The Hanford spent nuclear metal fuel multi-canister overpack and vacuum drying {ampersand} hot conditioning process

Nuclear production reactors operated at the U.S. Department of Energy`s Hanford Site from 1944 until 1988 to produce plutonium. Most of the irradiated fuel from these reactors was processed onsite to separate and recover the plutonium. When the processing facilities were closed in 1992, about 1,900 metric tons of unprocessed irradiated fuel remained in storage. Additional fuel was irradiated for research purposes or was shipped to the Hanford Site from offsite reactor facilities for storage or recovery of nuclear materials. The fuel inventory now in storage at the Hanford Site is predominantly N Reactor irradiated fuel, a metallic uranium alloy that is coextruded into zircaloy-2 cladding. The Spent Nuclear Fuel Project has rommitted to an accelerated schedule for removing spent nuclear fuel from the Hanford Site K Basins to a new interim storage facility in the 200 Area. Under the current proposed accelerated schedule, retrieval of spent nuclear fuel stored in the K East and West Basins must begin by December 1997 and be completed by December 1999. A key part of this action is retrieving fuel canisters from the water-filled K Basin storage pools and transferring them into multi@ister overpacks (MCOS) that will be used to handle and process the fuel, then store it after conditioning. The Westinghouse Hanford Company has developed an integrated process to deal with the K Basin spent fuel inventory. The process consists of cleaning the fuel, packaging it into MCOS, vacuum drying it at the K Basins, then transporting it to the Canister Storage Building (CSB) for staging, hot conditioning, and interim storage. This presentation dekribes the MCO function, design, and life-cycle, including an overview of the vacuum drying and hot conditioning processes.