DRC-2010-006585 - 0901a068801ec697

RC-20lO-00658'i
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DEC 2010
Division of
Radiation Contro
Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax : [phone]
www.denisonmines.com
MINES
December 27, 2010
VIA E-MAIL AND OVERNIGHT DELIVERY
Mr. Rusty Lundberg, Execufive Secretary
Utah Division of Radiation Control
Utah Department of Environmental Quality
195 North 1950 West
P.O. Box 144810
Salt Lake City, UT 84114-4820
Dear Mr. Lundberg:
Re: State of Utah Ground Water Discharge Permit ("GWDP") No. UGW370004 White Mesa Uranium
Mill - Status Report on Cell 1 Leak Detection system ("LDS") and Transmittal of Confirmatory Video
Documentation
This letter report responds to the Utah Division of Radiation Control's September 22, 2010 Conditional Approval
and Confirmatory Action Letter regarding the White Mesa Mill (the "Mill") Cell 1 leak detection system ("LDS")
and Denison Mines (USA) Corp's ("Denison's") telephone conversations with DRC on August 23, September
15, and September 21, 2010. A separate letter which summarized Denison's inspection of the LDS level
measurement process and resolved apparent inconsistencies in Cell 1 LDS depth and liquid level
measurements, as requested in DRC's September 22, 2010 letter, was submitted to DRC on September 30,
2010.
Status of Required Actions in DRC's September 22, 2010 Letter
Item 1. Determine the root cause of the apparent discrepancies of the Estimation of Cell 1 Leakage
Rate. (Table 1) and submit written findings bv September 30, 2010 for Executive Secretary review and
approval.
As mentioned above, the requirements in Item 1 were addressed in a letter submitted under separate cover.
Item 2. Perform a video log of the Cell 1 LDS standpipe down to the T-|oint with the slotted collection pipe and
determine the total downslope distance to the nearest 0.1 foot. If anv debris is observed within the standpipe,
this debris will be removed. If debris is observed, another video log will need to be performed after the debris is
removed to document that the standpipe is free of debris. Both video logs will be performed and submitted for
DRC review and approval bv November 1, 2010.
As required by Item 2, the initial video logging was completed on October 22, 2010 by Denison's contractor
RNR Enterprises ("RNR"). A status update report was transmitted to DRC on November 11, 2010 accompanied
by a CD Rom copy of the initial video images of the Cell 1 LDS pipe. Based on the images, and consistent with
N;\Cell 1 Plan and Repairs 2010\Cell 1 LDS closing report to DRC 12 27 lO.doc
Letter to Rusty Lundberg - Cell 1 LDS Update Report
December 27, 2010
Page 2
Item 2 of DRC's September 22 letter, Denison determined that the LDS pipe did require maintenance to remove
the debris, accumulated sediments, precipitates, and soil material. Denison discussed and agreed upon
approached with Mr. Philip Goble of DRC on November 18, 2010. Mr. Goble's email requested that cleanout be
completed and video images be submitted to DRC by year-end 2010.
Denison's contractor, RNR, performed the cleanout on December 1 and 2, 2010 using a vacuum truck and,
while on site, did comparable maintenance in the Cell 3 LDS pipe system. Denison provided DRC a seven-day
notice of the cleanout date and Mr. Goble of DRC was present during most of the cleanout and video work.
Mill environmental personnel also removed from the Cell 1 LDS pipe all broken tubing, to the extent practicable,
leaving one segment of unreachable tubing that does not obstruct operation of the Cell 1 LDS blow pipe
system.
Following the cleanout, Denison's contractor, RNR, performed confirmatory camera scans of both the Cell 1
LDS and Cell 3 LDS pipes on December 2, 2010.
Enclosed with this letter, Denison is providing a copy in CD-ROM format of the continuous video images from
the pre- cleanout and post-cleanout camera inspection of both the Cell 1 and Cell 3 LDS's. Review of the video
images indicates that the work was successful in removing almost all of the dirt and debris from both LDS's.
Denison respectfully subnriits that all requirements regarding maintenance ofthe Cell 1 LDS system have been
completed.
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: Rich E. Bartlett
David C, Frydenlund
Ron F. Hochstein
Harold R. Roberts
David E. Turk
Kathy Weinel
Enclosure: CD-Rom Video of Cell 1 and Cell 3 LDS Pre and Post-Cleanout
DENISO
MINES