Pathfinder - Shirley Basin North

1.0 General Site Information

Site Location:	Mills, WY
Former NRC License No.:	SUA-442
NRC Docket No.:	40-6622
Agreement State Contact:	Omar Nusair	307-777-7057
NRC Agreement State Site Monitor:	Duncan White	Duncan.White@nrc.gov
NRC Site Monitor:	John Saxton	John.Saxton@nrc.gov

2.0 Site Description

The Pathfinder Shirley Basin Uranium Recovery Facility is a former conventional mill site located in Carbon County, Wyoming, approximately 35 miles South of Casper, Wyoming (Figure 1). The nearest major surface water body is Spring Creek, which abuts the northern site perimeter (Figure 2).

Figure 1. Shirley Basin Uranium Mill Site Location Map

Figure 2. Shirley Basin Site Layout.
Source: Pathfinder Mines Corporation. “Shirley Basin Mine Tailings Reclamation Plan.” Volume 2. Mills, Wyoming: Pathfinder Mines Corporation. 1993

3.0 Site History

The mill actively produced yellowcake from ore between 1971 and 1992.  In 1992, an estimated 15.3 million tons of tailings were deposited in the tailings impoundment. The former facility area included two solid tailings impoundments (covering approximately 158 acres and 135 acres) and a 30-acre solution pond (Pond 3), now being used for ISR disposal. The former mill has been decommissioned according to the decommissioning plan submitted to the NRC in 1992. Pathfinder has completed other reclamation activities, including grading, radon clay barrier installation, sand layer installation, topsoil installation and reseeding (Area 3 north waste dump, Area 3 south waste dump, and former topsoil piles), and rock mulch installation for all ponds except Pond 3. The licensee requested that a portion of the tailings impoundment (Pond 3) remain open for future acceptance of byproduct material, primarily from ISR facilities.  It was estimated that the impoundment could accommodate an additional 1.7 tons of byproduct material (ADAMS Accession Number ML20073S255).  In an agreement with Wyoming, the site was permitted to receive an additional 54,650 cubic yards of byproduct material.  Surface reclamation has been performed with the exception of the open tailings impoundment.  It is estimated that the operational life expectancy to reach the capacity is 50 years.

The site has been owned by Pathfinder Mines Corporation.  Pathfinder Mines Corporation was a subsidiary of Cogema until 2013 at which time Pathfinder Mines Corporation became a subsidiary of UR-Energy.   The NRC had regulatory authority over the site until Wyoming became an Agreement State in 2018 and acquired regulatory oversight.  In 2021, The State of Wyoming approved ISR operations at the site.

4.0 Current NRC actions/status

None. Upon completion of the expected 50-year operations, WDEQ/LDQ will submit a Completion Review Report for NRC's review.

5.0 Expected Transfer to DOE for LTS&M

2047 (See DOE LM Site Management Guide, June 2022)