Computational fluid dynamics simulations of fuel cladding and basket surface temperatures in multipurpose canister rail cask during normal transport

Abstract

AbstractA two-dimensional finite volume model of a Multi-Purpose (MPC) in a rail cask with twenty-one pressurised water reactor (PWR) assemblies inside was constructed. Steady state thermal simulations were performed for a range of fuel heat generation rates, for both nitrogen and helium cover gas, and different fuel cladding emissivities. Geometrically accurate computational fluid dynamics (CFD) simulations were employed to calculate buoyancy induced motion in, and natural convection and radiation heat transfer across, all gas filled regions. The results are compared to stagnant-gas CFD (S-CFD) simulations in the same geometrically accurate mesh, and to simulations that employ Effective Thermal Conductivities (ETC) in a mesh with homogenized fuel/cover gas regions. The cask Thermal Dissipation Capacity (QTDC) is defined as the fuel heat generation rate that causes the fuel cladding to reach its allowed temperature limit. QTDC is 27% larger when helium is the backfill gas than for nitrogen. The QTDC predi...