Estimation on tritium production and inventory in beryllium

Beryllium has been proposed as a candidate material for neutron multiplier on fusion blanket design, tritium will be produced and accumulated in beryllium during neutron irradiation. It is very important to estimate the tritium inventory on blanket design. Tritium production and inventory under 3.0 GW fusion power were calculated for the layered pebble bed blanket, with Li2O breeder and beryllium multiplier. Neutronics calculations were carried out by one-dimensional transport code, ANISN and tritium production was calculated by direct reaction of 9Be(n,T)7Li and two-step reactions of 9Be(n,α)6Li(n,α)T. At the position near first wall, the direct reaction occupied the majority of tritium production. However, at the position of the mid-depth, contribution of the two-step reaction was included the production from neutron slow down by beryllium itself. The ratio accounting for 50% of total tritium production of two-step reaction production over whole blanket for one year full power operation (FPY) was resulted