3.2 feet. This calculation is illustrated on Attachment 4. The Groundwater Quality Discharge Permit, No. UGW370004, for the White Mesa Mill requires that the minimum freeboard be no less than 3.0 feet for any of the existing Cell construction, but based on the above calculation the freeboard would be set 3.2 feet below the top of liner. The freeboard for Ce1l4A would therefore be 5595.3 amsl (top of liner 5598.5 -3.2 feet). The calculation of the Total Required Freeboard for Cell 4A will be calculated annually and the calculation sheet filed in the Mill Central File. White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 d) Roberts Pond 3/10 Revision: Denison-7 Page 16 of37 The freeboard limit for Roberts Pond is a liquid maximum elevation of 5,624.0 feet above mean sea level, as spccified in the GWDP. 6.4. Annual Leak Detection Fluid Samplcs 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. 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 ImlJection Data and Quarterly Inlpection Data forms included as Appendix A and described in Sections 2, 3,4 and 5 respectively, and the Operating Foreman's Daily Impection and Weekly Mill Inspection forms described in Sections 2 and 3, respectively, the following additional reports shall also be prepared: 8.1. Monthly Tailings Reports Monthly tailings reports are prepared every month and summarize 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 concern 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 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. White Mesa Mill-Standard Operating Procedures Book 11: Environmental Protection Manual, Seetion 3.1 8.2. DMT Reports 311 () Revision: Denison-7 Page 17 of37 Quarterly reports of DMT monitoring activities of all required information required by Part l.F.2 of the GWDP relating to the inspections described in Section 3.l(b) (Slimes Drain Water Level Monitoring), 3.1(d) (Tailings Wastewater Pool Elevation Monitoring), 3.2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3.3 (Weekly Feedstock Storage Area Inspections) will be provided to the Executive Secretary on the schedule provided in Table 5 of the GWDP. 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 current year monthly values and a graphic comparison to the previous year. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIX A FORMS 3/10 Revision: Denison-7 Page 18 of37 White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual. Section 3. I 3/1 0 Revision: Denison-7 Page 19 of37 APPENDIX A (CONT.) DAILY INSPECTION DATA Any Item not "OK" must be documented. A check mark = OK, X = Action Required I. TAILINGS SLURRY TRANSPORT SYSTEM I Inspection Items Conditions of Potential Concern Cell I Slurry Pipeline Leaks, Damage, Blocka"e, Sharp Bends Pipeline Joints Leaks, Loose Connections Pipeline Supports Damage, Loss of Support Valves Leaks, B locked, Closed Point(s) of Dischar"e Improper Location or Orientation II. OPERATIONAL SYSTEMS I Insoection Items Conditions of Potential Concern Cell I Water Level Greater Than Operating Level. Large Change Since Previous Inspection Beach Cracks, Severe Erosion. Subsidence Liner and Cover Erosion of cover, Exposure of Liner Cell 2 Cell 2 Inspector:. _______ _ Date; __ ---:-c-___ _ Accompanied by.: ____ _ Time:. ________ _ Cell 3 CeIl4A ! Cell 3 CeIl4A I White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 III. DIKES AND EMBANKMENTS 3/1 0 Revision: Denison-7 Page 20 of37 I Insllection Items Conditions of Potential Concern Dike Dike 1-Dike 2 Dike 3 Dike 4A-Dike4A- Slopes Sloughs or Sliding Cracks, Bulges, Subsidence, Severe Erosion, Moist Areas, Areas of Seepage Outbreak Crest c:racks_, Subsidence, Severe Erosion ....... IV. FLOW RATES I Slurrv Line!s) Pond Return GPM V. PHYSICAL INSPECTION OF SLURRY LINES(S) Walked to Discharge Point Observed Entire Discharge Line VI. DUST CONTROL Dustin" Wind Movement of Tailin"s Precipitation: inches liquid General Meteorological conditions: I-I IA S-X Tails _____ yes _____ yes Cell 2 Cell 3 S Snrav Svstem _____ ~No ______ No W Ce1l4A White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 VII. DAILY LEAK DETECTION CHECK Cell I Leak Detection System Checked Checked Wet Dry Initial level Final level Gal. pumped I 3/1 0 Revision: Denison-7 Page 21 of 37 Cell 2 Cell 3 Checked Checked Wet Dry Wet Dry Initial level Initial level Final level Final level Gal. pumped Gal. pumped Ce1l4A Checked Wet Dry Initialleve! Final level Gal. pumped VIII OBSERVATIONS OF POTENTIAL CONCERN Action Required White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection ManuaL Section 3.1 [MAP OF TAILINGS AREA] 311 0 Revision: Denison-7 Page 22 of 37 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 31l 0 Revision: Denison-7 Page 23 of37 Date:: ______ _ 1. Pond elevations (msl,ft) APPENDIX A (CO NT) DENISON MINES (USA) CORP. WEEKL Y TAILINGS INSPECTION Inspectors: _____________ _ Cell I: (a) Pond Solution Elevation (b) FML Bottom Elevation __ 5597 __ (c) Depth of Water above FML «a)-(b)) _____ _ Cell 3: (a)Pond Solution Elevation (b)FML Bottom Elevation ___ 5570 __ _ (c)Depth of Water above FML «a)-(b)) Cell 4A: (a)Pond Solution Elevation (b )FML Bottom Elevation 5564 __ (c)Depth of Water above FML «a)-(b)) Roberts Pond: (a)Pond Solution Elevation (b )FML Bottom Elevation __ 5612.34_ (c)Depth of Water above FML «a)-(b) _____ _ 2. Slimes Drain Liquid Levels Cell 2 Pump functioning properly ___ _ Pump Timer set at 15min on 45 min off ___ _ _______ Depth to Liquid pre-pump _______ Depth to Liquid Post-pump (all measurements are depth-in-pipe) Pre-pump head is 38'-Depth to Liquid Pre-pump = Post-pump head is 38' -Depth to Liquid Post- pump= __ White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3.1 3. Leak Detection Systems Observation: Cell I Cell 2 Is LOS wet or dry? wet dry wet If wet, Record Ft to Ft to liquid level: Liquid Liquid If sufficient fluid is Volume Volume present, record Flow Rate Flow Rate volume of fluid pumped and flow rate: dry 311 0 Revision: Denison-7 Page 24 of 37 Cell 3 Ce1l4A wet dry wet Ft to Ft to Liquid Liquid * Volume Volume Flow Rate Flow Rate dry Was fluid sample __ yes __ no __ yes __ no __ yes __ no __ yes __ no collected? 4. Tailings Area Inspection (Note dispersal of blowing tailings): 5. Control Methods Implemented: _____________________ _ 6. Remarks: ________________________________ _ 7. Contaminated Waste Dump: * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (elevation 5556.14 amsl)? 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. White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 APPENDIX A (CO NT.) 3/ I 0 Revision: Denison-7 Page 25 of 37 MONTHLY INSPECTION DATA Inspector: ____________ _ Date: ____________ _ 1. Slnrry Pipeline: ___________________________ _ Pipe Thickness: ______ (To be measured only during periods when the Mill is operating) 2. Diversion Ditches and Diversion Berm: Observation: Diversion Ditch I Diversion Ditches: Sloughing __ yes __ no Erosion __ yes __ no Undesirable __ yes __ no Vegetation Obstruction of Flow __ yes __ no Diversion Berm: Stability Issues Signs of Distress Diversion Ditch 2 Diversion Ditch 3 __ yes __ no __ yes __ no __ ycs __ no __ ycs __ no __ yes __ no __ yes __ no __ yes __ no Yes no ---- Diversion Berm 2 __ yes __ no __ yes __ no Comments: ___________________________________ _ 3. Summary of Activities Around Sedimentation Pond: ________________ _ White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3. I 4. Ovcrspray Dust Minimization: Overspray system functioning properly: ____ yes no 3110 Revision: Denison-7 Page 26 of 37 Overspray carried more than 50 feet from the cell: ___ yes no If "yes", was system immediately shut off? __ yes __ no Comments: ________________________________ _ 5. Relnarks: __________________________________ _ 6. Settlement Monitors Cell2Wl: Cell 2W3-S: CeIl3-1N: ____ _ Cell 2 W2: CeIl2EI-N: ____ _ Cell 3-1C: ____ _ Cell 2 W3: CeIl2El-lS: ____ _ CeIl3-1S: ____ _ Cell 2 W4: CeIl2EI-2S: ____ _ Cell 3-2N: ____ _ Cell 2W7-C: ____ _ Cell 2 East: Cell 2W5-N: ___ _ Cell 2 W7N: ____ _ Cell 2 W7S: Ceil 2 W6N: ___ _ Cell 2 W6C: Cell 2 W6S: Ceil 2 W4N: ___ _ CeIl4A-Toe: ____ _ Cell 2 W4S: Cell 2 W5C: Cell 3-2C: Cell 3-2S: ____ _ 7. Summary of Daily, Weekly and Quarterly Inspections: _____________ _ 8. Monthly Slimes Drain Static Head Measurement for Cell 2 (Depth.in-Pipe Water Level Reading): White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3. I APPENDIX A (CO NT.) 311 0 Revision: Denison-7 Page 27 of 37 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector: ________________________ __ Date: __________________________ __ 1. Embankment Inspection: ________________________________________ _ 2. Operations/Maintenance Review: 3. Construction Activities: ______________________________________ _ 4. Summary: __________________________________________________ __ White Mesa Mill -Standard Operating Procedures Book II: Environmental Protect.ion Manual, Section 3, I APPENDIX A (CONT.) 3/1 0 Revision: Denison-7 Page 28 01'37 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 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): _________________ _ Conditions of storage areas for materials: Other comments: White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3. I APPENDIXB 3/1 0 Revision: Denison-7 Page 29 of 37 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 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 concern regarding the tailings areas. Notifications: The inspector is required to record whether all inspection items are normal (satisfactory, requiring no action) or that conditions of potential concern exist (requiring action). A "check" mark indicates no action required. If conditions of potential concern exist the inspector should mark an "X" in the area the condition pertains to, note the condition, and specify the corrective action to be taken. If an observable concern is made, it should be noted on the tailings report until the corrective action is taken and the concern 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 pipeline is to be inspected for leaks, damage, and sharp bends. The pipelinejoints are to be monitored for leaks, and loose connections. The pipeline supports are to be While Mesa Mill -Slandard Operaling Procedures Book 11: Environmental Protection Manual, Section 3.1 3/10 Revision: Denison-7 Page 30 of 37 inspected for damage and loss of snpport. 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 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 liner or absence of cover from erosion are potential items of concern for ponds and covered areas. These should also be noted on the daily inspection form. Cells 1, 3 and 4A 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 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 serious 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 turned into the Maintenance Department. All such repairs should be noted in the report and should contain 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 concern are sloughs or sliding cracks, bulges, subsidence, severe erosion, moist areas, and areas of seepage outbreak. For crests, areas of concern 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 3, 4A-S and 4A-W, should be inspected closely for mice holes and more importantly for prairie dog holes, as the prairie dogs are likely to burrow in deep, possibly to the liner. If any of these conditions exist, the inspection report should be marked accordingly. White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3, I 4. Flow Rates: 3/10 Revision: Denison-7 Page 31 of37 Presence of all flows in and out of the cells should be noted. Flow rates are to be estimated in gallons per minute (OPM). Rates need to be determined for slurry lines, pond return, SX- tails, and the spray system. During 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 Sluny Line(s): A physical inspection of all slurry lines has to be made every 4 hours during operation of the 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, and 4A. 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 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 concern during the inspection should be noted in this section. Corrective action should follow each area of concern 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. White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3, J I. Cover area 2. Beach/tailing sands area 3. Solution as it exists 4. Pump lines 3/10 Revision: Denison-7 Page 32 of 37 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 rules applicable to the mill are applicable when in the tailings area. These rules meet the required MSHA regulations for the tailings area. Please pay particular notice to the following rules: 1. The posted speed limit for the tailings area is 15 mph and 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 restricted 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 usc of a safety belt or harness 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 worn 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 instruction on the tailings system inspection program, designated individuals will be certified to perform daily tailings inspections. The Radiation Safety Officer authorizes certification. Refer to the Certification Form, Appendix C. This form should be signed and dated only after a thorough review of the White Mesa Mill-Standard Operating Procedures 3/10 Revision: Denison-7 Book 11: Environmental Protection Manual, Section 3.1 Page 33 of 37 tailings information previously presented. The form will then be signed by the Radiation Safety Officer and filed. White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 APPENDIXC CERTIFICATION FORM Date: __________ _ Name: ___________ _ 3/ 10 Revision: Denison-7 Page 34 0[37 I have read the document titled "Tailings Management System, White Mesa Mill Tailings Inspector Training" and have received on-site instruction at the tailings system. This instruction 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 thc White Mesa Mill. Radiation Safety Personnel! Tailings System Supervisor White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 APPENDIXD FEEDSTOCK STORAGE AREA 3/10 Revision: Denison-7 Page 35 of 37 S:\BM\US Proje.."1s\o,!Qrolorm\a.'I9\",,:te..~2004_0reJ'td.m.g, f,;!d ctJ:W9 ~ S.sxl1p. 08l03(.l:OOS 4:JO:I6 1'1\:, Xef()~ 0545 PS,pc3, l€ttEr L -~ International Uranium (USA) Corporation Projoe' WHITE MESA MILL REVISIONS un : tale: Utah Date B ocatton: Feedstock Storage Area Map Scale: N/A Dale:oa/o3/2006 wh-"L200'LortJ_p Author: unknown Drafied By: bm White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3. I APPENDIXE TABLES 3/10 Revision: Denison-7 Page 36 of 37 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3. I Table 1 Caleulated Action leakage Rates for Various head Conditions Ce1l4A White mesa Mill Blanding, Utah 311 0 Revision: Denison-7 Page 37 of 37 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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-6.1 Page 1 of 38 WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM AND DISCHARGE MINIMIZATION TECHNOLOGY (DMT) MONITORING PLAN 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. UT1900479 (the "Radioactive Materials License"), as well as procedures for operating and maintenance of monitoring 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 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. DAIL Y 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 four tailings cells will be inspected. Observations will be made of the current 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, except on weekends when the Shift Foreman will perform the weekend tailings inspections. The Radiation Safety Officer 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, White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3. I Revision: Denison-61 Page 2 of38 which includes a tailings cells map, and spaces to record observations, especially those of immediate concern 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 concern is and what corrective measures will resolve the problem. This observation of concern 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, and 4A, Dikes 1,2,3, 4A-S, and 4A-W, wind movement of tailings, effectiveness of dust minimization methods, spray evaporation, Cell 2 spillway, Cell 3 spillway, Cell 3 and 4A liquid pools and associated liquid return equipment, cell leak detection systems, and the wildlife ponds. Operational features of the tailings area are checked for conditions of potential concern. 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 return 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 sluny lines from CCD to the active tailings cell; SX raffinate lines that can discharge into Cell 1, Cell 3 or Cell 4A; the pond return line from the tailings area to the Mill; and, lines transporting pond solutions from one cell to another. b) CellI. c) Cell 2. d) Cell 3. e) Ce1l4A. f) Dike structures including dikes 1,2,3, 4A-S, and 4A-W. g) The Cell 2 spillway, Cell 3 spillway, Cell 3 and Cell 4A liquid pools and associated liquid return equipment. h) Presence of wildlife and/or domesticated animals in the tailings area, including waterfowl and burrowing animal habitations. i) Spray evaporation pumps and lines. White Mesa Mill -Standard Operating Procedures Book II : Environmental Protection Manual, Section 3.1 911G&l.Q Revision: Denison-el Page 3 of38 j) 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. During tailings inspection, general surface conditions will be evaluated for the following: 1) 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 minimization activities. k) Observation of flow and operational status of the dust control/spray evaporation system(s). 1) Observations of any abnormal variations in tailings pond elevations in Cells 1,3, and 4A. m) 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. n) An estimate of flow for active tailings slurry and SX line(s). 0) An estimate of flow in the solution return line(s). p) 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 trigger for further action when evaluating the measurements in the CellI and Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours. The solution level in Cell 4A leak detection is not allowed to be more than 1.0 foot above the lowest point on the bottom flexible membrane liner (elevation 5556.14 feet amsl). If any of these observation 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 LD.6 and LG.3 of the Groundwater Discharge Permit must be adhered to when the solution level trigger for Cell 4A has been exceeded. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-61 Page 4 of38 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 of the License Conditions. q) 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 and 4A. Items (a), (m), (n), and (0) are to be done only when the Mill is operating. When the Mill is down, these items cannot be performed. 2.2. Daily 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 ofthe 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. 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 during 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 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 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 hislher duties as an inspector. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 2.5. Tailings Emergencies Revision: Denison-f,? Page 5 of 38 Inspectors will notify the Radiation Safety Officer and/or Mill management immediately if, during 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 Radiation Technician or Radiation Safety Officer, 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 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). 3. WEEKL Y 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 tailings 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 Ce1l4A leak detection system is 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. The water level data is downloaded to a laptop computer on a weekly basis and incorporated into the Mill's environmental monitoring data base, and into the files for weekly inspection reports of the tailings cell leak detection systems White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-€;2 Page 6 of38 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 LDA shall be returned 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 Materials License. For CeIl4A, under no circumstance shall fluid head in the leak detection system sump exceed a I-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 leak detection system, 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. The maximum daily LDS flow volume will be compared against the measured cell solution levels detailed on Table 1 in Appendix E, to determine the maximum daily allowable LDS flow volume for varying head conditions in Cell 4A. b) Slimes Drain Water Level Monitoring (i) Cell 3 is an active tailings cell while Cell 2 is partially reclaimed with approximately 90% of the surface covered by platform fill. Each cell has a slimes drain system which aids in dewatering the slimes and sands placed in the cell; (ii) Cell 2 has a pump placed inside of the slimes drain access pipe at the bottom of the slimes drain. As taken from actual measurements, the bottom of the slimes drain is 38 feet below a water level measuring point at the centerline of the slimes drain access pipe, at the ground surface level. 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 construction reports, is at a depth of 39 feet below the water level measuring point on the slimes drain access pipe for Cell 2; White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-f)1 Page 7 of38 (iii)The slimes drain pump in Cell 2 is on a timed system, under which it pumps for 15 minutes each hour, thereby allowing the slimes wastewater to recharge for 45 minutes before being pumped again. Based on measurements taken in August 2006, the water level in the Cell 2 slimes drain recharges to a depth of about 28.50 feet before each pumping and is pumped to a depth of 38 feet after each pumping, in each case measured below the water level measuring point on the slimes drain access pipe. The average wastewater head in the Cell 2 slimes drain is therefore about 5 feet. The depth to water of about 28.50 feet after recharge is below the phreatic surface of tailings Cell 2, which is at a depth of about 20 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 at these intervals is satisfactory and is as low as reasonably achievable. Based on past experience, cycling the pump more than 15 minutes every hour can result in more replacement costs for pumps and more resulting system downtime; (iv)The Cell 2 slimes drain pump is checked weekly to observe that it is operating and that the timer is set 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 slimes drain access pipe shall be monitored and recorded weekly to determine maximum and minimum fluid head before and after a pumping cycle, respectively. 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; (vi)On a monthly basis, the slimes drain pump will be turned off and the wastewater in the slimes 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 the Monthly Inspection Data form, by measuring the depth to water below the water level measuring point on the slimes drain access pipe; (vii) No process liquids shall be allowed to be discharged into Cell 2; (viii) 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 I.G.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 Cell4A are currently active, no pumping from the Cell 3 or Cell 4A slimes drain is authorized. Prior to initiation of tailings dewatering operations for Cell 3 or Cell 4A, a similar procedure will be developed for ensuring that average White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-{}] Page 8 of38 head elevations in the Cell 3 and Ce1l4A slimes drains are kept as low as reasonably achievable, and that the Cell 3 and Ce1l4A 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 tailings or dusting and control measures shall be taken if needed. d) Tailings Wastewater Pool Elevation Monitoring Solution elevation measurements in Cells 1, 3 and 4A and Roberts Pond are to be taken by survey on a weekly 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"); (ii) The survey will be performed using 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; (iii)The reference Points (the "Reference Points") for Cells 1, 3 and 4A, 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 3 and cell 4A, 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 3 and ce1l4A) is at 5,607.83 FMSL; (iv) The Surveyor will set up the Survey Instrument 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 11R0berts Pond Reference Point. For Cell 3 and Cell 4A, this is typically on the road on the Cell 3 dike approximately 100 feet east of the Cell 3 Reference Point; (v) Once in location, the Surveyor will ensure that the Survey Instrument is level by centering the bubble in the level gauge on the Survey Instrument; (vi)The Assistant will place the Survey Rod vertically on the Reference Point (on the metal disk on the Cell 11R0berts Pond Reference Point and on the top of the rebar on the Cell 3 and cell 4A 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; (vii) 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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 -9,3/{-)gLQ Revision: Denison-€t] Page 9 of38 represents the number of feet the Survey Instrument is reading above the Reference Point; (viii) 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 or Roberts Pond, 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: I. Cell 3 A stake has been place in the central area of the south dike of Cell 3. The Assistant will walk perpendicular to the dike from the stake to the nearest point on the liquid surface of Cell 3 and place the Survey Rod at that location; B. Cell4A The Assistant will walk down the slope in the northeast corner of Cell 4A and place the Survey Rod at the liquid level. C. CellI 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 D 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 CellI 322,196 2,579,277 Cell 3 320,508 2,577,760 Cell4A 320,300 2,579,360 These coordinate locations may vary somewhat depending on solution elevations in the Pond and Cells; White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 911G&lQ Revision: Denison-61 Page 10 of38 (ix)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; (x) The Surveyor will focus the cross hairs of the Survey Instrument on the scale on the Survey Rod, and record the number (the "Pond Surface Reading"), which represents the number of feet the Survey Instrument 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) Summary In addition, the weekly inspection should summarize all activities concerning 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. Weekly 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. If the pond solution elevation at the Pond Surface Reading area is at or below theFML 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: ~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; afl:€l ajQl-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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-6] Page 11 of 38 B1.Q}all alternate 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 variance in stored materials from this requirement or observed leaking alternate feedstock drums or other containers will be brought to the attention of Mill Management and rectified within 15 days. 4. MONTHL Y 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 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 critical points of the pipe include bends, slope changes, valves, and junctions, which are critical to dike stability. These locations to be monitored will be determined by the Radiation Safety Officer or his designee from the Radiation Safety Department during the Mill run. b) Diversion Ditches Diversion ditches 1, 2 and 3 shall be monitored monthly for sloughing, erosion, undesirable vegetation, and obstruction 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 summarized 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 overs pray is carried more than 50 feet from the cell, the overs pray system should White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3. I be immediately shut-off. Revision: Denison-6] Page 12 of 38 White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 e) Remarks Revision: Denison-61 Page 13 of 38 A section is included on the Monthly Inspection Data form for remarks in which recommendations can be made or observations of concern 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. QUARTERL Y 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 Review, a Construction 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. 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 Construction Review consists of reviewing any construction changes or modifications made to the tailings area on a quarterly basis. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3. I d) Summary Revision: Denison-67 Page 14 of 38 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 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 structures. 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 structures. In the event tailings capacity evaluations (as per SOP PBL-3) were performed for the receipt of alternate 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 summarize observations of potential concern. 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. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-62 Page 15 of 38 The registered engineer will obtain copies of selected tailings inspections, along with the monthly and quarterly summaries of observations of concern 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 September 1 st of every year to: Directing Dam Safety Engineer State of Utah, Natural Resources 1636 West North Temple, Suite 220 Salt Lake City, Utah 84116-3156 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 a) Tailings Cells 1 and 4A The freeboard limits are as per January 10, 1990 Drainage Reportfor Cells 1 and 4A and are stated below: (i) A liquid maximum elevation of 5,615.4 feet mean sea level in Cell 1. (ii) A liquid maximum elevation of 5,596.4 feet mean sea level in Cell4A. b) Tailings Cell 3 The freeboard limit for Cell 3 IS determined annually using the following procedure: (i) From a survey of Cell 3, the pool surface will be determined. (ii) An estimate of the maximum tons of dry tailings to be generated during the next 12 months will be made. This estimate is multiplied by 1.5, a factor of safety, to yield the Maximum Mill Production. (iii) The Maximum Mill Production is divided by the number of tons required White Mesa Mill Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-6:Z Page 16 of38 to reduce the pool size by one acre and then subtracted from the pool surface (determined in Step i), yielding the Reduced Pool Area. (iv) The PMP Flood Volume Requirement, as per the January 10, 1990 Drainage Report, is 123.4 acre feet. The PMP Flood Volume Requirement is divided by the Reduced Pool Area to determine the PMP Freeboard Level. (v) The Wave Run Up of 0.78 feet (as specified in the January 10, 1990 Drainage Report) is added to the PMP Freeboard Level to determine the Total Required Freeboard. The calculation of the Total Required Freeboard for Cell 3 will be calculated annually and the calculation sheet filed in the Mill Central File. c) Tailings Cell 4A The freeboard limit for Cell 4A is determined annually using the following procedure: The Cell4A design includes a concrete spillway between Cell 3 and CeIl4A, with the invert elevation 4 feet below the top of the Cell 3 dike, at an elevation of 5604.5 feet amsl. Should Cell 3 receive the full PMP volume of 123.4 acre feet of water, approximately 62 acre feet of that volume would flow through the spillway into Ce1l4A. 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). This would result in a total flood volume of 98 acre-feet, including the 62 acre-feet of solution from Cell 3. The freeboard depth required for Cell 4A from the PMP event would be 2.44 feet, plus a wave run-up depth of 0.77 feet (from the 1990 Drainage Report), for a total freeboard requirement of 3.2 feet. This calculation is illustrated on Attachment 4. The Groundwater Quality Discharge Permit, No. UGW370004, for the White Mesa Mill requires that the minimum freeboard be no less than 3.0 feet for any of the existing Cell construction, but based on the above calculation the freeboard would be set 3.2 feet below the top of liner. The freeboard for Cell4A would therefore be 5595.3 amsl (top of liner 5598.5 -3.2 feet). The calculation of the Total Required Freeboard for Cell4A will be calculated annually and the calculation sheet filed in the Mill Central File. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 d) Roberts Pond Revision: Denison-67 Page 17 of38 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 determine the origin of the solution. 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 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. Monthly Tailings Reports Monthly tailings reports are prepared every month and summarize 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 concern 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 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. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 8.2. DMT Reports 9,i/(.}gJD Revision: Denison-{,1 Page 18 of38 Quarterl y reports of D MT monitoring activities of all required information required by Part I.F.2 of the GWDP relating to the inspections described in Section 3.I(b) (Slimes Drain Water Level Monitoring), 3.I(d) (Tailings Wastewater Pool Elevation Monitoring), 3.2 (Weekly Inspection of Solution Levels in Roberts Pond) and 3.3 (Weekly Feedstock Storage Area Inspections) will be provided to the Executive Secretary on the schedule provided in Table 5 of the GWDP. 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 repOlts shall include both the current year monthly values and a graphic comparison to the previous year. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIX A FORMS Revision: Denison-(}] Page 19 of38 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-61 Page 20 of38 APPENDIX A (CONT.) DAILY INSPECTION DATA Any Item not "OK" must be documented. A check mark = OK, X = Action Required I. TAILINGS SLURRY TRANSPORT SYSTEM I Inspection Items Conditions of Potential Concern CellI Slurry Pipeline Leaks, Damage, Blockage, Sharp Bends Pipeline Joints Leaks, Loose Connections Pipeline Supports Damage, Loss of Support Valves Leaks, Blocked, Closed Point( s) of Discharge Improper Location or Orientation II. OPERATIONAL SYSTEMS I Inspection Items Conditions of Potential Concern CellI Water Level Greater Than Operating Level, Large Change Since Previous Inspection Beach Cracks, Severe Erosion, Subsidence Liner and Cover Erosion of cover, Exposure of Liner Cell 2 Cell 2 Inspector: _______ _ Date;, ________ _ Accompanied by: ___ _ Time:. _________ _ Cell 3 Cell4A Cell 3 Cell4A White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 III. DIKES AND EMBANKMENTS f)'i/Q&] 0 Revision: Denison-el Page 21 of38 I InsQection Items Conditions of Potential Concern Dike Dike 1-Dike 2 Dike 3 Dike 4A-Dike4A- Slopes Sloughs or Sliding Cracks, Bulges, Subsidence, Severe Erosion, Moist Areas, Areas of Seepage Outbreak c:rest Cracks, Subsidence, Severe Erosion IV. FLOW RATES I Slurry Line(s) Pond Return GPM V. PHYSICAL INSPECTION OF SLURRY LINES(S) Walked to Discharge Point Observed Entire Discharge Line VI. DUST CONTROL Dusting Wind Movement of Tailings Precipitation: inches liquid General Meteorological conditions: I-I lA S-X Tails ______ yes ______ yes Cell 2 Cell 3 S Spray SYstem ______ No ______ .No W Ce1l4A White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 VII. DAILY LEAK DETECTION CHECK CellI Leak Detection System Checked Checked Wet Dry Initial level Final level Gal. pumped I Revision: Denison-61 Page 22 of38 Cell 2 Cell 3 Checked Checked Wet Dry Wet Dry Initial level Initial level Final level Final level Gal. pumped Gal. pumped Cell4A Checked Wet Dry Initial level Final level Gal. pumped VIII OBSERVATIONS OF POTENTIAL CONCERN Action Required White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 [MAP OF TAILINGS AREA] Revision: Denison-61 Page 23 of38 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 9JA)&lQ Revision: Denison-67 Page 24 of38 Date: 1. Pond elevations (msl,ft) APPENDIX A (CONT) DENISON MINES (USA) CORP. WEEKL Y TAILINGS INSPECTION Inspectors: _____________ _ CellI: (a) Pond Solution Elevation (b) FML Bottom Elevation __ 5597 __ (c) Depth of Water above FML «a)-(b» _____ _ Cell 3: (a)Pond Solution Elevation (b)FML Bottom Elevation ___ 5570 __ _ (c)Depth of Water above FML «a)-(b» _____ _ Ce1l4A: (a)Pond Solution Elevation (b )FML Bottom Elevation __ 5564 __ (c)Depth of Water above FML «a)-(b» _____ _ Roberts Pond: (a)Pond Solution Elevation (b)FML Bottom Elevation __ 5612.34_ (c)Depth of Water above FML «a)-(b» _____ _ 2. Slimes Drain Liquid Levels Cell 2 Pump functioning properly ___ _ Pump Timer set at 15min on 45 min off ___ _ _______ Depth to Liquid pre-pump _______ Depth to Liquid Post-pump (all measurements are depth-in-pipe) Pre-pump head is 38' -Depth to Liquid Pre-pump = Post-pump head is 38' -Depth to Liquid Post- pump= __ _ White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 3. Leak Detection Systems Observation: CellI Cell 2 Is LDS wet or dry? wet dry wet If wet, Record Ft to Ftto liquid level: Liquid Liquid If sufficient fluid is Volume Volume present, record Flow Rate ---Flow Rate volume of fluid pumped and flow rate: dry 9;i/{.}glQ Revision: Denison-fr} Page 25 of38 Cell 3 Cell4A wet dry wet Ft to Ftto Liquid Liquid * Volume Volume Flow Rate Flow Rate dry Was fluid sample __ yes __ no __ yes __ no __ yes __ no __ yes __ no collected? 4. Tailings Area Inspection (Note dispersal of blowing tailings): 5. Control Methods Implemented: ______________________ _ 6. Remarks: _________________________________ _ 7. Contaminated Waste Dump: _______________________ _ * Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (elevation 5556.14 amsl)? no __ yes If Cell4A 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. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIX A (CONT.) -9}/Q~JQ Revision: Denison-6] Page 26 of38 MONTHLY INSPECTION DATA Inspector: ________________________ __ Date: __________________________ __ 1. Slurry Pipeline: Pipe Thickness: ___________ (To be measured only during periods when the Mill is operating) 2. Diversion Ditches and Diversion Berm: Observation: Diversion Ditches: Sloughing Erosion Undesirable Vegetation Obstruction of Flow Diversion Berm: Stability Issues Signs of Distress Diversion Ditch 1 Diversion Ditch 2 ____ yes ____ no ____ yes ____ no ___ yes ___ no __ yes ___ no ___ yes ___ no __ yes ___ no __ yes ____ no ___ yes __ no Diversion Ditch 3 Diversion Berm 2 ___ yes ___ no ___ yes ___ no __ yes ___ no ___ yes ___ no ___ yes ____ no ____ yes ____ no Comments: ____________________________________ _ 3. Summary of Activities Around Sedimentation Pond: ______________________________ _ White Mesa Mill -Standard Operating Procedures Book J J: Environmental Protection Manual, Section 3.1 4. Overspray Dust Minimization: Overspray system functioning properly: ___ .yes ___ n0 Revision: Denison-67 Page 27 of 38 Overspray canied more than 50 feet from the cell: __ yes __ no If "yes", was system immediately shut off? __ yes __ no Comments: ______________________________________ _ 5. Remarks: ______________________________________ _ 6. Settlement Monitors CeIl2WI: CeIl2W3-S: CeIl3-IN: Cell 2 W2: CeIl2EI-N: CeIl3-IC: Cell 2 W3: Cell 2EI-IS: CeIl3-IS: Cell 2 W4: CeIl2EI-2S: Ce1l3-2N: Ce1l2W7-C: Cell 2 East: CeIl2W5-N: Cell 2 W7N: Cell 2 W7S: Cell 2 W6N: Cell 2 W6C: Cell 2 W6S: Cell 2 W4N: CeIl4A-Toe: Cell 2 W4S: Cell 2 W5C: Ce1l3-2C: Cell 3-2S: 7. Summary of Daily, Weekly and Quarterly Inspections: ___________________ _ 8. Monthly Slimes Drain Static Head Measurement for Cell 2 (Depth-in-Pipe Water Level Reading): White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIX A (CONT.) WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM QUARTERLY INSPECTION DATA Inspector: ____________ _ Date: ______________ __ 1. Embankment Inspection: 2. Operations/Maintenance Review: Revision: Denison-6] Page 28 of38 I 3. Construction Activities: ___________________ _ 4. Summary: _______________________________ _ White Mesa Mill-Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIX A (CONT.) Revision: Denison-ft] Page 29 of38 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 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): ________________ _ Conditions of storage areas for materials: Other comments: White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIXB Revision: Denison-e] Page 30 of38 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 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 concern regarding the tailings areas. Notifications: The inspector is required to record whether all inspection items are normal (satisfactory, requiring no action) or that conditions of potential concern exist (requiring action). A "check" mark indicates no action required. If conditions of potential concern exist the inspector should mark an "X" in the area the condition pertains to, note the condition, and specify the corrective action to be taken. If an observable concern is made, it should be noted on the tailings report until the corrective action is taken and the concern is remedied. The dates of all corrective actions should be noted on the repOlts 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 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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 Revision: Denison-67 Page 31 of38 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 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 liner or absence of cover from erosion are potential items of concern for ponds and covered areas. These should also be noted on the daily inspection form. Cells 1, 3 and 4A 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 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 serious 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 turned into the Maintenance Department. All such repairs should be noted in the report and should contain 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 concern are sloughs or sliding cracks, bulges, subsidence, severe erosion, moist areas, and areas of seepage outbreak. For crests, areas of concern 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 3, 4A-S and 4A-W, should be inspected closely for mice holes and more importantly for prairie dog holes, as the prairie dogs are likely to burrow in deep, possibly to the liner. If any of these conditions exist, the inspection report should be marked accordingly. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3. I 4. Flow Rates: Revision: Denison-6] Page 32 of38 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 determined for slurry lines, pond return, SX- tails, and the spray system. During 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 during operation of the 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, and 4A. 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 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 concern during the inspection should be noted in this section. Corrective action should follow each area of concern 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. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 1. Cover area 2. Beach/tailing sands area 3. Solution as it exists 4. Pump lines 9YMJQ Revision: Denison-6:Z Page 33 of 38 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 rules applicable to the mill are applicable when in the tailings area. These rules meet the required MSHA regulations for the tailings area. Please pay particular notice to the following rules: 1. The posted speed limit for the tailings area is 15 mph and 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 restricted 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 harness 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 worn 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 instruction on the tailings system inspection program, designated individuals will be certified to perform daily tailings inspections. The Radiation Safety Officer authorizes certification. Refer to the Certification Form, Appendix C. This form should be signed and dated only after a thorough review of the White Mesa Mill -Standard Operating Procedures Book II: Environmental Protection Manual, Section 3.1 Revision: Denison-6] Page 34 of 38 tailings information previously presented. The form will then be signed by the Radiation Safety Officer and filed. White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIXC CERTIFICATION FORM Dme: ________________________ _ Name: ______________________ __ l,'J/O&lQ Revision: Denison-€t2 Page 35 of 38 I have read the document titled "Tailings Management System, White Mesa Mill Tailings Inspector Training" and have received on-site instruction at the tailings system. This instruction 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 White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIXD FEEDSTOCK STORAGE AREA Revision: Denison-€l] Page 36 of38 i I I . t S:\BM\US Projects\Chloroform\tfug'Wtde3~~200'COfeJ<sd.dwg, fsj sU, strg area B.Sxllp, 08103/2006 4:10:16 PM, XerOx 0545 PS.pc3, letter International Uranium (USA) Corporation Project WHITE MESA MILL REVISIONS State: Utah Date B Feedstock Storage Area Map Scale: N/A Author: unknown White Mesa Mill -Standard Operating Procedures Book 11: Environmental Protection Manual, Section 3.1 APPENDIXE TABLES Revision: Denison-(c;'] Page 37 of 38 White Mesa Mill -Standard Operating Procedures Book I I: Environmental Protection Manual, Section 3. I Table 1 Calculated Action leakage Rates for Various head Conditions Cell 4A White mesa Mill Blanding, Utah Revision: Denison-fo} Page 38 of38 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