Effect of selection of calculation parameters in discrete ordinate code DOT3.5 for analyses of fusion blanket integral experiments in JAERI-USDOE collaborative program

The effect of the parameters selected for discretization in the discrete ordinate code DOT3.5 on the calculated results was examined for neutronics analysis of the JAERI-USDOE collaborative program on fusion blanket neutronics. The parameters examined were the group structure and Legendre expansion for the cross-section library, and the sizes of the directional and spatial meshes. The group structure and the mesh size were more effective for high energy and for low energy neutrons respectively. From these calculation surveys, the recommended parameters for the DOT3.5 code can be obtained for application to fusion blanket design calculations.