DRC-2010-003220 - 0901a0688018afbe

Department of
Environmental Quality
Amanda Smith
Acting Executive Director
DIVISION OF RADIATION CONTROL
Dane L. Finerfroclc
Director
DRC-2010-003220 State of Utah
JON M. HUNTSMAN, JR.
Governor
GARY HERBERT
Lieutenant Governor
May 10, 2009
CERTIFIED MAIL
(Retum 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: March 12, 2010 DUSA Response Letter, White Mesa Uraniunn Mill Ground Water
Discharge Permit No. UGW370004 - New Decontamination Pad [NDP]; Proposed White
Mesa Mill Tailings Management System and Discharge Minimization Technology
(DMT)Monitoring Plan (DMT Plan) 3/JO Revision: Denison-9; February 4, 2010 DRC
Letter on the NDP; Request for Information
We have reviewed the subject response letter from DUSA dated March 12, 2010. Our review of this
response follows the same outline given in the DUSA letter. The outline provided two sections. Section 1
below reviews the DUSA response to the subject DRC lener dated February 4, 2009 (actual chron. date,
February 4, 2010). Section 2 reviews the information DUSA provided in the subject letter regarding the
current Ground Water Discharge Permit requirements for the NDP found in Parts I.H.4 and I.H,5.
Contrary to the statement on page 4 of the subject DUSA letter, DUSA is not authori2ed to use the NDP
without prior written authorization from the Executive Secretary. For details, see Part I.H.4 of the
currently approved Ground Water Discharge Permit.
Section 1,
Our review is in this part regards the concrete settling tank system (CST). The CST is to be operated as an
approved best available technology (BAT) facility. The subject letters above followed a numbering
system, which is used in our comments listed below:
A. Regarding Items 1-4 in the subject DRC Letter dated February 4, 2009, DUSA provided a
compound response, to address these items, and stated that:
"Included as Attachment A to this letter is the draft White Mesa Mill Tailings Management System
and Discharge Minimization Technology (DMT) Monitoring Plan, 3/10 Revision: Denison-9 (the
"DMT Plan"). The DMT Plan incorporates the foregoing requirements, as such requirements were
modified by correspondence dated March 10. 2010 from DRC staff, as well as the requirements set
out in Part I.H.4 of the GWDP. The attached [subject] DMT Plan is marked to indicate changes
168 North 1950 West • Salt Uke City, UT
Mailing Address: P.O. Box 144850 • Sail Lake City, UT 84114-4850
Telephone [phone] • Fax [phone] • T.D.D. [phone]
Primed on 100% recycled p;iper
David C. Frydenlund
May 10, 2010
Page 2
over the previous draft submitted to DRC.
"Also, included as Attachment B to this letter, for Executive Secretary Review and Approval, is
the draft White Mesa Uranium Mill Contingency Plan, 3.10 Revision: DUSA-2 (the "Contingency
Plan"), which incorporates the requirements of Part I.H.4.(2) of the GWDP. The attached
Contingency Plan is marked to indicate changes over the previous draft submitted to DRC."
Item 1: In response to DRC's request, in the proposed DMT Plan 3/JO Revision: Denison-9, Appendix A,
in the Weekly Tailings Inspection section, page 29, a DMT Plan form has been changed to include
checking all three of the CST leak detection system (LDS) monitoring portals to determine the
following:
a. Whether the LDS is wet or dry.
b. The depth of any liquid in each LDS portal.
On page 10 of said plan, a new subsection 3.I.e is titled, "Decontamination Pads." This subsection
indicates inspection will be made by physically measuring the depth to water with an electrical
sounding tape/device, and that the water level depths will be recorded to the nearest 0.01 foot, as
DRC requested.
Item 2: In accordance with DRC's request, in the proposed subject DMT Plan, Section 8.2 titled, "DMT
Reports," DUSA will subnnit written quarterly reports, which will include the weekly check for the
presence of any fluid in any CST LDS portal, and measurement of any water level in the portals
during the quarter.
However, Section 8.2.b of the subject DMT Plan states that, ".. .a summary of the daily water level
(depth) inspections for the quarter..." will be submitted in the reports. This dailv frequency must
be changed to weekly, to be in agreement with the weekly frequency described in the DMT Plan,
as mentioned in the paragraph above.
Per an earlier telephone conversation with you, the original records of all weekly readings in the
LDS portals will be retained on site, rather than copies of weekly inspections being submitted with
the quarterly reports. The weekly depth to water level readings will be presented in a summary
table in the Quarterly Reports. Retention of the weekly field records shall comply with Part II.H of
the Permit, and the DRC shall be given access to review and copy of said records pursuant to Part
ILK.
Item 3: DRC requested that DUSA, ".. .revise the DMT/BAT Monitoring Plan to include a performance
standard for depth to water in the above mentioned observation pipes, such that the water level
shall not exceed a depth equivalent to 0.1 foot above the concrete floor at any time." Please
provide a minimum depth to water performance criteria for each observation pipe that is equivalent
to a standing water head of 0.1 foot above the concrete floor for each observation pipe. Section
3.1.e.D ofthe subject DMT Plan includes this requirement.
Item 4: DRC requested that DUSA, "Please provide a revised copy of the DMT/BAT Monitoring Plan in
its entirety, for review and approval." A "red-line copy" of the plan was provided. However, a
final black lined copy of an adiusted DMT Plan will still need to be provided.
B. Regarding Design issues:
David C. Frydenlund
May 10, 2010
Page 3
5. Permeabilitv of the CST Concrete. A revised estimate for the range of permeability for the as-built
CST concrete was submitted. The estimate was done by Precision Systems Engineering, submitted
as Attachment C to the subject March 12, 2010 DUSA Letter. The estimated permeability range is
1.7 X 10"'° cm/second to 0.45 X 10"'° cm/second, corresponding to curing times of 1 week to 10
years respectively. This permeability range is acceptable for the CST concrete, and this issue is
resolved.
6. As-Built Drawings. We requested a set of labeled "as-built" drawings complete with some specific
elevations. Drawings labeled "As-Built Drawings'] were provided as Attachment D to the subject
March 12, 2010 DUSA Letter. These drawings, on jsheets one and six, show elevations from
specific cross-sections of the CST. On sheet one, iri Section 7-E the top of a CST floor in one
settling basin is shown to be at 5583.5 feet amsl and the top of the exterior wall to be at 5589.5 feet
amsl. On sheet six. Section 9-F shows the top of a CST observation port access pipe, with cap
removed, to be 5589.8 feet amsl.
Please confirm:
a) . The concrete floor is at the same elevation in each settling basin.
b) . that the top of the exterior wall is at the sarhe elevation for all 3 settling basins, and
c) . that the top of the access pipe (with cap removed) is at the same elevation in all 3 settling
basins.
Altematively, provide unique elevations for each ofthe elements listed above.
7. The CST Floor. We requested DUSA please confirm that the CST floor is flat. DUSA responded
that, "the bottom of all three CST compartments is flat," in the subject letter of March 12, 2010.
8. No Comment.
9. No Comment.
10. No Comment.
11. The hydrostatic test certificate, as provided in Attachment E of the subject DUSA letter of March
12, 2010, does not state the hydraulic head on the steel liner in the individual compartments of the
CST during the apparent 48-hour hydrostatic test. Please explain how the hydraulic head used
during the test was representative (or conservatively higher) than the expected operating head.
What was the status of any water being held during the test?
Section 2.
Our review in this section regards the information DUSA provided in the subject letter pertaining to the
current Ground Water Discharge Permit requirements for the NDP and the existing decontamination pad
(EDP). These requirements are respectively found in the Parts I.H.4 and I.H.5 ofthe Permit. DUSA
submitted the subject revised DMT Plan and a revised Contingency Plan to meet these requirements ofthe
Ground Water Discharge Permit.
a. Regarding Part I.H.4 of the Current Permit:
1. Pertaining to Part I.H.4.a.2. the upcoming revision of the Contingencv Plan must include
provisions for corrective actions and timelines for completion thereof, if cracks or other
physical discrepancies are observed on the concrete wash pad.
David C. Frydenlund
May 10, 2010
Page 4
b.
2. Paragraph 3.1.e.i.F of the subiect DMT Plan must include a provision that soil and debris
will be removed from the existing decontamination pad (EDP) immediately prior to
inspection of the concrete wash pad for cracking.
Regarding Part 1.H.5 of the Current Permit:
1. Paragraph 3.1.e.ii.A of the subiect DMT Plan must include a provision that soil and debris
will be removed from the EDP immediately prior to inspection of the concrete wash pad
for cracking.
2. Paragraphs 6.5.b of the subiect DMT Plan, should also include detailed provisions and
deadlines to examine the steel tank for visible leakage and bubbling indicating leakage
with respect to the annual removal of tank water and sediment to inspect for visible cracks
and corrosion.
3. This comment regards the Annual Report form for both Decontamination Pads, on page 35
of the subject DMT Plan. For continuity to prevent omissions, we recommend the Annual
Decontamination Pad Inspection form (on page 22). which pertains to the annual report,
should also include the stated requirements of paragraph 8.2.d ofthe proposed DMT Plan
and a summarv of the weekly inspections.
Please review the above comments, and respond in writing, submitting the requested information. We
request a revised red-line copy and a clean black-line copy of the DMT and Contingency Plans be
submitted for approval. Please provide the formation requested above, so that the review may proceed
forward. If you have any questions on the above, please contact me or Dave Rupp.
erely,
iLoren B. Morton, P.G.
•Manager, Geotechnical Services Section
LBM:DAR:d.r
F:\drupp\DUSA\GWDPermit\RFI3 NDP 5-2010.doc
File: Documentum