Sequential evaluation of the potential geologic repository site at Yucca Mountain, Nevada, U.S.A

1996 will be remembered as a year of transition, even upheaval, for the United States' program for geologic disposal of spent reactor fuel and high-level nuclear wastes from military reprocessing. The 1996 budget for the U.S. Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) combined with reduced funding levels anticipated through the end of the decade make it necessary to substantially modify the United States' waste management program. The two major changes DOE has made in response to the 1996 budget involve, 1) resequencing the technical and statutory milestones for Yucca Mountain characterization, and 2) terminating further development of most waste acceptance activities, multi-purpose canister development, and generic transportation work. Budget reductions combine with legislation now before the 104th U. S. Congress that, if it is signed into law, would redirect the program to authorize temporary storage of waste at an interim storage facility and de-emphasize long-term disposal and isolation. This paper explains the changes that are being planned for the characterization program at Yucca Mountain. Yucca Mountain, Nevada is the only site being studied in the United States for a geologic repository: an arid terrane of 12 million-year-old unsaturated, stratiform volcanic tuff. Funding for the site characterization program at Yucca Mountain for l996 was cut by roughly one half from that anticipated in 1994 as needed to complete three major milestones by 2001. These project milestones included, 1) a time-phased determination of Site Suitability, and if a positive finding, 2) completion of an Environmental Impact Statement, and 3) preparation of a License Application to the U.S. Nuclear Regulatory Commission (NRC) to authorize repository construction. In reaction, the Yucca Mountain Site Characterization Project has shifted from parallel development of these milestones to a sequenced approach with the Site Suitability Evaluation being replaced with a management assessment, and completion of an EIS and LA being de-emphasized until the beginning of the next decade. Changes to the regulatory structure for the disposal program are under consideration by DOE(its siting guidelines) and the NRC (repository regulation). The possibility for NRC and DOE to develop a site-specific regulatory structure follow from the National Energy Policy Act of 1992 that authorized the U.S. Environmental Protection Agency to develop a site-specific environmental standard for Yucca Mountain. (author)