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	NRC NEWS U. S. NUCLEAR REGULATORY COMMISSION
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No. 97-164

November 4, 1997

The Nuclear Regulatory Commission has released Western Nuclear, Inc.'s Day Loma uranium processing site in Wyoming for unrestricted use. The agency found that the site has been successfully remediated to meet federal requirements.

At the Day Loma site, Western Nuclear used the heap leach process to extract uranium from low-grade ore-bearing material that was transferred from its Split Rock uranium mill, about 20 miles away.

In a heap leach process, a coated concrete or asphalt pad (like a parking lot) is placed on the ground and crushed uranium ore is piled in a heap on top of the pad. A sprinkler is positioned over the top of the heap, and an acid is continually sprayed over the pile. The acid trickles through the ore (in a manner similar to a drip coffee maker) and mobilizes the uranium and other metals into solution. The uranium is then extracted from the solution for further processing. The remaining pile, through which the acid was poured, is considered to be a waste product.

Western Nuclear obtained a license in 1962 for the Day Loma heap leach site, which is located about 25 miles northeast of Jeffrey City, in an area known as the Gas Hills Region, which is rich in naturally occurring deposits of uranium ore. Widespread activity by several organizations involved in uranium mining and milling occurred in the region from the late 1950s into the 1980s. Western Nuclear terminated operations at the Day Loma site in 1972, and in 1976 the Day Loma license was combined with the license for Split Rock (currently an inactive uranium mill). In 1996, following reclamation activities at Day Loma, Western Nuclear requested that all references to the Day Loma site be removed from the license. NRC approved this request on October 29.

The Day Loma site is surrounded by exposed mine wastes and unreclaimed mining lands of the Gas Hills area. Reclamation of the site was completed in 1985 under a plan approved by the NRC. The heap leach material was placed on an impervious liner and covered with about 8 to 13 feet of clay and random fill material. This disposal cell is designed to minimize releases of radioactive materials to the environment.

The NRC prepared an environmental assessment of the proposed release of the site for unrestricted use. Based on a series of conservative analyses, the assessment concluded that potential radiation doses to members of the public from the released site would be well below the NRC's public dose limits and also less than the doses resulting from the naturally occurring uranium ore deposits that surround the site.

Copies of the environmental assessment and of a technical evaluation report written by the NRC staff are available for review and copying at the NRC Public Document Room, 2120 L Street, N.W., Washington, DC 20555; phone: 202/634-3273.

A Federal Register notice published on October 28 describes procedures that should be followed by persons who wish to request a hearing with respect to the technical evaluation report and environmental assessment, which form the basis for the decision to release the Day Loma site for unrestricted use. The requests must be filed by November 28.