Design of a Universal Canister System for US High-­Level Waste

A concept for a universal canister system for storage, transportation, and eventual disposition of certain high-level waste has been developed to support the safe clean-up mission of the US Department of Energy’s Office of Environmental Management (DOE-EM). This concept supports the near-term storage and transportation of high-level radioactive waste (HLW) at several clean-up sites, including the cesium and strontium capsules at the Hanford Site, cesium that will be processed using non-elutable or elutable resins at the Hanford Site, and the calcine waste at Idaho National Laboratory. Specifically, the universal canister concept has been developed for near-term onsite dry storage of the cesium and strontium capsules at the Hanford Site. In addition, the universal canister system concept would be compatible with a deep borehole or a mined geologic repository concept. This universal canister system was developed to provide a sealed canister that would never be opened and would be compatible with dry storage, transportation, and eventual disposition. This universal canister system is based on the concept of nested canisters (i.e., canisters inside of canisters), that can be moved to dry storage in near-term, with the flexibility to ensure that the universal canister would never have to be opened regardless of the disposal concept. Additionally, monitoring capabilities are being developed that will be integrated into the universal canister system to provide real-time waste configuration information.This paper describes the universal canister concept and presents detailed shielding, thermal, and structural analyses results demonstrating how loaded universal canisters could satisfy current regulatory requirements for storage and transportation of HLW. Once a disposal pathway is selected and disposal regulations are developed, this concept is positioned to satisfy those requirements as well. One manner of achieving this goal would be to develop disposal overpacks that would be compatible with the universal canister system while ensuring that the disposal requirements were satisfied.