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Home My WebLink AboutDRC-2012-001249 - 0901a068802bc856DENISO MINES March 19 2012 Mi Denison 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 Rusty Lundberg Co Executive Secretary Utah Water Quality Board Utah Department of Environmental Quality 195 North 1950 West PO Box 144810 Salt Lake City UT 84114 4810 i Re State of Utah Ground Water Discharge Permit No UGW370004 White Mesa Uranium Mill - Notice Pursuant to Part I G 3 of the Permit and UAC R317 6 6 16(C) Dear Mr Lundberg Please take notice pursuant to Part I G 3 of the White Mesa Mill s (the Mill s ) State of Utah Groundwater Discharge Permit No UGW370004 (the Permit) and Utah Administrative Code ( UAC ) R317 6 6 16(C) that Denison Mines (USA) Corp ( Denison ) as operator of the Mill and holder of the Permit failed to meet the Best Available Technology ( BAT ) standards in Part I D 12a) 1) of the Permit as a result of a malfunctioning interface in the Cell 4B leak detection system ( LDS ) as descnbed in more detail below The malfunction was discovered dunng the daily tailings inspection on Wednesday March 14 2011 Initial notice of this failure to maintain BAT was given by telephone to Mr Russ Topham of the Utah Division of Radiation Control ( DRC ) at 1 35pm on Wednesday March 14 2011 at 801 536 4256 (within 24 hours of the discovery) 1 Facts and Background Information a) DRC provided authonzation for use of Cell 4B on January 27 2011 b) Part 1 E 12 a) 1) of the Permit requires that the permittee shall provide continuous operation of the leak detection system pumping and monitonng equipment including but not limited to the submersible pump pump controller head monitonng and flow meter equipment approved by the Executive Secretary c) Section 3 1a) of the Best Available Technology/Discharge Minimization Technology Plan states that The Cell 4A and 4B leak detection systems are monitored on a continuous basis by use of a pressure transducer that feeds water level information to an electronic data collector The water levels are measured every hour and the information is stored for later retneval Y \Notices\03 15 12 Notice to R Lundberg cell 4B\03 19 12 Notice to RLundberg Cell 4B LDS doc Letter to Mr Rusty Lundberg March 19 2012 Page 2 d) Daily monitonng of the Cell 4B LDS pnor to the week of March 14 2012 indicated that the components of the pumping and flow monitonng system (pump pump controller flow meter flow totalizer and all other components) were working properly e) Daily monitonng of the Cell 4B LDS on March 14 2012 indicated that the system was measunng solution level total gallons pumped and hourly flow rate but was only displaying and recording solution level and total gallons pumped That is the hourly flow rate was not being recorded A data download indicated that the system had not recorded hourty readings since 15 00 (3 00 PM) on Tuesday March 13 2012 several hours after the previous days daily tailings inspection f) The pump controller flow meter and totalize were all working correctly g) Mill environmental personnel reported the finding to the Mill manager and to Mill engineering personnel on March 14 2012 Mill engineenng personnel began immediate telephone communications with the supplier to diagnose and troubleshoot the malfunction h) Corporate environmental management determined on March 14 2012 that notification to DRC of the status of troubleshooting and repair plans was required under Part I G 3 of the Permit and UAC R317 6 6 16(c) and notification was made as stated above 2 Action Taken a) Mill environmental and engineenng personnel determined that the failure appeared to result from a disconnect between the flow meter and the processor and as a result flow rate data was being measured but not recorded or stored and could not be downloaded b) The manufacturer Environmental Pump Solutions determined on Thursday March 15 2012 that the failure required replacement of the Programmable Logic Controller ( PLC ) unit in the processor The manufacturer shipped a replacement PLC unit overnight c) A replacement PLC unit was received at the Mill on Fnday March 16 2012 d) The unit was installed on March 16 2012 System checking and startup was completed on Fnday March 16 2012 e) Mill engineenng personnel mill environmental personnel and Corporate environmental management discussed the corrective steps taken and a path forward on March 16 2012 f) Daily inspection and monitonng of the system will continue to confirm that the repair has corrected the over recording problem 3 Root Cause The root cause analysis is as follows a) The flow rate meter is one of the data input devices whose data is controlled by the PLC unit It was determined that the nature of the failure to record flow required replacement of the PLC unit DENISO MINES J Letter to Mr Rusty Lundberg March 19 2012 Page 4 There was no discharge of solutions from the Mill s tailings impoundments Please contact the undersigned if you have any questions or require any further information Yours very truly DENISON MINES (USA) CORP /do Ann Tischler Director Compliance and Permitting cc Dan Hillsten David C Frydenlund Harold R Roberts David E Turk Central files DENISO MINES