Most spent nuclear fuel at Department of Energy (DOE) and commercial reactor sites is stored underwater. When this fuel is prepared for placement in a dry independent spent fuel storage installation, residual water and environmental changes are important considerations.

“The real interest in drying is knowing how dry the SNF [spent nuclear fuel] must be in order to prevent issues with fuel damage, pressurization, or corrosion. What makes it difficult is the presence of cladding damage in some percentage of the fuel that may allow collection of water within the fuel that cannot readily be removed but may cause long term storage issues in the hot, dry storage environment,” says Eric Shaber, advisory engineer/scientist, Idaho National Engineering and Environmental Laboratory (INEEL).

To address these challenges, a proposed guide on the drying behavior of spent nuclear fuel is being developed by a task group of ASTM Committee C26 on Nuclear Fuel Cycle “to review vacuum drying methods and identify sources and forms of water that may remain in spent nuclear fuel and/or its container after drying,” says Shaber, the task group chairman. “The effects of this residual water on spent nuclear fuel integrity and the container will be explored mechanistically as a function of container environment to provide guidance on situations that may require extraordinary drying methods, specialized handling, or other treatments.” Initiated in June by a 12-member task group of Subcommittee C26.13 on Repository Waste, the proposed guide will provide owners and regulators initial baseline guidance to evaluate potential drying issues. Interested parties are invited to develop the guide with the task group of nuclear laboratory scientists, engineers, repository owners, manufacturers, consultants, and representatives of the DOE, Nuclear Regulatory Commission, INEEL, and the National Spent Nuclear Fuel Program.

For further technical information, contact Eric Shaber, Bechtel BWXT Idaho, LLC., PO Box 1625, Idaho Falls, ID 83415-3765 (208/526-8145; fax: 208/526-4313; e-mail: ). Committee C26 meets Jan. 21-25 in Reno, Nev. For meeting or membership details, contact Lisa Drennen, ASTM (610/832-9735). //

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