A coordinated US program to address full burnup credit in transport and storage casks

The benefits of burnup credit and the technical issues associated with utilizing burnup credit in spent nuclear fuel (SNF) casks have been studied in the United States for almost two decades. The issuance of the U.S. Nuclear Regulatory Commission (NRC) staff guidance for actinide-only burnup credit in 2002 was a significant step toward providing a regulatory framework for using burnup credit in transport casks. However, adherence to the current regulatory guidance (e.g., limit credit to actinides) enables only about 30% of the existing pressurized-water-reactor (PWR) SNF inventory to be transported in high-capacity (e.g., 32-assembly) casks. Work has been done to demonstrate that the allowable inventory percentage could potentially increase to nearly 90% if credit for fission products were allowed. Thus, Oak Ridge National Laboratory has worked with the U.S. Department of Energy Office of National Transportation (DOE/ONT), the NRC, and the Electric Power Research Institute (EPRI) to coordinate a research program that will (a) obtain and evaluate experiment data to support the safety basis for fission product credit validation, (b) investigate unresolved technical issues associated with PWR full burnup credit, and (c) recommend approaches for boiling-water reactor (BWR) burnup credit in transport and storage casks. This paper will review the program of research and discuss the progress to date.