Impact Analysis of the Model on CFETR Neutronics Calculation

Abstract

Chinese Fusion Engineering Testing Reactor (CFETR) is a test tokamak reactor to bridge the gap between ITER and future fusion power plant and to demonstrate generation of fusion power in China. Fusion reactors have the characteristics of a strong anisotropic neutron flux distribution, wide range of neutron energy and spatial non-uniformity of the power density distribution caused by the external fusion neutron source. The different neutronics models were used in different research stage. The neutronics analyses of CFETR with helium cooled solid breeder blanket have been carried out to find out the effects of the 1D/2D/3D simplified geometric descriptions and 3D complex geometric descriptions for computational models. The tritium-breeding ratio, power density distribution and irradiation damage are calculated to evaluate the nuclear performance using the Monte Carlo transport code MCNP and nuclear data library FENDL-2.1. Comparison of the results shows that the value of TBR calculated by the 1D/2D/3D simplified model overestimates. The power density distribution and irradiation damage based on the 2D and 3D simplified models are similar since they all consider the effects of the axial components, but they are underestimated compared with the 3D complex models. So the simplified models of the fusion reactor for neutronics calculation are usually used at the beginning of the preliminary conceptual design. In order to obtain the accurate results, 3D complex geometric descriptions are needed.