Comparative thermo-hydraulic study of different nuclear spent fuel cask designs using CFD codes

The dry storage of nuclear spent fuel is a common solution chosen by many nuclear power plants to store their fuel after depleting the nuclear spent fuel pool. The process of designing and licensing a cask is long and complicated. It is not uncommon that a cask design suffers modifications after being licensed, which must be approved by the regulator in a license amendment.In this paper, the thermo-hydraulic response of two different designs of the same cask will be studied and analyzed comparatively, using one of the most common tools for this purpose in the state of the art of nuclear spent fuel casks, the Computational Fluid Dynamic codes (specifically, Ansys CFX). Despite the small design differences, significant differences were found across the models.Additional studies introducing gaps in the cask components where performed. The gaps caused large heat flux distribution changes, with appreciable difference between both designs.