DRC-2013-004465 - 0901a06880415e11

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DRC-2013-004465
SAFETY EVALUATION REPORT
FOR THE
Amendment Request to Process an Alternate Feed Material (the "Uranium
Material") at White Mesa Mill (the "Mill") from Dawn Mining Corporation
("DMC") Midnite Mine, Washington State
Energy Fuels Resources (USA) Inc. (EFRI)
(formerly known as
Denison Mines (USA) Corp.)
White Mesa Uranium Mill
San Juan County, Utah
In Consideration of an Amendment to
Radioactive Materials License No. UTl 900479
to Authorize Receipt and Processing of the Uranium Material as an Alternate Feed
Material Primarily for the Recovery of Uranium and Disposal of the Resulting Residuals
in the Mill's Uranium Tailings Impoundments as
lie.(2) Byproduct Material
PREPARED BY:
URS Professional Solutions, LLC for
the Utah Department of Environmental Quality
Division of Radiation Control
August 9, 2013
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Table of Contents
1.0 INTRODUCTION 1
1.2 Previous Alternate Feed Proposals and Alternate Feed Assessment
Process 2
1.3 Uranium Material Generation Process Description 3
1.3.1 Filter Press Dewatering 4
1.4 Additional Background Information: Midnite Mine Site 5
1.5 Review Scope: Environmental Analysis 6
2.0 CHARACTERISTICS OF THE WHITE MESA MILL SITE AND VICINITY .. 6
3.0 OPERATIONS 7
4.0 ASSESSMENT OF POTENTIAL ENVIRONMENTAL EFFECTS 8
4.1 Radiological and Non-Radiological Impacts 8
4.1.1 Radiological Impacts 8
4.1.2 Non-Radiological Impacts 17
4.2 RCRA Listed Materials Analysis 18
4.3 RCRA Characteristic Materials Analysis 18
4.4 Surface Water and Groundwater Effects 32
4.4.1 Surface Water Effects 32
4.4.2 Groundwater Effects 34
4.5 Evaluation of Need for Additional Groundwater Monitoring Compliance
Parameters 35
4.6 Alternatives 39
4.7 Long-Term Impacts 39
4.8 Report Findings 42
5.0 REQUIRED LICENSE AMENDMENTS AND PERMIT MODIFICATIONS.. 43
5.1 License Amendments Proposed 43
5.2 GW Permit Modifications 44
6.0 REFERENCES 45
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List of Tables
Table 1. Range of Radionuclide Concentrations in DMC Uranium Material (2010
Analytical Results) 8
Table 2. Analytical Results - Uranium Material for RCRA Listed Hazardous Waste
(Radiochemistry Analysis [2010]) 9
Table 3. Concentrations of Total Uranium, Radium-226 and Thorium-230 in Uranium
Material vs. Average Acid Leached Ore-Derived Uranium Mill Tailings in
Utah 10
Table 4. Summary of Arizona 1 Ore Grades (Dry Weight Basis) 10
Table 5. Comparison of Radionuclide Activity Concentrations in Proposed Uranium
Material and Previous Alternate Feeds 11
Table 6. Range of Radionuclide Concentrations in DMC Uranium Material - Filter Press
Cake Samples (2011 Analytical Results) 12
Table 7. Derived Air Concentrations for Ores and Selected Alternate Feed Materials.... 13
Table 8.Chemical Characteristics of the Uranium Material 17
Table 9. Metals and Inorganic Constituents Confirmed Present in Uranium Material .... 18
Table 10. Uranium Materials Metals Analysis and Selenium for RCRA Toxicity
Characteristics (2010 TCLP Testing) 19
Table 11. Uranium Material Analyses for RCRA Listed Hazardous Waste (Metals,
Calcium and Selenium [2010]) 20
Table 12. Uranium Material Analyses for RCRA Listed Hazardous Waste (Volatile
Organics [2010]) 23
Table 13. VOC Detections in Laboratory QC Blanks 24
Table 14. Uranium Material Analyses for RCRA Listed Hazardous Waste (Semi-
Volatiles [2010]) 25
Table 15. Uranium Material Analyses for RCRA Listed Hazardous Waste (Other
Organics [2010]) 25
Table 16. Concentrations of Selected Inorganics in Uranium Material Compared to
Typical Colorado Plateau Uranium Mill Tailings and Uranium Ores 26
Table 17. Selected Inorganic Constituents Present in Previous Alternate Feed Materials
Processed at Mill 27
Table 18. Extractable Metals (TCLP Testing) and Extractable Selenium in DM Uranium
Material - Filter Press Cake Samples (2011) 28
Table 19. EPA Soil Screening Levels 30
Table 20. Nutrients, Inorganics and Metals, and Organic Constituents Reported Detected
in Uranium Material and Not Added as Groundwater Monitoring Parameters. 38
List of Figures
Figure I. Primary Transportation Corridors in Utah 48
List of Attachments
ATTACHMENT A: Table A-1 49
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ABBREVIATIONS AND ACRONYMS
11 e.(2) Section 11 e.(2) of the Atomic Energy Act of 1954, as amended
u Micro
ALARA As Low as Reasonably Achievable
AO (Air) Approval Order
avg Average
Ba Barium
Be Beryllium
Bq Becquerel
CCD Countercurrent Decantation
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
Ci Curie
DAC Derived Air Concentration
Director Director of Utah Radiation Control Division
DMC Dawn Mining Corporation
DUSA Denison Mines (USA) Corp.
EFN Energy Fuels Nuclear, Inc.
EFRI Energy Fuels Resources (USA) Inc.
EPA U.S. Environmental Protection Agency
FES Final Environmental Statement
FS Feasibility Study
GMP Groundwater monitoring program
gpm Gallons per minute
g/cm Grams per cubic centimeter
GWDP Ground Water Discharge Permit
GWQS Ground Water Quality Standard
HDPE High-density polyethylene
Kd Distribution coefficient
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Kg Kilogram
lb/fT Pounds per cubic foot
LSA Low Specific Activity
max Maximum
MDL Method Detection Limit
mg/kg Milligrams per kilogram
ml Milliliter
mrem Millirem
MSDS Material Safety Data Sheet
N Nitrogen
NEA Nuclear Energy Agency
NIOSH National Institute for Occupational Safety and Health
NPDES National Pollutant Discharge Elimination System
NRC U.S. Nuclear Regulatory Commission
OECD Organization for Economic Co-operation and Development
OSHA Occupational Safety and Health Administration
pCi/g Picocuries per gram
PEL Permissible Exposure Limit
ppm Parts per million
RCRA Resource Conservation and Recovery Act
RfC Reference concentration
RfD Reference dose
RI Remedial Investigation
RML Radioactive Materials License
RMPR Radioactive Material Profile Record
ROD Record of Decision
RSL Risk Screening Level
SER Safety Evaluation Report
SOB Statement of Basis
v
SSL Soil Screening Level
Sv Sievert
SX Solvent Extraction
TCE Trichloroethylene
TCLP Toxicity Characteristic Leaching Procedure
TEDE Total Effective Dose Equivalent
TTLC Total Threshold Limit Concentration
U-nat Natural uranium
U Uranium
UAC Utah Administrative Code
U3O8 Triuranium octoxide; yellowcake
UDRC Utah Division of Radiation Control
UV Ultraviolet (radiation)
WTP Water Treatment Plant
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1.0 INTRODUCTION
1.1 Background and Need for Proposed Action
This draft Safety Evaluation Report (SER) has been prepared to evaluate the environmental
impacts resulting from the proposed receipt and processing of alternate feed material (Uranium
Material) from the Dawn Mining Corporation (DMC) Midnite Mine located in Wellpinit,
Washington state, at the White Mesa Uranium Mill. The White Mesa Mill site is located in San
Juan County, Utah, approximately 5 miles south of Blanding.
The White Mesa Mill is licensed by the Utah Division of Radiation Control (UDRC) under State
of Utah Radioactive Materials License (RML) No. UT1900479. This license and its amendments
authorize Energy Fuels Resources (USA) Inc. (EFRI) to receive and process natural uranium-
bearing ores and certain specified alternate feed materials, and to possess byproduct material in
the form of uranium waste tailings and other uranium byproduct waste generated by the
licensee's milling operations.
EFRI, formerly Denison Mines (USA) Corp. (DUSA), submitted a License Amendment Request
(Amendment Request), in a letter with supporting attachments dated April 27, 2011, to the
UDRC to amend its State of Utah RML No. UT1900479. The amendment request, if approved
by UDRC, would allow EFRI to receive and process up to 4,500 tons (dry weight) of Uranium
Material from the DMC Site.
The Uranium Material results from treatment of pumped groundwater and surface water at the
Midnite Mine site's Waste Treatment Plant (WTP) using either centrifuge or filter press
technology. Pilot testing performed by DMC indicates that this Uranium Material is expected to
have an average moisture content of 55% to 75% (i.e., a dry solids content between 25% and
45%) for centrifuge-generated material, or approximately 60% to 65% (i.e., a dry solids content
between 35% and 40%) for the filter-press generated material.
The Washington Department of Health issued an RML in 1992 for the Uranium Material
generated from the Midnite Mine WTP, which was constructed in 1988 and began treating water
in 1992. The license was terminated after December 31, 2008 and the regulatory authority for
operation of the WTP was transferred as part of the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) to the U.S. Environmental Protection Agency
(EPA). The Dawn Mill processing facility has been decommissioned and Uranium Material is no
longer processed at this location. After December 2008, the Dawn Mill tailings facility accepted
Uranium Material for direct disposal as source material in accordance with U.S. Nuclear
Regulatory Commission (NRC) guidance on Disposal of Atomic Energy Act Non-Section
1 le.(2) Byproduct Material of Tailings Impoundments. Direct disposal in the tailings
impoundment has not been an option as of the 2010 operating season because of the upcoming
scheduled reclamation of the Midnite Mine tailings facility.
EFRI is requesting that the Uranium Material be received and processed at the White Mesa Mill
based on its source material content. Byproducts (residuals) from the extraction of source
material would be disposed within one or both of the mill's active lined uranium tailings
management/disposal cells (Cells 4A and/or 4B). A groundwater detection monitoring program
is currently in place for the tailings management cell area that includes the Cell 1 evaporation
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pond, and tailings Cells 2, 3, 4A, and 4B. Before the NRC Agreement State status with the State
of Utah was formalized, the NRC had approved similar amendment requests for processing of
separate alternate feed materials under this license.
Groundwater quality at the White Mesa Mill site is also regulated under State Ground Water
Discharge Permit (GWDP) Number UGW370004 (hereafter referred to as the "Permit"). After
review of the subject EFRI License Amendment Request, the Director has determined that the
existing Permit is sufficient for monitoring local groundwater quality to assess possible effects of
disposal of the byproducts left after processing of the proposed alternate feed material.
1.2 Previous Alternate Feed Proposals and Alternate Feed Assessment Process
In the Final Application for Uranium Mills and Mill Tailings made by the State of Utah to the
NRC Office of State and Tribal Affairs, the following commitment was made by the State of
Utah:
"The State of Utah recognizes the importance of and supports the uranium mining
and milling industry. The State recognizes that to remain viable at this time,
uranium mills must be able to engage in activities other than milling
conventionally mined uranium such as processing alternate feed materials for the
recovery of uranium alone or together with other minerals."
The State of Utah also agreed to use the most recent NRC guidance (SECY 95-211, SECY-99-
012, and NRC Regulatory Issue Summary 2000-23) for review and decisions regarding the
acceptability of receipt of alternate feed materials for processing at the Mill and that each
amendment would be considered a major amendment for the purposes of licensing. Criteria used
for decision-making regarding the acceptance of alternate feed material are:
1. Determination of whether the feed material is an ore.
For the tailings and wastes from the proposed processing to qualify as 1 le.(2) byproduct
material, the feed material must qualify as "ore." In determining whether the feed material is
ore, NRC has established the following definition of ore: "Ore is a natural or native matter
that may be mined and treated for the extraction of any of its constituents or any other matter
from which source material is extracted in a licensed uranium or thorium mill."
The Uranium Material is derived from treatment of natural surface water and groundwater
that have come into contact with uranium ore at the Midnite Mine site, which would be
processed at the licensed White Mesa Mill primarily for its source material (uranium)
content, and therefore qualifies as "ore" under this definition. Additionally, the uranium
concentration in the Uranium Material exceeds 0.05% on both a wet and dry basis, thereby
causing the Uranium Material to also meet the definition of source material.
2. Determination of whether the feed material contains hazardous waste.
If the proposed feed material contains hazardous wastes, listed under subpart D Sections
261.30-33 of 40 Code of Federal Regulations (CFR) (or comparable Resource Conservation
and Recovery Act (RCRA) authorized State regulations), it would be subject to the EPA or
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State regulation under RCRA. If the licensee can show that the proposed feed material does
not contain a listed hazardous waste, this issue is resolved.
Feed material exhibiting only a characteristic of hazardous waste (ignitable, corrosive,
reactive, toxic) would not be regulated as hazardous waste and could therefore be approved
for recycling and extraction of source material. However, this does not apply to residues from
water treatment, so determination that such residues are not subject to regulation under
RCRA will depend on their not containing any characteristic hazardous waste. Staff may
consult with EPA (or the State) before making a determination of whether the feed material
contains hazardous waste.
If the feed material contains hazardous waste, the licensee can process it only if it obtains
EPA (or State) approval and provides the necessary documentation to that effect.
Additionally, for feed material containing hazardous waste, the staff will review
documentation from the licensee that provides a commitment from the U.S. Department of
Energy or the State to take title to the tailings impoundment after closure.
The Uranium Material is classified as 1 le.(2) byproduct material. Under 40 CFR 261.4(b)(7),
solid wastes from the extraction, beneficiation, and processing of ores and minerals are not
hazardous wastes. In the application for license amendment request made by DUSA on April
27, 2011, DUSA demonstrated that the Uranium Material contained no known listed wastes
under Subpart D Sections 261.30-33 of 40 CFR. Therefore, this condition is satisfied.
3. Determination of whether the ore is being processed primarily for its source-material content.
For the tailings and waste from the proposed processing to qualify as 1 le.(2) byproduct
material, the ore must be processed primarily for its source-material content. If the only
product produced in the processing of the alternate feed is uranium product, this
determination is satisfied. If, in addition to uranium product, another material is also
produced in the processing of the ore, the licensee must provide documentation showing that
the uranium product is the primary product produced.
Section 3.2 of EFRI's (formerly DUSA's) April 27, 2011 report states that the Uranium
Material would be milled primarily for its uranium content. This condition is satisfied.
Currently, EFRI has received UDRC approval of a total of one license amendment authorizing
the mill to receive and process alternate feed materials from Fansteel Metals Resources, Inc.'s
(FMRI's) site in Oklahoma, described in License Condition 10.19.
1.3 Uranium Material Generation Process Description
The Midnite Mine Uranium Material consists of solid material resulting from treatment of
stormwater and groundwater collected from Pit 3 and Pit 4 at the inactive Midnite Mine uranium
mine site in Wellpinit, Washington. Water treatment is conducted in an on-site WTP. The WTP
employs a conventional lime treatment high-density solids process in which the metals and
uranium are precipitated out in the treatment process, and involves addition of barium chloride
for removal of radium. Barium chloride is added to the influent water stream, which is then
mixed with approximately 90 gallons per minute (gpm) of the total process stream from the
clarifier bottoms (clarifier underflow) to increase the overall final WTP solids density. Hydrated
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lime is then added to precipitate uranium and metals. Waters recovered from the dewatering
process are also added back to the process stream at this point in the process. An anionic water
soluble polymer (Neo Solutions, NS-6852) is subsequently added as a coagulant to facilitate
clarification. The resultant slurry is settled and filtered to produce a solution free of solids for
surface discharge under the Clean Water Act National Pollutant Discharge Elimination System
(NPDES) program and EPA CERCLA program.
Sludge generated by the WTP was previously centrifuged and the final solids contained on
average 0.18 wet weight percent uranium (0.21 wet weight percent U308) at an average historical
solids content of 15%. No other chemical addition to the sludge generation process occurs in the
WTP.
The process stream is sent to one of two clarifiers. The precipitated solids are drawn from the
clarifier bottom and approximately 20% of the clarifier underflow (approximately 90 gpm) is
pumped back to the agitation tank at the beginning of the process to increase overall WTP solids
density. Under the previous centrifuge process, the liquid fraction of the remaining process
stream (approximately 36 gpm) was decanted from the top of the clarifier for further treatment
and discharged separately from the solids, while the remaining solids fraction from the clarifier
underflow was sent to the centrifuge for dewatering.
The dewatered solids were transferred from the centrifuge to the transport truck via a discharge
conveyor. The transport truck was housed within the WTP building and remained in that location
until it was used to haul the processed sludge material for final disposal or to a stockpile area
awaiting future disposal, thereby eliminating any opportunity for other waste materials to be
introduced into the Uranium Material.
1.3.1 Filter Press Dewatering
In 2010, DMC proposed using a filter press as part of the WTP operations to further reduce the
moisture content of the WTP solid residual material, with the goal of reducing trucking costs for
transporting the Uranium Material having less weight than material produced using the
centrifuge process. The centrifuges were replaced with a hydraulic filter press in 2011,
increasing the percent solids of the final Uranium Material to between 25% and 45%, resulting in
a proportional increase in weight percent uranium estimated to be between 0.3 and 0.55 wet
weight percent uranium (0.35 and 0.63 wet weight percent U3O8). As uranium ores and alternate
feed materials are typically evaluated on a dry percent U3O8 basis, the actual (dry) percent U3O8
of the Uranium Material resulting from the filter press process is estimated to be approximately
1.5 percent U308 (EFRI 2013a).
Pilot-scale filter press testing was performed at the Midnite Mine WTP between September 16
and September 23, 2011. Six test runs were performed to determine resulting filter cake percent
solids, sludge volume reduction, evaluate effects of polymer addition, and assess press cycle
times and ease of press cleaning. Operational parameters were varied during the six tests.
Laboratory analyses were performed on filter cake samples to determine total uranium (dry
weight); radioactive concentrations of uranium, Radium-226 and Radium-228, and Thorium-
230; and density. Samples were also analyzed for Toxicity Characteristic Leaching Procedure
(TCLP), seven RCRA metals, and selenium (EFRI 2012a).
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The pilot testing sequence included closing the filter press, filling the press, pressurizing the
membrane squeeze, then blow down of the press, using a series of batch tests wherein
characteristics of each (e.g., duration of air blow; use of lack of membrane squeeze) were varied.
For all tests that used the membrane squeeze, "no free water was observed and the resulting cake
was extremely competent and in some cases requiring a screwdriver to break up" (EFRI 2012a).
EFRI subsequently further indicated that the term "competent" means the cake was "dry, hard,
and difficult to break with hand pressure" (EFRI 2013a, p. 32).
The pilot testing developed a range of Uranium Material characteristics and properties (e.g.,
moisture, density, metals, and radionuclide content) for bounding the material variability likely
expected due to differences in filter equipment between the pilot test and full-scale filter press
operations. The Uranium Material density ranged from 1.16 g/cm3 (72.4 lb/ft3) to 1.34 g/cm
(83.6 lb/ft3) and moisture content varied from 59.3% to 65.4% (EFRI 2013a, p. 31). EFRI
indicated that no significant differences are expected to occur between the pilot-testing
equipment and full-scale equipment, with the exception of the equipment size. Both the pilot-
and full-scale presses use membrane squeeze and similar pressures for the membrane squeeze
and residual material slurry feed (EFRI 2013a, p. 31).
Total uranium results ranged from 8,210 to 9,190 milligram per kilogram (mg/kg) (dry weight
basis). Analytical results for radionuclides Radium-226, Radium-228, and Thorium-230 were
less than 3.4 picocuries per gram (pCi/g) (dry weight basis).
Analytical results for four samples of the produced filtered solid product from six filter press
pilot test runs for the metals ranged from <0.02 mg/L to <10 mg/L. The laboratory-calculated
solids contents ranged from 34.6% to 40.7%, depending on the duration of the filling and
membrane squeeze cycles.
EFRI estimated that approximately 10 filter press runs will be performed per each approximate
20 cubic yard shipment. A Seiko (or similar) field moisture analyzer will be used to test for
moisture content of the filter cake.
EFRI also indicated that composite filter cake field moisture content will be measured on a
minimum of three filter press runs per shipment, and that grab samples from the selected filter
press runs would be composited and an average moisture content determined for each shipment
from this composite sample. The number of filter press run samples used for each composite
sample and the measured moisture content will be recorded on a Filter Press Moisture Content
log sheet and a copy of the sheet will provided with the shipping papers of each shipment. EFRI
also stated (EFRI 2013a, p. 31) that if significant variability in composite moisture content is
observed (i.e., greater than 15% moisture content between filter press runs) or if the moisture
content is greater than 70%, the filter cake will be tested more frequently for moisture content
prior to shipping.
1.4 Additional Background Information: Midnite Mine Site
A Remedial Investigation (RI) was completed for the Midnite Mine Site in 2005. The selected
remedy identified for the site is Alternative 5a (Complete Pit Backfill with Passive Drains and
Ex-Situ Water Treatment) of the Feasibility Study (FS). Based on the FS and issued in the
Record of Decision (ROD) as the selected remedy ("Remedy"), Pits 3 and 4 will be backfilled,
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waste rock and proto-ore will be moved and capped, and a new passive water collection system
will be installed to capture groundwater from these and other backfilled pit areas. The ROD
specifies that a surface water management will be designed to divert surface flows around
sources of contamination and therefore minimize the volume of water to be treated after the
Remedy is implemented.
The existing Midnite Mine WTP is located on a waste rock pile that must be removed for the
Remedy. Therefore, a new water treatment plant will be built before construction of the Remedy
begins. It is estimated that the construction will begin in 2013 and will require approximately
two years (through the end of 2014) to complete. The new WTP will have a targeted year-round
water treatment capacity of 1,000 gpm for the construction phase. It is likely that the new WTP
will be comparable to the current treatment employed using lime and barium chloride addition
for removal of constituents from the feed water. The flow rate is designed to allow for rapid
dewatering of the pits during backfilling, as well as groundwater collection and surface water
collection treatment. After construction, it is expected that the flows will be reduced to an
ultimate annual value of 65 million gallons and that it will take an estimated 6 to 7 years to reach
these reduced flows.
1.5 Review Scope: Environmental Analysis
In accordance with UAC R313-22-38 and R313-24-3, this SER has been prepared to evaluate the
following items with respect to the proposed acceptance and processing of the Uranium Material
at the Mill:
(1) Assess the radiological and non-radiological impacts to the public health;
(2) Assess potential impacts on waterways and groundwater;
(3) Consider alternatives, including alternative sites and engineering methods;
(4) Consider long-term impacts including decommissioning, decontamination, and
reclamation impacts; and
(5) Present information and analysis to support UDRC findings and conclusions with respect
to approval of the proposed license amendment.
2.0 CHARACTERISTICS OF THE WHITE MESA MILL SITE AND VICINITY
The climate in the White Mesa facility vicinity is characterized as semi-arid with an annual
average precipitation of approximately 12 inches and a mean annual temperature of about 50° F.
Runoff in the project area is directed by the general surface topography either westward into
Westwater Canyon, eastward into Corral Creek, or to the south into an unnamed branch of
Cottonwood Wash. The San Juan River, a major tributary to the Colorado River, is located
approximately 18 miles south of the site.
The population density of San Juan County is approximately 1.7 persons per square mile. The
town of Blanding is the largest population center near the facility and has a population of about
3,600. Approximately 3.5 miles south, southeast of the site is the White Mesa Reservation, a
community of approximately 350 members of the Ute Mountain Ute Tribe. The nearest resident
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to the Mill is located approximately 1.4 miles to the northeast of the Mill, which is in the
prevailing downwind direction from the Mill site (DUSA 2008).
Approximately 60% of San Juan County is federally owned land administered by the U.S.
Bureau of Land Management, the U.S. National Park Service, and the U.S. Forest Service.
Primary land uses include livestock grazing, wildlife range, recreation, and exploration for
minerals, oil, and gas. A quarter of the county is Native American land owned by either the
Navajo Nation or the Ute Mountain Ute Tribe. The land within 5 miles of the site is primarily
owned by residents of Blanding. EFRI owns or has claims or leases on approximately 5,500
contiguous acres, of which the White Mesa Mill site encompasses approximately 500 acres.
Groundwater beneath the site mainly occurs in two water-bearing systems: a shallow unconfined
perched groundwater zone hosted by the Dakota Sandstone and the Burro Canyon formations,
and a deep confined groundwater aquifer in the Entrada/Navajo Sandstone. The perched water
zone is found at a depth of about 80 to 100 feet below ground surface beneath the tailings cells
area and consists of groundwater perched over the Brushy Basin Member of the Morrison
Formation. The deep Entrada/Navajo Sandstones host one of the most permeable aquifers in the
region, found at a depth of over 1,000 feet below ground and separated from the shallow aquifer
by hundreds of feet of low-permeability shales and mudstones (Brushy Basin and Recapture
Members of the Morrison Formation, the Summerville Formation, etc.). Recharge to the aquifers
occurs by infiltration along the flanks of the Abajo, Henry, and La Sal Mountains, and along the
flanks of structural folds in the terrain.
Groundwater in the shallow perched water-bearing zone (Dakota Sandstone and Burro Canyon
Formation) is monitored by EFRI as part of the Mill's GWDP. Water in this zone generally
flows southward to south westward.
Approximately 95 groundwater applications for wells located within a 5-mile radius of the site
are on file with the Utah State Engineer's Office. The majority of applications are by private
individuals and for wells drawing small, intermittent quantities of water (flow rates less than
8 gpm) from the Burro Canyon formation. For the most part, these wells are located upgradient
(north) of the facility. Stockwatering and irrigation are listed as the primary uses. Two deep
water supply wells are completed in the Entrada/Navajo Sandstone located approximately
4.5 miles southeast of the site on the Ute Mountain Ute Tribe Reservation. The well casings for
these deep water supply wells are perforated at a depth of approximately 1,200 feet below the
ground surface.
3.0 OPERATIONS
The White Mesa Mill was built in the late 1970s by Energy Fuels Nuclear, Inc. (EFN) as an
outlet for the many small mines that are located in the Colorado Plateau. After about two and
one-half years, the mill ceased ore processing and entered a total shutdown phase. In 1984, a
majority ownership interest was acquired by Union Carbide Corporation's (UCC) Metals
Division, which later became UMETCO Minerals Corporation (UMETCO), a wholly-owned
subsidiary of UCC. The partnership between UMETCO and EFN continued until May 26, 1994,
when EFN reassumed complete ownership of the mill. In May 1997, IUC (International Uranium
[USA] Corporation) purchased the assets of EFN and operated the facility until December 2006.
Denison Mines (USA) Corp. operated the facility between December 2006 and August 2012,
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when EFRI took ownership of the Mill. The mill has gone through several operational and
shutdown periods from 1980 to date.
EFRI currently operates the Mill. Current License Condition 10.1 specifies a maximum
yellowcake production rate of 4,380 tons of yellowcake per year. License Condition 10.1 .D.
limits the quantities of feed material stored at the White Mesa site, including alternate feed
materials or other ores, to the total material storage quantity found in the currently approved mill
surety pursuant to License Condition 9.5, unless prior approval for additional storage is first
obtained from the Director of the UDRC. The maximum mill throughput is limited in part by
annual freeboard limits established for the tailings disposal cells. Freeboard calculations are
required to be submitted to the UDRC annually, in accordance with License Condition 10.3.
4.0 ASSESSMENT OF POTENTIAL ENVIRONMENTAL EFFECTS
4.1 Radiological and Non-Radiological Impacts
4.1.1 Radiological Impacts
Radionuclide Concentrations in DMC Uranium Material
The Radioactive Materials Profile Record (RMPR) submitted with the April 27, 2011
Amendment Request indicates the following radionuclides exist in the Uranium Material
alternate feed material: Radium-226, Thorium-228, Thorium-230, Thorium-232, Lead-210, and
uranium. Reported minimum and maximum concentrations or activities of specific radionuclides
and radionuclide isotopes detected in samples of the Uranium Material (tested in 2010) are
summarized in Table 1 below. Table 2 presents specific analytical results from three samples
collected in 2010 from the WTP solids (Samples WTPS) [WTPS-2, -2, and -3]. The
radionuclides detected in the samples are commonly associated with the natural uranium decay
series and natural thorium decay series.
Table 1. Range of Radionuclide Concentrations in DMC Uranium Material
(2010 Analytical Results)
Result
(dry weight
basis)
Total
Uranium
(mg/kg)
Thorium-
228
(pCi/g)
Thorium-
230
(pCi/g)
Thorium-
232
(pCi/g)
Lead-
210
(pCi/g)
Ra Total
(pCi/g)
Radium-
226
(pCi/g)
Min 15,000 0.93 20.4 0.66 32.0 36.6 22.8
Max 16,000 1.50 21.4 21.4 34.7 41.0 25.7
Laboratory-reported uncertainties/standard deviations not listed.
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Table 2. Analytical Results - Uranium Material for RCRA Listed Hazardous Waste
(Radiochemistry Analysis [2010])
Target Analyte Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
Total Uranium SW6020A
Total Uranium mg/kg 15,000 16,000 15,000 15,333
Gross Alpha/Beta GFPC
Gross Alpha pCi/g 4,310±690 4,830±770 5,440±870 4,860
Gross Beta pCi/g 4,870±780 4,780±760 4,860±780 4,867
Lead-210 Liquid
Scintillation
Lead-210 pCi/g 33.1±8.0 34.7±8.4 32.0±7.8 33.3
Radium-226 GFPC
Radium-226 pCi/g 22.8±5.8 25.7±6.6 23.8±6.1 24.1
Total Alpha
Emitting Radium
GFPC
Total Radium pCi/g 39.7±10 41 ±11 36.6±9.4 39.1
Total Radium
(duplicate sample)
pCi/g 35.8±9.2
Isotopic Thorium Alpha
Spectroscopy
Thorium-228 pCi/g 1.24±0.99 1.50±0.74 0.93±0.67 1.22
Thorium-230 pCi/g 20.4±3.8 21.4±3.9 20.4±3.7 20.7
Thorium-232 pCi/g 1.14±0.48 0.66±0.34 0.71±0.32 0.84
l ''AII values as reported by ALS Laboratory as dry weight values.
GFPC = Gas Flow Proportional Counting
The test results presented in Table 2 above establish that the average U-nat content of the
Uranium Material is approximately 1.5% on a dry weight basis: 15,333 mg/kg 1 x 106 mg/kg =
0.0153 kg/kg or 1.5% (EFRI 2013a, p. 12).
The available analytical data indicate that the concentration of total uranium in the Uranium
Material is higher than total uranium concentrations present in Colorado Plateau-derived
uranium ores typical of those processed at the White Mesa Mill (e.g., Abdelouas 2006, Table 2).
On the other hand, available data indicate that Thorium-230 levels and Radium-226 levels in the
Uranium Material are lower than in typical Utah area acid-leach ore-derived uranium mill
tailings. Table 3 below compares Thorium-230, total uranium, and Radium-226 concentrations in
the Uranium Material to concentrations of the same parameters present in typical uranium mill
tailings previously tested at Utah-area acid leach mills.
9
URS
The average U308 content of the Uranium Material (1.4%) is higher than the range of U308
contents (approximately 0.15% to 0.30%) present in typical Colorado Plateau-derived uranium
ores, as presented by DUSA/EFRI (see Table 3 below). However, this average concentration is
comparable to the range of U308 concentrations in ores mined at the Arizona 1 uranium mine in
the Arizona Strip between 2010 and 2012, which averaged between approximately 0.56% and
0.66%, and is lower than the maximum U308 concentrations observed in ores mined during each
of these three years (2.0 to 2.8 % U3Og (see Table 4).
Table 3. Concentrations of Total Uranium, Radium-226 and Thorium-230 in Uranium
Material vs. Average Acid Leached Ore-Derived Uranium Mill Tailings in Utah
Uranium Material Typical Utah Uranium Mill Tailings
Thorium-230: 20.4-21.4 pCi/g (dry weight
basis)
Thorium-230: 875 pCi/g 1
Uranium (Total): 15,000-16,000 ug/g Uranium (Total): 531 ug/g 1
% U308:1.4% (dry weight %Y % U3O8:0.15% to 0.30%
Radium-226: 22.8-25.7 pCi/g (dry weight basis) Radium-226: 710 pCi/g 1
Data from Abdelouas 2006.
Based on information provided by DUSA in its April 27. 2011 Amendment Request.
Table 4. Summary of Arizona 1 Ore Grades
(Dry Weight Basis)
Year
2010
2011
2012
Minimum
(% u3o8)
0.18
0.14
0.22
Maximum
(%u3o8)
2.4
2.0
2.8
Arithmetic Mean
(%U3Q8)
0.56
0.66
0.62
Table 5 below, summarizes the ranges of radionuclide concentrations of the Uranium Material
and compares those concentrations to radionuclide concentrations in other alternate feed
materials already approved for processing, and successfully processed at the Mill. These data
demonstrate that the primary gamma emitting radionuclide content (uranium, thorium and
radium) of the Uranium Material are below the maximum of the range of relevant radionuclide
activity concentrations of conventional ores and already-approved alternate feed materials.
Therefore, the gamma radiation and radon emissions from this Uranium Material will be
correspondingly less than other conventional ores and alternate feed materials that have been
processed or licensed for processing at the Mill.
10
Table 5. Comparison of Radionuclide Activity Concentrations in Proposed Uranium
Material and Previous Alternate Feeds
Radionuclide
Range of Uranium
Material Radionuclide
Activity Concentrationl
(pCi/g dry)2
Range of Colorado
Plateau Ores and
Alternate Feed
Radionuclide Activity
Concentrations3,4
(pCi/g dry)2
Source for Alternate
Feed Information
Radium-226 22.8 to 25.7 2,000 avg.; 10,400 max. W.R. Grace Application
April 2000
Total Radium 36.6 to 41.0 1,190 max (Radium-
228+Radium-226)
Heritage Application July
2000
Thorium-228 0.93 to 1.50 2,000 avg.; 3,222 max. W.R. Grace Application
April 2000
Thorium-230 20.4 to 21.4 2,000 avg.; 10,400 max. W.R. Grace Application
April 2000
Thorium-232 0.66 to 1.14 8,000 avg.; 31,500 max. W.R. Grace Application
April 2000
Lead-210 32.0 to 41.0 2,805 max. Based on 1% U,
conventional ores
U-nat 15,000 mg/kg to 16,000
mg/kg
686,000 mg/kg U-nat max.7 Mill lab monthly assays
Cameco UF4
Gross Alpha 4310±6790to 5440±870 7,600 avg.;
22,400 max.
Linde Application March
2005 conventional ores5
Gross Beta 4780±87 to 4870±780 3,800 avg.;
17,000 max.
Linde Application March
2005 conventional ores6
Attachment 2 of the April 2011 Amendment Request (Radioactive Material Profile Record, p. 2 of 11 and associated
tables).
pCi/g unless otherwise noted.
Selected concentrations for constituents found in characterization data for other alternate feed materials licensed for
processing at the Mill, for comparison purposes only.
Mined ores range from 0.1% to higher than 1%. Some Arizona strip ores have ranged as high as 2% IbOs (1.7% U-nat).
Abundance of uranium daughters can be estimated from the assumption that ores are in secular equilibrium.
Estimated based on assumption of 1% U3O8 (0.85% U) at 2830 pCi/g and eight alphas in Uranium-238 series, and neglecting
the contribution from Uranium-235.
Estimated based on assumption of 1% U3O8 (0.85% U) at 2830 pCi/g and six betas in Uranium-238 series and neglecting the
contribution from Uranium-235.
Monthly average grade assays of Cameco UF4 have periodically been as high as 80.7% U308 (68.6% U).
DMC arranged for analytical testing of four samples of filter press cake produced from the
dewatering filter press pilot testing (testing conducted between September 16 through 23, 2011)
for total uranium and the radionuclide isotopes Radium-226, Radium-228, and Thorium-230.
Minimum and maximum concentrations of these analytes detected in the samples are
summarized in Table 6 below.
11
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Table 6. Range of Radionuclide Concentrations in DMC Uranium
Material — Filter Press Cake Samples (2011 Analytical Results)
Result (dry
weight basis)
Min
Max
Total
Uranium
(mg/kg)
8,210
9,980
Thorium-230
(pCi/g)
2.7
<3.4
Radium-226
(pCi/g)
0.07
0.2
Radium-228
(pCi/g)
<0.2
<0.2
As described above and as summarized in Table 5. the radionuclide activity of the primary
gamma emitting radionuclides are below the maximum of the range of relevant radionuclide
activity concentrations of already approved alternate feed materials. Therefore, the potential
gamma emissions and potential worker exposure to gamma radiation will be within the range of
those already appropriately managed and monitored at the Mill (EFRI 2013a, pp. 8-9).
Demonstration that the uranium, radium, and thorium activity concentrations of the Uranium
Material are below the maximum range of previously approved conventional ores and alternate
feed materials indicates that radon levels resulting from processing of the Uranium Material are
expected to be within the range for which the existing approved controls and monitoring
programs are currently established and considered appropriate. Therefore, no change to the
existing radon exposure controls or the radiological monitoring program is considered necessary.
Attachment 2 to the April 2011 Amendment Request includes a completed RMPR. Page 10 of
the RMPR presents Uranium Material Analyses for RCRA Listed Hazardous Waste in the top
half of the table, and radionuclide data in the bottom half of the table. The second to last line of
this table presents total Thorium-232 concentrations in three representative samples of the
Uranium Material from the 2010 treatment season (WTPS-1, -2, -3). Thorium-232 results range
from 0.66 ± 0.34 pCi/g to 1.14 ± 0.48 pCi/g with an average of 0.84 pCi/g on a dry weight basis.
Based on the following calculations, these test results establish that the average Thorium-232
content of the Uranium Material is approximately 0.00076% on a dry weight basis (EFRI 2013a,
p. 13). The Thorium-232 level in the Uranium Material is well below the levels the Mill has been
licensed to process in the past.
Thorium-232 specific activity1 -1.1.x 10"7 Ci/g (1.1 x 105 pCi/g)
0.84pCi/g+ 1.1 x 105pCi/g = 0.0000076 or 0.00076%
Consistent with NRC Reg. Guide 3.59. the radionuclides in uranium ore are generally assumed
to be in secular equilibrium with Uranium-238, Radium-226, Thorium-230, and Lead-210
concentration can be approximated from U-nat content or ore grade, based on this assumption
and the following relationship:
' Argonne National Laboratory, EVS. Human Health Fact Sheet, August 2005. URL:
http://wvvvv.evs.anl.aov/pub/doe/Thorium.pdf
12
1JJR19
Assuming the U-nat content is 84.8% of U308, and that the major contributor to activity is
Uranium-238, the activity concentration of natural ore is approximately 12,350 Bq/g U (or
12,350 Bq/g x 27.0 pCi/Bq = 333,800pCi/g U); 0.25% U308 x 84.8% U-nat x 12,350 Bq/g x 27.0
pCi/Bq = 708 pCi/g for each of the isotopes in equilibrium with Uranium-238. This value is
slightly lower than the approximate value of 825pCi/g (initially mistakenly typed as pCi/L) in
Section 2.6.1 of the April 2011 Amendment Request and stated in EFRI 2013a, p. 14).
The activities of Radium-226, Thorium-230 and Lead-210 of approximately 24.1 pCi/g, 20.7
pCi/g and 33.3 pCi/g (on a dry basis) are well below the activities associated with Colorado
Plateau ores with grades of 0.25% U308.
Derived Air Concentrations from Processing of Uranium Material
The Derived Air Concentrations (DACs) for each Mill Area ("Circuit") involved in processing
the proposed Uranium Material are provided in Table 7, below. The DACs are compared with
those for conventional ores and a number of other alternate feed materials.
Table 7. Derived Air Concentrations for Ores and Selected Alternate Feed Materials
Mill Area
("Circuit")
Ore
Leach
CCD
SX
Precipitation
Packaging
Tailings
Dawn
Mining
DAC
2.6E-10
3.4E-10
3.9E-10
3.9E-10
5.0E-10
2.2E-11
2.0E-11
Conventional
Ore (based on
Arizona Strip)
6.0E-11
1.10-E-10
1.2E-11
1.2E-11
5.0E-10
2.2E-11
1.7E-11
UF4
2.1E-10
3.0E-10
2.9E-10
2.9E-10
5.0E-10
2.2E-11
1.7E-11
KF
2.6E-10
3.4E-10
3.9E-10
3.9E-10
5.0E-10
2.2E-11
1.7E-11
Regen
Material
4.2E-10
4.6E-10
4.2E-10
4.2E-10
5.0E-10
2.2E-11
1.7E-11
Calcined
Material
1.3E-11
2.5E-11
1.3E-11
1.3E-11
5.0E-10
2.2E-11
1.7E-11
Heritage
4.4E-12
8.6E-12
4.4E-12
4.4E-12
5.0E-10
2.2E-11
8.4E-12
Section 4.1.2 of the Mill's approved Radiation Protection Manual addresses the factors taken into
account in calculating Derived Area Concentration (DACs) for alternate feed materials. In order
to apply the procedures set out in Section 4.1.2 of the Radiation Protection Manual to the
calculation of specific DACs for specific alternate feed materials, the Mill developed an Excel
spreadsheet for the calculation of such DACs. Appropriateness of the assumptions and accuracy
of use of the spreadsheet are confirmed by an independent consultant as part of the Mill's
ALARA audit process. The DACs listed in Table 7 were derived using the calculation
spreadsheet and the following assumptions (EFRI 2013a, p. 16):
• Conventional ores are assumed to have uranium daughter isotopes in secular equilibrium.
Because most alternate feed materials have been processed in one form or another prior
to receipt at the Mill, they are not assumed to have uranium daughter isotopes in secular
equilibrium. As a result, DACs are calculated separately for each alternate feed material
for each applicable part of the Mill. In process steps where conditions and material
13
IIDC
properties are the same for every feed (such as yellowcake precipitation and packaging),
the conventional ore DACs are applied to every alternate feed material.
• The DACs for inhalation of each radionuclide were taken from Appendix B of 10 CFR
20 for the indicated solubility class;
• The assigned solubility classes for airborne alpha activity assume:
o conventional ores are insoluble,
o 50% of dust in the leach area is from the precipitation area and 50% is from ore
(due to proximity),
o uranium is in soluble form in the Countercurrent Decantation (CCD), Solvent
Extraction (SX), and Precipitation areas, and,
o yellowcake in the packaging area has mixed solubility based characteristics (from
Kalkwarf [1979]);
• The DAC for tailings is adjusted for the recovery efficiency, nominally assumed at 95%
(i.e., 95% of uranium is recovered and the remaining 5% of the uranium and virtually all
uranium daughters remain with tailings);
• Activity from the Uranium-235 chain is not significant and can be, and is typically,
ignored (see discussion below); and
• Concentrations of Thorium-232 and its decay products are negligible and can be ignored.
As indicated in the Table 7 above, the Mill has processed ores and/or alternate feeds with DACs
that are lower (more restrictive) than the Dawn Mining Uranium Material by as much as two
orders of magnitude, depending on the plant area to which the DAC applies. Consequently, the
existing radiation protection measures and standard operating procedures developed for worker
safety for the processing of natural ores and previous alternate feed materials are deemed
sufficient for the processing of the Uranium Material, and no additional personnel protective
measures or safety procedures are expected to be required.
Transportation of Uranium Material
DMC/EFRI proposes to transport the Uranium Material in covered end- or side-dump haul
trucks. The Uranium Material would be shipped as radioactive low-specific activity (LSA 1)
hazardous material. Midnite Mine's shipping company would track the shipment until it reaches
the Mill. DMC would ship approximately 25 trucks per year, or an average of one truck per week
for the six-month annual period. The amount of trucks used per year may vary depending on
Uranium Material production. An estimated range of trucks per year is 2 to 73. The highest
number of trucks would be expected in the two years of construction of the DMC Mine Site
Remedy.
Trucks transporting the Uranium Material to the Mill site would be surveyed and
decontaminated, as necessary, prior to leaving the Midnite Mine site as well as prior to leaving
the White Mesa Mill site.
Projected Additional Traffic Volumes
The primary transportation corridors in Utah are illustrated in Figure 1. The Uranium Material
would be hauled through Utah southward on Interstate 15, east on Interstate 70 and then south to
the Mill on Interstate 191. Section 4.2.2(b) of the April 2011 Amendment Request addresses
14
traffic impact considerations for this route. The analysis identifies that the original 1979 Final
Environmental Statement (FES) and 1978 Environmental Report contemplated the transportation
impacts associated with approximately 68 round trips on local highways by 30-ton ore trucks to
the Mill per day. In addition, the FES contemplated approximately 183-275 truck shipments of
yellowcake from the Mill per year, which equates to one truck every one to two days based on a
seven-day work week (one truck every day or so, based on a five-day work week).
Sections 4.2.2(b )(ii) and (iii) of the April 2011 Amendment Request assesses the current truck
traffic on Interstate Highways 15, 70, and 191, which are the principal Utah roadways on which
trucks carrying the Uranium Material would reach the Mill. These sections identify that, based
on 2009 data from the Utah Department of Transportation (UDOT), an average of ten additional
trucks per month traveling this route to the Mill from May to October represents an increased
traffic load of less than two one hundredths of one percent (0.02%).
Information obtained on July 14, 2010 from UDOT, indicated that on average during 2009, 2,350
multi-unit trucks traveled southward daily on Interstate 15 from Idaho into Utah. On average,
between 740 and 6,518 multi-unit trucks traveled southward daily on Interstate 15, across
Interstate 50 to Interstate 70. Based on the 2009 UDOT truck traffic information, an average of
10 additional trucks per month traveling this route to the Mill from May to October represents an
increased traffic load of less than one half of one percent. This level of truck transportation
volume is well below the level contemplated in the original FES and represents a minute fraction
of the existing truck volume on the transportation route. EFRI (2013) concludes that
transportation impacts associated with the movement of the Uranium Material by truck from the
Midnite Mine WTP facility to the Mill are not expected to be significant.
Information provided by the UDOT on July 14, 2010, stated that in 2009, on average, 1,628
multi-unit trucks traveled southward on State Road 191 from Moab across the Grand County line
each day. On average, between 285 and 610 multi-unit trucks per day traveled the stretch of State
Road 191 south of Monticello, UT toward Blanding, UT. Also, based on the 2009 UDOT truck
traffic information, an average of five additional trucks per month traveling this route to the Mill
from May to October represents an increased traffic load of less than one quarter of one percent.
Based on this information, the truck traffic to the Mill from this project is expected to be an
insignificant portion of the existing truck traffic in the area, and well within the level of truck
traffic expected from normal Mill operations.
In addition, the amount of yellowcake to be produced from processing the Uranium Material is
expected to be transported in approximately one truck load per year. This amount of yellowcake
transport would not result in exceedance of the total truck transport frequency associated with
yellowcake transport from the Mill at licensed capacity (between 183 and 275 truck shipments of
yellowcake from the Mill per year, as contemplated by the 1979 FES).
Radiological Transport Considerations
The transport of radioactive materials is subject to limits on radiation dose rate measured at the
transport vehicle as specified in the US CFR. The external radiation standards are specified in
10 CFR 71.47 sections (2) and (3) and are less than 200 millirems per hour (mrem/hr) at any
point on the outer surface of the vehicle, and less than 10 mrem/hr at any point two meters from
the outer lateral surfaces of the vehicle. To prevent migration of ore dust during transportation,
15
URS
all trucks transporting the Uranium Material to the Mill Site would be covered by tarpaulins or
similar cover. From a radiologic standpoint, the Uranium Material is within the bounds of other
ores and alternate feed materials transported for processing at the Mill. No significant
incremental radiological impacts are expected to occur with transportation of Uranium Material
to the Mill over and above those for other previously approved ores and alternate feed materials
at the Mill or from licensed activities at other facilities in the State of Utah. EFRI will be
required to comply with applicable requirements of 49 CFR Part 172 and Part 173, and the
selected transport company will be required to have all the mandatory training and emergency
response programs and certifications in place.
Storage of Uranium Material at Mill Site
EFRI proposes to store the Uranium Material at the Mill Site in the same manner to that used for
storing conventional uranium ore at the site. The Uranium Material would be stored on ore pad
for temporary storage pending processing. Tarped haul trucks holding the transported Uranium
Material would enter the site, roll back the tarp covering and dump their loads onto the ore pad
as with conventional ore deliveries. Because the Uranium Material would be temporarily stored
on the ore pad awaiting processing and because the Uranium Material does not significantly
differ in radiological activity from other ores and alternate feed materials handled at the Mill,
EFRI indicates that it expects that gamma radiation and radon emanation from the Uranium
Material will be within the levels associated with other ores and alternate feed materials routinely
handled at the Mill on a regular basis. The TCLP data provide evidence indicating that the metals
present in the Uranium Material do not readily leach and the Uranium Material is not likely to
exhibit hazardous waste characteristics if the material were to be exposed to more severe
conditions than may be anticipated to occur on the ore storage pad.
EFRI has proposed to control potential air transport of Uranium Material particulates from
storage and handling by using standard approved dust control and worker protective equipment
practices (EFRI 2013a, p. 6, and April 2011 Amendment Request Section 4.10.2(d), p. 17,
Section 5.0, p. 17). EFRI supported this approach by indicating that the Uranium Material will
have a moisture content of approximately 25 to 45 percent (Attachment 2 of the April 2011
Amendment Request), which is 6 to 11 times greater than the minimum moisture content
currently contemplated for ores and feeds stored on the ore pad by the Mill's State of Utah Air
Approval Order ("AO") for minimization of the potential dust generation.
EFRI furnished an Affidavit signed by the Site Manager for Dawn Mining Company (see
Attachment 2 to the April 2011 Amendment Request) providing testimony, based on more than
10 years of first-hand experience, that the Uranium Material "is not prone to degrading to fine
dust sized particles". The Affidavit is based on operational experience gained during operation of
the WTP at the Midnite Mine Site over a period of more than 10 years.
Weather conditions at the Mill Site are dryer than at the Midnite Mine Site, and possibly higher
winds speeds coupled with lower humidity levels may lead to differences in behavior of the
Uranium Material with regard to its susceptibility to degrade to a finer dust sized particle than
would be expected from ores or other alternate feeds. For this reason, and to help reduce the
likelihood of potential future release(s) of fine dust sized particles from Uranium Material in
storage at the Mill site, the UDRC will add language to the new license condition to RML No.
16
UTl 900479 requiring that: (1) Uranium Material stored (stockpiled) at the Mill Site be covered
with a geomembrane cover and sufficient ballast be placed over the cover to prevent wind uplift
of the cover during peak wind conditions at the site; and (2) If at any time, visible dust is
observed to be originating from Uranium Material stored on site, that the EFRI RSO or his or her
authorized representative take actions within 30 minutes to stop the generation of visible dust.
4.1.2 Non-Radiological Impacts
Based on information provided in the April 27, 2011 submittal (RMPR), the known and possible
chemical components in and hazardous waste characteristics of the Uranium Material are
summarized in Table 8 below:
Table 8.Chemical Characteristics of the Uranium Material
(Y) (N) (Y) (N) (Y) (N)
Listed HW Derived-
From HW
Toxic
Cyanides Sulfides Dioxins
Pesticides Herbicides PCBs X*
Explosives Pyrophorics Solvents X*
m. Organics Phenolics Infectious X*
P Ignitable Corrosive Reactive
Antimony Beryllium Copper
v. Nickel Thallium Vanadium
Alcohols Arsenic aa. Barium
bb. Cadmium cc. Chromium dd. Lead
ee. Mercury Selenium 99 Silver
hh. Benzene Nitrate Nitrite
kk. Fluoride Oil mm. Fuel
nn. Chelating
Agents oo. Residue from Water Treatment
pp. Other Known or Possible Materials or Chemicals
The WTP solids were not tested for this component but process knowledge indicates that these
components would not be present in the WTP solids.
For a detailed list of all the non-radiological chemical constituents (and their concentrations)
found in the Uranium Materials, refer to Attachment 2 of the April 27, 2011 Amendment
Request. Key results of prior testing samples of the Uranium Material for non-radiological
constituents further described below.
17
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4.2 RCRA Listed Materials Analysis
As stated in Section 1.3, the Uranium Material is considered to be the result of natural ore
processing. Based on the testing results, no listed RCRA materials are present in the Uranium
Material and the Uranium Material is also exempt under 40 CFR 261.4(b)(7).
4.3 RCRA Characteristic Materials Analysis
The following metals and inorganic constituents (Table 9) were confirmed present in the
Uranium Material (Attachment 2 and Attachment 4 of the April 27, 2011 Amendment Request).
Table 9. Metals and Inorganic Constituents Confirmed Present in Uranium
Material
Class
Alkali Metals
Alkaline Earths
Transition Metals,
Lanthanides, and
Actinides
Other Metals
Metalloids
Non-Metals
Halogens
Volatile Organic
Compounds
Semi-Volatile Organic
Compounds
Component of DRC Uranium Material*
N/A
Barium, beryllium, calcium, magnesium, radium
cadmium, chromium, copper, cobalt, iron, manganese, nickel,
silver, thorium1, zinc.
lead
N/A
selenium
N/A
N/A
N/A
*Bold Type = elements or compounds in the Dawn Uranium Material, that are not currently included in the
Mill's current GWDP
N/A = Not applicable or not analyzed
' Thorium is indirectly monitored under the current GWDP through monitoring for gross alpha
Metals, Calcium and Selenium
A summary of the RCRA evaluation findings for the metal analytes and selenium identified in
the Uranium Material is provided below in Table 10 and Table 11 of this report.
The April 27, 2011 Amendment Request (Section 4.5) indicates the following:
"'Every metal and non-metal cation and anion component in the Uranium Material already exists
in the Mill tailings system and/or is analyzed under the Mill's groundwater monitoring program.
18
URS
Every component in the Uranium Material has been:
1. Detected in analyses of the tailings cells liquids;
2. Detected in analyses of tailings cells solids;
3. Detected in analyses of alternate feed materials licensed for processing at the Mill; or
4. Detected in process streams or intermediate products when previous alternate feeds were
processed at the Mill; or at concentrations that are generally comparable to the
concentrations in the Uranium Material; at concentrations that are generally comparable
to the concentration in the Uranium Material. Due to the small annual quantities of the
Uranium Material, an increase in the concentration of any analyte in the Mill's tailings is
not expected to be significant.
The constituents in the Uranium Material are expected to produce no incremental additional
environmental, health, or safety impacts in the Mill's tailings system beyond those produced by
the Mill's processing of natural ores or previously approved alternate feeds."
The DMC Uranium Material metals analytical results are presented below in Table 10.
Additionally, three Uranium Materials samples were collected during the 2010 WTP operations
period. A summary of the RCRA listed hazardous waste test results for metals analyses is
provided in Table 11. The results indicate that 13 metals; barium, beryllium, cadmium, calcium,
chromium, cobalt, copper, iron, lead, manganese, nickel, silver, and zinc were detected in the
Uranium Material. Selenium was detected in the Uranium Material at an average of 26 mg/kg
(Table 10). Additional discussion of concentrations of metals and selenium detected in the
Uranium Material is presented following Table 10 and Table 11 below.
All of the metals are known to be constituents of natural uranium ores and present at a range of
concentrations with the exception of barium, which is added to the pumped groundwater and
surface water at the Midnite Mine site as part of the WTP process to facilitate radon removal.
Residues from creation of the Uranium Material from the WTP process are not RCRA listed
hazardous wastes.
Table 10. Uranium Materials Metals Analysis and Selenium for RCRA Toxicity
Characteristics (2010 TCLP Testing)
Sample
ID
Sample Date Arsenic
(mg/L)
Barium
(mg/L)
Cadmium
(mg/L)
Chromium
(mg/L)
Lead
(mg/L)
Mercury
(mg/L)
Selenium
(mg/L)
Silver
(mg/L)
2002 <0.05 <10 =0.1 <0.5 <0.5 <0.02 <0.1 <05
2003 <0 5 <10 0.2 <0.5 <0.5 <0.02 <0.1 <0.5
2004 <0.5 <10 =0.1 <0.5 <0.5 <0.02 <0.1 <0.5
2005 =0.5 <10 <0.1 <0.5 <0.5 =0.02 =0.1 <0.5
2006 <0,5 0.25 <0.5 <0.5 <0.02 =0.1 <0.5
2007 <05 <10 <0.1 <0.5 =0.5 <0.02 =0.1 <0.5
2008 <0.5 <10 =0.1 =0.5 <0.5 <0.02 <0.1 <0.5
5/20/2009 <0.5 <10 <0.1 <0.5 <0.5 <0.02 <0.1 <05
9/17/2009 <0.06 0.083 <0.005 <0.01 <0.04 <0.0002 <0.06 <0.01
9/19/2009 <0.04 0.16 0.019 O.01 <0.04 <0.0002 <0.04 <0.01
9/23/2009 <0.04 0.12 0.011 <0.01 <0.04 <0.0002 =0.04 <0.01
19
URS
Table 10. Uranium Materials Metals Analysis and Selenium for RCRA Toxicity
Characteristics (2010 TCLP Testing)
Sample
ID
Sample Date Arsenic
(mg/L)
Barium
(mg/L)
Cadmium
(mg/L)
Chromium
(mg/L)
Lead
(mg/L)
Mercury
(mg/L)
Selenium
(mg/L)
10/6/2009 <0.1 0.066 0.03 0.03 <0.08 <0.0002 0.2
WTPS-1 4/13/2010 <0.1 <0 05 <0.1 <0.03 <0.002 0.051
WTPS-2 4/13/2010 <0.1 <0 05 <0.1 <0.03 <0.002 0.054
WTPS-3 4/13/2010 <0.1 <0.05 <0.1 <003 <0.002 0054
Count 15 15 15 15 15 15
Min <0.04 0.066 <0.01 <0.03 <0.002 <0.04
Max <0.1 <10 <0.05 <0.5 <0.5 <0.02 0.2
40 CFR Part 261.24 100 0.2
Pass? Yes Yes Yes Yes Yes Yes Yes
WTPS-Waste Treatment Plant Samples
Table 11. Uranium Material Analyses for RCRA Listed Hazardous Waste
(Metals, Calcium and Selenium [2010])
Target Analyte (D Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
Total ICP Metals SW6010B
Arsenic mg/kg <5.9 <5.9 <5.7 <5.8
Barium mg/kg 8,100 7,900 7,200 7,733
Beryllium mg/kg 33 36 36 35
Cadmium mg/kg 40 44 43 42
Calcium mg/kg 15,000 16,000 16,000 15,667
Chromium mg/kg 19 20 19 19
Cobalt mg/kg 1,200 1,200 1,100 1,167
Copper mg/kg 160 180 170 170
Iron mg/kg 690 740 740 723
Lead mg/kg 18 19 17 18
Manganese mg/kg 110,000 110,000 96,000 105,333
Molybdenum
Nickel
Selenium
Silver
Thallium
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
<5.8
1,700
25
11
<580
<6.0
1,800
26
12
<600
<5.7
1,800
26
11
<570
<5.8
1,767
26
11
<583
20
mm mmmrn^ jmm
URS
Table 11. Uranium Material Analyses for RCRA Listed Hazardous Waste
(Metals, Calcium and Selenium [2010])
Target Analyte ID Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
Tin mg/kg <29 <30 <29 <29
Vanadium mg/kg <5.8 <6.0 <5.7 <5.8
Zinc mg/kg 3,400 3,600 3,600 3,533
Total Mercury SW7471A
Total Mercury mg/kg <0.19 <0.2 <0.19 <0.19
(D All values as reported by ALS Laboratory as dry weight values.
Concentrations of some inorganic constituents (e.g., nickel at concentrations between 1,700 and
1,800 mg/kg; cobalt [1,110 to 1,200 mg/kg]; manganese [96,000 to 110,000 mg/kg]; zinc [3,400
to 3,600 mg/kg]; and beryllium [33 to 36 mg/kg]) detected in the WTP solids samples (Table 10)
appear to be elevated with respect to typical uranium ores in the Colorado Plateau (e.g., Miesch
1963, Table 2). Calcium concentrations detected in the Uranium Material are also elevated
compared to the natural ground and native substrate at the Midnite Mine Site as a result of
calcium being added to the pumped groundwater and surface water as part of the WTP process
(Section 8.0 of Attachment 5 of the April 27, 2011 Amendment Request). However, the range of
calcium concentrations (15,000 to 16,000 mg/kg) detected in the WTP solid samples are within
the range of calcium concentrations (9,500 to 20,000 mg/kg) reported for typical uranium ores in
the Colorado Plateau (Miesch 1963, Table 2) and lower than the calcium concentration value
(63,100 mg/kg) reported for typical acid-leached uranium mill tailings in the Utah area
(Abdelouas 2006, Table 2). The State of Utah has no Ground Water Quality Standard (GWQS)
for calcium.
The 2005 RI conducted at the Midnite Mine site indicated that the range of nickel concentrations
in groundwater present in Pits 3 and 4, and in surface water in the Pollution Control Pond at the
Midnite Mine (up to 2,700 ug/L in Pit 3 and up to 2,760 ug/L in the Pollution Control Pond
[from which some water was pumped to Pit 3] from Tables 5-15 thru 5-17 of the 2005 RI)
exceeds the Utah GWQS (100 Lig/L) and exceeds the range of nickel concentrations detected in
wells at White Mesa. However, the range of nickel concentrations in Pits 3 and 4, and in the
Pollution Control Pond are lower than the nickel concentrations detected in the tailings waste
water samples collected by International Uranium Corporation (IUC) and the NRC between 1980
and March 2003 (7,200 - 370,000 ug/L [82,600 ug/L avg.]) as summarized in the 2004 UDRC
Statement of Basis (UDRC 2004).
Similar results to those found and described above for nickel also apply for cobalt, manganese,
zinc, and beryllium, with most reported concentrations of zinc in the water in the pits and the
surface water pond at the Midnite Mine Site being lower the Utah GWQS for zinc, and the
average concentration of manganese in the waters in the pits and the surface water pond at the
Midnite Mine Site being similar to the average concentration of manganese detected in tailings
21
URS
waste water samples sampled by the IUC and NRC (UDRC 2004). Because concentrations of
nickel, cobalt, manganese, zinc, and beryllium in water in the pits and surface water control pond
at the Midnite Mine Site are less than (or comparable to, in the case of manganese) the
concentrations of these same constituents detected in the tailings waste water samples, the
presence and expected concentrations of these constituents in the Uranium Material is not likely
to produce any incremental additional environmental, health, or safety impacts in the Mill's
tailings system beyond those produced by the Mill's processing of natural uranium ores.
According to the April 27, 2011 Amendment Request, if selenium oxides were to be introduced
in sufficient quantities to the acid leach circuit the potential exists for unwanted excess chemical
reactivity; however, this situation would not occur from processing the Uranium Material at the
Mill for the following reasons:
• Selenium and its oxides are incompatible with strong acids, organic materials, and
ammonia according to manufacturer's Material Safety Data Sheets (MSDS) and National
Institute for Occupational Safety and Health (NIOSH) safety hazard information, and
high concentrations of selenium oxides or selenium oxides in pure form pose a fire and
explosion risk in contact with organic materials and ammonia. Selenium was detected in
the Uranium Material at concentrations between 25 and 26 mg/kg (Table 8). These levels
are comparable to or lower than selenium concentrations reported for typical uranium
ores in the Colorado Plateau (Miesch 1963, Table 3). Although the Uranium Material
contains trace amounts of ammonia, the concentrations (7.9 to 8.3 mg/kg) are not
sufficiently high to create instability within the Uranium Material as delivered to the
Mill; and
• During the Mill process, selenium oxides will not be in contact with organic materials or
ammonia at any time. Insoluble salts of selenium will be precipitated with solids removed
from the post-leach thickeners in the alternate feed circuit and will be discharged to the
tailings and will proceed no further with the uranium through subsequent processing
steps.
Volatile Organic Constituents
The Volatile Organic Constituents (VOCs) sampling results reported in the April 27,-2011
Amendment Request (Table 4 of Attachment 4), and listed below in Table 12, indicate that
acetone, chloroform, methylene chloride, and toluene were reported at very low concentrations
in the three WTP samples for total analyses. Acetone was reported at concentrations ranging
from 22 ug/kg to 33 ug/kg with an average value of 28 ug/kg. Methylene chloride was reported
at concentrations ranging from 3.7 ug/kg to 5.8 ug/kg with an average value of 4.4 ug/kg.
Toluene was reported at concentrations ranging from 1.3 to 2.2 ug/kg with an average value of
1.8 ug/kg. Trichloroethylene (TCE) was also detected and reported at very low concentrations
(1.5 and 2.7 ug/L) in extract samples from the TCLP testing of two samples of the WTP material
(Section 4.1 of Attachment 5 of the Amendment Request).
22
Table 12. Uranium Material Analyses for RCRA Listed Hazardous Waste
(Volatile Organics [2010])
Target Analyte* Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
GC/MS Total
Volatile
Organics
SW8260
Chloromethane <1.1 <1.2 <1.1 <1.1
Acetone Mg/kg 22 B 29 B 33 B 28
Methylene
Chloride
Mg/kg 3.8 J, B 3.7 J, B 5.8 J, B 4.4
2-Butanone Mg/kg <5.7 <5.9 <5.7 <5.8
Tetrahydrofuran Mg/kg <7.2 <7.4 <7.2 <7.3
Chloroform Mg/kg 1.7 J 2 J 1.2 J 1.6
Carbon
Tetrachloride
Mg/kg <1.3 <1.4 <1.3 <1.3
Benzene Mg/kg <0.94 <0.96 <0.93 <0.94
Toluene Mg/kg 2.2 J, B 1.9 J, B 1.3 J, B 1.8
m,p-Xylene Mg/kg <1.9 <1.9 <1.9 <1.9
o-Xylene Mg/kg <0.95 <0.97 <0.94 <0.95
Naphthalene Mg/kg <1.4 <1.4 <1.4 <1.4
All values as reported by ALS Laboratory as dry weight-basis values.
B=This flag is used when the analyte is detected in the associated method blank as well as in the
sample. It indicates probable blank contamination and warns the data user. This flag shall be
used for a tentatively identified compound as well as for a positively identified target compound.
J= This flag indicates an estimated value. This flag is used as follows: (1) when estimating a
concentration for tentatively identified compounds where a 1:1 response is assumed; (2) when
the mass spectral and retention time data indicate the presence of a compound that meets the
volatile and semi-volatile GC/MS identification criteria, and the result is less than the reporting
limit but greater than the method detection limit (MDL); and (4) the reported value is estimated.
Of the five VOC constituents reported detected in the Uranium Material, four were detected in
the solids samples and one in the TCLP leachate sample. Additionally, all five VOCs were
detected in the associated laboratory quality control blanks for the coinciding sample runs.
Review of the site operational history, WTP processes, and chemical history for the Midnite
Mine WTP site, did not identify any potential source of these constituents. There are no VOCs
used in the mining processes or WTP processes and these chemicals have never been used on the
Midnite Mine WTP site or stored at the Midnite Mine WTP site. Chloroform was reported
23
detected in the three samples just above the Method Detection Limit (MDL). The method blank
samples did indicate low levels of total chloroform; however, the detection of chloroform in the
blank was below the MDL and was therefore not reported by the laboratory. Information
provided in the laboratory reports indicated that acetone, chloroform, methylene chloride, and
toluene were therefore attributable to laboratory interferences and are not present in the Uranium
Material.
The sample results and laboratory quality control samples for the VOC analyses were reviewed
in detail to determine the source of the detections in the Uranium Material. Review of the
analytical data indicated that the five VOCs were detected in the laboratory quality control
blanks, as presented in Table 13 and discussed below. The table below summarizes the VOC
detections in the laboratory quality control blanks.
Table 13. VOC Detections in Laboratory QC Blanks
Acetone
ug/kg dry
Chloroform
pg/kg dry
Methylene
Chloride
ug/kg dry
Toluene
ug/kg dry
Trichloroethene
M9/L
Matrix Solid Solid Solid Solid TCLP Leachate
Reporting
Limit
Laboratory
Blank
5.07 0.2* 1.95 1.57 3.3 J
* This detection is slightly below the method detection limit but was noted by the laboratory in correspondence
which was submitted in the April 2011 Amendment Request.
The frequency of the reported detections of TCE and the fact that these detections are less than
10 times the amount found in the method blank raised the concentration to the Reporting Limit
(5 Mg/L).
Because there is no source for these VOCs at the Midnite Mine WTP site and because results
associated with method blank contamination are considered questionable, EFRI reasserts that
these data are false positives caused by laboratory artifacts (EFRI 2013a). These results and the
results for the other VOCs discussed above, indicate that these VOCS are not present in the
Uranium Material.
Semi- Volatile Organic Constituents
Analytical results from the 2010 WTP samples for semi-volatile organic constituents (SVOCs) as
presented in Attachment 2 and Table 4 of Attachment 4 of the April 27, 2011 Amendment
Request, and summarized in Table 14 below, indicate that there were no detectable
concentrations of any of the SVOCs tested for. These results are consistent with plant operations
and activities historically conducted at the mine site.
24
URS
Table 14. Uranium Material Analyses for RCRA Listed Hazardous Waste
(Semi-Volatiles [2010])
Target Analyte (1) Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
GC/MS Total Semi-
Volatile Organics
SW8270D
Pyridine MQ/kg <310 <320 <320 <317
1,4-dichlorobenzene Mg/kg <310 <320 <320 <317
2-methylphenol Mg/kg <310 <320 <320 <317
3 + 4-methylphenol Mg/kg <310 <320 <320 <317
Hexachloroethane Mg/kg <310 <320 <320 <317
Nitrobenzene Mg/kg <310 <320 <320 <317
2,4,6-trichlorophenol Mg/kg <310 <320 <320 <317
2,4,5-trichlorophenol Mg/kg <310 <320 <320 <317
2,4-dinitrotoluene Mg/kg <310 <320 <320 <317
Hexachlorobenzene Mg/kg <310 <320 <320 <317
Pentachlorophenol Mg/kg <490 <500 <500 <497
(i) All values as reported by ALS Laboratory on a dry weight-basis.
Other Organics
There were no detectable levels of other organic compounds tested in three WTP samples tested
in 2010 as presented in Attachment 2 and Attachment 4 of the April 27, 2011 Amendment
Request and as summarized in Table 15 below.
Table 15. Uranium Material Analyses for RCRA Listed Hazardous Waste
(Other Organics [2010])
Target Analyte (D Method Units
Laboratory Results
WTPS-1 WTPS-2 WTPS-3
Calculated
Average
Gasoline Range Organics SW8015B
Gasoline Range Organics mg/kg <0.38 <0.35 <0.39 <0.37
Diesel Range Organics SW8015MB
Diesel Range Organics mg/kg <6.5 <6.6 <6.8 <6.6
Oil & Grease
Oil & Grease mg/kg <120 <120 <120 <120
(i) All values as reported by ALS Laboratory as dry weight values.
25
URS
Alkaline Earth Metals
Barium concentrations in the Uranium Material are elevated compared to barium levels in typical
uranium mill tailings in the Utah area (Abdelouas 2006, Table 2) and reported for typical
uranium ores in the Colorado Plateau (Miesch 1963, Table 2). As described in Section 1.3 above,
barium is added to the pumped groundwater and surface during the WTP process.
Data reported in Miesch (1963; Tables 2 and 3) and Abdelouas (2006), based on data from
Morrison and Chan (1991), allow the following comparisons (see Table 16) between barium and
beryllium concentrations in the Uranium Material to barium and beryllium concentrations
detected in: (1) uranium ore from a uranium mine deposit and mill pulp samples from over 200
mine sites on the Colorado Plateau; and (2) uranium mill tailings from different locations in Utah
(for acid-leached uranium ores):
Table 16. Concentrations of Selected Inorganics in Uranium Material Compared to
Typical Colorado Plateau Uranium Mill Tailings and Uranium Ores
Analyte
Average Concentration
in Colorado Plateau
Uranium Ores and Mill
Pulp Samples1
Average
Concentration in
Utah Area Uranium
Mill Tailings2
Analytical Results
of Uranium
Material
(average value,
dry weight basis)
Ba 550 - 750 pg/g 1,010 ug/g 7,733 ug/g
Be ~ 0.3 0- 0.4 pg/g Not Reported 35 pg/g
1 Miesch 1963
2 Abdelouas 2006
The information in Table 16 indicates that concentrations of barium and beryllium in the
Uranium Material appear to be elevated relative to Colorado Plateau-derived ores that may have
been processed at the White Mesa Mill and/or compared to their concentrations in typical
uranium mill tailings in the Utah area.
Barium may be associated with one RCRA listing, P013, if it resulted from the disposal of
barium cyanide commercial chemical products, off-spec commercial chemical products, or
manufacturing chemical intermediates. As described above, residual barium is present as a
byproduct of the Uranium Material solution treatment (as result of the addition of barium
chloride to the Pit 3 influent line in the WTP). Based on information provided by DUSA/EFRI,
there is no reason to suspect that barium would have been present in any of the forms mentioned
in the RCRA listing P013. Therefore the P013 RCRA listing does not apply to the Uranium
Material.
Beryllium may be associated with one RCRA listing, P015, if it resulted from the disposal of
commercial chemical beryllium powdered products, off-spec commercial chemical products, or
manufacturing chemical intermediates. Information provided by DUSA/EFRI indicates that there
is no reason beryllium would be present as a chemical product, off-spec product or
manufacturing byproduct on the DMC site.
26
URS
Non-Metals
Chlorides, fluorides, and sulfates have been introduced into the Mill's uranium circuit in
association with natural ores and alternate feeds previously processed at the mill at
concentrations higher than those that are present in the Uranium Material. Chlorides have
previously been handled at the Mill in concentrations as high as 89,900 mg/kg (see Table 17
below). The average chloride concentration in the Uranium Material is 40 mg/kg. Fluorides have
been introduced into the Mill's circuit at levels as high as 460,000 mg/kg (Table 17). The
average fluoride concentration in the Uranium Material is 39 mg/kg. Sulfates have also
previously been introduced into the Mill's circuit during processing of natural ores and alternate
feeds at levels up to 300,000 mg/kg (Table 17). The reaction of sulfuric acid with other metal
cations has also generated sulfates in the acid leach system. The mill has previously managed
chlorides, fluorides, and sulfates in the Mill circuit and tailings system with no adverse process,
environmental, or safety issues.
Table 17 below summarizes levels of five specific constituents which have been introduced into
the Mill's uranium circuit during processing of previous alternate feed materials through the
Mill.
Table 17. Selected Inorganic Constituents Present in Previous Alternate Feed
Materials Processed at Mill
Chemical
Value in
Amendment
Request Tab 5,
Section 4.3 or
8.1
Supporting or Additional
Information Source
Nitrates 350,000 mg/kg 35% (350,000 mg/kg) in Cameco
Regen Product alternate feed
Section II of Regen
Product MSDS, in
Appendix L of
EFRI 2013a
Chloride 89,900 mg/kg Maximum sample from Molycorp
ponds alternate feed, 89,900 mg/kg
TTLC table (in
Appendix M of this
letter) from
December 2000
Molycorp
Amendment
Request
Fluoride 460,000 mg/kg Honeywell/Converdyne/Allied
Signal alternate feed, up to 2% U,
98% calcium fluoride and fluoride
impurities (48% or 480,000 mg/kg
F based on all being as CaF2)
MSDS for CaF2
product, in
Appendix N of
EFRI 2013a
Sulfate in Mill
(Section 4.3)
300,000 mg/kg A 4.8 million pound (1.4 million
gallon) inventory of 93% (930,000
mg/kg) sulfuric acid is introduced
into the CCD and pre-leach steps
during conventional ore
Mill process
description. 1991
RML renewal
application and
2007 RML renewal
27
URS
Table 17. Selected Inorganic Constituents Present in Previous Alternate Feed
Materials Processed at Mill
Chemical
Value in
Amendment
Request Tab 5,
Section 4.3 or
8.1
Supporting or Additional
Information Source
processing, (these concentrations
far exceed those identified in Tab
5, Sections 4.3 and 8.1 of the April
2011 Amendment Request.)
application
Sulfate in
Tailings
(Section 8.1)
No value listed in
Tab 5, Section
4.3 or Section
8.1
64,900 to 267,000 mg/L in Cell 4A
solutions.
119,000 to 134,000 mg/L in Cell 4B
solutions.
2012 Annual
Tailings Cells
Wastewater
Sampling Report,
in Appendix O of
EFRI 2013a
Ammonia No value listed in
Tab 5, Section
4.3 or Section
8.1
A 108,000 pound (31,000 gallon)
inventory of 100% anhydrous
ammonia is used to prepare
concentrated ammonia solutions
introduced into the yellowcake
precipitation area during
conventional ore processing.
Ammonia in this form is added far
downstream of feed area and is
never in contact with ores or feeds.
(These concentrations afar exceed
those identified in Tab 5, Sections
4.3 and 8.1 of the April 2011
Amendment Request.)
Mill process
description, 1991
RML renewal
application and
2007 RML renewal
application
2011 Analytical Results for Extractable Metals (TLCP Testing)
DMC arranged for TCLP analytical testing of four samples of filter press cake produced from the
dewatering filter press pilot testing (pilot testing conducted between September 16 through 23,
2011) for seven metals and selenium. Reported concentrations for the TCLP testing for the eight
tested TCLP extractable analytes are summarized in Table 18 below.
Table 18. Extractable Metals (TCLP Testing) and Extractable Selenium in DM
Uranium Material - Filter Press Cake Samples (2011)
Analyte
Arsenic
Barium
Units
mg/L
mg/L
mg/L
Test #2
<0.5
<10
Test #3
<0.5
<10
Test #5
<0.5
<10
Test #6
<0.5
<10
28
URS
Table 18. Extractable Metals (TCLP Testing) and Extractable Selenium in DM
Uranium Material - Filter Press Cake Samples (2011)
Analyte Units
mg/L Test #2 Test #3 Test #5 Test #6
Cadmium mg/L <0.1 <0.1 <0.1 <0.1
Chromium
Lead
Mercury
Selenium
Silver
mg/L
mg/L
mg/L
mg/L
mg/L
<0.5
<0.5
<0.02
<0.1
<0.5
<0.5
<0.5
<0.02
<0.1
<0.5
<0.5
<0.5
<0.02
<0.1
<0.5
<0.5
<0.5
<0.02
<0.1
<0.5
Environmental/Exposure Considerations for Non-Radiological Constituents
Barium
As discussed above in this section, barium concentrations detected in the Uranium Material
(7,200 to 8,100 ug/g) are elevated somewhat compared to barium levels in typical Colorado
Plateau uranium ores in the Utah area and other ores processed at the Mill.
The RCRA characteristic hazardous waste concentrations are based on the TCLP, and the
concentration thresholds in 40 CFR 261 Characteristic D List are TCLP values. The TCLP limit
for barium is 100 mg/L. As described in the Technical Memorandum in Attachment 5 of the
April 2011 Amendment Request, based on analytical testing, the Uranium Material does not
exhibit the TCLP characteristic for barium as defined in Table 1 of 40 CFR Part 261.24(b)
(Table 3). No TCLP limit has been established for beryllium.
The potential for migration of barium-enriched pore-liquids from the tailings cells (derived from
residuals from processing of the Uranium Material) to groundwater is addressed in Section 4.3
below.
Barium Toxicity Information
If an individual were to be exposed to excessive levels of barium, health effects might include,
but not be limited to, the following (e.g., IPCS INCHEM 1990; ATSDR 2007a):
• In humans, ingestion (accidental or intentional) of barium compounds may cause
gastroenteritis (vomiting, diarrhea, abdominal pain), hypertension, cardiac arrhythmias,
skeletal muscle paralysis, and other conditions;
• Evidence indicates that the kidney is a sensitive target of barium toxicity; and
• Inhalation of barium carbonate powder has been found to be associated with paralysis in
a male worker.
29
URS
Table 19 below contains information extracted from the U.S. EPA Pacific Southwest Region 9
Risk Screening Level (RSL) Tables as updated in November 2012. (No comparable regulatory
levels were identified for Region 8.) The Soil Screening Levels (SSLs) presented are based on an
assumption of a post-remediation industrial use scenario, carcinogenic target risk levels of 1 in
one million (1 x 10"6) and a non-cancer hazard index of 1. The assumption of industrial use is
extremely over-conservative for the Mill site which, in post-reclamation condition, will be
transferred to the U.S. Department of Energy for oversight in perpetuity.
No carcinogenic target risk levels have been proposed for barium. As shown in the Table 19,
barium is present in the Uranium Material at levels more than 20 times lower than the lowest
SSL, that is, the SSL based on a non-carcinogenic hazard index of 1.
Table 19. EPA Soil Screening Levels
Uranium
Material
(mg/kg)
Ingestion
SL
TR=1.0E-6
(mg/kg)
Dermal
SLTR=
1.0E-6
(mg/kg)
Inhalation
SL TR=1.0E-
6 (mg/kg)
Carcinogenic
SL
TR=1.0E-6
(mg/kg)
Ingestion
SL HG=1
(mg/kg)
Dermal SL
HG=1
(mg/kg)
Inhalation
SL HG=1
(mg/kg)
Non-
carcinogenic
SL
Hl=1 (mg/kg)
Ba 8,100
(8 1E+3)
No limit
proposed
No limit
proposed
No limit
proposed
No limit
proposed
2.0E+05 No limit
proposed
3.0E+06 1.9E+05
Be1 36
(3.6E+1)
No limit
proposed
No limit
proposed
6.9E+03 6.9E+03 2.0E+03 No limit
proposed
1.2E+05 2.0E+03
Be - Beryllium & Be Compounds
Beryllium
The relatively low concentrations of beryllium in the Uranium Material do not pose a significant
health and safety hazard. The average measured beryllium concentration in the Uranium Material
is between 33 and 36 parts per million (ppm) as identified in Attachment 5, Table 6, Column B
of the April 2011 Amendment Request. The baseline beryllium concentration in the existing
tailings is 0.5 ppm as identified in Attachment 5, Table 6, Columns F and I of the April 2011
Amendment Request. The maximum estimated beryllium concentration in mill tailings in Cell
4A during the ten-year period evaluated would be 0.6 ppm as identified in Attachment 5,
Table 6, Column I0L of the April 2011 Amendment Request. The incremental concentration
attributable to the Uranium Material processing would be 0.1 ppm. The average expected
beryllium concentration in the Uranium Material is approximately 190 times lower than the SSL
(Table 19 above) associated with the acceptable chronic/cancer risk and approximately 55 times
lower than the lowest SSL associated with an acceptable non-carcinogenic risk. Health impacts
from beryllium exposure and additional analysis of the potential for impacts from processing of
the Urani um Material at the Mill are discussed below.
Beryllium Toxicity Information
Beryllium is a toxic metal and a known carcinogen. The principal exposure pathways for
beryllium from Uranium Material are inhalation, ingestion and dermal contact. Inhalation can
cause irritation to the nose, throat, lungs, and mucous membranes. In some individuals, possibly
due to genetic factors, beryllium may cause chronic beryllium disease, a hypersensitivity or
allergic conditions causing inflammation and fibrosis resulting in a restriction of the exchange of
oxygen between the lungs and the bloodstream (Materion 2011). Beryllium can also be taken
30
into the body by ingestion of water and food or through the skin. Although skin absorption does
not appear to be a major pathway, skin contact can cause an allergic dermal response in sensitive
individuals and skin contact with beryllium dusts can result in sensitization (NIOSH 2008). The
solubility of the beryllium compound affects the toxicity. The more soluble beryllium salts can
cause irritant and allergic contact dermatitis. Delayed hypersensitivity dermal granulomas may
be caused by the less soluble forms of beryllium in contaminated wounds (Wambach 2008).
Potential Exposures to Beryllium from Uranium Material Processing
The only potential complete exposure pathway at the Mill for members of the public is inhalation
of airborne particulate matter from the tailings. Engineered and administrative controls limit
public access at the Mill. An analysis by EFRI (2013a; 2013b) evaluated public health limits
from radioparticulates potentially derived from wind transport of tailings particulates and
assumed those levels of particulate transport with the beryllium concentrations in the Uranium
Material and subsequent tailings. The approach taken was to estimate the mass concentration of
particulates in air to which the public could hypothetically be exposed but still remain within the
effluent limits set by 10 CFR 20, Appendix B, Table 2 (the effluent limit for Th-230 was used for
estimating the maximum allowable particulate tailings mass concentration in air at the site
boundary because this parameter represents the lowest [and therefore most critical] value for the
radiological constituents of the tailings). These estimated public exposure levels of airborne
beryllium were then compared to the EPA reference concentration (RfC) to assess the potential
for adverse public health impact from the beryllium in windblown tailings or Uranium Material.
The RfC, i.e., the concentration that is "likely to be without an appreciable risk of deleterious
effects during a lifetime", for beryllium is 0.02 ug/m3 (EPA 2013). Assuming a Thorium-230
concentration in the tailings of 980 pCi/g and a 10 CFR 20 effluent limit of 2 x 10"14 uCi/ml
(10 CFR Part 20, Appendix B, Table 2, Column 1), and an estimated (average) beryllium
concentration in the ore/alternate feed materials and/or tailings of 0.1 mg/kg (1 x 102 ug/kg), the
maximum allowable mass concentration of Th-230 in air to reach the 10 CFR 20 Appendix B
effluent limit would be 20 ug/m3 ([2 x 10"'4 uCi/ml x 1 x 106ml/ m3x 1 x 106ug/g]/ [980 pCi/g x
1 x 10"6 uCi/Ci] - 20 ug/m3). At the hypothetical maximum airborne particulate concentration of
20 ug/m3, the beryllium mass concentration in the airborne particulates, given the beryllium
concentrations in the ores, feed material, and tailings and the calculated Th-230 air concentration
of 20 ug/m3, would be 2 x 10"6 ug/m3 (1 x 102 ug Be/kg feed x 20 ug feed/m3 x 10"9 kg feed/ug
feed = 2 x 10"6 ug/m3 beryllium), or a factor of 10,000 below the beryllium RfC. Based on this
finding, processing the Uranium Material is not expected to present any significant risk to the
general public from beryllium in airborne particulates from the Mill.
Occupational exposures to beryllium might include skin, inhalation, and inadvertent ingestion of
beryllium. The concentrations of beryllium in the Uranium Material and tailings solutions are
36 ppm (Attachment 5, Table 6, Column B of the April 2011 Amendment Request) and less than
1 ppm (Attachment 5, Table 6, Column 10L), respectively. The New Hampshire Department of
Environmental Services Beryllium Health Information Summary notes that skin exposure to
concentrated beryllium can result in allergic skin response (NHDES 2010). Because of the very
low concentrations in the Uranium Material and tailings, beryllium is not likely to cause an
allergic response from skin contact. The reported adverse effects on skin are generally for the
pure beryllium compounds or metal. In any case, the normally required personal protective
31
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equipment and safe work practices at the Mill facility are expected to protect workers from direct
contact with the beryllium in Uranium Material, tailings, and mill process solutions.
Inadvertent ingestion is not likely to result in an individual exceeding the reference dose (RfD).
The RfD is an estimate of the daily oral intake for humans, including sensitive subgroups that
would not result in "appreciable risk of deleterious effects during a lifetime" (EPA 2013). The
oral RfD for beryllium, is 0.002 mg/kg-day. Assuming a 70-kg adult worker and a beryllium
concentration of 36 mg/kg in the Uranium Material (Attachment 5, Table 6, Column B of the
April 2011 Amendment Request), a worker would have to inadvertently consume nearly 4 g of
Uranium Material per day (0.002 mg/kg x 70 kg adult + 36 mg/kg Be concentration = 4 g). The
amount of uranium in the 4 g of Uranium Material (16,000 mg/kg [Table 5 of Attachment 5] =
0.016 g/g x 4 g = 0.064 g = 64 mg U-nat) far exceeds the regulatory intake limit of 10 mg U-nat
per week. As such, normal uranium mill work rules and existing controls are expected to provide
a reasonable assurance that neither the uranium nor the associated beryllium in the Uranium
Material would be inadvertently ingested at levels likely to cause significant occupational health
risk.
The concentration of beryllium in workplace air resulting from Uranium Material airborne dust
would be below the Occupational Safety and Health Administration (OSHA) Permissible
Exposure Limit (PEL; 2 ug/m3) as long as the regulatory limits on airborne uranium
concentrations are met. The concentration of Uranium Material in airborne particulates that
would meet the 10 mg/week regulatory limit on intake of soluble uranium would be
approximately 13 mg/m3 assuming a breathing rate of 1.2 m3/hour. a normal 40-hour work week,
and a uranium concentration of 16,000 ppm. At 13 mg/m3 of soluble uranium the Be
concentration in airborne particulates associated with the Uranium Material would be
approximately 0.5 ug/m3, a factor of 4 below the OSHA PEL of 2 ug/m3. It is unlikely that a
worker would be exposed to airborne particulate matter associated with the Uranium Material for
8 hours per day, 5 days per week. The concentration of beryllium in tailings attributable to
processing of the Uranium Material is estimated to be 0.1 ppm (Attachment 5, Table 6,
Column 9M of the April 2011 Amendment Request); therefore, inhalation of tailings dust would
result in an even lower occupational exposure.
The information provided above indicates that there are no implications to potentially applicable
and relevant personnel health criteria from beryllium levels in the Uranium Material as compared
to ores and other alternate feed materials previously processed at the Mill. Existing controls and
operating procedures used to maintain radiological and non-radiological exposures from ores and
other alternate feed materials to protect public and occupational health are considered adequate
for handling the proposed Uranium Material.
4.4 Surface Water and Groundwater Effects
4.4.1 Surface Water Effects
There would be no discharge of Mill effluents associated with processing of the Uranium
Material at the Mill to local surface waters. All mill process effluent, laundry, and analytical
laboratory liquid wastes will be discharged to the Mill's tailings impoundments for disposal by
evaporation. Runoff from the Mill and facilities is directed to the tailings impoundments.
Sanitary wastes are discharged to State-approved leach fields. As a result, there is no likely
32
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pathway for Uranium Material to impact surface water due to processing of the Uranium
Material or disposition of the process residues to the tailings cells. Further, as indicated in semi-
annual effluent reports filed by the Mill to date, there is no indication that the Mill is impacting
surface waters. No incremental impact is expected to occur to surface waters from any airborne
particulates associated with processing of the Uranium Material.
Uranium Material will be transported to the Mill in covered exclusive-used trucks. Upon
introduction to the Mill circuit, EFRI proposes that the Uranium Material be processed in a
similar fashion as other ores and alternate feed materials. The Uranium Material will be
relatively moist, with an expected average moisture content of 55-75%. This moisture is bound
water of hydration, and a minor amount of moisture held in capillary tension that is not driven
off by the high-pressure filter press. (There is no free water associated with these solids as stated
in Section 4.7 of the April 27, 2011 Amendment Request.) This will minimize any potential for
dusting while the Uranium Material is introduced into the Mill process. In addition, standard
procedures at the Mill for dust suppression will be employed during processing of the Uranium
Material and during disposal of the process residuals if necessary. Therefore, there will be no
new or incremental risk of discharge to surface waters resulting from the receipt and processing
of Uranium Material at the Mill or disposition of the resulting residuals in the tailings disposal
cells.
Potential impacts to surface waters from Uranium Material delivery and storage at the Mill Site
might include: (1) release of site surface runoff containing Uranium Material contaminants;
and/or (2) airborne transport of Uranium Material particulates related to delivery and temporary
storage of these materials. Protection of surface water from potential impacts related to receiving
and storage and processing this Uranium Material will be accomplished through control of
potential surface water discharges using the Mill's existing stormwater and liquid effluent
controls (Section 4.7 of the April 2011 Amendment Request). Specifically, stormwater runoff
from the Mill and facilities, including the ore storage area where the Uranium Material will be
received and stored, is directed to the tailings impoundments through approved stormwater
controls contained in the Stormwater Best Management Practices Plan for White Mesa Mill
(EFRI 2012b). These are the same controls used for storage of all other areas and alternate feed
materials.
Attachment 4 of the April 2011 Amendment Request demonstrates that the Uranium Material
passes the TCLP test, which was designed to simulate the leaching of solids within a landfill
environment. The pH conditions of the TCLP (pH between 3 and 5 S.U., depending on the
material characteristics; EPA Method 1311) are set to be representative of acidic chemical
conditions within landfills and tend to be as or more aggressive (lower pH) than conditions
experienced under ambient meteoric conditions to which the Uranium Material would typically
be exposed during storage (typically pH ~ 5.4; USGS 2001). The Uranium Material therefore
does not readily leach and does not exhibit the hazardous waste characteristic of toxicity when
exposed to more severe conditions than would be anticipated on the ore storage pad stated on
page 13 of the April 2011 Amendment Request. Additionally, the Uranium Material does not
exhibit the hazardous characteristics of reactivity, ignitability, or corrosivity, as determined by
the specific test results reported in the RMPR in Attachment 2 to the April 2011 Amendment
Request.
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Based on the TCLP data, moisture content, physical characteristics of the Uranium Material, and
observations made during loading, hauling, and storage of the Uranium Material at the Dawn
Mining Company Midnite Mine site in Washington State over the past several years
(Attachment 2 of the April 2011 Amendment Request), the Uranium Material is expected to be
stable during periods of temporary storage at the Mill Site under ambient environmental
conditions with respect to expected future precipitation and climatic conditions at the site.
However, owing to the more arid climatic conditions at the White Mesa Mill Site compared to
the Midnite Mine Site, the potential may exist, if unmitigated, for Uranium Material temporarily
stored at the Mill to experience some drying, with possible airborne release of some fine-grained
particles from the Uranium Material during windy periods. A new license condition will be
added to RML No. UT 1900479 to provide additional protective measures and practices during
storage of the Uranium Material to address this potential concern (Section 5.1).
Because the chemical and radiological makeup of the Uranium Material are sufficiently similar
to natural ores and the resulting tailings, the existing surface water monitoring program at the
Mill is sufficient to detect any potential impacts to surface water.
4.4.2 Groundwater Effects
The design of the existing tailings management cells (Cells 4A and 4B) that would be used for
disposal of the process residuals from processing of the Uranium Material has been approved by
the UDRC. EFRI is required to conduct regular monitoring of the leak detection systems in
Cells 4A and 4B and monitoring of groundwater conditions in the vicinity of these disposal cells
to detect leakage should it occur.
The receipt and processing of this Uranium Material at the Mill is not expected to pose any
incremental additional impacts on groundwater compared to the current uranium mill tailings and
alternate feed material residual inventories.
EFRI currently performs groundwater monitoring program at the Mill. With the exception of
barium, all constituents identified in the Uranium Material are included in the groundwater
monitoring program.
Barium will be introduced into either disposal Cell 4A or 4B with the disposal of the process
residuals resulting from the processing of the Uranium Material. Excluding barium, the chemical
and radiological makeup of the Uranium Material is similar to other ores and alternate feed
materials processed at the Mill, and the resulting residual materials disposed in the tailings cells
will have the chemical composition of typical uranium process tailings, for which the Mill's
tailings cells were designed. Based on the considerations described in the following section of
this SER, the existing groundwater monitoring program at the Mill is expected to be adequate to
detect potential future impacts to groundwater resulting from processing of the Uranium
Material.
34
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4.5 Evaluation of Need for Additional Groundwater Monitoring Compliance
Parameters
With the introduction of the Uranium Material into the mill process, each contaminant found in
these materials needs to be considered in order to determine if additional groundwater
monitoring compliance parameters should be added to the Ground Water Discharge Permit.
In Attachment 5 of the April 27, 2011 submittal Table 6, "Historical Mill Tailings Composition
and Uranium Material Comparison", information is summarized for 26 constituents found in the
Uranium Material in relation to concentrations of these constituents present in uranium ores and
other alternate feed materials previously licensed for processing at the White Mesa Mill. Because
in the last column of Table 6, the units for the listed constituent concentrations in ores and
alternate feed materials are given as "mg/L or ppm", direct comparisons between individual
constituent concentrations in the Uranium Material and ores and previously licensed alternate
feed materials is not always possible. Additional comparisons of constituent concentrations
found in the Uranium Material to uranium ores and selected other alternate feed materials, where
each concentration is expressed in the same unit (ug/g), are presented above in this SER.
In determining if additional groundwater compliance monitoring parameters were needed for the
Permit the following questions and criteria were considered for the 48 contaminants:
1) Is the constituent already included as a groundwater monitoring compliance parameter in
the Permit?
2) Are concentrations reported for the constituent in the Uranium Material clearly higher
than in uranium ores typically processed at the Mill and/or than present in other alternate
feed materials previously licensed for processing at the Mill?
3) Will there be a significant increase in concentration in the tailings inventory?
4) Does available information indicate that the contaminant could be mobile in the
groundwater environment (e.g., does it have a relatively low soil-water partitioning
coefficient (Kd) or have a Kd value that is equal to or less than that of a chemically
similar constituent already included as a groundwater monitoring compliance parameter
in the Permit, or does it exhibit high solubility)?
5) Does the contaminant represent a known human toxicity hazard?
6) Is there an existing and reputable groundwater quality compliance standard for the
constituent?
7) Are there EPA-approved analytical methods for the constituent and do the approved
methods have a detection limit low enough to readily allow determination of whether the
constituent concentration exceeds the applicable groundwater quality compliance
standard?
As described in Section 4.1 above, the UDRC observed that many of the trace, naturally-
occurring constituents identified in the Uranium Material have never been quantified in the
Mill's tailings cells and, as a result, have not been considered to date for inclusion in the Permit.
However, the overall concentrations of these newly-quantified constituents in the tailings cells
35
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following processing of the Uranium Material and disposal of the residuals in the cells are not
expected to change significantly as a result of handling the Uranium Material at the Mill, since
these constituents are expected to be present at roughly similar concentrations in the uranium
mill tailings and in other alternate feed materials previously processed at the Mill.
According to Table 6 of Attachment 5 in the EFRI (formerly DUSA) April 27, 2011 Amendment
Request, for those constituents detected in the Uranium Material and that are already included in
the Mill's ongoing groundwater detection monitoring program, the percentage of the total mass
in the tailings disposal cells after completion of processing of the Uranium Material (processing
of shipments periodically received over a 10-year period) contributed by constituent inventories
are projected to be 3% or less for all constituents with the exception of the following:
(1) beryllium (approximately 9.2% contribution); (2) copper (approximately 100% contribution);
(3) calcium (approximately 5.8% contribution); (4) manganese (approximately 51%
contribution); and (5) silver (approximately 14% contribution). A total of 16 of the constituents
reported detected in samples of the Uranium Material tested are already required as groundwater
monitoring parameters in the Permit.
Barium is not a required groundwater monitoring parameter in the current Ground Water
Discharge Permit, and was omitted from the original Permit because concentrations of barium in
tailings wastewater samples were found to be less than or equal to the Utah-prescribed
groundwater quality standard for barium (see 12/01/04 UDRC Statement of Basis [SOB],
Table 5). The State of Utah Department of Environmental Quality has adopted a groundwater
quality standard for barium of 2 mg/L (UAC R317-6-2, Table 1).
It is stated in Section 4.6 of the April 2011 Amendment Request and in Section 9.2 of
Attachment 5 ("Review of Chemical Contaminants in the DMC Uranium Material to Determine
Worker Safety and Environmental Issues and Chemical Compatibility at the Denison Mines
White Mesa Mill") included in the April 27, 2011 DUSA submittal that the distribution
coefficient (Kd) for barium is 100 to 150,000 L/kg for sandy to clayey soil types. DUSA (2011)
also indicated that the UDRC SOB for the GWDP (UDRC 2004) assumes Kd values for calcium
ranging from 5 to 100 L/kg. On this basis, DUSA proposed that barium would be less mobile in
groundwater than calcium, and that calcium therefore would serve as an effective analogue for
barium.
EFRI (2013) submitted additional information indicating that the chemistry of the tailings cells
would likely limit the mobility of barium due to the existing abundance of sulfate in the tailings
cells. As described above, barium chloride is used to treat radium in the Midnite Mine WTP
influent water. In waters where sulfate is present, radium is easily removed by addition of barium
chloride: barium chloride dissolves and in the presence of sulfate, the dissolved barium
immediately re-precipitates as barium sulfate due to its very low solubility (0.022 mg/L in cold
water; Weast 1987). Dissolved radium co-precipitates with the barium sulfate (NEA & IAEA,
2002). In Midnite Mine WTP solids, barium is present as barium sulfate (BaS04).
The solubility of barium sulfate in cold water is 0.022 mg/L and in concentrated sulfuric acid is
0.025 mg/L (Weast 1987). Once in the EFRI Mill circuit, barium sulfate would remain as barium
sulfate due to its very low solubility in concentrated sulfuric acid (0.025 mg/L). At the listed
concentrations of sulfate in the tailings solutions (67,600 mg/L to 87,100 mg/L in Cell 4A), a
36
irpc
change in the ambient barium concentration in the tailings solutions (0.02 mg/L) due to
placement of the Uranium Material residues to the tailings would be expected to be very small to
negligible. Therefore, given the strong tendency of barium to partition to solids, especially in the
presence of sulfate, the potential for barium to migrate to groundwater from the tailings cells at
the Mill in the event of a release from the tailings cells is considered to be low.
Given the conditions present in the tailings cells, it is likely that mobilization of barium in water
will be limited primarily due to solubility considerations. This finding generally supports EFRI's
conclusion that barium would be expected to be less mobile than calcium once solubilized and in
the groundwater system. For this reason, barium will not be added to the Permit as an additional
groundwater monitoring compliance parameter. Should additional information become available
at a future date that would suggest that the degree of mobilization of dissolved barium in the
tailings pore-water environment is higher than anticipated, UDRC may consider whether barium
should be added to the Mill's groundwater compliance monitoring program.
The beryllium in the Uranium Material is derived from beryllium in uranium ores that has
dissolved into the local groundwater, which is then precipitated as part of the water treatment
process described in the application and Attachments 4 and 5 of the April 2011 Amendment
Request. Lime softening is used at the Midnite Mine WTP to precipitate heavy metals, including
beryllium, with the metals precipitating in the hydroxide form (Hendricks 2006). In the WTP
solids, beryllium is present as beryllium hydroxide, Be(OH)2.
Be(OH)2 is insoluble in water but dissolves in sulfuric acid (NTP 2011) forming beryllium
sulfate, BeS04 (Wiberg, et al. 2001). Therefore, once in the EFRI Mill circuit, beryllium will be
present as BeS04. BeS04 is readily soluble in water (37 to 42.5 g/100 mL) and has low solubility
in concentrated sulfuric acid (solubility does not exceed 2.5% in the range of 88 to 98 wt%
sulfuric acid) (Walsh 2009).
Analysis of tailings pore water in the Cell 2 slimes drain (MWH 2010) indicates high sulfate
concentrations (60,600-74,000 mg/L) and low pH (3.11-3.28) conditions, indicating that BeS04
solubility in the tailings will be more comparable to the above-reported solubility in sulfuric
acid.
Excluding barium, the chemical and radiological makeup of the Uranium Material is similar to
other ores and alternate feed materials previously processed at the Mill, and it is expected that
the resulting residuals left after processing of this material would have a chemical composition
similar to that of typical uranium process tailings, for which the Mill's tailings system was
designed.
The Mill currently monitors groundwater for a number of other dissolved constituents, such as
chloride, fluoride, and sulfate, each of which is an anion that is expected to have a higher
mobility in groundwater than a cation such as barium. These anions can be used as indicators of
potential tailings cell seepage, and because of their mobility, as 'early warning' indicators for
less-mobile constituents such as barium. Chloride, in particular, is a conservative solute that is
not retarded with respect to groundwater flow. Chloride salts are highly soluble, so chloride is
rarely removed from water by precipitation except under the influence of freezing or evaporation
37
(Davis and DeWiest 1966). Chloride is also relatively free from effects of exchange, adsorption,
and biological activity.
Based on the above considerations, the existing groundwater monitoring program at the Mill is
adequate to detect potential future impacts to groundwater from potential releases from the
tailings cells where the Uranium Material process residuals would be disposed. Rationale for not
adding other remaining constituents found in the Uranium Material to the current groundwater
monitoring program is discussed below.
Constituents Omitted from Consideration in Groundwater Monitoring Program
The 29 nutrients, inorganics and metals, and organic constituents or groups of constituents
detected in the Uranium Material listed in Table 20 below were not added to the Mill's
groundwater monitoring program because they: (1) are already required as groundwater
monitoring compliance parameters in the Permit; (2) are considered common laboratory
contaminants; and (3) are already addressed by surrogate radiologic monitoring parameters (e.g.,
gross alpha serves as a surrogate for Radium-226, Thorium-232, Uranium-238, etc..) in the
existing groundwater monitoring program.
Table 20. Nutrients, Inorganics and Metals, and Organic Constituents Reported Detected
in Uranium Material and Not Added as Groundwater Monitoring Parameters
Nutrients (2) Ammonia as N and nitrate/nitrite as N
Inorganics and Metals (28) Beryllium, calcium, cadmium, chromium, cobalt, copper, fluoride, gross
alpha, gross beta, Radium-226, thorium isotopes, iron, lead, manganese,
nickel, selenium, silver, chloride, sulfate, total uranium, and zinc
Organics (5) Acetone, methylene chloride, toluene, chloroform, and trichloroethylene1
The laboratory reports note that all five organic constituents reported detected were also detected in method blank
samples, indicating that that these detections are due to laboratory influences.
Besides barium, the remaining 24 constituents detected in the Uranium Material, after
discounting the five organic constituents attributable to laboratory contamination, which are not
proposed as additional groundwater monitoring parameters include the following constituents,
categorized into two groups with their corresponding UDRC findings.
Cyanide
Although no data were provided on cyanide concentrations in the Uranium Material, if cyanide
were to be present in this material, it would be expected to off-gas in the high acid environment
of the White Mesa Mill process. Therefore, cyanide was omitted from consideration. Should
cyanide be found in future tailings wastewater sampling under Part 1.H.5 of the GWDP, the
UDRC may consider whether it should be added as a compliance monitoring parameter at a
future date.
Metals, Metalloids, Lanthanides, and Actinides: Thorium
Thorium is not required as a groundwater monitoring parameter in the Permit. Although present
in the Uranium Material, concentrations of Thorium-230 detected in the Uranium Material are
38
TIDC
lower than those reported present in typical Utah area acid-leached uranium mill tailings and
concentrations of Thorium-232 found in the Uranium Material are lower than those reported
present in other alternate feed materials previously accepted and processed at the Mill
(Section 4.1). For this reason, thorium was eliminated for monitoring consideration.
Conclusions
Table A-1 in Attachment A summarizes the projected percentages of the total constituent mass
and concentrations in the tailings disposal cells contributed by constituents in residuals that
would be placed in the tailings cells following processing of the Uranium Material (processing of
shipments of the Uranium Material periodically received over a 10-year period). These
percentages range from between about 5% and 100%; however, the estimated total mass
contributed to the tailings from these constituents is less than 0.02% of the estimated total mass
in the tailings cells that would receive these process residuals (EFRI 2013a).
The analytical results of the Uranium Material indicated that a total of 24 different nutrients and
inorganic constituents were detected in the Uranium Material. Five organic constituents were
reportedly detected in the Uranium Material; however, each of those detections was determined
to be attributable to laboratory influences and therefore none of these five constituents are
present in the Uranium Material. This left a total of 24 constituents detected in the Uranium
Material for groundwater monitoring compliance consideration. Of these 24 constituents, 16 are
already required as groundwater monitoring compliance parameters in the Ground Water
Discharge Permit.
Based on the review of the information provided by EFRI (EFRI 2011; 2012a; 2013a) and as
discussed in this SER, the Director of the UDRC has determined that the addition of any of the
remaining 8 constituents to the Permit as a new groundwater monitoring compliance parameter is
not warranted.
4.6 Alternatives
The action that the UDRC is considering is approval of an amendment request to RML No. UT
1900479 issued pursuant to UAC R313-24 Uranium Mills and Source Material Mill Tailings
Disposal Facility Requirements. Subparagraph UAC R313-24-3(l)(c) requires that alternate sites
and engineering methods be considered in the analysis of the license amendment request.
Based on its review, the UDRC has concluded that the environmental impacts associated with
the proposed action do not warrant either limiting EFRI's future operations or denying the
license amendment. The UDRC has concluded that there are no significant environmental
impacts associated with the proposed action. Other alternatives need not be evaluated.
4.7 Long-Term Impacts
Based on its review of the Amendment Request and the supporting information provided by
EFRI, the UDRC does not anticipate any significant impacts on the reclamation,
decommissioning, and decontamination of the White Mesa facility, if the Uranium Material is
processed as an alternate feed. In general, the Uranium Material has similar radiological and non-
radiological properties to other alternate feeds and natural ores that are processed and have
already been processed by EFRI.
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Generally, the concentrations of constituents identified in the tailings liquids or solids, feed
materials, or process streams at the mill are at concentrations that are generally comparable to the
concentrations in the Uranium Material. Due to the small annual and total quantities of the
Uranium Material, increases in the concentration of these analytes in the Mill's tailings are
determined not to be significant. A few other constituents, such as barium, beryllium, silver,
manganese, copper, and calcium are present in the Uranium Material and are either present in
lower concentrations in the ores and other alternate feeds at the mill, or as in the case of copper,
information on concentration in the ore and other alternate feeds was not available.
Although the percent total of these constituents contributed from the Uranium Material to the
mill tailings in the 10-year period appears to be high in some cases - between 5 and 100% (for
barium) of these constituents present in the tailings is from the Uranium Material - the total mass
contributed is less than 1% of the total mass in the tailings cell (EFRI 2013a, p. 233). In the case
of barium, introduction of the Uranium Material into the Mill's tailings cells would substantially
increase the amount of barium currently stored (See Table A-1). As discussed in this SER,
however, barium dispensed to the tailings cell environment is expected to be precipitated in the
form of barium sulfate solids. Barium sulfate is a sparingly soluble sulfate salt: the solubility of
barium sulfate in cold water is 0.022 mg/L and in concentrated sulfuric acid only increases to
0.025 mg/L.
Geochemical modeling with the PHREEQC modeling tools2 using the above solubility data and
the geochemical conditions present in the Mill tailings (average tailings sulfate concentration of
65 g/L) predicts that barium from the Uranium Material will remain stable in the tailings
impoundment as the solid phase barium sulfate, and would not be expected to dissolve. Given
the low solubility of barium sulfate, especially in the presence of sulfate, there is, therefore, no
reasonable potential for barium to migrate from the tailings into groundwater.
As discussed in detail in the Mill's approved Reclamation Plan, the components of the
decontamination and decommissioning phase and reclamation phase of Mill closure are:
• Demolition of buildings, structures, and facilities (including Cell 1)
• Decontamination to free release standards of any equipment to be released from the site
• Disposal of all demolished structures and equipment in the Mill's tailings cells
• Decontamination of environmental media (onsite and offsite soil) to levels committed in
the Reclamation Plan
• Restoration of any potential groundwater contamination to groundwater compliance
limits or approved Alternate Corrective Action Compliance Limits
The long-term impacts that an alternate feed material could potentially have on the
decontamination and decommissioning phase, reclamation phase, or post-reclamation conditions
are:
• Increase in volume of material in the tailings cells
• Addition of a new contaminant that cannot be managed or contained by the existing
tailings reclamation design
2 See http://wwvvbrr.cr.usgs.aov/proiects/GWC coupled/phreeqc/.
40
URS
• Increase in concentration of a contaminant to a level that cannot be managed or contained
by the existing tailings reclamation design
• Contamination of soils or sediments requiring management at reclamation
• Change in nature of groundwater conditions requiring restoration at reclamation, to meet
applicable groundwater quality standards
As discussed in the April 2011 Amendment Request and in EFRI 2013a, processing of the
Uranium Material is not expected to produce any of these impacts because:
• The Uranium Material will not increase the volume of tailings. As discussed in the
April 2011 Amendment Request, the Uranium Material will produce no greater volume
of tailings than would be produced from processing the same volume of ore. Processing
of the Uranium Material does not require the use of any new or modified equipment;
hence no additional volume of demolition material would be added to tailings.
• The RMPR, analytical data, and technical memorandum in the April 2011 Amendment
Request demonstrate that the sampling and analytical data are representative of the
Uranium Material, and the Uranium Material contains no new constituents.
• Processing of the Uranium Material will not require the use of additional chemicals not
already in use at the Mill. Therefore, processing of the Uranium Material will not
introduce any new chemical constituent that cannot be managed or contained by the
existing tailings reclamation design.
• Processing of the Uranium Material is not expected to increase the concentration of any
contaminant to a level that cannot be managed or contained by the existing tailings
reclamation design. With the exception of barium, all constituents present in the Uranium
Material have already been introduced into the Mill at levels higher than the levels
present in the Uranium Material. Anticipated increases in barium levels in tailings will
have no effect on the integrity of the tailings liner.
• As discussed in Sections 4.1.1 .a and 4.1.2, processing of the Uranium Material is not
expected to produce any additional mechanism for, or cause a significant increase in
airborne deposition in soils or sediments.
• As discussed in Sections 4.2, 4.3, and above in this section, processing of the Uranium
Material is not expected to produce any additional pathway for, or cause a significant
increase in, concentrations of any constituents present in the Uranium Material in
groundwater. Specifically, each constituent in the Uranium Material is either monitored
under the Mill's approved GWDP, or represented by a constituent monitored in the
GWDP, and the monitoring program required by the GWDP meets the requirements of
NRC Reg. Guide 4.14 (NRC 1980) and Utah groundwater regulations. Hence, processing
of the Uranium Material is not expected to change the nature of groundwater conditions
in a way that would require additional groundwater restoration at or before reclamation.
The constituents in the sands and liquids resulting from processing the Midnite Mine Uranium
Materials are not expected to be significantly different from those in the conventional ores either
in composition or in concentration of constituents (EFRI 2013a, p. 232). Table 6 of Attachment 5
to the April 2011 Amendment Request indicates that when comparing the Uranium Material to
the tailings, all of the constituents found in the Uranium Material are currently processed in the
Mill's main circuit and/or the alternate feed circuit in other ores and alternate feed materials with
41
URS
the exception of copper. No information on the concentration of copper in the ores or alternate
feeds is currently available but copper is analyzed under the existing GWDP.
Residuals resulting from processing the Uranium Material would be disposed in Cell 4A, 4B or
newer cells that may be constructed during the period of processing. Cells 4A and 4B are
constructed of 60-mil high-density polyethylene (HDPE) manufactured by GSE. Manufacturer's
material product performance information, including a chemical resistivity list, was provided in
Appendix P of EFRI 2013a. Manufacturers generally do not include specific metal cations in
chemical resistivity lists since synthetic liners are generally compatible (resistive to) metals,
metal halide salts, and many other metal salts in all proportions.
Based on the above information, including a comprehensive chemical compatibility listing for
the HDPE geomembrane liner material used in Cells 4A and 4B, the presence of the inorganic
and organic constituents in the Uranium Material as listed in Tables 8 through 12 would not be
expected to result in any additional detrimental impacts to the HDPE geomembrane liners in
CelHA or 4B.
In the unlikely event that EFRI were to close prior to processing the Uranium Material, the
surety funds would be issued to the Director of the UDRC and the Uranium Material that was on
site at the time would be hauled to one of the disposal cells and disposed of directly into the cell.
The financial surety does not need to be increased or modified for the acceptance of the Uranium
Material, because the Mill cannot possess at any one time, more feed material than can be placed
in the cells. Therefore, there is a limit as to how much ore and alternate feed that can be on site
for processing at any given time. Surety reviews and adjustments are performed annually by the
UDRC. No changes to the surety are necessary for receipt and processing of the Uranium
Material.
4.8 Report Findings
Based on the foregoing evaluation of the environmental impacts of the proposed action as
described in the April 27, 2011 Amendment Request, in the December 5, 2012 Supplementary
Information Letter Report, and in the June 14, 2013 and August 7, 2013 Letters to Mr. Rusty
Lundberg of the UDRC (EFRI 2013a; 2013b), and with implementation of the proposed new
license condition requiring that: (1) Uranium Material stored at the Mill Site be covered with a
durable, UV-tolerant geomembrane and ballast be applied over the geomembrane to prevent
wind-induced uplift of the geomembrane; and (2) the EFRI RSO or his or her designee take
prompt action to stop generation of any visible dust originating from the stored Uranium
Material, the UDRC has determined that no significant adverse effects on public health or the
environment are expected to result from implementing the proposed action. The following
statements support and summarize this conclusion:
1. An acceptable environmental and effluent monitoring program is in place to monitor
effluent releases from the Mill and associated facilities and to detect whether applicable
regulatory limits established for environmental media are exceeded. A GWDP for the
shallow-perched, water-bearing zone is in place to detect potential seepage of
contaminants from the tailings cells. The confined Entrada/Navajo Sandstone Aquifer is
separated by low-permeability formations from the tailings cells, further decreasing a
potential impact to deep groundwater resources. The potential for seepage to occur while
42
wrpc
the material is temporarily stored on the storage pad is minimal due to the dry climate and
highly compacted ore pad surface, and the limited duration of storage. Further,
decommissioning and reclamation activities at the storage pad can remove any such
contamination, should it occur, to the tailings cells for long-term control. An existing dust
suppression program is implemented at the Mill to reduce the potential for airborne
releases.
2. An approved radiation safety program is in place at the Mill. Site perimeter postings
required by License Condition 9.9 are in place at entrances to the Mill. In the past, all
worker Total Effective Dose Equivalents (TEDEs) have been found to be well below the
0.05 Sievert (Sv), or 5 rem, annual limit specified in UAC R313-15-201 (10 CFR
20.1201). The licensee has also implemented a bioassay program consistent with NRC
Regulatory Guide 8.22, "Bioassay at Uranium Mills."
3. The State's existing Air Approval Order (AO) No. DAQE-ANO 112050018-11 requires
that visible emissions from ore-loading areas not exceed 15% opacity, and specifies
approved testing methods for testing the opacity level. The AO also requires that EFRI
comply with all applicable requirements of UAC R307-205 for Fugitive Emission and
Fugitive Dust sources, and requires that all ore/feed material storage piles be watered to
minimize generation of fugitive dusts as dry conditions warrant or as determined
necessary by the Director of the Utah Division of Air Quality, in accordance with
requirements contained in UAC R307-401-8.
4. Information provided in the April 2011 Amendment Request and in 2013 (EFRI 2013a;
2013b) indicate that, with the exception of barium, there are no concentrations in the
Uranium Material of any constituent in excess of the concentrations in alternate feed
materials previously licensed for receipt and processing at the Mill. The Mill's existing
airborne effluent monitoring program, which has been designed to comply with the
requirements of Reg. Guide 4.14, and which has been in place during the processing of
those previously approved alternate feed materials, is considered appropriate for
monitoring the potential releases from the acceptance, temporary storage, and processing
of the Uranium Material, and from disposal of the processed residual materials in the
tailings cells.
Present and potential environmental impacts from the receipt and processing of the Uranium
Material were assessed. No significant impacts have been identified as a result of implementing
this proposed action. Therefore, UDRC staff have determined that there is not expected to be any
significant increased risk to public health or in environmental hazards from the acceptance,
temporary storage, and processing of the Uranium Material, and from disposal of the processed
residual materials in the designated tailings cells (Cells 4A and/or 4B).
5.0 REQUIRED LICENSE AMENDMENTS AND PERMIT MODIFICATIONS
5.1 License Amendments Proposed
The following license condition changes (new license conditions) would result from this license
amendment:
43
mm wmwma* ak9m
URS
"10.20 The licensee is authorized to receive and process source material from the Dawn Mining
Company's Midnite Mine site in Wellpinit, Washington, in accordance with statements,
representations, and commitments contained in the Amendment Request submitted to the
Executive Secretary dated April 27, 2011 and supplemented by a Letter Report (with
attachment) submitted to the Director of the Utah Division of Radiation Control
(Director) on December 5, 2012, a Letter Report (with attachments) submitted to the
Director on June 14, 2013, and a Letter submitted to the Director on August 7, 2013."
"A Uranium Material stored (stockpiled) at the Mill Site longer than 14 days shall be
covered with a durable geomembrane cover, resistant to damage by ultraviolet (UV)
radiation and sufficient ballast shall be placed over the cover to prevent wind uplift of the
cover during peak wind conditions at the site; and (2) If at any time, visible dust is
observed to be originating from Uranium Material stored on site, the EFRI RSO or his or
her authorized representative shall take actions within 30 minutes to stop the generation
of visible dust."
[Applicable UDRC License Amendment: 6]
5.2 GW Permit Modifications
No permit modifications are required as a result of acceptance of the Uranium Material for
processing at the Mill.
44
YTDQ
6.0 REFERENCES
Abdelouas, A. 2006. "Uranium Mill Tailings: Geochemistry, Mineralogy, and Environmental
Impact," in Elements, Vol. 2, pp. 335-341. December 2006. URL:
http://gnews.wustl.edu/elements/e2 6/e2 6 art abdelouas.pdf.
Agency for Toxic Substances and Disease Registry (ATSDR) 2002. Toxicological Profile for
Beryllium. U.S. Department of Health and Human Services Public Health Service, ATSDR.
September 2002.
Agency for Toxic Substances and Disease Registry (ATSDR) 2007a. Toxicological Profile for
Barium and Barium Compounds. U.S. Department of Health and Human Services Public Health
Service, ATSDR. August 2007.
Agency for Toxic Substances and Disease Registry (ATSDR) 2007b. Toxicological Profile for
Arsenic. U.S. Department of Health and Human Services Public Health Service, ATSDR.
August 2007.
Agency for Toxic Substances and Disease Registry (ATSDR) 2007c. Toxicological Profile for
Lead. U.S. Department of Health and Human Services Public Health Service, ATSDR. August
2007.
Allison, J.D., and Allison, T.L. 2005. Partition Coefficients for Metals in Surface Water, Soil,
and Waste. U.S. Environmental Protection Agency, Office of Research and Development,
Washington, DC (EPA/600/R-05/074). July 2005. URL:
http://www.epa.gov/athens/publications/reports/Ambrose600R05074PartitionCoefficients.pdf.
Baes, CF. (Ill), R.D. Sharp, A.L. Sjoreen, and R.W. Shor. 1984. A Review and Analysis of
Parameters for Assessing Transport of Environmentally Released Radionuclides through
Agriculture. Oak Ridge National Laboratory Report ORNL-5786. ORNL, Oak Ridge, TN.
Dames and Moore 1978. Environmental Report White Mesa Uranium Project, San Juan County,
Utah.
Davis, S.N. and R. J. M. DeWiest. 1966. Hydrogeology. John Wiley and Sons, 463 pp.
Denison Mines (USA) Corp (DUSA) 2008. Environmental Report in Support of Construction of
Tailings Cell 4B, White Mesa Uranium Mill, Blanding, Utah. April 30, 2008.
Denison Mines (USA) Corp (DUSA) 2011. "Amendment Request to Process an Alternate Feed
Material (the "Uranium Material") at White Mesa Mill (the "Mill") from Dawn Mining
Corporation ("DMC") Midnite Mine, State of Utah Radioactive Material License No. 1900479,
April 27, 2011.
Energy Fuels Resources (USA) Inc. (EFRI) 2012a. State of Utah Radioactive Material License
No. UT 1900479, April 27, 2011 Amendment Request to Process an Alternate Feed Material
from Dawn Mining Company- Transmittal of Supplementary Information. Letter Report to Mr.
Rusty Lundberg, Utah Division of Radiation Control, December 5, 2012.
IPCS PNCHEM. 1990. Concise International Chemical Assessment Document 33, Barium and
Barium Compounds.
45
URS
Energy Fuels Resources (USA) Inc., 2012b. Stormwater Best Management Practices Plan for
White Mesa Mill. September 2012.
Energy Fuels Resources (USA) Inc. (EFRI) 2013a. White Mesa Uranium Mill - RML
UT1900479: April 27, 2011 Request to Amend Radioactive Materials License to Allow
Processing of Alternate Feed Materials from Dawn Mining Company's Midnite Mine Water
Treatment Plant ("WTP") - Response to January 22, 2013 and January 23, 2013 Utah Division of
Radiation Control Requests for Information. Letter Report to Mr. Rusty Lundberg, Utah Division
of Radiation Control, June 14, 2013.
Energy Fuels Resources (USA) Inc. (EFRI) 2013b. White Mesa Uranium Mill - RML
UT 1900479: April 27, 2011 Request to Amend Radioactive Materials License to Allow
Processing of Alternate Feed Materials from Dawn Mining Company's Midnite Mine Water
Treatment Plant ("WTP") - Response to July 31, 2013 URS Email Comments. Letter to
Mr. Rusty Lundberg, Utah Division of Radiation Control, August 7, 2013.
Hendricks, D.W. 2006. Water Treatment Unit Processes: Physical and Chemical. Boca Raton,
Florida: Taylor & Francis.
Kalkwarf, D.R. 1979. "Solubility Classification for Airborne Products from Uranium Ores and
Tailings Piles". U. S. Nuclear Regulatory Commission. NUREG/CR-0530. PNL-2870. January
1979.
Kennedy, W., Strenge, D.L., Meek, R., and Daily, C. 1992. Residual Radioactive Contamination
from Decommissioning - Technical Basis for Translating Contamination Levels to Annual Total
Effective Dose Equivalent. Final Report, NUREG/CR-5512, PNL-7794, Vol. 1. October 1992.
NRC ADAMS Accession No. ML05222031. Available at URL: http://www.nrc.gov/about-
nrc/regulatory/decommissioning/reg-guides-comm/guidance.html.
Materion 2011. Beryllium Hydroxide Powder, Material Safety Data Sheet - No. D03. March 8,
2011.
Meisch, A.T. 1963. Distribution of Elements in Colorado Plateau Uranium Deposits - A
Preliminary Report. U.S. Geological Survey Bulletin 1147-E. U.S. Government Printing Office,
Washington, D.C. 1963. URL: http://pubs.usgs.gOv/bul/l 147e/report.pdf.
Morrison, S.J., and Cahn, L.S. 1991. "Mineralogical Residence of Alpha-Emitting
Contamination and Implications for Mobilization from Uranium Mill Tailings", in Journal of
Contaminant Hydrology, 8: pp. 1-21.
MWH Americas (MWH) 2010. Revised Infiltration and Contaminant Transport Modeling
Report, White Mesa Mill Site, Blanding Utah. Prepared for Denison Mines. March, 2010.
NEA & IAEA (OECD Nuclear Energy Agency, International Atomic Energy Agency), 2002.
Environmental Remediation of Uranium Production Facilities. Paris, France: OECD (Eds).
New Hampshire Department of Environmental Services (NHDES). 2010. Beryllium: Health
Information Summary (ARD-EHP-35). Accessed 4/22/13 at
http://des.nh.gov/organization/commissioner/pip/factsheets/ard/documents/ard-eph-35.pdf
46
f TDC
Nuclear Regulatory Commission (NRC) 1979. Final Environmental Statement Related to
Operation of White Mesa Uranium Project.
NRC 1980. US Nuclear Regulatory Commission (NRC). Regulatory Guide 4.14, Radiological
Effluent and Environmental Monitoring at Uranium Mills. Revision 1. April, 1980.
NTP 2011. U.S. Department of Health and Human Services, Public Health Service, National
Toxicology Program (NTP). (2011). Report of Carcinogens, Twelfth Edition.
Utah Division of Radiation Control (UDRC) 2004. Statement of Basis for a Uranium Milling
Facility at White Mesa, South of Blanding, Utah, December 1, 2004.
U. S. Environmental Protection Agency (EPA). 2013. Integrated Risk Information System
(IRIS). Beryllium and compounds (CASRM 7440-41-7). Accessed at
http://www.epa.gov/iris/subst/0012 htm on 4120/13.
USGS, 2001 US Geological Survey, Environmental Canada Climate Information Branch,
National Water Conditions. pH of Precipitation for November 26-December 23, 2001.
http:/water.us.gov/nwc/NWC/pH/html/ph.html
Utah Department of Environmental Quality Division of Radiation Control 2011. Ground Water
Discharge Permit, Permit No. UGW370004. February 15, 2011.
Utah Division of Air Quality 2011. Air Approval Order Number DAQE-ANOl 12050018-11.
Wambach, P. F. and J. C. Laul 2008. Beryllium health effects, exposure limits and regulatory
requirements. Journal of Chemical Health and Safety. Volume 15, Number 4.
Walsh, K. 2009. Beryllium Chemistry and Processing. ASM International.
Weast, R.C. (ed.) 1987. CRC Handbook of Chemistry and Physics, 68th edition.
Wiberg, N., Holleman, A.F. and E. Wiberg (Eds.) 2001. Inorganic Chemistry.
47
URS
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Uranium Materia! Transportation Route In Utah
Figure 1. Primary Transportation Corridors in Utah
48
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ATTACHMENT A:
Table A-1
Total Percentages of Mass and Concentrations Contributed by Uranium Material
Constituents to Tailings Over a 10-Year Period
49
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Table A-1. Total Percentage of Mass and Concentrations Contributed by Uranium Material Constituents to Tailings Over a 10-Year Period
Midnite Mine Uranium Material
Composition Cell 3 Composition in 2004
Baseline for Cell 4A
(or 4B)
Component
Cone, in Ores
and Other
Alternate Feeds
(PP™)1
Range in
Uranium Material
<m9/k9>'
Estimated
Average Cone. In
Uranium Material
i™g/kg>3
Estimated
Historical
Maximum Annual
Mass in Uranium
Material (tons)4
Estimated Cone.
Range In Cell 3
Mill Tailings
solution (mg/L or
PP™)'
Estimated
Average Cone. In
Cell 3 Mill
Tailings solution
(mg/L or ppm)'
Estimated Mass
in Cell 3 Mill
Tailings 2004
(tons)'
H
Estimated
Annual Mass in
Cell 4A or 4B Mill
Tailings (tons)'
Cone. In Cell 4A
(or 4B) Mill
Tailings (ppm)'
Estimated Mass
in Uranium
Material (tons)'
1K
Mass in Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing
(tons)"
1L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing
(PP™>"
1M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing
<PPm>"
U 28-514 192 340 41.3 41.3 192.0 0.0
Ammonia (NH«) 100-730 8.0 0.002 3-13,900 3.131 5.539 673.2 673.2 3130.6 -0.4
Arsenic (As)
Barium (Ba)
Beryllium (Be)
Cadmium (Cd)
Calcium |Ca) up to 217,000 15.000-16,000
Cobalt (Co)
Chromium (Cr)
Chloride (Cl) 2.110-8,000
Copper (Cu)
Fluoride (F)
Iron (Fe) up to 46.000
Lead (Pb)
Manganese (Mn) 96 000-110.000
Mercury (Hg)
Molybdenum (Mo)
Nickel (Nl)
Nitrates (NOx)
Selenium (Se)
Silver (Ag)
Sulfate (SO.=) 28.900-190.000
Thallium (TT)
Tin (Sn) 20,900-116,000
Vanadium (V) 56.5 263.0
Zinc (Zn)
Total Selected Components 30.2
Total Tailings Cell Mass 215000.0 215030.2
* - Assume 20% reduction per year for 5 years from historical maximum levels (190 tons per year) to final remedy estimate of 18 tons per year dry uranium material.
1. The concentration in other alternate feeds represents some selected concentrations for constituents found in characterization data for other alternate feed materials licensed for processing at the Mill, for comparison purposes.
2. The range in the Uranium Material is based on three sampling events for the DMC WTP solids.
3. The estimated average concentration in Uranium Material has been calculated as the mean value reported.
4. Estimated mass in the Uranium Material is calculated by assuming 197 tons dry annually from historical values.
5. Mill tailings range and average concentrations were taken from Mill tailings samples to date, as summanzed in Table 5 of the draft Statement of Basis for the Utah Groundwater Discharge Permit for the Mill (November 29. 2004).
6. Estimated current mass in Mill tailings is calculated by multiplying the estimated average concentration in the Mill tailings in Column F by 1,769.000 dry tons of tailings reported in the Mill's active Tailings Cell No. 3.
7. The baseline estimated annual mass in Mill tailings for cell 4A or 4B is calculated by multiplying the estimated mass in Cell 3 (Column G) by the ratio of Cell 4A (or 4B) total mass capacity of 2.150.000 dry tons to capacity of Cell 3 of 1,769.000 dry tons as of November;
and dividing it by ten years as the estimated time to fill cell 4A (or 4B).
8. The baseline concentration in Cell 4A (or 4B) Mill tailings is calculated by dividing Column H by 215,000 dry tons as the assumed annual mass addition ot tailings lo the Cell without the Uranium Material
9. Year 1 and Year 2 estimated mass in the Uranium Material is assumed to be equal to Column D historical values.
10. The mass in Mill tailings after Uranium Material processing is calculated by adding the total tailings mass from the previous year to the total additional tailings mass added in the current year.
11. The concentration in Cell 4A (or 4B) Mill tailings after Uranium Material processing is calculated by dividing the Mass in Cell 4A (or 4B) Mill tailings for that year by the total cumulative mass in cell 4A (or 4B) tailings after Uranium Material is processed.
12. The increase in baseline Mill tailings concentration after Uranium Material processing is calculated by subtracting baseline concentration (Column I) from the concentration in Cell 4A (or 4B) after Uranium Material processing for that year.
13. The Year 3 and Year 4 approximate estimated mass in the Uranium Material is assumed to be 5 times the amount in Column D based on the estimated increased flow treated to be 1,000 gpm for 7 months of the year and 450 gpm for the remaining 5 months.
14. The Year 5 through Year 10 approximate estimated mass in the Uranium Material is assumed to be reduced from the maximum historical value per year to the final remedy estimate of dry Uranium Material (20 %reduction per year) after 2 years of construction.
15. The Estimated Mass in Uranium Material over 10-Year Period is the Cumulative Contribution from the Uranium Material to the tailings
16. The Estimated Mass in Cell 4A (or 4B) Mill tailings over 10-year period after Uranium Material processing is the total cumulative mass contribution from including Uranium Material to the tailings
17. The approximate percent total contributed from Uranium Material is the 10-year contribution to the tailings from the Uranium Material.
50
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Table A-1. Total Percentage of Mass and Concentrations Contributed by Uranium Material Constituents to Tailings Over a 10-Year Period
Year 2 Year 3 (Const) Year 4 (Const)
Component
Estimated Mass in
Uranium Material
(tons)'
2K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)1'
2L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
2M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)"
Estimated Mass in
Uranium Material
(tons)"
3K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)"
3L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)1'
3M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)1'
Estimated Mass in
Uranium Material
(tons)1'
4K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)"
4L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
4M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing
(PP™)"
Acetone 82.6 192.0 0.0 123.8 191.9 -0.1 165.1 191.9 -0.1
Ammonia (NH«; 1346.3 3130.6 -0.4 2019.5 3129.9 -1.1 2692.7 3129.6 -1 4
Arsenic (As)
Barium (Ba)
Beryllium (Be)
Cadmium (Cd)
Calcium (Ca)
Cobalt (Co)
Chromium (Cr)
Chloride (Cl)
Copper (Cu)
Fluoride (F)
Iron (Fe)^
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nickel (Nl)
Nitrates (NOx)
Selenium (Se)
Silver (Ag)
Sulfate (SQ,=)
Thallium (Tl)
Tin (Sn)
Vanadium (V)
Zinc (Zn)
Total Selected Components 30.2 160.0 160.0
Total Tailings Cell Mass 430060.4 645220.4 860380.3
- Assume 20% reduction per year for 5 years from historical maximum levels (190 tons per year) to final remedy estimate of 18 tons per year dry uranium matenal.
1. The concentration in other alternate feeds represents some selected concentrations for constituents found in characterization data for other alternate feed materials licensed for processing at the Mill, for comparison purposes.
2. The range in the Uranium Material is based on three sampling events for the DMC WTP solids.
3. The estimated average concentration in Uranium Material has been calculated as the mean value reported
4. Estimated mass in the Uranium Material is calculated by assuming 197 tons dry annually from historical values.
5. Mill tailings range and average concentrations were taken from Mill tailings samples to date, as summarized in Table 5 of the draft Statement of Basis for the Utah Groundwater Discharge Permit for the Mill (November 29. 2004).
6. Estimated cun-ent mass in Mill tailings is calculated by multiplying the estimated average concentration in the Mill tailings in Column F by 1,769,000 dry tons of tailings reported in the Mill's active Tailings Cell No. 3.
7. The baseline estimated annual mass in Mill tailings for cell 4A or 4B is calculated by multiplying the estimated mass in Cell 3 (Column G) by the ratio of Cell 4A (or 4B) total mass capacity of 2,150,000 dry tons to capacity of Cell 3 of 1,769,000 dry tons as of
November 29. 2004 and dividing it by ten years as the estimated time to fill cell 4A (or 4B).
8. The baseline concentration in Cell 4A (or 4B) Mill tailings is calculated by dividing Column H by 215,000 dry tons as the assumed annual mass addition of tailings to the Cell without the Uranium Material
9. Year 1 and Year 2 estimated mass in the Uranium Material is assumed to be equal to Column D historical values.
10. The mass in Mill tailings after Uranium Material processing is calculated by adding the total tailings mass from the previous year to the total additional tailings mass added in the current year.
11. The concentration in Cell 4A (or 4B) Mill tailings after Uranium Material processing is calculated by dividing the Mass in Cell 4A (or 4B) Mill tailings for that year by the total cumulative mass in cell 4A (or 4B) tailings after Uranium Material is processed.
12. The increase in baseline Mill tailings concentration after Uranium Material processing is calculated by subtracting baseline concentration (Column I) from the concentration in Cell 4A (or 4B) after Uranium Material processing for that year.
13. The Year 3 and Year 4 approximate estimated mass in the Uranium Material is assumed to be 5 times the amount in Column D based on the estimated increased flow treated to be 1,000 gpm for 7 months of the year and 450 gpm for the remaining 5 months.
14. The Year 5 through Year 10 approximate estimated mass in the Uranium Material is assumed to be reduced from the maximum historical value per year to the final remedy estimate of dry Uranium Matenal (20 %reduction per year) after 2 years of construction.
15. The Estimated Mass in Uranium Matenal over 10-Year Penod is the Cumulative Contribution from the Uranium Material to the tailings
16. The Estimated Mass in Cell 4A (or 4B) Mill tailings over 10-year period after Uranium Material processing is the total cumulative mass contnbution from including Uranium Material to the tailings
17. The approximate percent total contributed from Uranium Matenal is the 10-year contribution to the tailings from the Uranium Material.
51
URS
Table A-1. Total Percentage of Mass and Concentrations Contributed by Uranium Material Constituents to Tailings Over a 10-Year Period
YearS
Component
Estimated Mass in
Uranium Material
(tons)14
5K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)'"
SL
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
5M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)"
Estimated Mass in
Uranium Material
(tons)14
6K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)10
EL
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
6M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)1'
7J
Estimated Mass in
Uranium Material
(tons)14
7K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)1"
7L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
7M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)"
206.4 191.9 -0.1 247.7 191.9 -0.1 0.000 289.0 191.9 -0.1
Ammonia (NH4) 3365.8 -12 4039.0 3130.0 -1.0 0.001 4712.2 3130.1 -0 9
Arsenic (As)
Barium (Ba)
Jieryllium (Be)_
Cadmium (Cd)
Calcium (Ca)
Cobalt (Co)
• (Cr)
Chloride (Cl)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Molybde 1 (Mo)
Nickel (Ni)
Nitrates (NOx)
Selenium (Se|
Silver (Ag)
Sulfate (SO,=)
Thallium (Tl)
Tin (Sn)
Vanadium (V)
Zinc (Zn)
Total Selected Components 30.2 24.7 19.3
Total Tailings Cell Mass 1075410.5 1290435.3 1505454.5
- Assume 20% reduction per year for 5 years from historical maximum levels (190 tons per year) to final remedy estimate of 18 tons per year dry uranium material.
1. The concentration in other alternate feeds represents some selected concentrations for constituents found in characterization data for other alternate feed materials licensed for processing at the Mill, for comparison purposes.
2. The range in the Uranium Material is based on three sampling events for the DMC WTP solids.
3. The estimated average concentration in Uranium Material has been calculated as the mean value reported.
4. Estimated mass in the Uranium Material is calculated by assuming 197 tons dry annually from historical values.
5. Mill tailings range and average concentrations were taken from Mill tailings samples to date, as summarized in Table 5 of the draft Statement of Basis for the Utah Groundwater Discharge Permit for the Mill (November 29, 2004).
6. Estimated current mass in Mill tailings is calculated by multiplying the estimated average concentration in the Mill tailings in Column F by 1,769.000 dry tons of tailings reported in the Mill's active Tailings Cell No. 3.
7. The baseline estimated annual mass in Mill tailings for cell 4A or 4B is calculated by multiplying the estimated mass in Cell 3 (Column G) by the ratio of Cell 4A (or 4B) total mass capacity of 2.150,000 dry tons to capacity of Cell 3 of 1.769.000 dry tons as of November 29, 2004
and dividing it by ten years as the estimated time to fill cell 4A (or 48).
8. The baseline concentration in Cell 4A (or 4B) Mill tailings is calculated by dividing Column H by 215,000 dry tons as the assumed annual mass addition of tailings to the Cell without the Uranium Material
9. Year 1 and Year 2 estimated mass in the Uranium Material is assumed to be equal to Column D historical values.
10. The mass in Mill tailings after Uranium Material processing is calculated by adding the total tailings mass from the previous year to the total additional tailings mass added in the current year.
11. The concentration in Cell 4A (or 4B) Mill tailings after Uranium Material processing is calculated by dividing the Mass in Cell 4A (or 4B) Mill tailings for that year by the total cumulative mass in cell 4A (or 4B) tailings after Uranium Material is processed.
12. The increase in baseline Mill tailings concentration after Uranium Material processing is calculated by subtracting baseline concentration (Column I) from the concentration in Cell 4A (or 4B) after Uranium Material processing for that year.
13. The Year 3 and Year 4 approximate estimated mass in the Uranium Material is assumed to be 5 times the amount in Column D based on the estimated increased flow treated to be 1,000 gpm for 7 months of the year and 450 gpm for the remaining 5 months.
14. The Year 5 through Year 10 approximate estimated mass in the Uranium Material is assumed to be reduced from the maximum historical value per year to the final remedy estimate of dry Uranium Material (20 %reduction per year) after 2 years of construction.
15. The Estimated Mass in Uranium Material over 10-Year Period is the Cumulative Contribution from the Uranium Material to the tailings
16. The Estimated Mass in Cell 4A (or 4B) Mill tailings over 10-year period after Uranium Material processing is Ihe total cumulative mass contribution from including Uranium Material to the tailings
17. The approximate percent total contributed from Uranium Material is the 10-year contribution to the tailings from the Uranium Material.
52
URS
Table A-1. Total Percentage of Mass and Concentrations Contributed by Uranium Material Constituents to Tailings Over a 10-Year Period
Estimated Mass in
Uranium Material
(tons)14
8K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)"
8L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)11
8M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)1'
Estimated Mass in
Uranium Material
(tons)14
9K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)1'
9L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)1'
9M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing (ppm)"
10J
Estimated Mass in
Uranium Material
(tons)14
10K
Mass in Cell 4A (or
4B) Mill Tailings
after Uranium
Material
Processing (tons)"
10L
Cone. In Cell 4A
(or 4B) Mill
Tailings after
Uranium Material
Processing (ppm)1'
10M
Increase in
Baseline Mill
Tailings Cone.
After Uranium
Material
Processing
(PPm)"
Acetone 330.2 191.9 -0.1 371.5 192.0 0.0 0.000 412.8 192.0 0 0
Ammonia (NH,) 5385.3 6058.5 3130.2 -0.8 0.000 6731.7 3130.3 -0.7
Arsenic (As)
i(Ba)
Beryllium (Be)
Cadmium (Cd)
Calcium (Ca)
Cobalt (Co)
Chromium (Cr)
Chloride (Cl)
Copper (Cu)
Fluoride (F)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nickel (N_i)_
Nitrates (NOx)
Selenium (Se)
Silver (Ag)
Sulfate {SO.=l
Thallium (Tl)
Tin (Sn)
Vanadium (V)
Zinc (Zn)
Total Selected Components 13.8 8.3 2.9
Total Tailings Cell Mass 1720468.3 1935476.7 2150479.5
- Assume 20% reduction per year for 5 years from historical maximum levels (190 tons per year) to final remedy estimate of 18 tons per year dry uranium material.
1. The concentration in other alternate feeds represents some selected concentrations for constituents found in characterization data for other alternate feed materials licensed for processing at the Mill, for comparison purposes.
2. The range in the Uranium Material is based on three sampling events for the DMC WTP solids.
3. The estimated average concentration in Uranium Matenal has been calculated as the mean value reported.
4. Estimated mass in the Uranium Material is calculated by assuming 197 tons dry annually from historical values.
5. Mill tailings range and average concentrations were taken from Mill tailings samples to date, as summanzed in Table 5 of the draft Statement of Basis for the Utah Groundwater Discharge Permit for the Mill (November 29, 2004).
6. Estimated cunent mass in Mill tailings is calculated by multiplying the estimated average concentration in the Mill tailings in Column F by 1.769,000 dry tons of tailings reported in the Mill s active Tailings Cell No. 3.
7. The baseline estimated annual mass in Mill tailings for cell 4A or 4B is calculated by multiplying the estimated mass in Cell 3 (Column G) by the ratio of Cell 4A (or 4B) total mass capacity of 2.150,000 dry tons to capacity of Cell 3 of 1.769,000 dry tons as of November 29, 2004
and dividing it by ten years as the estimated time to fill cell 4A (or 4B)
8. The baseline concentration in Cell 4A (or 4B) Mill tailings is calculated by dividing Column H by 215,000 dry tons as the assumed annual mass addition of tailings to the Cell without the Uranium Material
9. Year 1 and Year 2 estimated mass in the Uranium Material is assumed to be equal to Column D historical values.
10. The mass in Mill tailings after Uranium Material processing is calculated by adding the total tailings mass from the previous year to the total additional tailings mass added in the current year.
11. The concentration in Cell 4A (or 4B) Mill tailings after Uranium Material processing is calculated by dividing the Mass in Cell 4A (or 4B) Mill tailings for that year by the total cumulative mass in cell 4A (or 4B) tailings after Uranium Material is processed.
12. The increase in baseline Mill tailings concentration after Uranium Material processing is calculated by subtracting baseline concentration (Column I) from the concentration in Cell 4A (or 4B) after Uranium Material processing for that year.
13. The Year 3 and Year 4 approximate estimated mass in the Uranium Material is assumed to be 5 times the amount in Column D based on the estimated increased flow treated to be 1.000 gpm for 7 months of the year and 450 gpm for the remaining 5 months.
14. The Year 5 through Year 10 approximate estimated mass in the Uranium Matenal is assumed to be reduced from the maximum historical value per year to the final remedy estimate of dry Uranium Material (20 %reduction per year) after 2 years of construction.
15. The Estimated Mass in Uranium Matenal over 10-Year Period is the Cumulative Contribution from the Uranium Material to the tailings
16. The Estimated Mass in Cell 4A (or 4B) Mill tailings over 10-year period after Uranium Matenal processing is the total cumulative mass contribution from including Uranium Material to the tailings
17. The approximate percent total contributed from Uranium Matenal is the 10-year contribution to the tailings from the Uranium Material.
5^
URS
Table A-1. Total Percentage of Mass and Concentrations Contributed by Uranium Material Constituents to Tailings Over a 10-Year Period
Component
Acetone
Ammonia (NH<)
Arsenic (As)
Barium (Ba)
Beryllium (Be)
'(Cd)
Calcium (Ca)
Cobalt (Co)
Chromium (Cr)
Chloride (Cl)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nickel (Ni)
Nitrates (NOx)
Selenium (Se)
Silver (Ag)
Sulfate (SO.-)
Thallium (Tl)
Tin (Sn)
Vanadium (V)^
Zinc (Zn)
Total Selected Components
Total Tailings Cell Mass
Final
N
Estimated Mass
in Uranium
Material over
10-year Period
(tons)"
0.0
0.0
479.5
Estimated Mass
in Cell 4A (or
4B) Mill Tailings
over 10-year
Period After
Uranium
Material
Processing
(tons)"
412.8
6731.7
2150479.5
Percent Total
Contributed
from Uranium
Material"
0.000%
0.0223%
- Assume 20% reduction per year for 5 years from historical maximum levels (190 tons per year) to final remedy estimate of 18 tons per year dry uranium material.
1. The concentration in other alternate feeds represents some selected concentrations for constituents found in characterization data for other alternate feed materials licensed for processing at the Mill, for comparison purposes.
2. The range in the Uranium Material is based on three sampling events for the DMC WTP solids.
3. The estimated average concentration in Uranium Material has been calculated as the mean value reported.
4. Estimated mass in the Uranium Material is calculated by assuming 197 tons dry annually from historical values.
5. Mill tailings range and average concentrations were taken from Mill tailings samples to date, as summarized in Table 5 of the draft Statement of Basis for the Utah Groundwater Discharge Permit for the Mill (November 29, 2004).
6. Estimated current mass in Mill tailings is calculated by multiplying the estimated average concentration in the Mill tailings in Column F by 1.769.000 dry tons of tailings reported in the Mill's active Tailings Cell No. 3.
7. The baseline estimated annual mass in Mill tailings for cell 4A or 4B is calculated by multiplying the estimated mass in Cell 3 (Column G) by the ratio of Cell 4A (or 4B) total mass capacity of 2.150.000 dry tons to capacity of Cell 3 of 1.769.000 dry tons as of November 29. 2004
and dividing it by ten years as the estimated time to fill cell 4A (or 4B).
8. The baseline concentration in Cell 4A (or 4B) Mill tailings is calculated by dividing Column H by 215.000 dry tons as the assumed annual mass addition of tailings to the Cell without the Uranium Material
9. Year 1 and Year 2 estimated mass in the Uranium Material is assumed to be equal to Column D historical values.
10. The mass in Mill tailings after Uranium Material processing is calculated by adding the total tailings mass from the previous year to the total additional tailings mass added in the current year.
11. The concentration in Cell 4A (or 4B) Mill tailings after Uranium Material processing is calculated by dividing the Mass in Cell 4A (or 4B) Mill tailings for that year by the total cumulative mass in cell 4A (or 4B) tailings after Uranium Material is processed.
12. The increase in baseline Mill tailings concentration after Uranium Material processing is calculated by subtracting baseline concentration (Column I) from the concentration in Cell 4A (or 4B) after Uranium Material processing for that year.
13. The Year 3 and Year 4 approximate estimated mass in the Uranium Material is assumed to be 5 times the amount in Column D based on the estimated increased flow treated to be 1.000 gpm for 7 months of the year and 450 gpm for the remaining 5 months.
14. The Year 5 through Year 10 approximate estimated mass in the Uranium Material is assumed to be reduced from the maximum histoncal value per year to the final remedy estimate of dry Uranium Matenal (20 %reduction per year) after 2 years of construction.
15. The Estimated Mass in Uranium Material over 10-Year Period is the Cumulative Contribution from the Uranium Material to the tailings
16. The Estimated Mass in Cell 4A (or 4B) Mill tailings over 10-year period after Uranium Material processing is the total cumulative mass contribution from including Uranium Material to the tailings
17. The approximate percent total contributed from Uranium Material is the 10-year contribution to the tailings from the Uranium Material.
54