DRC-2020-021462 - 0901a06880e5a401

Department of
Environmental Quality
L. Scott Baird Executive Director
DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL
Ty L. Howard
Director
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State of Utah
GARY R. HERBERT
Governor
SPENCER J. COX
Lieutenant Governor
MEMORANDUM
TO: File C-2020-47
THROUGH: Phil Goble, Section Manager pp...6 /0 7,0c,
FROM: Russell J. Topham, P.E. f
DATE: December 3, 2020
SUBJECT: 2020 Engineering Module 76, Annual Technical Evaluation Report; Radioactive Materials
License UT1900479 (RML)
On November 24, 2020, the Utah Division of Waste Management and Radiation Control (DWMRC) received the
2019 Annual Technical Evaluation Report (ATER) dated November 20, 2020 and covering the November 1, 2018
to October 31, 2019 monitoring period. The report was due December 1, 2020. DWMRC received the Report in
both hard copy and CD formats.
Summary
After review of the ATER, DWMRC staff findings and recommendations are as follows:
The DWMRC should monitor performance of the tailings management system closely as Impoundment 4A fills,
and Energy Fuels Resources (EFR) closes Impoundment 3 and deposits tailings in Impoundment 4B, looking for
recurrence of historic problems maintaining freeboard. This comment repeats a notation in the ATER reviews for
2012 through 2019.
General Requirements
Condition 12.3 of the RML requires preparation of the ATER, specifies the content, and fixes the date by which
the DWMRC must receive the ATER. The Tailings Management System (TMS) document guides much of the
work reviewed and reported in the ATER. EFR used TMS revision 2.5, dated March, 2017 (the most recent
revision) in the preparation of the 2019 ATER. The report as prepared and submitted meets the requirements for
content and timeliness.
Maintaining Freeboard
The 2011 ATER contained detail of instances where EFR failed to maintain appropriate freeboard in the various
impoundments involved in the TMS. The reports for 2012 through 2020 contain data showing that EFR
successfully maintained fluid levels without exceeding freeboard during from 2012 through 2020. As processing
DWMRC-20 195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. [phone]
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Page 2
of ore and alternate feeds continues, the tailings beach in Impoundment 4A expands. Given the problems
maintaining freeboard during the 2011 monitoring period, the DWMRC should monitor freeboard performance
closely as Impoundment 4A fills.
Monitoring of Lateral Displacement
Movement monitors for Impoundments 4A and 4B showed no evidence of horizontal displacement. In 2018, data
presented for Movement Monitor MM-25-4B indicated an unexplained increase in elevation. Mill personnel
identified this condition and had surveyors check the survey work done to determine the elevation of the
monitoring point. The check revealed a calculation error, which was substantiated by the 2019 and 2020 surveys
showing no significant change in elevation from 2017. No further Division action is indicated by the data
presented in the report.
Monitoring of Vertical Displacement
Settlement monitors for Impoundment 2 show acceleration of settlement with the addition of the radon barrier
material, as expected. The rate of settlement is decreasing with time since placement of the radon barrier material
in 2016 and 2017.
Impoundment 3 has sufficient fluid in interstices in the tailings mass that areas receiving fill, i.e., placement of
plant waste, imported 11 e.(2) decommissioning debris and cover, are settling, while areas that are not receiving
fill are heaving. This is not surprising, inasmuch as the saturated tailings are behaving like a fluid, rather than a
solid. Once dewatering of the impoundment commences, this situation should stabilize.
Monitors at the toe of the Impoundment 4A embankment reveal no motion. The toe is stable.
lle.(2) Byproduct Disposal
The Licensee disposed 461.5 cubic yards of 11e.(2) byproduct from in-situ recovery facilities during the reporting
period (reported separately from the Annual Technical Evaluation Report). This material was placed exclusively
in Impoundment 3 at the tailings surface. Inspection of this activity and an audit of paperwork have been
performed separately from the review of this report. The disposal has been conducted and documented according
to Standard Operating Procedure PBL-10.
Tailings Transport System
The licensee uses HDPE pipe to carry tailings slurry to the active impoundment, in this case Impoundment 4A.
Identical solution lines run between the mill and Impoundments 1 and 4B for fluid management. These pipelines
are inspected daily for leakage and repaired as required to prevent releases. No releases were reported.