Neutronics Design Optimization on Cross Cooled Solid Blanket of Fusion Reactor

Aiming at the outline of fusion reactor solid blanket design, the crossed helium cooling channel solid blanket concept was developed. It adopted separated Be and Li₂TiO₃ pebble bed as neutron multiplier and tritium breeder. Two kinds of cooling tubes were cross arranged, and the blanket was cooled by two loops of helium channels at the same time in order to increase the blanket availability. The 11.25° symmetric model was set up by using MCNP. After preliminary estimation, 4 cases of ⁶Li enrichment arrangement were compared. The results show that lower ⁶Li enrichment away from first wall in poloidal would be appropriate, and the ⁶Li enrichment in the breeder zone near to the first wall should be high enough to reduce the effect of Li depletion on the tritium breeding performance during long time operation. Global tritium breeding ratio (TBR) reaches 1.176, and it obtains a relative steady tritium breeding performance over whole operation time. The burn up of Li is relatively uniform during blanket lifetime.