Numerical study of transient temperature thermal stress coupled heat transfer in spent fuel storage cask based on Gaussian random heat source.

• User-defined function (UDF) based on the Gaussian moving heat source is applied. • A 3D thermal-stress coupling numerical model is established. • The variation law of the thermal stress in the spent fuel storage tank is obtained. • The main factor affecting stress is the variation in temperature gradient. Spent fuel storage is a necessary part of the entire lifecycle to achieve intrinsic safety in the application of nuclear energy as a clean energy source, and should be adequately investigated. Based on a Gaussian stochastic heat source, this paper presents a three-dimensional coupled numerical model of the heat-stress multiphysics field for the dry storage cask. Comparison with the literature model is carried out to verify that the error is less than 10%, and the temperature field and stress field distribution law of the storage cask under different initial temperatures of the spent fuel rods are studied and discussed. The raise of the initial temperature enhances the heat transfer and the change of the temperature gradient across the shell is the main cause of the stress change. This study provides a reference for the subsequent design study of spent fuel storage casks. [ABSTRACT FROM AUTHOR]