Assessment of the shielding efficiency of the HCLL blanket for a DEMO-type fusion reactor

International audienceThis work summarizes the results of a neutronic study on the HCLL blanket for a DEMO-type fusion reactor. The analysis is based on three-dimensional Monte Carlo calculations using the MCNP-4C code. It comprises the assessment of the shielding efficiency in terms of the radiation loads to the superconducting TF-coils and the neutron induced production of He and H gas in the steel structure of the blanket and at locations where the welding of pipe connections is assumed. The analysis is performed utilizing three-dimensional 9$^0$-sector model representing the modular HCLL breeder blanket developed by CEA. The shielding performance of the blanket/shield/vacuum vessel system is assessed at the torus mid-plane considering three variants of a two-component shield, arranged in between the central inboard modules and the Vacuum Vessel. Estimates of radial distributions of the He and H gas production in the steel structure of the blanket are obtained and the radial depth where the re-weldability criterion for the He production