Effect of Blanket Structure on Tritium Breeding Ratio in Fusion Reactors

Effects of blanket composition, including materials and their thicknesses, on the tritium breeding ratio in tokamak fusion reactors are investigated for the Li₂0 blanket having a separable first wall. The sensitivities of the breeding ratio to the thicknesses of the materials for the first wall are estimated as follows (unit: T_BR/cm): S_sic= −.05, S_cu= −.13, S_Al= −.04, S_ss= −.03, S_He= 0.0, S_D2o= −.02, S_H2o= −.09. From these results, aluminum and stainless steel are seen as suitable for such first-wall structural materials as cooling tubes, and heavy water is appropriate for the coolant of the first wall. The lead multiplier of 5-cm thickness is used along with Li₂0, without 6_Li enrichment, as the tritium breeding material. The tritium breeding ratio of the blanket is estimated as 1.08.