Validation Issues for Depletion and Criticality Analysis in Burnup Credit

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
(radiochemical assays and critical experiments) covering the full range and characteristics of spent nuclear fuel in
away-from-reactor systems. The paper will also introduce recent efforts initiated at Oak Ridge National
Laboratory (ORNL) to provide technical information that can help better assess the value of different
experiments. The focus of the paper is on experience with validation issues related to use of burnup credit for
transport and dry storage applications.