Development of neutronics model for the K-DEMO water cooled ceramic breeder blanket with MCNP code

During the conceptual design study on the Korean fusion demonstration reactor (K-DEMO) featured by high magnetic field (BT0 = 7.4 T), R=6.8 m, a=2.1 m, and a steady-state operation [1,2], the 3D neutronics models have been developed to evaluate the main parameters such as neutron wall load (NWL) distribution, tritium breeding ratio (TBR) and nuclear heating. To perform neutronics analysis, 3D global models were created from the CAD program (Pro-Engineer™) and imported into the integrated interface program by the help of Monte Carlo Automatic Modeling system (MCAM) to produce input files for the Monte Carlo neutron photon transport code (MCNP) analyses. The appropriate K-DEMO neutronics model configuration, proper shield thickness and assembly gaps between blanket modules were verified based on the comparative study of Monte Carlo analysis results. After comparison of neutronics analysis results, it is shown that the global TBR was slightly different depending on the gap between blanket modules and the nuclear heating in TF coils was proportional to thickness of gap between blanket modules. In the neutron wall loading calculation, the peaks at inboard and ouboard blanket first walls are 3.18 and 3.93 MW/m2 respectively.