DRC-2011-007905 - 0901a06880303c1a

State of Utah
GARY R HERBERT
GREG BELL
Lieutenant Governor
Fepartment of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director
2iii-007905
MEMORANDUM
TO
FROM
DATE
SUBJECT
Phil Goble, Section Manager
Russell J Topham, P E
November 30, 2011
Review of the 2011 Annual Techmcal Evaluation Report (dated November 7-9, 2011)
(ATER) Radioactive Materials License UT 1900479 (License) - Denison Mines (USA)
Corp (DUSA) White Mesa Mill, Blanding, Utah
This IS a summary of Utah Division of Radiation Control (DRC) staff review of the DUSA Annlhl
Techmcal Evaluation Report (ATER) dated November 7-9, 2011 for the Denison USA White Mesa Mill,
and covenng the November 1, 2010 to October 31, 2011 monitoring period DRC received the Report on
November 16, 2011 in both hard copy and soft copy CD formats Discussions in this document reference
the Radioactive Materials License UT1900479, Revision DRC-04 (License) The DMT/BAT Plan in force
during the Period in question was executed on June 21, 2010
After review ofthis report, DRC staff findings and recommendations are as follows
1 DRC should require of DUSA a root cause analysis of the freeboard exceedance problem, and
adoption of a procedure sufficient to prevent future violations Previous exceedance issues have
been formally closed out, but the root cause ofthe freeboard exceedances has not been
documented and addressed
2 DUSA should provide an explanation of the discrepancy in findings for the settlement monitors,
as well as the results of investigations into the cause(s) of the excessive displacements identified
Maintaining Required Freeboard
1 Section 3 0 of Appendix D to the License establishes freeboard limits for the tailings cells These
elevations can be modified through Executive Secretary action or through License amendment
During the reporting penod the freeboard requirements for Cells 3 and 4A were modified by
Executive Secretary action documented in letters dated January 27, 2011 and March 14, 2011
The March 14, 2011 letter from the Executive Secretary formally closed out the violation issues
associated with exceedances to that date, but did not address the broader issue of why the
exceedances occurred in the first place
2 On Page 3 of the ATER DUSA asserts, "In an effort to maintain freeboard limits solutions were
transferred between cells " On Page 5 of the ATER DUSA states, "solution is penodically
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pumped back and forth between cell 4A, Cell 3, and Cell l-I to maintain required freeboard limits
in the entire system "
3 DUSA claims on Page 5 of the ATER that no freeboard exceedances were detected for Cell 1 -I
for the reporting penod
4 Page 6 of the ATER references removal of the freeboard limit for Cell 3 through Executive
Secretary action during the monitoring period DUSA reveals on Page 7 of the ATER that, until
removal of the freeboard limit, Cell 3 solution pool elevations consistently exceeded the freeboard
limits established m the License
5 Page 7 of the ATER references removal of the freeboard limit for Cell 4A through Executive
Secretary action during the monitoring period DUSA reveals on Pages 7-8 of the ATER that, in
January 2011, pnor to removal of the freeboard limit. Cell 4A solution pool elevations
consistently exceeded the freeboard limits established in the License
6 On Page 8 of the ATER DUSA indicates that Cell 4B solution pool elevations did not exceed
freeboard limits established in the License during the reporting period
7 Based on items 1 through 6 above, it appears that DUSA consistently operated outside the
freeboard limits of the License during the monitonng period until Cell 4B was placed in service
Solution pool elevation maintenance protocols have not prevented exceeding the limits imposed
in the License DRC has been working with DUSA over the monitoring period, as evidenced by
the cited Executive Secretary letters DRC should require DUSA to provide a root cause analysis
of the freeboard exceedance problem, and adoption of a procedure sufficient to prevent ftiture
violations In light of the ongoing dialog on this issue, a Notice of Enforcement Discretion would
seem appropriate
Monitoring of Settlement and Lateral Displacement
1 Monitonng of lateral and vertical movement of the tailings cell dikes and cover provides
important measures ofthe stability of the cells Settlement plates provide a common set of
locations from which to measure vertical displacements of the ground surface Most plates show
expected degrees of settlement, indicating stability of the cell dikes and proper filling of void
spaces during material placement
2 Page 9 of the ATER contains language asserting settlement on the order of 0 64 feet for all
settlement monitors referenced to one of several control points The subject points cover part of
the westem end of Cell 2 DUSA assumes disturbance of the control point used for vertical
reference, or techmcian error, have responsibility for this apparent subsidence condition DUSA
promises follow-up measurements to clarify this issue No time table is provided
3 According to the ATER, Cell 3 settlement monitors show subsidence withm expectation, i e , less
than 0 1 foot between successive monthly readings
4 On November 3, 2011 the Executive Secretary granted approval of a document called Movement
(Displacement) Monitoring Standard Operating Procedures (SOP) which, among other things,
defines the demarcation between acceptable and unacceptable settlement rates Such limits were
not in place pnor to approval of the SOP The ATER was written withm the first month following
approval of the SOP
Page 3
The SOP requires an investigation and possible corrective actions if a difference of greater than
0 1 foot of elevation is detected in any one monitor The SOP requires resurvey of the affected
monitor, documentation of site conditions, intemal wntten communication ofthe suspected
causes of the excessive displacement, and reporting to the Executive Secretary withm 30 days
The data will also appear in the ATER, a condition which was met
A detailed review of the survey data for the settlement monitors reveals all Cell 2 settlement
monitors exhibiting settlement within the 0 1 foot month-to-month limit, but shows Momtor 3-IN
settling 0 32 feet between June 14 and July 29, 2011, with subsequent monitoring substantiating
the excess settlement
DUSA should provide an explanation of the discrepancy in findings for the settlement monitors,
as well as the results of investigations into the cause(s) of the excessive displacements identified