Neutronics Optimization of Tritium Breeding Blan-ket for the FDS

<正>1. IntroductionNuclear energy utilization is important to meet en-ergy demand in the past, the present and the future.The nuclear industry is falling down because of safetyproblem and difficulties in disposal of long-lived ra-dioactive wastes from fission power stations, on theother hand, fusion power still needs a long time to be-come commercial. However, the Fusion-Driven sub-critical System (FDS) has many attractive advan-tages and it can be the intermediate step betweenfission application and fusion application [1]. All the