Structural Integrity Assessment of Spent Nuclear Fuel Rod Under Drop Accident Condition

Abstract

The structural integrity of spent fuel assembly is a key element for flexible and economic management of spent nuclear fuel (SNF) considering handling and transportation operations in most of the management scenarios. In order to better understand the SNF rod behavior under drop accident condition and to study the effects of various uncertain parameters on the fuel rod structural integrity, a detailed finite element (FE) model for pressurized water reactor (PWR) fuel rod is being developed using ABAQUS. This paper describes the FE model and discusses the influence ofthe parameters relevant to design safety with concern of post-irradiated fuel conditions such as degradation of cladding mechanical properties, pellet-to-cladding mechanical interaction (PCMI), spacer grids (SGs) spring stiffness degradation, rod internal pressure (RIP). Based on the proposed model and preliminary simulation results of sensitivity analysis, we can initially prioritize the importance of data in managing and studying the structural integrity of the SNF for the next assessment stage. This work is part of a bigger research on the structural integrity of SNF in cask-loaded condition, whereby it might help in proposing guidelines for safe handling of SNF.