NRC SFST ISG-11: Cladding Considerations for the Transportation and Storage of Spent Fuel
The staff has broadened the technical basis for the storage of spent fuel including assemblies
with average burnups exceeding 45 GWd/MTU. This revision to Interim Staff Guidance No. 11
(ISG-11) addresses the technical review aspects of and specifies the acceptance criteria for
limiting spent fuel reconfiguration in storage casks. It modifies the previous revision of the ISG
in three ways: (1) by clarifying the meaning of some of the acceptance criteria contained in
Revision 2, (2) adding acceptance criteria to allow higher cladding temperature limits for certain
conditions of storage, and (3) providing justification for allowing licensees to continue to use the
570C cladding temperature limit for short-term fuel loading operations of previously certified
dry cask storage systems licensed to store low burnup (less than 45 GWd/MTU) spent
fuel only.
The staff is currently reevaluating the technical basis for the transportation of spent fuel
including assemblies with average assembly burnups exceeding 45 GWd/MTU. The staff is
reviewing data and technical reports to further understand the mechanical and fracture
toughness properties of spent fuel cladding in relation to the transportation of high burnup fuel
under 10 CFR 71.55. Therefore, until further guidance is developed, the transportation of high
burnup commercial spent fuel will be handled on a case-by-case basis using the criteria given in
10 CFR 71.55, 10 CFR 71.43(f), and 10 CFR 71.51.
This ISG focuses on the acceptance criteria needed to provide reasonable assurance that
commercial spent fuel is maintained in the configuration that is analyzed in the Safety Analysis
Reports (SARs) for spent fuel storage. Further, this guidance is applicable to all intact
commercial spent fuel, independent of the burnup level, unless otherwise noted.
Revision 3
