Neutronics and shielding design of CFETR HCCB blanket

Abstract

Tritium breeding blanket (TBB) is one of the most important components of China Fusion Engineering Test Reactor (CFETR) with functions of tritium breeding, heat generating and nuclear shielding. This paper presents the progress on the neutronics and shielding design of the helium cooled ceramic breeder tritium breeding blanket (HCCB TBB) developed by the Southwestern Institute of Physics (SWIP). Based on the latest profile and layout configuration of CFETR TBB, the preliminary neutronics design, optimization and analysis of HCCB TBB have been completed. After several rounds of neutronics design and optimization, the TBR of HCCB TBB is 1.177, and the value drops to 1.101 considering the influence of auxiliary systems, which can meet the design objectives of CFETR. The total nuclear heating of HCCB TBB is 1402 MW with 1500 MW fusion power. Among all the blanket modules, blanket module #3 is subjected to the strongest neutron irradiation. Meanwhile, the overall shielding analysis for TF coils of CFETR has been performed based on the current design of HCCB TBB, and the preliminary shielding design and optimization for the weak shielding areas such as HCCB TBB, divertor and neutral beam injector (NBI) port have been carried out. After shielding optimization, the fast neutron fluence and nuclear heating of all TF coils are below the design limit. By increasing the number of source neutron histories and using some variance reduction techniques in the MCNP calculation, the relative errors of neutronics and shielding analysis results for HCCB TBB are all less than 5%.