DRC-2009-003395 - 0901a0688012f726

State of Utah
JON M. HUNTSMAN, JR.
Governor
GARY HERBERT
Lieutenant Governor
^^"^"7 ^tc-^^(y^'Ooi3is
Department of
Environmental Quality
Amanda Smith
Acting Executive Director
DrVlSlON OF RADIATION CONTROL
Dane L. Finerfrock
Director
August 6, 2009 I iir
(7U^\ ^ xn-CERTIFffiD MAIL ICXTl "Cri^^^ QOQO
(Return Receipt Requested)
David C. Frydenlund
Vice President Regulatory Affairs and Counsel
Denison Mines (USA) Corp. (DUSA)
1050 Seventeenth Street, Suite 950
Denver, CO 80265
Dear Mr. Frydenlund:
SUBJECT: June 5, 2009 DUSA Letter, White Mesa Uranium Mill Ground Water Discharge
Permit No. UGW370004 - New Decontamination Pad [NDP]; May 20, 2009,
DUSA Drawings of NDP; Request for Information
We have reviewed the subject drawings of the New Decontamination Pad system. Our review is
focused on the concrete settling tank system (CST). The CST is to be operated as an approved
best available technology (BAT) facility. We have the following comments:
A. DRC proposed modifications to paragraph r) in Attachments - Proposed Modifications to the
DMT Plan found in the letter dated June 29, 2009 by Denison Mines (USA) Corp. (hereafter
"DUSA"):
1. Modify the Daily Inspection Form (found in Section VII) to include a location on the form
to record the daily visual inspection information for presence of fluid in all leak detection
system (LDS) vertical inspection portals for the three chambers in the concrete settling
tank system for the decontamination pad.
2. On a quarterly basis submit with the DMT Performance Standard Monitoring Report a
summary of the daily visual inspections for the quarter for the presence of fluid in all LDS
vertical inspection portals for the primary and secondary containment for the three
chambers in the concrete settling tank system for the decontamination pad. The report will
also include an electronic or hard copy of daily inspection forms for the quarter and
reporting of any BAT failures for the decontamination pad.
168 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 • Salt Lake City. UT 84114-4850
Telephone [phone]- Fax [phone] • T.D.D. [phone]
www.deq.Utah.gov
Printed on 100% recycled paper
Page 2
.;, 3. Should any fluid be observed in any of the LDS vertical inspection portals for the three
chambers in the concrete settling tank system for the decontamination pad, the
decontamination pad well be immediately taken out of service and be reported to the
Executive Secretary as required in Part I.G.3(a) ofthe Permit (see below).
Permit Part I.G.3(a): Failure to Maintain DMT or BAT Required by Permit
a) Permittee to Provide Information - in the event that the Permittee fails to maintain
DMT or BAT or otherwise fails to meet DMT or BAT standards as required by the
permit, the Permittee shall submit to the Executive Secretary a notification and
description of the failure according to R317-6-6.16(C)(1). Notification shall be given
orally 'within 24 hours ofthe Permittee's discovery of the failure of DMT or BAT, and
shall be folio-wed up by written notification, including the information necessary to
make a determination under R317-6-6.16(C)(2), within five days ofthe Permittee's
discovery of the failure of best available technology.
B. Regarding Design issues:
4. Will the transmissivity of the compressed geonet, under fully loaded conditions,
significantly impede the flow of any horizontal flow of water through the geonet to the
monitoring locations? Please demonstrate that the compressed geonet, under fully loaded
conditions will not significantly affect the flow of any leakage to the LDS monitoring pipe
locations.
5. The permeability of the concrete for the CST needs to be determined. The permeability of
the concrete can be estimated by analyzing the concrete mix design, as discussed in the
publication of the Portland Cement Association, Design and Control of Concrete Mixtures,
EBOOl, 13"^ Ed., and other field and sampling methods. We recommend the first method
be used, and the calculation for the estimated permeability of the concrete be submitted for
review and approval.
6. Sheet 3 of the drawings indicate the CST subgrade is to be prepared level. The as-built
elevations and grades of the concrete floors and elevations of the walls of the CST must be
submitted for review and approvaL
7. With respect to the above determination, the CST leakage monitoring pipes must be placed
at the locations of the lowest floor elevation within each chamber of the CST. Please
revise the as-built drawings to show the new locations of the CST leakage monitoring
pipes and submit the revised drawings for review and approval.
8. Related to the above, the upper and lower elevations of the water level measuring pipes at
these new locations mentioned above must be determined and shown on the final as-built
drawings.
9. The details of the overlap of the steel liner cover over the exterior CST concrete walls,
with a specified drip type edging, is not shown on the drawings. The design of the edging
must be so that it prevents intrusion of precipitation and wash water into the space between
the steel cover and the concrete surfaces. Please revise the as-built drawings to show the
Page 3
details of a specific drip type edging over the exterior CST walls, which meets the
foregoing criteria, and submit the revised drawings for review and approval.
10. The exterior edges of the installed steel liner cover over.the CST must be tested to
demonstrate a "roofing" ability, as discussed in item 9 above. Please submit the results of
this testing for review and approval.
11. It is recommended DUSA perform a hydrostatic test on the steel liner prior to installation.
This test should be done outside the CST, before the steel liner is installed, so leaks can be
easily observed and repaired. Please provide an appropriate standardized and industry
approved method for this testing (e.g. ASTM), for DRC review and approval.
Please review the above comments, and submit the requested information. If you have any
questions on the above, please contact me.
Dren B. Morton, P.G.
lanager, Geotechnical Services Section
LBM:DAR:DH:dr
F:\dnipp\DUSA\GWDPenmt\Decon Pad Monitoring & Tech Cmts7-2009.doc
File: IUC04.01 As-Builts: New DeConPad at SE Cor Ore Pad 2009