Neutronic Analysis of the IFMIF Tritium Release Test Module Based on the EVEDA Design

The International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based intense neutron source to test fusion reactor materials under irradiation conditions expected to be experienced by a future fusion power plant (DEMO). The Tritium Release Test Module (TRTM) is intended for the irradiation of solid breeder ceramics as well as beryllium involving in-situ tritium release measurements in IFMIF. During the EVEDA (Engineering Validation Engineering Design Activities) phase, a detailed engineering design for the TRTM has been elaborated. A new 3-dimesional Monte Carlo geometry model of TRTM was prepared for a neutronic analysis directly from engineering CAD data using the McCad conversion software developed at KIT. The analysis was performed with the latest version of the Monte Carlo code McDeLicious, an enhancement to MCNP5 for IFMIF neutronics calculations, using a state-of-the-art nuclear data library FENDL-3. The result emphasizes the importance of the neutron reflector which should be placed behind TRTM in order to make the irradiation properties close to the European HCPB DEMO. Although the achievable dpa is lower than that expected in DEMO, the T/dpa and He/dpa values can be simulated very well when the neutron reflector is appropriately designed, in particularly by utilizing beryllium.