Investigate the impact of different neutron source models on the neutronics performance for CFETR

The China Fusion Engineering Test Reactor (CFETR) is a magnetic confinement tokamak experimental device currently under development in China, which is used to bridge the scientific and technical gaps between the International Thermonuclear Experimental Reactor (ITER) and Demonstration (DEMO). The common reaction in fusion reactors is the D-T reaction, which produces neutrons with energies of up to 14 MeV. This has a significant effect on the surrounding components and may cause issues such as irradiation damage, activation of structural materials, etc. Therefore, in order to provide a reliable reference for subsequent structural design and safety, the study of neutronics performance under different neutron source models is essential. Using a 3D neutronics model containing the water-cooled ceramic blanket (WCCB) blanket, the impact of different neutron source models on the neutronics performance for the CFETR at 1.5 GW is studied. The nuclear analyses are carried out by the Monte Carlo N-particle transport code, including the tritium breeding ratio (TBR), neutron wall loading (NWL), fast neutron flux, and nuclear heating deposition. The results indicate that different descriptions of neutron source models have a relatively small impact on the TBR, fast neutron flux, and nuclear heat, but a more significant impact on NWL.