Depth Profile of Tritium Production in Concrete Around a Fusion Device

The depth profile of tritium in concrete near a fusion device has been calculated from an energy spectrum data of neutron which can be obtained by means of a radiation transport calculation code. The production of tritium increases gradually up to 8 cm depth in concrete, and the concentration at this depth is 1.5 times of that near the surface. The concentration will be 12 kBq/cm³ at the maximum point in concrete after 30 years operation at 3 GW fusion power. These profile data of tritium in concrete are useful for decommissioning of a facility.