FROM: Kim Morrison Date: 

-~~+. :3 \ -+ rn') 

Energy Fuels Resources (USA) Inc. 

225 Union Blvd. Suite 600 

Lakewood, CO, US, 80228 

303-97 4-2140 

www .energyfuels.com 

3 September 2014 

COMMENTS- EPA SUBPART W PUBLIC HEARING 

My name is Kim Morrison, and I am a consulting geotechnical engineer representing Energy 

Fuels, and the Environmental Manager for the proposed Sheep Mountain Project in Wyoming. 

The Sheep Mountain Project, which includes a proposed uranium heap leach facility, was 

heavily referenced by the EPA in the background information for the proposed rules. However, 

there is a clear misunderstanding by the EPA on the concepts of heap leaching; the reduced 

level of radium in a uranium heap leach facility as compared to a uranium tailings impoundment; 

and a fundamental misunderstanding of the differences between moisture saturation and 

moisture content. 

• When uranium ore is being leached on a heap leach facility, it is actively recovering 

uranium and is neither "tailings" nor 11 e.(2) byproduct material as defined by the Atomic 

Energy Act. When uranium recovery is complete, the spent ore then becomes 11 e.(2) 

byproduct material. But, at that time, the facility is no longer "active," nor "operational." 

As such, a heap leach facility, by definition, is not applicable to the Subpart W rules that, 

by title, are applicable to mill tailings in "operating" facilities. 

• If the position that heap leach facilities are applicable to Subpart W is maintained, then 

the EPA needs to understand the various types of heap leach facilities proposed for 

uranium recovery. The revised rules focus merely on regulating in-place permanent 

conventional heap leach facilities, but make no mention of other facilities, such as an onoff heap leach facility where material is leached on an engineered pad after which the 

leached ore is removed and placed in a permanent disposal facility. 

• The EPA has proposed that heap leach facilities maintain a minimum moisture content 

of 30%. Based on a review of the background information, it appears that the EPA are 

referring to the moisture content as a percentage of the weight. The proposed 30% 

water content is neither practical nor achievable if the heap leach facility is operated as 

intended. To put the proposed 30% moisture content into perspective, this would 

correspond to 185% ore saturation for the proposed Sheep Mountain Project. As such, 

this proposed rule would require that the ore be not only fully saturated, but "submerged" 

at all times. We have reviewed the background information EPA used to support the 

30% moisture content proposal, and found a number of invalid assumptions in their 

approach. For instance, moisture saturation as a percent of available void space and 

moisture content as a percent of weight are not interchangeable parameters, nor is the 

relationship between the two parameters a constant. 

• Low grade ore is typically processed by heap leach methods, and the low grade ore 

contained within a heap leach facility emits less radon than a conventional tailings 

impoundment of a similar size assuming similar physical conditions. For example, the 

proposed ore grade at the Sheep Mountain Project is approximately 0.1% uranium, while 

ore grades of about 0.2% to 0.7% uranium have been processed at the White Mesa Mill 

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3 September 2014 

Subpart W Commen1s 

over the past three years. As such, a one-size-fits-all approach to setting moisture 

content requirements is overly conservative, and should be determined instead based on 

data and analysis. 

~ Using liquid levels to control radon emissions from a heap leach facility conflicts with the 

overall operational concept of a heap leach facility; would significantly dilute the leaching 

solution; would have an adverse effect on the process; significantly increase driving 

head on the underlying liner system; would result in much greater construction and 

operating costs for the facilities; and, would result in the wasteful consumption of water. 

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