Study on Validation of the Thermal Calculation Method and the applicability of the Confinement Monitoring with Full-scale Mock-up Test of Concrete Cask

We manufactured a full-scale mock-up ventilated concrete cask and carried out thermal experiments under various conditions. All measured temperatures are within each acceptable limit and it is confirmed that the concrete cask has sufficient heat removal capability. Benchmark analyses using a combined thermal calculation method were carried out. At first airflows and temperatures outside the canister were calculated by 3-dimensional thermal-flow analysis. Next, its results were used as the boundary conditions in calculating maximum temperatures inside the canister by 2-dimensional heat transfer analysis. Both calculated results agreed well with the measurements and the validity of the combined method was confirmed. Exit Vent Outer Shell Inlet Vent Cask Lid Canister Radial Shield (Concrete) Base Plate Pedestal Shield Canister Shell Canister Lid Closure Ring Weld Spent fuel Fig.1 Bird’s Eye View of Ventilated Concrete Cask We newly propose a canister confinement monitoring system. It is based on the relation between the canister inner pressure and the temperature of the canister lid and the pedestal. The validity and applicability of the system is confirmed by the full-scale mock-up experiment results. The conceptual design of the monitoring system is considered and the system can realize low cost, high reliability and easy maintenance.