DRC-2009-002643 - 0901a06880361995

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TO: David Frydenlund & Harold Roberts
Denison Mines (USA) Corp
FROM: Ryan Jakubowski & Doug Oliver
DATE: April 30, 2009
SUBJECT: Response to commenls submitted on February 2, 2009 by the Utah Division of
Radiation Control in regard to Denison Mines (USA) Corp. Infiltration and
Contaminant TranspoiT Repoit dated November 2007
This memorandum provides responses to the comments submitted on February 2, 2009 by
Thomas Rushing of the Utah Dcpanment of Environmental Quality (UDEQ) Division of
Radiation Contiol (DRC) to Denison Mines (USA) Corp. (Denison) on the "Infiltration and
Contaminant Transport Modeling Report, White Mesa Mill Site, Blanding, Utah" (ICTM
Repoi't). The ICTM Report was prepared by MWH Americas, Inc. (MWH), for Denison and
submitted to the DRC in November 2007 to fulfill Part I.H. 1! of the White Mesa Ground Water
Dischai'ge Permit. The DRC's comments are provided in italics followed by our responses in
regular font.
In order to facilitate discussion and provide clai'ification regarding the DRC's comments, a
meeting was held between the DRC, Denison, and MWH on March 31, 2009 at the DRC's office
in Salt Lake City, Utah. The meeting was attended by Loren Morton and Thomas Rushing from
the DRC, David Frydenlund and Harold Robeits from Denison, and Doug Oliver, Ryan
Jakubowski, and Phil Crouse from MWH. These responses reflect the discussions and
agreements from that meeting.
White Mesa Cell 1
Per the ICTM, White Mesa states that Cell 1 will not contain mill tailings upon decommissioning
of the site. It appears that Cell 1 has not been included in the ICTM based on the determination
by Denison Mines U.S.A. that it does not meet the permit language requirement of a closed
tailings cell.
DRC does not agree with this interpretation for the foUowing reasons:
Comment J. The demolition and decommissioning wastes in question will be contaminated with
by-product material (See Utah Administrative Code (UAC) R313-12-3).
Response: As discussed during.the March 31 meeting, the demolition and decommissioning
(D & D) waste material will be contained in an approved facility. A portion of Cell 1 (a 10-acre
area on the southern side of Cell I, adjacent to the Cell 2 berm) may be used to contain
construction debris from decommissioning of the mill site. Disposal of the decommissioning
material in Cell 1 is identified as a contingency in case Cell 4A & Cell 4B do not have adequate
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