Optimal configuration of neutron reflector in He-cooled molten Li blanket

The objective of this study is to find the optimal configuration of a He-cooled molten Li (HCML) blanket in terms of tritium breeding ratio (TBR). A parametric optimization study is performed to assess the impact of thickness and position of neutron reflectors. As the neutron reflector, Be, 11B4C, graphite, and TiC are considered. In spite of some unfavorable material properties, Be appears to be far superior to others from the TBR point of view. It is shown that a graphite-reflected HCML blanket can provide a sufficient TBR without a neutron multiplier if the reflector is utilized in an optimal way. For a graphite-reflected HCML blanket, the impact of the Li-6 composition on TBR is also investigated. In addition, the blanket neutron energy multiplication factor (NEM) and the distribution of nuclear heating are evaluated.