Thermal-hydraulic analysis of a dry storage cask for VVER-1000 spent nuclear fuel

In this study, thermal-hydraulic analysis of a dry storage cask for Bushehr Nuclear Power Plant spent nuclear fuels is carried out. Geometry drawing and mesh generation were completed in SolidWorks and Gambit software, respectively. Three different cases were considered for the cask geometry and design including cask with/without spacers and cask with spacers and fins. Thermal-hydraulic analysis of the cask was performed for steady-state and normal storage conditions in ANSYS CFX solver package. Simulation results indicated a weak thermal-hydraulic behavior of the cask in the geometry without spacer and maximum fuel temperature exceeded the allowable safety limits. However, with the addition of spacers and fins in the geometry of the cask, thermal behavior of the cask was significantly improved and maximum fuel temperature achieved a proper margin compared to the allowable safety limits. As a result, the spent fuel integrity will be maintained in the normal storage conditions. The simulation results were compared with a literature published paper and it showed a good agreement between the calculated results.