Publications

A case for direct disposal of SNF in existing DPCs

Hardin, Ernest H.; Kalinina, Elena; Clark, Robert; Howard, Robert; Banerjee, Kaushik; Scaglione, John; Carter, Joe

Commercial spent nuclear fuel (SNF) continues to accumulate in dry storage, sealed into welded dual-purpose canisters (DPCs). Direct disposal of DPCs, without cutting them open and re-packaging the fuel, is technically feasible at least for some DPCs and some disposal concepts. Options for DPC direct disposal are taking form, based on an ongoing study by the U.S. Department of Energy. Direct disposal of DPCs should be viewed as one part of a diverse fuel management system that will eventually switch to loading standardized multi-purpose canisters (MPCs). Nearly all DPCs that are loaded before this switch could be directly disposed depending on the disposal environment selected. DPC direct disposal options have been developed for salt, crystalline and sedimentary host media. These options are suited to different populations of DPCs, ranging from those containing older, colder fuel (e.g., in sedimentary media) to all DPCs (salt). The timing of DPC use offers an opportunity to simplify the SNF management system. Commercial SNF will be generated in the U.S. for more than 90 years, whereas facility lifetimes are typically on the order of 50 years. Efficiencies could be realized by implementing disposal in "campaigns. " Additional accumulation of DPCs over the next 10 to 20 years, followed by a transition to MPCs, would define two such campaigns. A repository could first be constructed for MPCs, and disposal of DPCs could be deferred and addressed later using new, dedicated facilities. During the interim storage period DPC thermal output would decay, further expanding disposal options.