Wet repackaging facility design concept and cost and throughput analysis

Spent nuclear fuel (SNF) assemblies are stored in pools or dry casks at commercial reactor sites pending transfer to an interim storage facility (ISF) or a geologic repository for disposal. The cost of disposal will be dependent on the repository's geology and size, as well as the number and size of waste packages requiring emplacement. To meet acceptance criteria for repository waste package loading, fuel in dry storage may require repackaging into smaller quantities. A modular packaging facility design has been developed for fuel stored in dry casks at reactor sites or an ISF, as well as bare fuel assemblies shipped directly from reactor fuel pools. This facility provides for receipt and packaging of 1, 500 metric tons (MT) of fuel annually. Three sizes of storage, transportation and disposal canisters have been evaluated (a 4 pressurized water reactor (PWR)/9 boiling water reactor (BWR) can-in-carrier concept, a 12- PWR/32-BWR fuel canister, and a 21-PWR/44-BWR fuel canister) to determine the effect on facility throughput. Cost estimates have been developed for the packaging facility, and operating costs have been determined for packaging 1, 500 MT of SNF per year. Higher throughputs could be achieved for bare fuel because process steps for transfer and opening of the dual-purpose canister (DPC) are not necessary. Results from system modeling indicate that even for the more restrictive case where all fuel is received in DPCs, the desired throughput of 1, 500 MT/year could be attained for the receipt basis of 1, 000 MT PWR and 500 MT BWR fuel. Transfer of the fuel from transportation casks (TCs) (bare fuel) or DPCs to disposal canisters would be performed in a pool. The loaded canisters would be sealed, dried, and leak tested prior to being loaded into TCs for transport to a geologic repository or to an ISF. Additional facilities would be provided for decontamination of the TCs for reuse, as well as decontamination of the empty DPCs for disposal as low level radioactive waste (LLW). Conceptual layout and elevation drawings have been developed for a wet packaging facility to provide ∼30, 000 square feet of process area on two levels for cask and canister handling operations, 9, 600 square feet for packaging operations in the fuel handling pool, and ∼20, 000 square feet for railcar receipt and dispatch of TCs. Capital and annual operating cost estimates have been developed and are in the range of $1.3B-$1.5B for capital costs and $190M- $256M for annual operating costs, depending on the canister chosen for repackaging.