APPLICATION FOR APPROVAL OF CONSTRUCTION 

PIÑON RIDGE TAILINGS FACILITIES 

 Energy Fuels Resources Corporation 

Prepared By: 44 Union Boulevard, Suite 600 

 Lakewood, Colorado 80228 

 U.S. Environmental Protection Agency 

 Region 8, Indoor Air Program 

Prepared For: 1595 Wynkoop Street 

Mail Code: 8P-AR 

 Denver, Colorado 80202-1129 

August 2010
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TABLE OF CONTENTS 

Section Page

1.0 INTRODUCTION ................................................................................................... 1 

2.0 PHASED DISPOSAL .............................................................................................. 1 

3.0 PROJECT DETAILS ............................................................................................... 1 

3.1 Applicant .............................................................................................................. 2 

3.2 Project Location ................................................................................................... 2 

3.3 Technical Information .......................................................................................... 2 

4.0 MONITORING AND REPORTING ....................................................................... 3 

5.0 REFERENCES ........................................................................................................ 4 

FIGURES 

Figure 1 Site Location Map 

Figure 2 Site Plan 

ATTACHMENTS 

Attachment 1 Operating Plan, Tailings Cells and Evaporation Ponds, Piñon 

Ridge Mill by Energy Fuels 

Attachment 2 Uranium Mill Tailings Radon Flux Calculations by Golder 

Associates Inc. 

Attachment 3 Tailings Cell Design Report, Piñon Ridge Project, Montrose 

County, Colorado by Golder Associates Inc. 
1 

1.0 INTRODUCTION 

Energy Fuels Resources Corporation (Energy Fuels) is submitting this construction 

application to the U.S. Environmental Protection Agency (EPA) in compliance with 40 

CFR Part 61, Subpart W for constructing and operating the first of three 

uranium/vanadium tailings disposal cells (Tailings Cell A), each encompassing 

approximately 30.5 acres. In accordance with 40 CFR Part 61.252(b)(1), the cells would 

be constructed in a phased manner with no more than two cells or impoundments in 

operation at any one time. 

The tailings cells have also been designed to provide equivalent or enhanced protection 

of groundwater compared to the requirements outlined in 40 CFR 192.32(a) and 

equivalent regulations adopted by the Nuclear Regulatory Commission (NRC) and the 

State of Colorado. The Radiation Control Program of CDPHE is currently reviewing the 

tailings cell plans for compliance with these regulations. Because Colorado is an 

Agreement State with NRC, they are the responsible “regulatory agency” as defined 

under 40 CFR 192.31(g). 

2.0 PHASED DISPOSAL 

The Subpart W regulations currently require that tailings impoundments meet one of the 

two following work practices. 

(1) Work Practice 1: Phased disposal in lined tailings impoundments that are no more 

than 40 acres in area and meet the requirements of 40 CFR 192.32(a) as determined 

by the Nuclear Regulatory Commission. The owner shall have no more than two 

impoundments, including existing impoundments, in operation at any one time. 

(2) Work Practice 2: Continuous disposal of tailings such that tailings are dewatered 

and immediately disposed with no more than 10 acres uncovered at any one time 

and operated in accordance with 40 CFR 192.32(a) as determined by the Nuclear 

Regulatory Commission. 

Energy Fuels elected to design in accordance with Work Practice 1 for phased disposal as 

it is more economical, less likely to result in liner damage, and provides better control of 

radon emissions by maintaining the tailings in a saturated state. Work Practice 2 for 

continuous disposal would necessitate operating practices similar to those employed at 

landfills with large equipment working within lined areas and unsaturated materials 

exposed to the elements. However, continuous disposal does provide for a quicker 

transition to cell closure. Although continuous disposal has been used successfully at 

some mining projects, the phased disposal method using standard tailings impoundments 

appears to be the best method for this site in terms of mill worker health and safety and 

protection of the environment. 

3.0 PROJECT DETAILS 

This section of the application addresses the information required in the construction 

application under 40 CFR 61.07. These informational requirements include applicant 

information, project location, technical design and operating information, and emission 

estimates. The project documents included with this application provide detailed 
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technical information on the various aspects of the project and should be considered part 

of the application. 

The Piñon Ridge Mill Radioactive Material License Application with the CDPHE may 

also be referenced for additional information on the design, construction, operation, and 

closure of the mill and tailings facilities. The license application is available at: 

http://www.cdphe.state.co.us/hm/rad/rml/energyfuels/application/index.htm. 

3.1 Applicant 

The construction applicant is Energy Fuels Resources Corporation, a Colorado 

Corporation. Energy Fuels Resources Corporation is a wholly owned U.S. subsidiary of 

Energy Fuels Inc., a Canadian Corporation. Energy Fuels Resources Corporation’s 

headquarters is located at 44 Union Boulevard, Suite 600, Lakewood, Colorado 80228. 

3.2 Project Location 

The proposed Piñon Ridge Mill is situated in Montrose County, Colorado on an 880-acre 

private parcel. The Property is located in Paradox Valley, approximately 12 miles west of 

Naturita and approximately 7 miles east of Bedrock, along the northeastern edge of Davis 

Mesa. The site address is 16910 Highway 90, Bedrock, Colorado 81411. 

More specifically, the Property is situated in the southwest quarter of the southeast 

quarter of Section 5, all of Section 8, the north quarter of Section 17, and southeast 

quarter of the northwest quarter of Section 17 in Township 46 North, Range 17 West of 

the New Mexico Prime Meridian. Access to the Project site is via State Highway 90 to 

milepost 23. Refer to Figure 1, Site Location Map, for the general location of the 

Property, and Figure 2, Site Map, for the Property boundary. 

Table 1 provides a legal description and geographical centroid coordinates for each of the 

tailings impoundments. At this time, Energy Fuels is requesting construction approval for 

Tailings Cell A (i.e., Tailings Impoundments A1 and A2) only. 

Table 1 

Tailings Impoundment and Evaporation Pond Locations 

Feature 

Legal Description 

(1) Centroid Coordinates (2)

Tailings Impoundment A1 Southeast Quarter N 38° 14' 59" W 108° 46' 00" 

Tailings Impoundment A2 South Half N 38° 14' 59" W 108° 46' 10" 

Tailings Impoundment B South Half N 38° 15' 08" W 108° 46' 05" 

Tailings Impoundment C All Quarters N 38° 15' 16" W 108° 46' 05" 

Notes: 

(1) All locations are in Section 8 of Township 46 North, Range 17 West of the NMPM 

(2) Geographical coordinates are in NAD83 datum 

3.3 Technical Information 

Technical information requirements for the Application for Approval of Construction are 

outlined in 40 CFR Subpart A 61.07(b)(3) and (c)(1), (2), and (3). They include: 

“describing the proposed nature, size, design, operating design capacity, and method of 
3 

operation of the source, including a description of any existing source.” Each application 

shall also include: “(1) The precise nature of the proposed changes; (2) The productive 

capacity of the source before and after the changes are completed; and (3) Calculations of 

estimates of emissions before and after the changes are completed, in sufficient detail to 

permit assessment of the validity of the calculations. 

The Piñon Ridge Mill is a new facility with only natural sources of radiation currently 

present on site. Soil radon flux levels for the site fluctuate during the year but average 

approximately 1.7 ρCi/m2-s (ERG 2009). Although the application discusses phased 

tailings disposal over the 40-year projected mill life, this application is limited to 

constructing and operating Tailings Cell A (30.5 acres) at an average milling rate of 500 

tons per day. This cell will have a capacity of approximately 2.45 million tons of tailings. 

As discussed in the “Uranium Mill Tailings Radon Flux Calculations” report by Golder 

Associates Inc. (see below), the radon flux from the tailings cell is estimated to range 

between 3 and 8 ρCi/m2-s during normal operations. 

The following documents, which are included with this Application for Approval of 

Construction, provide detailed operating, emissions, and design information, respectively, 

for the proposed tailings facility. 

(1) Operating Plan, Tailings Cells and Evaporation Ponds, Piñon Ridge Mill by Energy 

Fuels: This plan provides a summary of the design components and a detailed 

review of operating and monitoring procedures for these facilities. 

(2) Uranium Mill Tailings Radon Flux Calculations by Golder Associates Inc. 

(Golder): This report evaluates radon flux from the tailings cells over a variety of 

operating conditions. The results of this modeling effort were used to develop the 

Operating Plan. 

(3) Tailings Cell Design Report, Piñon Ridge Project, Montrose County, Colorado by 

Golder: This report presents the design for the tailings cells. 

4.0 MONITORING AND REPORTING 

Monitoring and reporting requirements are outlined under 40 CFR 61.09. In accordance 

with this regulation, Energy Fuels will provide notification of the anticipated date of 

initial startup of Tailings Cell A not more than 60 days nor less than 30 days prior to the 

anticipated date. Further, a notification of the actual date of initial startup for Tailings 

Cell A will be submitted within 15 days after that date. In accordance with 40 CFR 

61.256, facilities designated under subpart W are exempt from the source reporting 

requirements listed in 40 CFR 61.10. 

Radon flux monitoring is required only for existing sources as of the effective date (i.e., 

December 15, 1989) of the regulation under subpart W in accordance with 40 CFR 

61.252(a). This monitoring is not required for new tailings impoundments as they are 

restricted in size by 40 CFR 61.252(b). The size limitations for new tailings 

impoundments were adopted to restrict potential radon emissions to levels that are 

considered to be protective of human health. 
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5.0 REFERENCES 

Environmental Restoration Group, Inc (ERG) 2009. Baseline Radiological Investigation 

Report. Piñon Ridge Uranium Mill. Montrose County, Colorado. October 5. This report 

may be found in Volume 9 of the Radioactive Materials License Application on 

CDPHE’s website. 
UV141

UV90

UV90

UV141

Nucla

Uravan

Bedrock

Naturita

3

1 0 1 2 3

Miles

Scale

Energy Fuels

Resources Corporation

Created Drawn By

FIGURE 1

Figure1_082010.mxd

See Scale Bar August 20, 2010 ZTR

SITE LOCATION MAP

^`

Moab

Nucla

Denver

Montrose

Blanding

Telluride

Canon City

Grand Junction

Colorado Springs

Legend

Cities/Towns

ProjectBoundary
EVAPORATION PONDS

ORE

PAD

MILL 

FACILITY

TAILINGS CELL C

TAILINGS CELL B

TAILINGS CELL A

Phase 1

Phase 2

A2 A1

N 38° 15' 16"

W 108° 46' 05"

N 38° 15' 08"

W 108° 46' 05"

N 38° 14' 59"

W 108° 46' 10"

N 38° 14' 59"

W 108° 46' 00"

8 9

7

17

5

16

18

4

6

UV90 3

1,000 0 1,000 2,000

Feet Scale

Energy Fuels

Resources Corporation

Created Drawn By

FIGURE 2

Figure2_081910.mxd

See Scale Bar August 25, 2010 ZTR

SITE PLAN

Legend

Project Boundary

Site Contour, 10-ft

Tailings Impoundment Contour, 10-ft

Evaporation Pond Contour, 2-ft

Centroid of Feature