This standard provides criteria for accounting for reactivity effects of fuel irradiation and radioactive decay in criticality safety control of storage, transportation, and disposal of commercial LWR UO2 fuel assemblies.

This standard assumes the fuel and any fixed burnable absorbers are contained in an intact assembly. Additional considerations could be necessary for fuel assemblies that have been disassembled, consolidated, damaged, or reconfigured in any manner.

In January 1999, the U.S. Department of Energy (DOE)/Office of Civilian Radioactive
Waste Management (OCRWM) submitted the Disposal Criticality Analysis Methodology
Topical Report, Revision 0 (TR) to the U.S. Nuclear Regulatory Commission (NRC) for
review and approval. The TR presents an overall approach for consideration of postclosure
disposal criticality of commercial and defense high-level waste to be placed at
the proposed Yucca Mountain site. During the course of the review and interactions

This paper reviews validation issues associated with implementation of burnup credit in transport, dry storage,
and disposal. The issues discussed are ones that have been identified by one or more constituents of the
United States technical community (national laboratories, licensees, and regulators) that have been exploring the
use of burnup credit. There is not necessarily agreement on the importance of the various issues, which
sometimes is what creates the issue. The broad issues relate to the paucity of available experimental data