A burnup credit methodology for PWR spent fuel storage pools: Application to a standard PWR nuclear power plant

Abstract

[EN] This paper proposes a methodology for burnup credit of spent nuclear fuel (SNF) pool storage based on the axial burnup of the fuel assemblies. Following the NRC guidance and normative for NPP safety, axial burnup profiles from a database were analysed, and a conservative theoretical profile that fits the safety conditions was obtained. This profile sets a limit on the upper criticality of the assemblies, and it is used to obtain the pool loading curve, which dictates if a fuel assembly fits to be loaded in the studied SNF pool based on its initial enrichment level and burnup. Although it takes burnup credit, this methodology follows strict safety normative and is deemed suitable for further analysis in SNF pools. This methodology can be used to conservatively reduce the requisites for the storage of spent fuel by establishing a burnup profile that bounds all other profiles. This approach allows for more flexibility in the spent fuel pool loading.