DRC-2011-001214 - 0901a068801f5c72

2011-001214
2,2^
/'2 4
January 14, 2011
o
t:5'
Received
JAN 2011
Division of
Radiation Control
Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax : [phone]
www.denlsonmines.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
P.O. Box 144810
Salt Lake City, UT 84114-4810
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") R313-6-6.16(C) that
Denison Mines (USA) Corp. ("Denison"), as operator of the Mill and holder of the Permit, failed to meet the
discharge minimization technology ("DMT") standards in Part I.D.6.d) of the Permit, by allowing the
wastewater elevation in the Mill's tailings Cell 4A to exceed the freeboard limit for that Cell by approximately
0. 12 inches, as described in more detail below.
This exceedance was discovered at 3:45pm on Monday January 10, 2011. Initial notice of this failure to
maintain DMT was given by telephone to Mr. Loren Morton of the Utah Department of Environmental Quality
at 11:40am on Tuesday January 11, 2011 at 801 -536-4262 (within 24 hours of the discovery).
1. Facts and Background Information
a) Condition 10.3 of the Mill's State of Utah Radioactive Materials License No. UT1900479 (the
"License") provides that freeboard limits for Cells 1, 3 and 4A shall be set in accordance with
procedures that have been approved by the U.S. Nuclear Regulatory Commission ("NRC"). Under
those procedures:
(i) The freeboard limits are set as per the January 10, 1990 Drainage Report for Cell 1 at a liquid
maximum elevation of 5,615.4 feet above mean sea level ("fmsl");
(ii) The freeboard limit for Cell 3 is determined annually using a formula set out in the procedure.
The current freeboard limit for Cell 3 was previously calculated under this procedure at 5,601.6
fmsl. However, in State of Utah Department of Environmental Quality ("UDEQ") correspondence
dated November 20, 2008 an interim variance and limit was established at 5,602.5 fmsl for Cell 3;
N:\Notices\Cell 4A Freeboard notices\01.14.11 Notice to RLundberg Cell 4A Freeboard.doc
Letter to Mr. Rusty Lundberg
January 14, 2011
Page 2
(iii) In conjunction with the variance established under (ii) above, an interim maximum elevation for
Cell 4A was also established at 5,593.74 fmsl;
(iv) The maximum elevation of 5,593.74 fmsl for Cell 4A has been set assuming that the total
probable maximum precipitation ("PMP") volume for Cells 2, 3 and 4A will be accommodated in
Cell 4A. By letter dated December 11, 2008, Denison applied for an amendment to the License
to set the freeboard limit for Cell 4A at 5,593.74 fmsl and to eliminate the need to set a freeboard
limit for Cell 3, given that the freeboard limit of 5,593.74 fmsl for Cell 4A is adequate to
accommodate the total PMP volume for Cells 2, 3 and 4A; and
(v) In addition. Part I.D.2 of the Permit provides that under no circumstances shall the freeboard of
any tailings cell be less than three feet, as measured from the top of the flexible membrane liner
("FML"). The top of the FML in Cell 1 is at 5,618.5 fmsl, and the top of the FML in Cell 3 is at
5,608.5 fmsl. This means that Part LD.2 of the Permit provides a secondary requirement that the
maximum wastewater pool elevations in Cells 1 and 3 cannot exceed 5,615.5 and 5,605.5 fmsl,
respectively.
(vi) Part I.D.6 of the Permit provides that under no circumstances shall the freeboard of Cell 4A be
less than three feet, as measured from the top of the FML. The top of the FML in Cell 4A is at
5,598.5 fmsl. This means that Part I.D.6 of the Permit provides a secondary requirement that the
maximum wastewater pool elevation in Cells 4A cannot exceed 5595.5 fmsl.
b) In a letter to Denison dated April 29, 2010, UDEQ has indicated their agreement with Denison's
position that the freeboard limit is not applicable to Cell 3, since Cell 3 is in pre-closure stages, and
the PMP flood volume of Cell 3 can be attributed to, and managed in. Cell 4A. The April 29 letter
indicated that to formalize this removal of freeboard limit, three documents needed to be revised,
specifically the Mill's Radioactive Materials License ("RML"), the Discharge Minimization Technology
("DMT") Plan, and the Cell 4A Operations and Maintenance ("O&M") Plan. Denison submitted
revisions to each of those documents for UDEQ approval on August 4, 2010.
c) In July, 2010, Denison received approval of a revision of the RML and Permit allowing construction of
tailings Cell 4B. Cell 4B has been constructed but has not yet been authorized for use. Denison has
submitted revisions to the Reclamation Plan, O&M Plan, DMT Plan, and Contingency Plan,: on
November 11, 2010, December 20, 2010, and January 10, 2011, 2010. These plans are still
undergoing review and revision, and UDEQ has not yet granted approval ofthe plans or authorization
for use of Cell 4B.
d) The Mill has been in the process of filling Cell 3 with tailings solids and closing the cell. Cell 3 no
longer has any capacity to receive tailings liquids. In the process of filling Cell 3 with solids, the Mill
alternately discharged CCD solids to Cell 3 and transferred liquids from Cell 3 to Cell 4A, through
October 2010.
e) On June 3, 2010 Denison notified UDEQ that an accumulation of fluid had been detected in the Cell 1
Leak Detection System ("LDS"). Following an intial series of FML repairs during June 2010, and as
a result of UDEQ's Conditional Approval and Confirmatory Action letter of September 22, 2010 and
telephone conversations and correspondence with UDEQ on August 18, August 23, September 15,
and September 21, 2010, Denison committed to maintain the liquid level in Cell 1 below 5613 fmsl to
allow inspection and repair of the FML surface above 5613 fmsl. To achieve and maintain this
reduced liquid level in Cell 1, the Mill has periodically transferred fluids from Cell 1 to Cell 4A.
DENiSOr
MINES
Letter to Mr. Rusty Lundberg
January 14, 2011
Page 3
f) The Mill experienced heavy precipitation during the week of December 27, 2010 and ongoing lesser
precipitation during the following two weeks, which also increased the liquid levels in both Cell 1 and
4A.
g) Therefore, since November 2010, Cell 4A has been the Mill's only tailings cell in full service and has
been used to manage the majority of ail tailings volume in the Mill system including:
a. CCD solids,
b. all other tailings liquids,
c. tailings solutions transferred from Cell 1, and
d. precipitation/runoff from the areas of Cells 2, 3 and 4A.
h) During the weekly inspection and survey on January 6, 2011, the survey of the tailings liquid pool
elevation indicated that Cell 4A had a pool elevation of 5593.28 fmsl resulting in 5.52 inches of
freeboard capacity (that is, was 5.52 inches below the freeboard limit). At that time, Cell 4A liquid
level was 29.28 inches below the spillway into Cell 4B.
i) Denison alerted DRC on January 6, 2011 that Cell 4A was filling and approaching its freeboard limit.
During that discussion UDEQ advised Denison that UDEQ could use enforcement discretion to
temporarily waive the Cell 4A freeboard limit until Cell 4B is authorized for service, provided that i)
Denison notified UDEQ when the Cell 4A freeboard limit is exceeded, and ii) Denison did not
discharge any fluids over the spillway into Cell 4B.
j) During the tailings survey measurement performed at approximately 3:45pm on January 10, 2011,
the wastewater pool elevation in Cell 4A was measured to be 5593.75 fmsl, compared to the current
freeboard limit for Cell 4A of 5593.74 fmsl, representing an exceedance of O.OIfeet, or 0.12 inches.
At that time. Cell 4A level was 23.64 inches below the spillway to Cell 4B.
k) Denison notified UDEQ by phone call at 11:40am on Tuesday that the Cell 4A liquid level had
exceeded the freeboard limit.
I) The Mill has been running on a 10-day on and 4-day off operating cycle.
2. Action Taken
Upon receipt of the initial survey results, the Mill's Environmental Coordinator notified the Mill Manager at
3:45pm that day. The following plan of action was immediately put into place in accordance with section 5.1
ofthe Mill's Contingency Plan:
a) The Mill Manager had operations crews stop the discharge of CCD solids into Cell 4A;
b) The Mill Manager order the Mill into a scheduled 4-day shutdown;
c) This plan was implemented beginning at 3:45pm on Monday January 10, 2011;
d) Verbal notification was given to the Executive Secretary at 11:40am on January 11, 2011, within 24
hours of discovery. This verbal notification was followed by this written notification within five days of
discovery;
DENISO
MINES
Letter to Mr. Rusty Lundberg
January 14, 2011
Page 4
e) Solutions cannot be transferred to any other cell to directly reduce the volume in Cell 4A, as no other
cell is available to receive liquids at this time.
f) On Thursday January 13, 2010, Denison formally requested that UDEQ grant a regulatory variance
from the freeboard limit in Cell 4A.
g) By email on Thursday January 13, 2010, UDEQ granted conditional approval of a regulatory variance
from the freeboard limit on Cell 4A. The conditional approval letter agreed that Cell 4A freeboard limit
exceedance will be resolved once Cell 4B is put in service and liquid is permitted to be pumped from
Cell 4A to Cell 4B, and required that:
a. Discharge of any tailings solids or wastewater in Cell 4B is prohibited until Denison received
written approval from UDEQ for use of Cell 4B,
b. Denison will make and report to UDEQ daily measurement of Cell 4A wastewater level, and
c. The variance will expire on March 1, 2011.
3. Root Cause
The root cause analysis is as follows
a) Due to the intentional filling and closure of Cell 3 and the requirement to reduce the level in Cell 1,
Cell 4A is currently the only tailings cell receiving liquids in the Mill tailings system.
b) Cell 4A has received all of the following materials:
a. CCD solids,
b. all other tailings liquids,
c. tailings solutions transferred from Cell 1, and
d. precipitation/runoff from the areas of Cells 2, 3 and 4A.
c) Heavy precipitation during the week of December 27, 2010 and ongoing precipitation since that week,
also increased the liquid levels in both Cell 1 and 4A.
d) UDEQ authorization for use of Cell 4B has not been received as the required plans submitted by
Denison are still undergoing re-review and revision.
e) Upon review of the circumstances, both UDEQ and Denison agreed that that Cell 4A freeboard limit
exceedance will be resolved once Cell 4B is put in service and liquid is pumped from Cell 4A to Cell
4B. Both UDEQ and Denison agreed to the need for an interim variance from the Cell 4A freeboard
level, which has been granted by UDEQ on January 13, 2011.
4. Actions That Will be Taken to Prevent a Reoccurrence of this Incident
The following actions will be taken to prevent a reoccurrence of this incident:
a) Solutions cannot be transferred to any other cell to directly reduce the volume in Cell 4A, as no other
cell is available to receive liquids at this time.
b) On Thursday January 13, 2011, Denison formally requested that UDEQ grant a regulatory variance
from the freeboard limit in Cell 4A.
DENISON
MINES
Letter to Mr. Rusty Lundberg
January 14, 2011
Page 5
c) By email on Thursday January 13, 2011, UDEQ granted conditional approval of a regulatory variance
from the freeboard limit on Cell 4A.
d) Denison has already begun making daily measurements of Cell 4A liquid level and has begun
reporting them to UDEQ. Liquid level data including the weekly level reading on December 31, 2010
and the daily level readings beginning on January 6, 2011 are provided in the attached Table 1.
5. Affirmative Defense
Denison believes that the affirmative defense in Part I.G.3.C) of the Permit should be applicable to this
incident, for the following reasons:
a) Notification
By virtue of the initial oral notification given to UDEQ at 11:40am on Tuesday January 11, 2011 (within 24
hours of the discovery) and this written notice, Denison has submitted notification according to UAC R317-6-
6.13.
b) Failure was not Intentional or Caused by the Permittee's Negligence
The exceedance of the freeboard limit was not intentional or caused by Denison's negligence, either in action
or in failure to act. The Mill was taking actions to manage the freeboard requirements of all of its active
tailings cells while filling Cell 3 for closure and maintaining a reduced level of Cell 1 as committed in the Cell 1
Repair Plan.
c) The Permittee has Taken Adequate Measures to Meet Permit Conditions
f) Denison has taken adequate measures to meet Permit conditions in a timely manner.
The provisions of the Mill's Contingency Plan were implemented immediately. UDEQ was notified in advance
of the impending exceedance and upon observance of the actual exceedance. Upon review of the
circumstances, both UDEQ and Denison agreed that that Cell 4A freeboard limit exceedance will be resolved
once Cell 4B is put in service and liquid is pumped from Cell 4A to Cell 4B. Both UDEQ and Denison agreed
to the need for an interim variance from the Cell 4A freeboard level, which has been granted by UDEQ on
January 13, 2011.
d) The Provisions of UCA 19-5-107 Have Not Been Violated
The provisions of Utah Code 19-5-107 have not been violated. There has been no discharge of a pollutant
into waters of the state. Denison has not caused pollution which constitutes a menace to public health and
welfare, or is harmful to wildlife, fish or aquatic life, or impairs domestic, agricultural, industrial, recreational, or
other beneficial uses of water, nor has Denison placed or caused to be placed any waste in a location where
there is probable cause to believe it will cause pollution.
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.
DENISO
MINES
Letter to Mr. Rusty Lundberg
January 14, 2011
Page 6
Yours very truly,
DENISON MINES (USA) CORP.
Jo Ann Tischler
Director, Compliance and Permitting
cc: Rich Bartlett
David C. Frydenlund
Harold R. Roberts
David E. Turk
Central files
DENISO
MINES
Table 1: Cell 4A Freeboard Observation Data
Liquid Pool
Elevation Freeboard elev. Inches to Elevation of Inches to
Date Time (fmsl) (fmsl) freeboard Spillway (fmsl) spillway
12/31/2010 1:20 PM 5593.13 5593.74 7.32 5595.72 31.08
1/6/2011 12:30 PM 5593.28 5593.74 5.52 5595.72 29.28
1/7/2011 8:30 AM 5593.37 5593.74 4.44 5595.72 28.2
1/10/2011 3:45 PM 5593.75 5593.74 -0.12 5595.72 23.64
1/11/2011 9:05 AM 5593.84 5593.74 -1.2 5595.72 22.56
1/12/2011 10:15 AM 5593.93 5593.74 -2.28 5595.72 21.48
1/13/2011"^ 7:45 AM 5593.97 5593.74 -2.76 5595.72 21
1/14/2011 9:30 AM 5594.01 5593.74 -3.24 5595.72 20.52
"^Receipt of UDEQ waiver requiring daily measurement and reporting of Cell 4A level.