DRC-2010-001281 - 0901a0688015df6e

J>h
J?^C~~ ^/a-cfoiztJ
Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax:[phone]
www.denisonmines.com
OENISO
MINES
January 14, 2010
Sent via Electronic Mail (PDF) and Federal Express
Dane L. Finerfrock, Executive Secretary
Utah Radiation Control Board
Utah Department of Environmental Quality
168 North 1950 West
P.O. Box 144810
Salt Lake City, UT 84114-4810
Re: White Mesa Mill Facility October 28-29, 2009 DRC Inspection Results:
Engineering Module 75E-Response to November 25, 2009 Request for Information
Dear Mr. Finerfrock,
In accordance with UDEQ's November 25, 2009 Request for Information, which was received
by Denison on November 30, 2009, the following responses and proposed revisions to Standard
Operating Procedures are provided relative to the findings of Mr. Rupp during his inspection of
October 28-29, 2009.
DRC Finding No. 1
In the S.W. corner of Cell 4A the tailings solution recycle pipe from the pump contacts a section
of the FML not protected by an FML "rub sheet" for approximately 10-feet. In the closeout
meeting on site on October 29, 2009 Mr. Bartlett offered to add a rub sheet under the piping to
protect the upper FML from the pipe by October 30, 2009, See photo no. 7 attached. We request
DUSA supply a photograph of the completed adjustment.
The Cell 4A BAT Monitoring, Operations and Maintenance Plan, under Cell Operation, p, 3
requires, "The initial solution discharge will be in the southwest corner of the Cell. The
discharge pipe will be routed down the Splash Pad provided in the corner of the Cell to protect
the pipeline running from the solution reclaim barge." The splash pad mentioned is the "rub
sheet" discussed above.
We recommend the Cell 4A BAT Monitoring, Operations and Maintenance Plan be modified to
require all pipelines entering or leaving Cell 4A be maintained with a rub sheet beneath them.
Denison Response to Finding No. 1
Denison installed a rub sheet under the subject piping as had been committed during the
inspection. This is documented on the attached photograph which UDEQ has requested (See
Attachment 1). Regarding the recommendation to modify the Cell 4A BAT Monitoring,
Operations and Maintenance Plan to require that all pipelines entering or leaving Cell 4A be
maintained with a rub sheet beneath them, Denison proposes a modification to the Plan by
adding a section g) on page 3 to incorporate the requirement for a rub sheet beneath the piping
that enters and exits Cell 4A (See Attachment 2).
DRC Finding No. 2
Feedstock and other materials were observed on or very near the northern fence line of the
feedstock storage area. See photos no. 13-15 attached. Feedstock boundary encroachment has
been observed during other site visits by DRC.
The Ground Water Discharge Permit modification that is currently in process will establish
certain performance standards for feedstock found outside the feedstock storage area.
We recommend that DUSA establish minimum distances between the feedstock storage fence and
feedstock materials to prevent future violations of feedstock storage requirements outside the
boundary of the designed area. Such a buffer zone should be documented by an SOP or other
proposed method.
Mr. Bartlett committed that the encroaching feedstock materials would be removed from the
northern fence line of the feedstock storage area prior to November 15, 2009. A future DRC
inspection will revisit this issue.
Denison Response to Finding No. 2
The area of concern at the northern fence line of the feedstock storage area was reconfigured to
maintain a buffer between the stored material and the fence lines. This was completed prior to
November 15, 2009. Concurrent with this effort Denison has established a proposed minimum
distance of 4 ft. between the stored material and the fence as a means of assuring that stored
feedstock does not encroach on the storage area boundary and remains on the storage pad. The
establishment of this minimum distance has been added as a proposed revision to the weekly
inspection criteria for the feedstock storage area under Section 3.3 of the Discharge
Minimization Technology Plan (DMT) (See Attachment 3)
DRC Finding No. 3
During our inspection it was apparent that some inspection notes taken by DUSA had been
discarded. Original handwritten copies of data should not be thrown away, even though data
may later be transcribed to electronic media. Please be advised that Part H.H of the Ground
DENISO
MINES
JOii
Water Discharge Permit requires that the "permittee shall retain records of all monitoring
information".
Denison Response to Finding No. 3
Denison acknowledges the DRC finding and agrees that original inspection notes will not be
discarded in the future despite transcription into electronic format. Denison has advised Mill
personnel to retain all copies of handwritten inspection notes and data.
DRC Finding No. 4
In March of 2009 the LDS in Cell 4A had an incident for a few days where the pressure head
reached 40-inches or 3.3 3-feet. DRC was not previously notified ofthis incident Documentation
of this event is discussed in a DUSA memo on the subject dated March 31, 2009 (end. 2). It
appears this event should have been reported per Ground Water Discharge Permit Part I D.6
and l.G.3.
It does appear this is an anomalous event, apparently caused by reversing the polarity of the
LDS sump pump, which effectively disabled the pump.
The DMT Plan, paragraph 2.1.p, in the Daily Comprehensive Tailings Inspection section of the
plan states, "The solution level in Cell 4A leak detection is not allowed to be more than 1.0 foot
above the lowest point on the bottom flexible membrane liner (elevation 5556.14 feet amsl). If
any of these observations are made, the Mill Manager should be notified immediately and the
leak detection system pump started."
The March 31, 2009 DUSA memo shows good faith effort was made in this regard, in that
repairs to the LDS pump were completed within 2-days of discovery of the problem and mill
management was notified.
Denison Response to Finding No. 4
As noted by the inspector, this was an anomalous event and a good faith effort was made to
correct the situation in a timely manner. Once the problem became apparent Mill personnel
consulted the Discharge Minimization Technology (DMT) Plan and followed Section 2.1.p),
notifying the Mill Manager immediately and proceeding with equipment repair to correct the
situation. Toward this end, the observation of the pumping problem and site personnel's
response to the problem were fully documented in the memorandum of 3-31-09 referenced
above. Unfortunately, the responding personnel did not consult the Groundwater Discharge
Permit, assuming that all reporting requirements were contained in Section 2.1 of the DMT Plan.
As such, and by inadvertent oversight, the notifications contemplated by Ground Water
Discharge Permit requirements at Parts 1. D.6 and I.G.3 were not undertaken. Mill staff have
been reminded of the need to consult the Groundwater Discharge Permit as well as the DMT
Plan in these circumstances.
DENISON
MINES
Oii
In response to this situation, Denison proposes a revision to the DMT Plan at Section 2.1.p) to
incorporate the requirements for UDEQ notification specified at Parts 1 D.6 and I.G.3 of the
GWDP directly into the Plan as a means of reducing the chance future notification failures (See
Attachment 4). Denison intends to review the DMT Plan and its other procedures to incorporate
similar references to Groundwater Discharge Permit requirements where appropriate.
DRC Finding No. 5
Weekly inspection reports observed since August 2009 show a seven-inch (7") water level in the
Cell 2 LDS. This water was analyzed by DUSA. Copies of an analysis ofthis water by Energy
Laboratories dated August 27, 2009 were provided DRC during the inspection. During the
inspection DUSA staff explained that DUSA had previously placed a lid on the LDS observation
port to prevent liquids intruding into the LDS monitoring pipe. The staff also mentioned
improvement ofthis lid is planned. DRC review ofthis matter is ongoing.
Denison Response to Finding No. 4
No response required
If you should have further questions or require additional information regarding this response to
the DRC inspection of October 28-29, 2009 please contact me.
Yours truly,
'ISteven D. Landau
DENISON MINES (USA) CORP.
Manager, Environmental Affairs
cc: Ron Hochstein
Harold Roberts
David Frydenlund
David Turk
DENISON
MINES
Dii
Attachment 1
Attachment 2
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
by a layer of non-woven geotextile to serve as an additional filter material.
This perforated collection pipe serves as the "backbone" to the slimes drain
system and runs from the far northeast corner downhill to the far
southwest corner of Cell 4A where it joins the slimes drain access pipe.
3) Slimes Drain Access Pipe -consisting of an 18-inch ID Schedule 40 PVC
pipe placed down the inside slope of Cell 4A at the southwest corner,
above the primary FML. Said pipe then merges with another horizontal
pipe of equivalent diameter and material, where it is enveloped by gravel
and woven geotextile that serves as a cushion to protect the primary FML.
A reducer connects the horizontal 18-inch pipe with the 4-inch SDC pipe.
At some future time, a pump will be set in this 18-inch pipe and used to
remove tailings wastewaters for purposes of de-watering the tailings cell.
f) Dike Splash Pads - A minimum of eight (8) 10-foot wide splash pads are
installed on the interior dike slopes to protect the primary FML from abrasion
and scouring by tailings slurry. These pads will consist of an extra layer of 60
mil HDPE membrane that will be placed down the inside slope of Cell 4A,
from the top of the dike and down the inside slope. The pads on the north side
of the Cell will extend to a point 5-feet beyond the toe of the slope to protect
the liner bottom during initial startup of the Cell. The exact location of the
splash pads is detailed on the As-Built Plans and Specifications.
g) Rub Protection Sheets - In addition to the splash pads described in f) above,
rub sheets are installed beneath all piping entering or exiting Cell 4A that is
not located directly on the splash pads.
hg) Emergency Spillway -a concrete lined spillway constructed near the western
comer of the north dike to allow emergency runoff from Cell 3 into Cell 4A.
This spillway will be limited to a 6-inch reinforced concrete slab set directly
over the primary FML in a 4-foot deep trapezoidal chaimel. No other spillway
or overflow structure will be constructed at Cell 4A. All storm water runoff
and tailings wastewaters not retained in Cells 2 and 3, will be managed and
contained in Cell 4A, including the Probable Maximum Precipitation and
flood event.
Cell Operation
Solution Discharge
Cell 4A will initially be used for storage and evaporation of process solutions
From the Mill operations. These process solutions will be from the
uranium/vanadium solvent extraction circuit, or transferred from Cell 1
Page 3
Attachment 3
White Mesa Mill -Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3.1
9/08 Revision: Denison-6
Page 10 of 36
(ix)The Assistant will hold the Survey Rod vertically with one end of the Survey Rod
just touching the pond surface. The Assistant will ensure that the Survey Rod is
vertical by gently rocking the rod back and forth until the Surveyor has established
a level reading;
(x) The Surveyor will focus the cross hairs of the Survey Instrument on the scale on
the Survey Rod, and record the number (the "Pond Surface Reading"), which
represents the number of feet the Survey Instrument is reading above the pond
surface level.
The Surveyor will calculate the elevation of the pond surface as FSML by adding the
Reference Point Reading for the Cell or Roberts Pond, as the case may be, to the Reference
Point Elevation for the Cell or Roberts Pond and subtracting the Pond Surface Reading for
the Cell or Roberts Pond, and will record the number accurate to 0.01 feet.
e) Summary
In addition, the weekly inspection should summarize all activities concerning the
tailings area for that particular week.
Results of the weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection
form. An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A.
3.2. Weekly Inspection of Solution Levels in Roberts Pond
On a weekly basis, solution elevations are taken on Roberts Pond, in accordance with the procedures
set out in Section 3.1 d) above. The Weekly solution level in Roberts Pond is recorded on the
Weekly Tailings and DMT Inspection form. Based on historical observations, the FML at the Pond
Surface Reading area for Roberts Pond, is approximately six inches above the lowest point on the
pond's FML. If the pond solution elevation at the Pond Surface Reading area is at or below the FML
for that area, the pond will be recorded as being dry.
3.3. Weekly Feedstock Storage Area Inspections
Weekly feedstock storage area inspections will be performed by the Radiation Safety Department,
to confirm that:
a) the bulk feedstock materials are stored and maintained within the defined area described in
the GWDP, as indicated on the map attached hereto as Appendix D; and
b) a 4 ft. buffer is maintained at the periphery of the storage area which is absent bulk
material in order to assure that the materials do not encroach upon the boundary of the
storage area: and
b)c} all alternate feedstock located outside the defined Feedstock Area are maintained within
Attachment 4
White Mesa Mill -Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 3 of 36
j) Wind movement of tailings and dust minimization.
Wind movement of tailings will be evaluated for conditions which may require
initiation of preventative dust minimization measures for cells containing tailings
sand. During tailings inspection, general surface conditions will be evaluated for
the following: 1) areas of tailings subject to blowing and/or wind movement, 2)
liquid pool size, 3) areas not subject to blowing and/or wind movement,
expressed as a percentage of the total cell area. The evaluations will be reviewed
on a weekly basis, ormore frequently if warranted, and will be used to direct dust
minimization activities.
k) Observation of flow and operational status of the dust control/spray evaporation
system(s).
1) Observations of any abnormal variations in tailings pond elevations in Cells 1,3,
and 4A.
m) Locations of slurry and SX discharge within the active cells. Slurry and SX
discharge points need to be indicated on the tailings cells map included in the
Daily Inspection Data form.
n) An estimate of flow for active tailings slurry and SX line(s).
o) An estimate of flow in the solution return line(s).
p) Daily measurements in the leak detection system (LDS) sumps of the tailings
cells will be made when warranted by changes in the solution level of the
respective leak detection system.
The trigger for further action when evaluating the measurements in the Cell 1 and
Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours. The
solution level in Cell 4A leak detection is not allowed to be more than 1.0 foot
above the lowest point on the bottom flexible membrane liner (elevation 5556.14
feet amsl). If any of these observation are made, the Mill Manager should be
notified immediately and the leak detection system pump started. In addition, the
requirement to notify the Executive Secretarv in accordance with Parts I.D.6
and I.G.3 of the Groundwater Discharge Permit must be adhered to when the
solution level trigger for Cell 4A has been exceeded.
Page 3