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Home My WebLink AboutDRC-2012-001152 - 0901a068802b0801DENISO MINES Februarys 2012 DRC-2012-00 1152 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 Mr Rusty Lundberg Utah Department of Environmental Quality 195 North 1950 West PO Box 144810 Salt Lake City UT 84114 4820 Re Utah Division of Radiation Control ( DRC ) Notice of Enforcement Discretion and Confirmatory Action Letter of December 20 2011 Dear Mr Lundberg This letter responds to Utah Division of Radiation Control s ( DRC s ) Notice of Enforcement Discretion ( NED ) and Confirmatory Action Letter of December 20 2011 regarding Denison Mines (USA) Corp s ( Denison s ) Annual Technical Evaluation Report (ATER ) for the White Mesa Mill tailings management system submitted on November 9 2011 Dunng a telephone discussion on October 26 2011 DRC and Denison discussed the settlement monitonng data published in the ATER relative to the Settlement Monitonng Standard Operating Procedure ( SOP ) conditionally approved by DRC on October 13 2011 DRC subsequently transmitted the above referenced NED Background Text in the ATER indicated that one or more of the settlement monitors on the western portion of Cell 2 indicated settlement of approximately 0 64 feet Dunng the October 26 2011 phone call Denison and DRC agreed that Denison would collect and evaluate survey data for at least two more months to assess whether the measurements of 0 64 feet were indications of actual settlement or of survey error DRC agreed to use enforcement discretion provided that Denison responded with the needed additional data and evaluation by one week after the end of January that is on or before February 4 2012 This letter has been submitted to meet that agreement and to respond to the December 20 2011 NED Although the NED referred to a SOP approved on November 3 2011 Denison believes DRC meant to refer to the Settlement Monitonng SOP approved on October 13 2011 In any case as discussed below the data in question in the ATER was collected in October 2010 before the current Settlement Monitonng SOP was in effect Data and Results The reference to an apparent settlement of 0 64 feet was with respect to a measurement taken at the end of October 2010 Subsequent measurements taken for the past year confirm that the measurement in question was indeed in error Denison has collected and evaluated the settlement monitor data for the months of Letter to Mr Rusty Lundberg January 12 2011 Page 2 October 2010 through January 2012 The attached Table 1 provides the survey results for ten (10) monitors on the west end of Cell 2 for that time period The data in Table 1 indicate that the one measurement from October 2010 was in error and all subsequent measurements are in line with measurements prior to October 2010 Conclusions Denison believes that no further action is required at this time Please contact me if you have any questions or require any further information Yours very truly DENISON MINES (USA) CORP Jo Ann Tischler Director Compliance and Permitting cc David C Frydenlund Harold R Roberts David E Turk K Weinel Central files DENISO MINES Letter to Mr Rusty Lundberg January 12 2011 Page 3 ATTACHMENTS DENISO MINES Table 1 Cell 2 West 1 Cell 2 West 2 Cell 2 West 3 Cell 2 West 4 2W5 C 2W4 N 2W4S 2W5 N 2W3 s 2W5 S 1/29/2010 5619 20 562111 5617 84 5617 37 5618 27 5619 22 5616 11 5618 85 5616 65 2/26/2010 5619 14 5621 08 5617 84 5617 36 5618 28 5619 24 5616 08 5618 86 5616 65 3/30/2010 5619 18 562109 5617 83 5617 38 5618 24 5619 21 5616 09 5618 82 5616 64 Intal 4/30/2010 5619 06 5620 94 5617 70 5617 24 5618 14 5619 08 5615 96 5618 70 5616 50 5614 06 5/28/2010 5619 16 5621 10 5617 84 5617 39 5618 26 5619 23 5616 09 5618 85 5616 65 5614 21 6/30/2010 5619 03 562105 5617 67 5617 24 5618 12 5619 06 5615 94 5618 67 5616 49 5614 05 7/29/2010 5618 97 5620 85 5620 61 5617 15 5618 05 5619 07 5615 87 5618 60 5616 43 5613 95 8/19/2010 5618 97 5620 87 5617 63 5617 17 5618 06 5619 09 5616 16 5618 64 5616 44 5613 97 9/17/2010 5618 97 5620 86 5617 60 5617 15 5618 06 5619 08 5615 88 5618 60 5616 43 5613 97 10/29/2010 5618 35 5620 23 5616 97 5616 51 5617 42 5618 44 5615 24 5617 95 5615 78 5613 31 11/30/2010 5619 07 5620 96 5617 71 5617 26 5618 03 5619 06 5616 14 5618 60 5616 22 5613 93 12/17/2010 5618 99 5620 87 5617 63 5617 17 5618 07 5619 09 5615 89 5618 63 5616 45 5613 97 1/13/2011 5618 99 5620 87 5617 62 5617 15 5618 07 5619 07 5615 87 5618 62 5616 41 5613 95 2/18/2011 5618 93 5620 81 5617 58 5617 12 5618 02 5619 05 5615 84 5618 59 5616 39 5613 91 3/17/2011 5618 97 5620 85 5617 60 5617 13 5618 05 5619 06 5615 85 5618 62 5616 41 5613 93 4/18/2011 5619 09 5620 96 5617 68 5617 17 5618 10 5619 13 5612 32 5618 68 5616 45 5613 98 5/27/2011 5618 96 5620 84 5617 58 5617 12 5618 03 5619 05 5615 76 5618 59 5616 41 5613 92 6/14/2011 5618 99 5620 91 5617 63 5617 18 5618 02 5619 10 5615 82 5618 66 5616 40 5613 93 7/29/2011 5618 97 5620 87 5617 59 5620 23 5618 03 5618 99 5618 47 5618 51 5619 34 5616 23 8/31/2011 5618 99 5620 86 5617 59 5620 23 5618 05 5618 99 5618 47 5618 51 5619 32 5616 19 9/27/2011 5618 99 5620 84 5617 60 5620 21 5618 03 5618 98 5618 45 5618 52 5619 31 5616 72 10/21/2011 5618 97 5620 87 5617 61 5620 26 5618 07 5619 00 5618 46 5618 53 5619 33 5616 15 11/28/2011 5619 06 5620 98 5617 65 5620 31 5618 11 5619 05 5618 52 5618 59 5619 37 5616 12 12/21/2011 5618 95 5620 85 5617 63 5620 27 5618 04 5619 01 5618 48 5618 53 5619 31 5617 04 1/31/2012 5618 97 5620 86 5617 62 5620 24 5618 05 5619 00 5618 45 5618 53 5619 30 5616 02