Closing the Fuel Cycle Through Vitrification -The West Valley Demonstration Project

摘要

The West Valley Demonstration Project (WVDP) demonstrated closure of the commercial nuclear fuel cycle in the United States. However, these closure processes are not being used in the United States even though they are currently taking place in France, United Kingdom, Russia, Japan, and India. Instead of reprocessing spent nuclear fuel, spent fuel assemblies in the U.S. are being stored underwater in pools and in highly shielded dry storage casks, awaiting shipment to a federal repository. The WVDP is located on the Western New York Nuclear Service Center approximately thirty miles south of Buffalo, New York, and was the only functional U.S. commercial spent fuel reprocessing facility. Approximately 640 metric tons of commercial and defense fuels were reprocessed using the PUREX and THOREX processes. More than 97 percent of the uranium and plutonium in the spent fuel was recovered and returned to government and commercial facilities to recycle these materials into new fuel. The reprocessing facilities operated from 1966 to 1972. High-level wastes (HLW) resulting from the reprocessing operations were left in storage at the site following discontinuing plant operations. In 1980, the West Valley Demonstration Project Act was signed, directing the U.S. Department of Energy (DOE) to clean up the site and remove most of the hazardous wastes left behind. Under the WVDP Act, the remaining spent fuel assemblies were shipped offsite, certain plant cells were cleared of highly radioactive equipment to reuse these areas for HLW processing, and die HLW liquids and sludge were pretreated to remove the bulk of the chemicals that were not compatible with the conversion of HLW to borosilicate glass. The pretreated HLW was vitrified into a stable borosilicate glass form that was packaged in stainless steel canisters. Additionally, the majority of the former reprocessing plant's equipment was decommissioned, dismantled, packaged, and shipped for disposal. The vitrification facility where the HLW was converted into a stable glass was then dismantled with its equipment decommissioned, packaged, and shipped for disposal except for certain major equipment that will be shipped over the next few years. Demolition of a number of site facilities has already taken place with more to follow in the next six years, including taking the main plant processing building and the vitrification facility down to ground level. To accomplish this, the HLW canisters need to be relocated from storage in the former reprocessing facility to a modular above-ground storage facility. The canisters will be stored in a shipment-ready configuration awaiting access to the federal repository for HLW and spent nuclear fuel. Phase I decommissioning of the former reprocessing facility and support facilities constructed under the WVDP is planned to be complete by 2018, with the remaining facilities to be decommissioned, demolished, and dispositioned in the follow-on Phase II effort. Completion of these Phase I and II activities will mark the complete closure of the fuel cycle at the West Valley site.