Analytical representation for neutron streaming through slits in fusion reactor blanket by Monte Carlo calculation

The neutron streaming through slits between the shielding blanket modules in DT fusion reactors are evaluated, and the helium production in the vacuum vessel, the nuclear heating density and the radiation damage in the super-conductive magnet are calculated by using three-dimensional Monte Carlo method. By changing systematically the blanket and the vacuum vessel thicknesses, the boron content in the vacuum vessel, and the slit width, the analytical representations on the helium production, the nuclear heating density and the radiation damage along the slit are established as functions of the slit width, thickness in the blanket and the vacuum vessel, and the boron content based on the Monte Carlo results. Their dependencies on the blanket and the vacuum vessel compositions are also clarified. The analytical formula thus-obtained is applied to clarify the shielding design conditions required to satisfy the shielding design criteria for DT fusion reactor.