DRC-2010-005163 - 0901a068801c55a2

Department of D R C ' 2 0 1 0 ' 0 0 5 1 6
Enviromnental Quality ^
Amanda Smith
Executive Director
DPVISION OF RADIATION CONTROL
Rusty Lundberg
Director
'-•'-L'Lli'"''
State of Utah
GARY R, HERBERT
Govemor
GREG BELL
Lieutenant Governor
September 22, 2010
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
Mr. David C. Frydenlund
Vice President and General Counsel .
Denison Mines (USA) Corp. (DUSA)
1050 Seventeenth St. Suite 950
Denver, Colorado, 80265
Subject: August 30, 2010 Denison Mines (USA) [DUSA] White Mesa Uranium Mill - Plan and
Schedule for Cell 1 Inspection and Repairs, Update - Conditional Approval and
Confirmatory Action Letter
Dear Mr. Frydenlund:
On June 3, 2010 DUSA nofified the Utah Division of Radiafion Control (DRC) by telephone that
on June 2, 2010 an accumulation of fluid was discovered within the Tailings Cell 1 leak detecfion
system (LDS). An inifial pH paper test showed that the fluid in the LDS indicated a pH of 2.0 to
3.0; therefore, the fluid found in the LDS originated from Cell 1. Written notificafion of the
Tailings Cell 1 leak was made in a June 7, 2010 DUSA letter. In the letter, DUSA states "...a
repair report will be submitted fo the Executive Secretary with 30 days ofthe inifial telephone
notification... " This repair report was not submitted by July 5, 2010 as committed to by DUSA.
To repair the liner, DUSA lowered the solufion level in Cell 1 to 5613.10 feet anfisl. This
appeared to eliminate the flow of wastewater to the LDS. DUSA maintenance identified some
FML damage and performed repairs during the period when the water level was lowest.
Following the repairs, the Cell 1 liquid level was allowed to retum to the June 3, 2010 level. The
Cell 1 LDS remained dry unfil fluid was observed again in the LDS on August 7, 2010. The DRC
was made aware of the August 7, 2010 Cell 1 leak in an August 8, 2010 telephone call. During an
August 12, 2010, telephone call, the DRC agreed with DUSA that both the June and August 2010
idenfifications of fluid in the Cell 1 LDS were part of one event. Apparenfiy, the repairs made to
the Cell 1 liner prior to August 7, 2010 were not successful in idenfifying all the damage which,
required repair.
During the August 12, 2010 phone call, DUSA agreed to provide the DRC with a written plan and
schedule for: 1) determinafion of the root cause, 2) idenfificafion of the extent of damage, and
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 • Salt Uke City, UT 84114-4850
Telephone [phone] • Fax [phone] • T.D.D. (801) 5364414
www.deq. iaah.gov
Printed on 100% recycled paper
Page 2
3) execufion and reporting of repairs to the Cell 1 liner system.
In an August 18, 2010 DUSA letter, DUSA provided a plan and schedule for Cell 1 Inspecfion
and Repair. DUSA's proposed plan and schedule was to be conducted in phases, as summarized
below:
Phase 1
1. Reduce the solution level contained in Cell 1 down to the same level it reached during the
June 2010 repairs. This was to be accomplished by approximately August 31, 2010.
2. Idenfify areas in Cell 1 with the highest potential of damage. These areas are estimated to
be approximately 200 feet of the Cell 1 inside slope.
3. Systemafically inspect and repair the FML areas with the highest likelihood of damage
first. This should be accomplished by approximately October 31, 2010.
4. Allow the solufion level within Cell 1 to recover to the pre-June 2010 levels and confirm
that solufions do not reappear in the LDS. It is estimated that this step will take
approximately 4 weeks, or until November 30, 2010.
Phase II
5. If after steps 1 - 4 have been completed and solufions reappear in the LDS, the solufion
level in Cell 1 will again be lowered to about 5613 feet amsl. This should be
accomplished by approximately December 31, 2010.
6. After the solufions level in Cell 1 is lowered, the next highest area of concem on the inside
slope will be uncovered and repaired. Following the repair, the Cell 1 solufion level will
be allowed to recover to pre-June 2010 levels.
7. If after steps 5 & 6 have been completed and if solutions reappear in the LDS, the solution
level contained in Cell 1 will again be lowered to 5613 feet amsl. The cycle steps will be
repeated as many times as necessary, until DUSA is able to achieve dryness in the Cell 1
LDS.
After review of the August 18, 2010 Cell 1 repair plan and schedule, the DRC idenfified three
concems, as follows:
• The proposed repair plan schedule,was open ended and there was no specific date where
DUSA committed it would have the Cell 1 leak fully repaired and the LDS dry.
• The phased approach as proposed may take several years before the Cell 1 leak repaired.
This is not appropriate, nor is it timely. DUSA needed to set a date when the entire liner
will be checked and repaired above 5,613 feet amsl.
• The August 18, 2010 repair plan failed to include a table for the esfimated Cell 1 leakage
rate for the leak idenfified on August 7, 2010.
On August 23, 2010 the DRC shared these concems with DUSA in a conference call. In the
meefing, DUSA agreed to submit a revised repair plan by August 30, 2010. This repair plan
would include a Cell 1 leakage rate for the leak identified on August 7, 2010 and a date when the
enfire Cell 1 liner will be checked and repaired fully and completely across all inside slope areas
above 5,613 feet amsl, if necessary.
Page 3
Conditional Approval
DUSA provided a revised Cell 1 Repair Plan in a letter dated August 30, 2010. In the letter,
DUSA committed that the enfire Cell 1 liner area above 5,613 feet amsl would be repaired by July
31, 2012. This schedule is hereby conditionally approved, confingent on compliance with the
additional confirmatory actions discussed below.
In the August 30, 2010 letter, DUSA also provided a Table 1 that included the estimated leakage
rate at Cell 1 for the leak identified on August 7, 2010. After reviewing the informafion contained
in Table 1, the DRC identified several discrepancies. The table showed the standpipe was
considered dry at different depths (i.e. 60 feet 2 inches, 63 feet 9 inches, 65 feet, and 66 feet 4
inches) for the August 7, 2010 leak, while the standpipe was considered dry at 63 feet 4 inches for
the June 2, 2010 leak.
On September 13, 2010 the DRC nofified Ms. Jo Ann Tischler of DUSA of these discrepancies.
Ms. Tischler said she would find out the cause of these problems and submit an updated table with
an explanation for these discrepancies. Ms. Tischler provided an updated table by e-mail on
September 14, 2010 and explained that the discrepancies were caused by a 6 foot extension added
to the standpipe on August 10, 2010, as requested by the DRC. However, the 6 foot extension
added to the standpipe doesn't explain why the depth considered dry was inconsistent from one
measurement to another (i.e. 63 feet 9 inches, 65 feet, and 66 feet 4 inches) after August 10, 2010.
A conference call was held with DUSA on September 15, 2010 to discuss this issue. During the
meefing, the DRC voiced a concem that perhaps debris had fallen down into the standpipe and
could be prevenfing DUSA from obtaining true reading within the Cell 1 LDS.
Confirmatory Action
During the September 15, 2010 conference call, DUSA committed to resolve these issues by
doing the following:
1. Detennine the root cause of the apparent discrepancies of the Esfimafion of Cell 1 Leakage'
Rate, (Table 1) and submit written findings by September 30, 2010 for Execufive
Secretary review and approval.
2. Perform a video log of the Cell 1 LDS standpipe down to the T-joint with the slotted
collecfion pipe and determine the total downslope distance to the nearest 0.1 foot.- If any
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 by November 1, 2010
3. If after review of both the above DUSA submittals, the DRC determines that additional
corrective acfion is required, DUSA will meet with the DRC to discuss and negofiate a
plan of acfion and schedule to resolve the Cell 1 LDS problems identified.
4. The Cell 1 liner will be checked and repaired fiilly and completely across all inside
sideslope areas above 5,613 feet amsl on or before July 31, 2012.
Page 4
5. Prepare and submit a Cell 1 Repair Report for Executive Secretary review and approval.
This Repair Report shall be included with the next quarteriy DMT Report, as required by
Part I.F.2 ofthe Permit.
Please respond in writing within seven calendar days of receipt of this letter ifyou disagree with
the above agreed upon resolution or compliance schedule.
Thank you for your continued cooperation.
UTAH WATER QUALITY BOARD
Rusty Lundberg (_y
Co-Execufive Secretary
RL/PRG;prg