A neutronic investigation of He-cooled liquid Li-breeder blankets for fusion power reactor

Configuration of a He-cooled liquid lithium blanket has been optimized in terms of the tritium breeding ratio (TBR) and the neutron shielding. For a model blanket, fundamental neutronic characteristics are analyzed with a Monte Carlo code. To improve the TBR, various neutron reflectors are compared, which are graphite, TiC and ZrH2, and the optimal application of the reflector is investigated, either lumped or layered. The TBR is analyzed as a function of the Li-6 enrichment for the reflected blanket, and the results are used in determining the lifetime of a natural lithium breeder. In addition, various types of moderated shields are assessed to improve the neutron shielding performance.