2010-08-09_REPORT - M2007044

• Permit No: M2007044
• IBM Index Class Name: REPORT
• Doc Date: 8/9/2010
• Doc Name: Application for venting and monitoring radon emissions at the Whirlwind Mine
• From: ENERGY FUELS RESOURCES CORP
• To: EPA
• Email Name: GRM
• Email Name: ACS
• Media Type: D
• Archive: No

? ENERGY FUELS RESOURCES
CORPORATION
April 1, 2009
Mrs. Angelique Diaz
USEPA Region 8, Indoor Air Program
1595 Wynkoop St.
Mail Code: 8P-AR
Denver, CO 80202-1129
[phone]
Re: 2008 Radon Emissions Modeling for the Whirlwind Mine
Dear Mrs. Diaz;
Please see the attached 2008 Radon Emissions Modeling report for the Whirlwind Mine.
The Whirlwind Mine is an underground uranium mine located at 30.100 5110 Road in
Gateway, Colorado. The effective dose equivalent of radon exposure to the nearest
resident, school or office to an underground uranium mine is required to be calculated by
40 CFR 61 Subpart B. The radon effective dose equivalent was calculated using the
COMPLY-R program.
The mine is operated by Mr. Jeff Osborn, General Manager and this report was prepared
by Zach Rogers, Environmental Engineer. Radon was measured using Landauer Radtrak
Environmental Monitors placed in the mine decline, near the portal. The mine portal is
the only ventilation point of the Whirlwind Mine. The following parameters were used to
calculate the radon effective dose equivalent:
• The portal measures approximately 12' wide by 9' tall.
• The flow rate at the portal was measured at 41,000 cfm in September, October, and
November and 5,700 cfm in December (the mine was put on stand=by in late
November and less ventilation was required).
• The effluent temperature was assumed to be 55 °F (COMPLY-R default value).
• No ventilation effluent controls are used at the Whirlwind Mine.
• The nearest public receptor is a part-time resident, located approximately 600 meters
northwest of the mine portal.
• The nearest meat producing receptor is cattle grazing operations located
approximately 6 km west of the mine portal and the closest farms are approximately 7
km northeast in the Town of Gateway.
• The average wind speed was assumed to be 2.0 m/s (COMPLY-R default value).
• The Whirlwind Mine began mining operations in September 2008.
• Average radon concentrations were measured at 18.5 pCi/L in September and 16.4
pCi/L in October through December.
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