The primary purpose of the plasma-facing component (PFC) is power exhaust and removal of impurity particles. The plasma-facing component consists of three layers and a support [1]. The first and third layers are made of tungsten alloy. The second layer is a mixture of Tungsten, CuCrZr, water, and a support is made of Eurofer alloy. This paper considers two different breeder blanket models of DEMO reactor: Water-Cooled Lithium Lead (WCLL) and Helium Cooled Pebble Bed (HCPB) and the same specified DEMO neutron source. Even though both models have the same divertor configuration, the neutron flux is slightly different.
MCNP6 code [2] and Joint Evaluated Fission and Fusion (JEFF 3.2) [3] nuclear data library were used for neutron flux calculations. MCNP6 is widely recognized and used for fusion neutronic applications. Neutrons are divided into 709 energy groups from 10-5 eV to 1000 MeV.
The statistical error of Monte Carlo calculation results for divertor PFC cells was less than 10% with 108 particle histories. In energy region from 0.166 × 10-4 eV up to 5.75 × 10-4 eV and in 3.47 MeV up to 15.6 MeV HCPB has 1.2 times more neutron than WCLL. While in region 5.75 × 10-4 eV - 3.47 MeV showed more neutrons in energy groups by factor 1.5 on average. However, in remaining groups there were no neutrons identified.