Loading...
HomeMy WebLinkAboutDRC-2012-001287 - 0901a068802bef2fDENISO MINES March 29 2012 DRC-2012-001287 Demson Mines (USA) Corp 105017th Street, Suite 950 Denver CO 80265 USA Tel 303 628 7798 Fax 303 389-4125 www denisonmines com VIA E MAIL AND OVERNIGHT DELIVERY Mr Rusty Lunijberg Executive Secretary Utah Radiation Control Board Utah Department of Environmental Quality 195 North 1950 West PO Box 144850 Salt Lake City UT 84114 4850 Re White Mesa Uranium Mill Radioactive Materials License No UT1900479 - Safety and Environmental Review Panel ( SERP') 2011 Annual Report DearMr Lundberg Enclosed please find the 2011 Annual SERP Report for the White Mesa Mill which is being submitted in compliance with condition 9 4 C of State of Utah Radioactive Materials License No UT 1900479 Please contact the undersigned if you have any questions or require any further information Yours very truly DENISON MINES (USA) CORP Jo Ann Tischler Director Compliance and Permitting cc David C Frydenlund I Ron F Hochstein Harold R Roberts David E Turk KathenneA Weinel Y\Required Reports\SERP Reports\2011 SERP Reports\03 29 12 Transmittal 2011 Annual SERP Report doc WHITE MESA MILL SAFETY AND ENVIRONMENTAL REVIEW PANEL (SERP) 2011 ANNUAL REPORT March 27 2012 ' ^ Submitted to the Utah Department of Environmental Quality Division of Radiation Control Submitted by White Mesa Uranium Mill License No UT 1900479 1 INTRODUCTION i This report is being submitted by Denison Mines (USA) Corp ( DUSA ) licensee of the White Mesa Uranium Mill (the Mill ) to the Utah Division of Radiation Control ( DRC ) in compliance with condition 9 4 C of State of Utah Radioactive Matenals License No UT 1900479 (the License ) I There were three Safety and Environmental Review Panel ( SERP ) evaluations conducted for the penod of January 1 2011 through December 31 2011 Each SERP evaluation and review was conducted in accordance with SERP procedures set forth in the Mill s Standard Operating Procedure PBL 1 Rev No R 4 (the SERP SOP ) The evaluations are summanzed below in Section 2 I 2 SUMMARY OF EVALUATIONS ' This section descnbes the changes tests or expenments evaluated by the SERP pursuant to License condition 9 4 and summanzes the evaluations performed and actions taken by the SERP relative to each In each case the SERP consisted of those individuals specified in License condition 9 4 C with additional members included as appropnate to address techmcal aspects , The SERP followed the SERP SOP as it performed its evaluations to ensure that the actions taken satisfy the following 3 conditions specified in License condition 9 4 B a) The change test or expenment does not conflict with any requirement specifically stated m the License or impair the licensee s ability to meet all applicable regulations | b) There is no degradation in the essential safety or environmental commitments in the License application or provided by the approved reclamation plan , c) The change test or expenment is consistent with the conclusions of actions analyzed and selected in the Environmental Assessment dated February 1997 (the 1997 Environmental Assessment) 2 1 SERP Report No 2011-01 March 11, 2011 Revisions to Standard Operatmg Procedure for Calcium Fluoride Processmg 2 11 Proposed Action Review and approval of revision to the Standard Operating Procedures for CaF2 Processing PBL 13 Rev No 1 2 12 Descnption of Change. Tests or Expenments The Mill has an existing license amendment to process altemate feed matenal fi'om Allied Signal Corporation s Metropolis Illinois facility The existing Standard Operating Procedure (the CaF2 SOP ) addressed processing the matenals in the Mill s main circuit The Mill proposes to process the matenals via an alkaline leach m the altemate feed circuit which requires a revision to the existing CaF2 SOP 2 13 Safetv and Environmental Evaluation of this SERP Action The SERP reviewed the proposed revision and determined that • The revised CaF2 SOP does not create any new emissions or sources • The revised CaF2 SOP does not generate any new occupational safety issues • The revised CaF2 SOP is consistent with License Conditions 10 6 and 10 7 regarding processing of matenal from this source • The revised CaF2 SOP is consistent with License Condition 10 le regarding tailings capacity The SERP concluded that a) The CaF2 SOP satisfies the requirement set out in License condition 9 6 that SOPs shall be established and followed for all operational process activities involving radioactive matenals The SOP addresses an alkaline leach process that has already been used at the Mill to process a feed that has previously been processed at the Mill successfully with no environmental or worker safety issues b) The revised CaF2 SOP will not produce any degradation in the essential safety or environmental commitments in the License application and its scope is within the envelope of environmental conditions assumed in the EA The CaF2 matenal will be processed in the existing altemate feed circuit whose equipment and reclamation is already addressed in the approved Reclamation Plan No new chemicals or reagents will be used under the revised CaF2 SOP All such chemicals and reagents have been used previously at the Mill c) The revised CaF2 SOP is not expected to produce any environmental impacts beyond those assessed in the EA dated Febmary 1997 and is consistent with the conclusions regarding actions analyzed in the EA The revised CaF2 SOP will involve processing of a previously approved altemate feed matenal whose composition is chemically similar and whose pnmary constituents are also within the levels of constituents in other altemate feeds previously successfully processed at the Mill under similar procedures No new chemicals or reagents will be used under the revised CaF2 SOP There will be no new chemical reactions or off gasses associated with processing the Matenals under the revised Procedure that haven t been expenenced and handled safely by the Mill in connection with processing other altemate feed matenals As a result the revised CaF2 SOP will not produce any additional worker safety issues or environmental emissions Therefore this cntenon is also satisfied 2 1 4 SERP Action The SERP concluded that the revised CaF2 SOP meets the cntena set forth in the SERP SOP for approval and approved the revision 2 2 SERP Report No 2011-02 October 7, 2011 Review and Approval of Standard Operatmg Procedure for FMRI and Cabot Processmg 2 2 1 Proposed Action Review and approve of the Standard Operating Procedures for FMRI and Cabot Processing PBL-11 Revision No R 0 Book 10 (the Procedure ) 2 2 2 Descnptions of Change, Tests or Expenments License condition 10 11 allow the Mill to receive and process feed matenals (the Matenals ) from the Fansteel Metals Recovery Inc facility in Muskogee Oklahoma and the Cabot Corporation facility m Boyertown Pennsylvania 2 2 3 Safetv and Environmental Evaluation of this SERP Action The SERP reviewed the Procedure descnbed above and concluded that a) In authonzing the Mill to receive and process the Matenals the Utah Department of Environmental Quality Division of Radiation Control ( DRC ) in the case of the Fansteel matenals (the FMRI matenals ) and the Nuclear Regulatory Commission ( NRC ) in the case of the Cabot matenals concluded that the receipt and processing of the Matenals would not result in any sigmficant incremental impacts to public health safety or the environment b) For the combined FMRI and Cabot Matenal run the proposed pre leach step would use a lower concentration of sulfunc acid than has been used in previous processing of Cabot matenal c) Provisions for HF sampling were included in the safety assessment to address the fluonde concentrations in the Matenals d) Area Concentration calculations ( DAC s ) for both Matenals were appropnate e) The Mill s Radiation Safety Officer ( RSO ) was directed to make certain revisions to the Hazard analysis sections of the SOP steps to mclude the final hazard ratings and the radiological concentrations measured in the Matenal pnor to implementation ofthe Procedure i 224 SERP Action The SERP concluded that a) The Procedure does not conflict with any requirements specifically stated in the license or impair Denison s ability to meet all applicable regulations The volumes of each Matenal present on site at the Mill and to be processed are within the volumes approved in the respective license amendments for each Matenal I b) The Procedure will not produce any degradation in the essential safety or environmental commitments in the license application or provided by the approved reclamation plan and therefore this cntenon is met All chemicals being used in the Process are chemicals that are currently used for Mill operations or have been used in the past There will be no new chemical reactions or off gasses ' c) Inherent in its approval of the License amendment authonzing processing of the Matenals NRC concluded for the Cabot Matenal and DRC concluded for the FMRI Matenal that the receipt and processing of the Matenals will not result in any significant incremental impacts to public health safety or the environment The uranium concentration in the Cabot Matenal is comparable to Colorado Plateau ores and will have comparable concentrations of uramum daughter products The uranium concentration in the FMRI Matenal is comparable to lower grade ores and will have comparable concentrations of uranium daughter products The SERP concluded that the Procedure meets the cntena set forth m the SERP SOP for approval and approved the procedure 2 3 SERP Report No 2011-03 November 22, 2011 Cabot Alternate Feed Material Volume 2 3 1 Proposed Action Review and Modification of Volume of Cabot Altemate Feed Matenal to Be Shipped to the Mill and Processed (the Change ) 2 3 2 Descnptions of Change, Tests or Expenments License condition 10 9 in License DRC 04 resulting from Amendment 4 to NRC License SUA 1358 approves the receipt of 16 000 dry tons of uramum matenal from Cabot (the Cabot Matenal ) The Mill had received and processed 15 952 dry tons at the time of the SERP meeting Cabot anticipates shippmg additional matenal including 252 additional dry tons beginning the week of November 21 2011 which are anticipated to reach the Mill in early December 2011 The SERP evaluated 1 Whether additional volume above 16 000 dry tons can be accepted at the Mill in accordance with SERP cntena 2 How much additional volume can be accepted under SERP procedures 2 2 3 Safetv and Environmental Evaluation of this SERP Action The SERP evaluated information and correspondence related to the proposed Change and determined that a) The matenal represented by the data that is current shipments of Cabot Matenal is chemically virtually the same as the Cabot Matenal approved in the License Amendment No 4 Cabot has provided a notanzed affidavit that the portion of the lot in shipment as well as the portion of the lot awaiting shipment consist of the same matenal from the same process source as the 16 000 dry tons already approved in License Condition 10 9 b) The matenal is chemically relatively more inert than the earliest shipments of Cabot matenal due to the effects of the addition of fly ash pnor to shipment from the Boyertown facility c) The email from the Executive Secretary of the Utah Radiation Control Board on November 16 2007 advised that the SERP process is acceptable for evaluating whether a limited quantity of matenal above the approved volume can be received at the Mill ( i 224 SERP Action The SERP concluded that a) The Change does not conflict with any requirements specifically stated in the license or impair Denison s ability to meet all applicable regulations NRC specifically granted approval for receipt and processing of the Cabot Matenal via License Amendment No 4 and the Executive Secretary has acknowledged that the SERP process may be used to evaluate whether a limited increase in Cabot shipments/volume can be received at the Mill which would include the volumes contemplated below i b) The Change (increase in volume) will not produce any degradation in the essential safety or environmental commitments in the license application or provided by the approved reclamation plan and therefore this cntenon is met The Cabot Matenal to be received is chemically and compositionally virtually the same matenal as the 16 000 dry tons already approved in License Condition 10 9 Processing will require no new chemicals produce no new reactions and produce no new emissions Processing of the matenal would offset the processing of an equivalent volume of ore and would result in the same volume of tailings as the processing of an equivalent volume of ore c) Inherent in its approval of the License Amendment authonzing processing of the Cabot Matenal NRC concluded for the Cabot Matenal that the receipt and processing of the matenals will not result in any significant incremental impacts to public health safety or the environment The yellowcake recovered from the Cabot Matenal will not cause the Mill to exceed the yellowcake production limit under the Mill s license The uranium concentration m the Cabot Matenal is comparable to Colorado Plateau ores and will have comparable concentrations of uranium daughter products The SERP concluded that an increase in volume of 5 000 dry tons would be consistent with the foregoing analysis and approved the increase from 16,000 to 21 000 dry tons The SERP also concluded that Denison will review analytical data from the lot to confirm the composition of the matenal before processing the matenal ATTACHMENT 1 1 ... f 't 1 f 1- ' •'^ < \ L •4. I J i f i No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 4 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #1 Equipment Component Individual Equipment No CaF? Dmm Dumping Node Parameter Process Matenal in Component PFD Calcium Fluonde Uramum Hydrofluoric Acid Sodium Carbonate Quantity in Equipment (lb) 600 <12 <03 4,000 Concentration (%) 60 80 <2 <0 05 10 Flashpoint °F TLV-TWA mg/m' STEL mg/m^ Radioactivity pCi/g Temperature °C Amb Amb Amb 80 Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The CaF2 matenal is a dry solid and can become airbome easily The matenal should be wetted with water after the dmms are opened for dust free handling Heating of the dry CaF2 matenal should be avoided as it may cause elevated emission of HF vapors The CaF2 material is also radioactive and you must follow established health physics controls If any CaFz gets on your clothmg or skm, wash it off with generous amounts of water NajCOa Make Up Tank Drums of CaF2 H,0 Drum Dumping Station No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of4 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions The CaF2 dmms must be kept sealed or covered as much as possible until all process components are ready for dumping the dmms • Make sure you are familiar with the MSDS for the CaF2 matenal • Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect safety showers and eyewash foimtains • Tum on the dmm dumper the weigh scale and the conveyor • Place a CaF2 dmm in position for handling • Undo the dmm lid carefully and report any unusual conditions to your supervisor • Examine the contents of the dmm If the contents of the drum have solidified to the extent that the matenal cannot be easily sampled or removed from the dmm then refasten the lid and transport the dmm to special handling For all other dmms proceed with the following steps • Weigh and record the dmm weight • Take a sample of the contents of the dmm and place the sample in the appropnately marked container to make up a composite sample for all ofthe dmms dumped on that day Make sure this composite sample container is marked clearly with the sample identification and date At the conclusion of the dmm dumping activities for the day make sure this composite sample is transported to the laboratory • Add the appropnate volume of sodium carbonate (soda ash) solution to the dumper vessel as instmcted by your supervisor • Add the appropnate amount of water to the contents of the dmm for dust control as instmcted by your supervisor • Place the dmm in the dmm dumper and dump its contents • If the empty drum is m good condition retain the empty dmm and lid for possible | use in special handling and store as instmcted by your supervisor | { t No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 3 of4 Date October 13 Title CaF2 Processmg 2010 • Repeat the process steps descnbed above for additional drums of CaF2 matenal until the target number of drums for the current batch as instmcted by your supervisor is reached • As needed transfer the slurry of dumped CaF2 matenal to the digestion tank as instmcted by your supervisor • Tum off the dmm dumper, the weigh scale and the conveyor • Clean up any spilled CaF2 matenal dmm parts tools etc and ensure your work area is free of hazardous obstmctions Prepare the area to handle the next batch of dmms Special handling of dmms of CaF2 matenal whose contents have solidified will be as follows • Use equipment and methods as instmcted by your supervisor to remove the dmm from its contents or to remove the contents from the drum • Use equipment and methods as instmcted by your supervisor to break up the solidified chunks of CaF2 matenal until the pieces are small enough to be loaded into dmms and fed to normal processing by the drum dumping station • Load the cmshed CaF2 matenal into dmms as instmcted by your supervisor fasten dmm lids and transport the drums to the dmm dumping station • For any dmms that cannot be re used cmsh the dmms for disposal and dispose of the cmshed dmms as instmcted by your supervisor • In all steps of special handling use water as instmcted by your supervisor to control dust emissions NOTE Whenever working m, around or on this process circuit you must wear appropriate PPE which may mclude Tyvex coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Officer No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 4 of4 Date October 13 Title CaF2 Processmg 2010 MOBILE EOUIPMENT The forklifl handling the dmms of CaF2 matenal will be operatedi according to normal operating procedures taking special precautions to avoid spilling, or mptunng any ofthe dmms of the CaF2 matenal f», i ... 1 r 3 i L No PBL 13 DENISON MDsfES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 2 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #2 Equipment Component Individual Equipment No CaF? Carbonate Digestion Node Parameter Process Matenal in Component 1 PFD Calcium Fluonde Uramum Sodium Carbonate Hydrogen Peroxide 'i Quantity in Equipment (lb) 30 000 600 8 300 75 Concentration (%) 30 06 10 50 ) Flashpoint °F 1 TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g Temperature °C 80 80 80 Amb 1 Pressure psig 1 Health Rating Hazard Rating Assessment Descnption Most of the contained uramum in the CaF2 matenal is dissolved in the heated sodium carbonate (soda ash) solution in this processing step The liquid in the digestion vessel is strongly basic Any splashing or contact with the skin should be avoided These materials can cause skm and eye burns The dissolved CaFi material is also radioactive and you must follow established health physics controls If any | carbonate digestion solution gets on you, wash it off with generous amounts of i water NajCOs Make Up Tank No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of 2 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions This node deals with digesting the CaF2 matenal in sodium carbonate (soda ash) solution at 80°C for about 4 hours • Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains • As the digestion tank is being filled from the drum dumping station once the level of slurry in the digestion tank is appropnate for starting agitation without causing splashing or spillage - then start agitation Continue receiving slurry from the dmm dumping station until a full batch has been received • Add the required volume of hydrogen peroxide solution to the digestion tank as instmcted by your supervisor Wear appropnate PPE for handling hydrogen peroxide • Add steam to the contents of the tank until the contents reach 80°C Continue adding steam as needed to maintain this temperature • Continue agitation of the tank contents at 80°C for 4 hours to complete the necessary digestion • At the end of the digestion time measure the volume of final digestion solution in the tank and take a sample of the contents of the tank and place the sample in an appropnately marked container Make sure this sample container is marked clearly with the batch number the sample identification and the date Make sure this sample is collected daily by laboratory technicians and transported to the laboratory • Whenever working in around or on this process you must avoid splashing and any contact with the skin and you must wear PPE which includes at a minimum hard hat coveralls mbber boots and gloves safety glasses with side shields and whatever level of respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 3 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #3 Equipment Component Filtration After Carbonate Digestion Node Individual Equipment No Parameter Process Matenal in Component PFD Calcium Fluonde Uranium Sodium Carbonate Filter Aid Quantity in Equipment (lb) 30 000 600 8 300 300 Concentration (%) 30 06 83 100 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g Temperature °C 80 80 80 Ambient Pressure psig Health Rating Hazard Rating 1 Assessment Descnption This processing step involves pressure filtration of a basic slurry Any splashing or contact with the skin should be avoided The basic chemicals m the hquid can cause skm and eye bums The solution and the filter cake are also radioactive and you must follow estabhshed health physics controls If any of the solution or filter cake gets on you, wash it off with generous amounts of water If any of the filter cake becomes dry respiration of the dust must be avoided The filter press and piping leading to it will be under pressure and should be handled carefully i Filter Aid c o Digestion Tank — ^1 I I WimmmmM 1 First Stage Filter Press No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of 3 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions In this processing step the undissolved CaF2 is separated from the dissolved uranium by pressure filtration Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect the filter feed pump and the filter press for leaks and proper assembly o Inspect safety showers and eyewash fountains Add water to the filter aid addition tank for pre coating the pressure filter according to instmctions from your supervisor Start agitation ofthe tank and then add pre coat filter aid to the tank according to instmctions from your supervisor Mix the contents of the tank thoroughly Make sure you are weanng the appropnate respirator as determined by the Radiation Safety Officer whenever handling or working in the vicimty of filter aid in its dry condition Adjust all necessary valves and tum on the pump to transfer pre coat filter aid slurry from the filter aid addition tank to the filter press Pump the entire contents of the filter aid addition tank through the filter press Then tum off the pump and adjust all necessary valves to leave the pre coated filter press filled with water under some pressure Adjust all necessary valves and tum on the pump from the digestion tank to the filter press Recycle filtrate back to the digestion tank until the solution clears and then adjust the appropnate valves to send the filtrate to the precipitation tank Pump the contents of the digestion tank through the filter press until the tank is empty or the pressure or flow rate indicates the filter press chambers are full of filter cake When the pressure or flow rate indicates the filter press chambers are full of filter cake tum off the pump from the digestion tank adjust the necessary valves and mn wash water through the filter press according to instmctions from your supervisor Send the filtrate from washing to the precipitation tank When the water wash is completed shut off the wash water adjust appropnate valves and mn compressed air through the filter press according to instmctions from your supervisor Send any liquid discharged from the filter press to the precipitation tank No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 13 Title CaF2 Processmg 2010 When the filter cake has been adequately dned by the compressed air shut off the air flow and depressunze the filter press Tum on the screw conveyor system under the filter press open the filter and dump and transfer all filter cake to the filter cake re pulp tank 1 j Add water to the filter cake re pulp tank according to instmctions from j your supervisor and agitate contents of the tank until the filter cake is fully re pulped Transfer the re pulped filter cake slurry to the tailings pond I according to instmctions from your supervisor | I Clean the filter press close it up and prepare it for its next filtration cycjle Repeat as needed steps for pre coating the filter filtenng the contents of the digestion tank and dumping and re pulping and transfernng the filter cake until the digestion tank is empty j • Make sure a sample is taken of the solids slurry transferred from the re pulp tank to tailings Whenever working in around or on this process you must avoid splashing and any contact with the skin and YOU MUST wear PPE which includes at a minimum hard hat coveralls mbber boots and gloves safety glasses with side shields and whatever level of respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles | Always keep your work area clean and ensure your work area is free ofj obstmctions I No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 2 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #4 Equipment Component Individual Equipment No NaOH Precipitation Node Parameter per Tank Process Matenal in Component PFD Uramum Sodium Carbonate NaOH Filter Aid Quantity m Equipment (lb) 600 8 300 2 500 350 Concentration (%) 07 10 50 100 Flashpoint, °F 1 TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g Temperature °C 70 70 Amb Amb Pressure psig Health Rating Health Hazard Assessment Descnption A uranium nch precipitate is formed by NaOH addition to the solution from the carbonate digestion of the CaF2 matenal in this processing step The liquid in the tank is strongly basic Any splashing or contact with the skin should be avoided These materials can cause skm and eye burns The solution and the precipitate that is formed are also radioactive and you must follow estabhshed health physics controls If any of the solution or precipitate gets on you, wash it off with generous amounts of water c o Filter Feed Tank Operatmg Instructions | This node deals with formation of a uramum nch precipitate by addition of NaOH to the final solution from the carbonate digestion of the CaF2 matenal No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of2 Date October 13 Title CaF2 Processmg 2010 Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains Maintain agitation of the filtrate solution from carbonate digestion of the CaF2 matenal in the precipitation tank Add steam if necessary to maintain the contents of the precipitation tank at least at 70°C (158°F) Make sure you are weanng all appropnate PPE for handling 50% NaOH (caustic) solution To the agitated contents of the precipitation tank carefully add 50% NaOH (caustic) solution until the pH of the contents of the tank reaches at least 13 0 as instmcted by your supervisor Measure the pH of the tank contents with pH paper obtained from the lab Do not measure the pH using an ordinary pH meter and probe - these may not give correct pH readings in this solution After the contents of the tank reach the target pH continue for about 4 hours to agitate the tank contents at the target temperature and continue to carefully add small volumes of the 50% NaOH solution to the tank as necessary to maintain the target pH After about four hours the precipitation reaction should be complete At this point add to the slurry in the precipitation tank the amount of filter aid as instmcted by your supervisor Make sure you are weanng the appropnate respirator as determined by the Radiation Safety Officer whenever handling or working in the vicinity of filter aid in its dry condition Then adjust the necessary valves tum on the pump and transfer the contents of the precipitation tank to the filter feed tank After the batch of matenal has been transferred as completely as practical from the precipitation tank to the filter feed tank then make sure the precipitation tank agitator IS tumed off and that all valves pumps etc have been retumed to the proper settings for starting handling of the next batch of solution from the digestion step Whenever working in around or on this process you must avoid splashing and any contact with the skin and YOU MUST wear PPE which includes at a minimum hard hat coveralls mbber boots and gloves safety glasses with side shields and whatever level of respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of3 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node#5 Equipment Component NaOH Precipitate Filtration Node Individual Equipment No Parameter per Tank Process Matenal in Component PFD Uramum Sodium Carbonate NaOH Filter Aid Quantity in Equipment (lb) 600 8 300 2 500 350 Concentration (%) 07 10 3 04 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g Temperature, °C (F) 70 70 70 70 Pressure psig Health Rating Health Hazard Assessment Descnption The uranium nch precipitate formed by NaOH addition to the solution from the carbonate digestion of the CaF2 matenal is separated from the solution by pressure filtration Make sure all pressunzed lines connections and fittings are in good condition and not leaking The liquid in the tank is strongly basic Any splashing or contact with the skin should be avoided The chemicals m the liquid can cause skm and eye burns The solution and the precipitate are also radioactive and you must follow estabhshed health physics controls If any of the solution or precipitate gets on you, wash it off with generous amounts of water The filter aid matenal is dusty in the dry condition and you must avoid breathing the dust Filtrate and Wash Surge Tank To Tails Cell 1 Comp Air H2O I HO \^^\ P'^te*"*^ Second Stage Filter Press Filter Cake CO Filter Cake Filter Aid Re Pulp Addition Tank Tank 2 H20 Filter Aid c Filter Feed Tank Y c 0 Filter Cake Acid Re Dissolution Tank No PBL 13 DENISONMINES (USA) CORPORATION Rev No R 1 STANDAIO) OPERATING PROCEDURES Page 2 of 3 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions This node deals with the pressure filtration processing step to recover the uranium nch precipitate formed by NaOH addition to the solution from the carbonate digestion of the CaF2 matenal • Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains o Inspect the filter to make sure it has been fully dumped cleaned and prepared to receive fresh feed matenal • Add water to the filter aid addition tank for pre coating the pressure filter according to instmctions from your supervisor Start agitation of' the tank and then add pre coat filter aid to the tank according to instmctions from your supervisor Mix the contents of the tank thoroughly Make sure you are weanng the appropnate respirator as j determined by the Radiation Safety Officer whenever handling or j working in the vicinity of filter aid m its dry condition f • Adjust all necessary valves and tum on the pump to transfer pre coat filter aid slurry from the filter aid addition tank to the filter press I Pump the entire contents of the filter aid addition tank through the , filter press Then tum off the pump and adjust all necessary valves to ' leave the pre coated filter press filled with water under some pressure • Adjust all necessary valves and tum on the pump from the filter feed tank to the filter press Recycle filtrate back to the filter feed tank until the solution clears and then adjust the appropnate valves to send all barren filtrate to the filtrate and wash surge tank Pump the contents of the filter feed tank through the filter press until the tank is empty or the pressure or flow rate indicates the filter press chambers are full of filter cake • Tum off the pump from the filter feed tank adjust the necessary valves and run wash water through the filter press according to instmctions from your supervisor Send the filter discharge to the filtrate and wash surge tank Shut off the wash water adjust the appropnate valves and mn compressed air through the filter press according to instmctions from No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 13 Title CaF2 Processmg 2010 your supervisor Send the filter discharge liquid to the filtrate and wash surge tank When the filter cake has been adequately dned by the compressed air shut off the air flow and depressunze the fllter press Tum on the screw conveyor system under the filter press open the filter and dump and transfer all filter cake to the filter cake re pulp tank 2 Add water to the filter cake re pulp tank 2 as instmcted by your supervisor and agitate the contents of the tank until the filter cake is fully re pulped Adjust appropnate valves and tum on the pump to transfer the re pulped filter cake slurry to the filter cake acid re dissolution tank according to instmctions from your supervisor Clean the filter press close it up and prepare it for its next filtration cycle Repeat pre coating the filter filtenng the contents of the filter feed tarJc and dumping and re pulping the filter cake and transfernng it to the filter cake acid re dissolution tank until the filter feed tank is empty Make sure the volume in the filtrate and wash surge tank is measured and recorded and make sure a sample of the contents of the tank is placed in an appropnately marked sample container for analysis by the lab Then send the contents of the filtrate and wash surge tank to tailings Whenever working in around or on this process you must avoid splashing and any contact with the skin and YOU MUST wear PPE which includes at a minimum hard hat coveralls mbber boots and gloves safety glasses with side shields and whatever level of respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles Always keep your work area clean and ensure your work area is free of obstmctions No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 2 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #6 Equipment Component Individual Equipment No Filter Cake Acid Re Dissolution Node Parameter per Tank Process Matenal in Component ') PFD Uranium Sulfunc Acid 11 1 Quantity in Equipment (lb) 1 800 1750 1 Concentration (%) 2 4 93 I ! Flashpoint °F ] TLV-TWA ppm STEL ppm n Radioactivity pCi/g 0 Temperature °C (F) 25 40 25 40 11 Pressure psig 0 100 11 Health Rating i ' Health Hazard !, Assessment Descnption The re pulped filter cake of basic uramum nch precipitate and the acidic solution in which it will be digested should be handled with caution Any splashing or contact with the skin should be avoided The acidic cheimcals m the hquid| can cause skm and eye burns The solution and the filter cake are also radioactive and you must follow estabhshed health physics controls If any of the solution or filter cake gets on you, wash it off with generous amounts of water Steam H2SO4 CO Fllter Cake Acid Re Dissolution Tank No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of 2 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions This node deals with the acid digestion of re pulped uranium nch filter cake • Make a safety inspection of all equipment i' It o Inspect safety showers and eyewash fountains | o Inspect valves and fittings in the acid line f • As the slurry of re pulped filter cake is being transferred to the filter I cake acid re dissolution tank tum on agitation in the tank as soon as the level is sufficient according to your supervisor s instmctions li 'i • Add water to the contents of the filter cake acid re dissolution tank J according to instmctions from your supervisor and carefully add , sulfunc acid to bnng the pH of the slurry to 2 0 or a lower pH as \ instmcted by your supervisor ji • Add steam to bnng the contents of the filter cake acid re dissolution ' tank to 40°C or another temperature as instmcted by your supervisor ji Agitate the slurry in the tank at the target temperature and pH for a ^ time of at least one hour as instmcted by your supervisor adding steam and sulfunc acid as needed to maintain these conditions | li • Whenever working in around or on this process you must avoid i' splashing and any contact with the skin and YOU MUST wear PPE [! which includes at a mimmum hard hat coveralls mbber boots and ^ gloves safety glasses with side shields and whatever level of ji respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles ' No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 3 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #7 Equipment Component Individual Equipment No Filtration After Acid Digestion of Filter Cake Node Parameter Process Matenal in Component PFD Uranium Dilute H2SO4 Filter Aid Quantity in Equipment (lb) 1 800 50 1000 Concentration (%) 2 4 0 1 02 1 2 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g Temperature °C 40 40 40 Pressure psig Health Rating Hazard Rating Assessment Descnption This processing step involves pressure filtration ofan acidic slurry Any splashing or contact with the skin should be avoided The acidic cheimcals m the hqmd can cause skm and eye burns The solution and the filter cake are also radioactive and you must follow estabhshed health physics controls If any of the solution or filter cake gets on you, wash it off with generous amounts of water If any of the filter cake becomes dry respiration of the dust must be avoided The filter press and piping leading to it will be under pressure and should be handled carefully i c 0 C 0 Impurity Removal Tank 1 Impunty Removal Tank 2 Third Stage Filter Press CO Fllter Cake Re Pulp Tanks Filter Cake Acid Re Dissolution Tank H2O Cake Washmg Tank Operatmg Instructions No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of 3 Date October 13 Title CaF2 Processmg 2010 In this processing step the used filter aid is separated from the dissolved uranium by pressure filtration • Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect the filter feed pump and the filter press for leaks and proper assembly o Inspect safety showers and eyewash fountains • Adjust all necessary valves and tum on the pump from the filter cake acid re dissolution tank to the filter press Recycle filtrate back to the filter cake acid re dissolution tank until the solution clears and then adjust the appropnate valves to send the filtrate to impunty removal tank 1 or tank 2 Pump the contents of the filter cake acid re dissolution tank through the filter press until the tank is empty or the pressure or flow rate indicates the filter press chambers are full of filter cake • When the pressure or flow rate indicates the filter press chambers are full of filter cake tum off the pump from the filter cake acid re dissolution tank adjust the necessary valves and mn wash water through the filter press according to instmctions from your supervisor Send the filtrate from washing to the same impunty removal tank • When the water wash is completed shut off the wash water adjust appropnate valves and run compressed air through the filter press according to instmctions from your supervisor Send any liquid discharged from the filter press to the same impunty removal tank When the filter cake has been adequately dned by the compressed air shut off the air flow and depressunze the filter press Tum on the screw conveyor system under the filter press open the filter and dump and transfer all filter cake to the filter cake re pulp tank 3 Add water to the filter cake re pulp tank according to instmctions from your supervisor and agitate contents of the tank until the filter cake is fully re pulped Transfer the re pulped filter cake slurry to the cake washing tank according to instmctions from your supervisor No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 13 Title CaF2 Processmg 2010 • Clean the filter press close it up and prepare it for its next filtration cycle • Repeat as needed steps for filtenng the contents of the filter cake acid re dissolution tank and dumping and re pulping and transfernng the filter cake until the filter cake acid re dissolution tank is empty • Transfer the clear supematant liquid from the cake washing tank back into the process to recover the contained uranium according to instmctions from your supervisor Wash the filter cake solids in the cake washing tank with water as instmcted by your supervisor Once the washing of the filter cake solids is sufficient transfer the solids from the cake washing tank to tailings according to instmctions from your supervisor • Make sure a sample is taken of the underflow solids slurry transferred from the cake washing tank to tailings • Whenever working in around or on this process you must avoid splashing and any contact with the skin and YOU MUST wear PPE which includes at a minimum hard hat coveralls mbber boots and gloves safety glasses with side shields and whatever level of respiratory protection is deemed appropnate by the Radiation Safety Officer and may include a face shield or safety goggles • Always keep your work area clean and ensure your work area is free of obstmctions No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 1 of 3 Date October 13 Title CaF2 Processmg 2010 Hazard Assessment Worksheet Node #8 Equipment Component Individual Equipment No Impunty Removal Node Parameter Process Matenal in Component PFD Uramum H2SO4 Ammonia Quantity in Equipment (lb) 1200 2400 50 500 100 250 Concentration (%) 24 93 100 Flashpoint ''F TLV-TWA mg/m' 25 STEL mg/m' 35 Radioactivity pCi/g 0 0 Temperature °C 40 20 20 Pressure psig Health Rating Hazard Rating Assessment Descnption In this step impunties will be separated from the uranium by pH adjustment and precipitation using ammonia followed by settling and decantation REMEMBER Ammonia vapor, fumes and mists are Toxic Atmospheres and cannot be detected by smell above approximately 100 ppm IF you smell strong ammonia fumes you must wear a full face respirator with universal cartridges and ventilate the area At high concentrations your skm and eyes can be burned The begmnmg solution and the precipitate are also radioactive and you must follow estabhshed health physics controls If any of the solution or precipitate gets on you, wash it off with generous amounts of water To Tails Cell 1 NH3 or H2SO4 Steam CO Steam CO NHjor H2SO4 Impunty Impunty Removal Removal Tanki Tank 2 To Normal Yellowcake Precipitation Product Holdmg Tank No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 2 of3 Date October 13 Title CaF2 Processmg 2010 Operatmg Instructions This node deals with the separation of uranium from impunties by adjusting pH with ammonia (NH3) to form a precipitate allowing the precipitate to settle to the bottom of the tank and then decanting and pumping away the clear liquid • Make a safety inspection of all lines and equipment • Inspect lines and tanks for leaks or seeps • Inspect safety showers and eyewash fountains • Measure contained volume and then tum on the agitator and take a sample of the tank contents for the impunty removal tank contaimng the acid digestion liquor that has most recently been clanfied by filtration in the filter press Place the sample in an appropnately labeled sample bottle for analysis by the lab • Add steam as necessary to the contents of the impunty removal tank according to instmctions from your supervisor to establish and maintain the target temperature for the tank contents Add ammonia to the contents of the impunty removal tank according to instmctions from your supervisor Continue adding ammoma until the contents of the tank reach and remain at the target pH as instmcted by your supervisor and then continue agitation for an additional 30 minutes • Tum off the agitator in the impunty removal tank and allow the precipitate to settle according to instmctions from your supervisor • Depending on the impunty being removed from the uranium the uranium may be contained in either the precipitate or in the supematant liquid Once your supervisor has determined that the precipitate in the impunty removal tank has settled sufficiently begin decanting the clear supematant liquid from the tank • If the uranium is m the precipitate then transfer the decanted liquid to tailings as instmcted by your supervisor Be sure to take a sample of the decanted liquid and record and report the volume of decanted liquid After the liquid is completely decanted as instmcted by your supervisor add water to wash the precipitate as instmcted by your supervisor and agitate settle and decant again After washing the No PBL 13 DENISON MINES (USA) CORPORATION Rev No R 1 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 13 Title CaF2 Processmg 2010 precipitate add water and sulfunc acid to the precipitate as instmcted by your supervisor and agitate until the uranium is all re dissolved Then either conduct other impunty removal steps on the liquor or transfer it to the product holding tank • If the uramum is in the decanted liquid then transfer the liquid to the other impunty removal tank if addition impunty removal is needed or else transfer the liquid to the product holding tank Once the decanting IS complete add water agitate settle and decant again to wash the precipitate, sending the liquid removed to the same tank as previously If the washed precipitate is sufficientiy low in uranium transfer it to tailings as instmcted by your supervisor Otherwise send the precipitate to re processing as instmcted by your supervisor • Once impunties have been sufficiently removed and the liquor has accumulated sufficiently in the product holding tank transfer the contents of the product holding tank slowly to the normal yellowcake precipitation area of the plant Each time a transfer from this tank occurs record and report the volume transferred and take a sample of the liquor transfened in a properly marked sample container • Whenever working m around or on this process circuit YOU MUST wear PPE which includes at mimmum Tyvex or Mill coveralls mbber boots or regular steel toed boots and gloves safety eye glasses a face shield and may include full face respirators ATTACHMENT 2 / I I 5^ ^ r • .3 =W ' 1 1 ? No PBL 11 DENISONMINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 1 of2 Date October 3 Title FMRI and Cabot Processing 2011 Hazard Assessment Worksheet Node #1 Equipment Component Individual Equipment No FMRI and Cabot Feed Preparation Node Parameter Process Matenal in Component PFD Uramum Quantity in Equipment (lb) 20 80 Concentration (%) 1 4 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g (FMRI) 895 4 Radioactivity pCi/g (Cabot) 3706 8 Temperature °C Amb Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The FMRI and Cabot matenals are industnal solid by products of relatively fine particle size that contain uranium along with a vanety of compounds including mainly calcium aluminum zirconium iron sodium and potassium compounds The FMRI or Cabot matenal may need to be separated from the super sacks in which it was shipped before it is ready to feed to the process Though the matenal normally contains sufficient moisture to keep it from easily becoming airbome there is a possibility for minor portions of the matenal to become airbome as it is separated from the super sacks The FMRI and Cabot materials are also radioactive and you must follow estabhshed health physics controls If any of these materials gets on your clothmg or skm, wash it off promptly with generous amounts of soap and water Operatmg Instructions The FMRI or Cabot matenal may have been stored in a pile of super sacks and if so it must be kept in the super sacks for control of dust emissions until a short tune before it is to be fed to the process Thus either the FMRI or the Cabot matenal may require preparation to separate the matenal from the super sacks pnor to feeding for other processing In this case the preparation should be performed according to the following procedure Make sure you are familiar with the MSDS for the FMRI or Cabot matenal whichever you will be handling No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 2 of2 Date October 3 Title FMRI and Cabot Processing 2011 Make a safety inspection of all equipment including the following o Inspect parts of the equipment that normally come into contact with the matenal to assure proper function o Inspect the operator s cab to assure that all closures for all possible openings that could admit dust into the cab are functioning properly and capable of being securely closed When it IS determined safe to do so and in accordance with your supervisor s instmctions mount the piece of equipment and enter the operator s cab with the intent to operate the piece of equipment Make sure the door seals tightly when it is closed and make sure all other openings through which dust could enter are also closed Fasten all restraimng devices and enable all appropnate safety systems for the piece of equipment Make sure all other personnel and equipment are clear from the piece of equipment you are about to start Then tum the piece of equipment on Proceed to operate the piece of equipment according to your supervisor s instmctions and the manufacturer s instmctions to separate the super sacks and other extraneous matenals from the FMRI or Cabot matenal to be processed for uranium recovery When the work to be accomplished is completed or when it becomes operationally necessary properly secure the piece of equipment and tum it off Exit the operator s cab closing the door behind you and dismount the piece of equipment in accordance with your supervisor s instmctions NOTE Whenever workmg around the piles of FMRI or Cabot material you must wear appropriate PPE which may mclude Tyvex coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Ofiicer No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 1 of 2 Date October 3 Title FMRI and Cabot Processing 2011 Hazard Assessment Worksheet Node #2 Equipment Component Individual Equipment No FMRI and Cabot Gnnding Node Parameter Process Matenal in Component PFD Uramum Quantity in Equipment (lb) 80 400 Concentration (%) 1 4 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g (FMRI) 895 4 Radioactivity pCi/g (Cabot) 3706 8 Temperature °C Amb Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The FMRI and Cabot matenals are industnal solid by products of relatively fine particle size that contain uranium along with a vanety of compounds including mainly calcium aluminum zircomum iron sodium and potassium compounds Though the matenal normally contains sufficient moisture to keep it from easily becoming airbome there is a possibility for minor portions of the matenal to become airbome as it is fed to the process The FMRI and Cabot materials are also radioactive and you must foUow estabhshed health physics controls If any of these materials gets on your clothmg or skm, wash it off promptly with generous amounts of soap and water No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 2 of 2 Date October 3 Title FMRI and Cabot Processing 2011 i c o Pulp storage Tank Operatmg Instructions The FMRI or Cabot matenal that has been prepared for feeding to uranium recovery processing will be sitting in a pile on the ore pad Before handling these matenals appropnate precautions should be taken to protect operators from inhaling airbome dusts of these matenals Operators can then proceed with the gnnding step as follows • Make sure you are familiar with the MSDS for the FMRI or Cabot matenal whichever you will be handling • Make a safety inspection of all lines and equipment o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains o Inspect operator s cabs of mobile equipment to be used to assure doors and all other opemngs through which dust might enter can be tightly sealed • Start up the gnnd circuit according to standard operating procedures Begin feeding the prepared FMRI or Cabot matenal to the gnzzly and continue feeding and processing through the gnnd circuit stonng the ground pulp in the pulp storage tanks according to standard operating procedures for the gnnd circuit No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 3 of 2 Date October 3 Title FMRI and Cabot Processing 2011 • When the appropnate tonnage of FMRI or Cabot matenal has been fed and processed in the gnnd circuit shut down the gnnd circuit according to standard operating procedures NOTE Whenever workmg m, around or on the grmd circuit you must wear appropriate PPE which may mclude Tyvex coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Officer No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 1 of 3 Date October 3 Title FMRI and Cabot Processing ' 2011 Hazard Assessment Worksheet Node #3 Equipment Component Individual Equipment No FMRI and Cabot Leaching Node Parameter Process Matenal in Component PFD Uranium H2SO4 Quantity in Equipment (lb) 3 500- 14 000 6 000 Concentration (%) 05-25 1 0 Flashpoint "F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g (FMRI) 895 4 Radioactivity pCi/g (Cabot) 3706 8 Temperature °C Amb Amb Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The FMRI and Cabot matenals are industnal solid by products of relatively fine particle size that contain uranium along with a vanety of compounds ' including mainly calcium aluminum zirconium iron sodium and potassium compounds In this processing step sulfunc acid is added to the pulp to dissolve some of the ^ contained uranium Adequate caution is needed to prevent splashing of acid or acidified pulp on any operators or equipment not designed for acid contact The FMRI and Cabot materials are also radioactive and you must follow established health physics ] controls If any of these materials gets on your clothmg or skm, wash it off promptly with generous amounts of soap and water ! Pulp storage Tank H2S04 t East Preleach Tank West Preleach Tank No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 2 of 3 Date October 3 Title FMRI and Cabot Processing 2011 Operatmg Instructions The FMRI or Cabot matenal in the form of a ground pulp is fed to the leaching step to dissolve some of the contained uranium by reaction with sulfunc acid Operators should perform the leaching step as follows • Make sure you are familiar with the MSDS for the FMRI or Cabot matenal whichever you will be handling and the MSDS for sulfunc acid • Make a safety inspection of all lines and equipment including the following o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains • Make sure agitation is mnning in the pre leach tanks Transfer ground pulp of the FMRI or Cabot matenal from one of the pulp storage tanks to the east pre leach tank at the rate of 60 tons per hour or as instmcted by your supervisor • Add sulfunc acid in a continuous stream if possible to the east pre leach tank sufficient to maintain a free acid concentration in the east pre leach tank of 15 grams per liter or as instmcted by your supervisor • At times it may be necessary to add water pond retum liquid, or other matenals or reagents to the east pre leach tank Make these additions only as instmcted by your supervisor • The west pre leach tank is operated to provide additional residence time for the leach reactions to proceed Normally there will be no additions of reagents to the west pre leach tank Make no additions to this tank unless instmcted to do so by your supervisor • Unless otherwise noted in the instmctions listed above or instmctions received from your supervisor operate the equipment of the pulp storage and pre leach areas according to standard operating procedures NOTE Whenever workmg m, around or on the pulp storage and pre-leach areas of the mill you must wear appropriate PPE which may mclude Tyvex No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 3 Title FMRI and Cabot Processing 2011 coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Officer J 1 No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 1 of 3 Date October 3 Title FMRI and Cabot Processing 2011 Hazard Assessment Worksheet Node #4 Equipment Component Individual Equipment No FMRI and Cabot Washing Node Parameter Process Matenal in Component PFD Uramum H2SO4 Quantity in Equipment (lb) 1200- 5 000 2 500 Concentration (%) 02-10 04 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g (FMRI) 895 4 Radioactivity pCi/g (Cabot) 3706 8 Temperature °C Amb Amb Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The FMRI and Cabot matenals are industnal solid by products of relatively fine particle size that contain uranium along with a vanety of compounds including mainly calcium aluminum zirconium iron sodium and potassium compounds In this processing step the acidified uranium beanng solution is separated from the leached solids Adequate caution is needed to prevent splashing of acidified liquid or pulp on any operators or equipment not designed for acid contact The FMRI and Cabot materials are also radioactive and you must follow established health physics controls If any of these materials gets on your clothmg or skm, wash it off promptly with generous amounts of soap and water ' 1 L Clarifler No PBL 11 DENISONMINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 2 of3 Date October 3 Title FMRI and Cabot Processing 2011 Operatmg Instructions In this processing step the leached pulp produced from the FMRI or Cabot matenal is washed in one or more CCD thickeners to separate the liquid containing the dissolved uramum from the leached solids which are sent to the tailings area for disposal Operators should perform the washing step as follows • Make sure you are familiar with the MSDS for the FMRI or Cabot matenal whichever you will be handling • Make a safety inspection of all lines and equipment including the following o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains • Transfer the leached pulp discharging from the west pre leach tank to the head tank for the #8 CCD thickener or another thickener as instmcted by your supervisor • Add a sufficient flow of pond retum liquid process water or a mixture of the two liquids as instmcted by your supervisor to the thickener head tank with the leached pulp to achieve a pulp density of about 25% solids or as instmcted by your supervisor • Proceed to operate the #8 CCD thickener and/or other CCD thickeners as instmcted by your supervisor according to the standard operating procedures for the CCD circuit thickeners This will include adding flocculant as needed to the thickener feed • Transfer the final overflow stream discharging from the CCD thickeners in use to the clanfier for further clanfication before processing in SX for uramum recovery • Transfer the final underflow stream discharging from the CCD thickeners in use to the tailings sump for disposal of the leached solids in the tailings area No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 3 of 3 Date October 3 Title FMRI and Cabot Processing 2011 NOTE Whenever working m, around or on the CCD thickeners and the CCD area of the mill you must wear appropriate PPE which may mclude Tyvex coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Officer 1 No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 1 of2 Date October 3 Title FMRI and Cabot Processing 2011 Hazard Assessment Worksheet Node #5 Equipment Component Individual Equipment No FMRI and Cabot SX and Precipitation Node Parameter Process Matenal in Component PFD Uramum H2SO4 Quantity m Equipment (lb) 100-200 1 500 Concentration (%) 0 02 - 0 04 04 Flashpoint °F TLV-TWA mg/m' STEL mg/m' Radioactivity pCi/g (FMRI) Same as processing ore Radioactivity pCi/g (Cabot) Same as processing ore Temperature "C Amb Amb Pressure psig Health Rating 2 Hazard Rating Assessment Descnption The solution obtained from leaching FMRI and Cabot matenals may contain varying concentrations of dissolved uranium calcium aluminum zirconium iron sodium and potassium compounds In these processing steps the uranium is separated from impunties and collected as a high punty yellowcake product Adequate caution is needed to prevent splashing of acidified liquid on any operators or equipment not designed for acid contact The uranium-bearmg hquids are also radioactive and you must follow estabhshed health physics controls If any of these materials gets on your clothmg or skm, wash it off promptly with generous amounts of soap and water f To Solvent Extraction and Yellowcake Precipitation Clanfier No PBL 11 DENISON MINES (USA) CORPORATION Rev No R 0 STANDARD OPERATING PROCEDURES Page 2 of2 Date October 3 Title FMRI and Cabot Processing 2011 Operatmg Instructions 1 In these processing steps the solution containing the uranium leached from the FMRI or Cabot matenal is treated to extract the uramum away from impunties and later precipitate the uranium as a punfied final product of the mill Operators should perform these steps as follows I • Make sure you are familiar with the MSDS for kerosene tertiary amine tn decyl alcohol ammonia and any other reagents to be used Also make sure you are familiar with the MSDS for yellowcake • Make a safety inspection of all lines and equipment including the following | o Inspect lines for leaks or seeps o Inspect safety showers and eyewash fountains • Transfer the uranium beanng solution from the clanfier to the SX feed tank and operate the SX circuit according to the established standard operating procedures • Transfer the loaded stnp solution produced by the SX circuit to the yellowcake precipitation and drying area and operate the yellowcake precipitation and drying area according to the established standard operating procedures 1 • Label and store the dmms of finished yellowcake produced in the yellowcake ' precipitation and drying area according to established standard operating ' procedures ' NOTE Whenever workmg m, around or on the SX or yellowcake precipitation and drymg areas of the mill you must wear appropriate PPE which may mclude Tyvex coveralls, rubber boots, gloves, safety glasses, face shield or full face respirators or whatever level of respiratory protection is deemed appropriate by the Radiation Safety Officer !