The U.S. Department of Energy needs to improve how it studies the long-term storage of commercial spent nuclear fuel, according to a February report to Congress and the secretary of energy by the Nuclear Waste Technical Review Board
The board performs independent technical and scientific peer review of DOE’s management and disposal of high-level radioactive waste and spent nuclear fuel.
DOE had the board look at its planning efforts for long-term dry storage of spent fuel, which in the case of commercially owned fuel is stored near the reactors that burned it. The study looked at three scenarios: storing the current casks where they are for 80 to 120 years; repackaging the fuel into smaller canisters before disposal elsewhere; or disposing the fuel in a new geologic repository.
“The Board observes that while DOE’s past evaluations have been informative, none has been fully comprehensive in considering all of the advantages and disadvantages of each alternative. The Board recognizes that DOE is aware of the issues that need to be addressed and commends DOE for working to address those issues,” the board’s report said.
Loose ends include timetables, costs, spent fuel in the casks that have not been approved for transportation, and comparing designs of large casks versus smaller casks for eventual permanent storage.
Criticality issues within the casks need more study, the board said. The board recommended that DOE establish a set of criteria to evaluate the various options for modifying fuel assemblies and baskets for loading fuel into the casks.
The U.S. has commercial spent fuel stored in roughly 4,000 dry-storage casks at approximately 70 reactor locations. By 2080, spent fuel is expected to take up roughly 10,000 casks.
Permanent storage sites are in limbo.
Development of a permanent repository at Yucca Mountain in Nye County, Nev., has been frozen since 2010. Proposed commercial consolidated interim storage sites in Texas and New Mexico are effectively on hold after a federal appeals court in 2023 ruled their Nuclear Regulatory Commission licenses were illegal.