Pathfinder - Shirley Basin

1.0 Site Identification

2.0 Site Status Summary

The Shirley Basin site is located in eastern Wyoming. The former uranium mill and mine site is located approximately 5 miles northeast of the former Shirley Basin town site. The town of Shirley Basin functioned primarily as a mining camp, and has been entirely abandoned for more than 10 years. The nearest residence is a ranch located approximately three miles east of the tailings site.

Uranium milling began on the site in 1971, and continued through 1992, when the last ore was processed. The site has two solid tailings impoundments, the largest covering approximately 158 acres, and the smaller 135 acres. A solution pond, which is also the disposal location for 11e.(2) byproduct material from ISL mines, covers approximately 30 acres. The mill has been decommissioned according to the DP submitted to NRC in 1992. Pathfinder has reclaimed approximately 90 percent of the tailings and has discontinued groundwater reclamation, due to staff's approval of the proposed alternate concentration limits (ACLs). Pathfinder intends to operate its ISL disposal area for the forseeable future.

3.0 Major Technical or Regulatory Issues

Staff issued the license amendment for ACLs at this site in October 2005. To address concerns regarding sudden pollutant loads to Spring Creek, a license amendment was added requiring Pathfinder to maintain its ground water remediation system until staff determine it is no longer needed. Post ACL sampling has been ongoing for the past 1.5 years. Some pulses of contamination have migrated toward Spring Creek, resulting in higher contaminant concentrations. However, concentrations are still protective of human health and the environment.

4.0 Estimated Date For Closure

TBD