Neutronics performance of a helium-cooled solid breeder blanket and shield for ITER

A neutronics analysis of a helium gas-cooled Li/sub 4/SiO/sub 4/ solid breeder blanket for the International Thermonuclear Experimental Reactor (ITER) has been performed. The 60 cm thick breeder blanket placed in the outboard zone of the tokamak is composed of beryllium and solid breeder (SB) rods. The rods are arranged so that homogeneity of Be and SB is realized as much as possible. Helium gas is utilized as both main coolant and purge flow for tritium extraction. The blanket is followed by a carbon reflector and a B/sub 4/C/PCA shield. The 48 cm-thick inboard shield consists of multi-layers of W and ZrH/sub 2/ cooled by helium gas. A Be layer of thickness 4.89 cm is added in the front of the shield to enhance the tritium breeding in the outboard blanket. Extensive 1-D analysis revealed an optimum configuration of the breeder resulting in a tritium breeding ratio (TBR) of 1.35 when 90% /sup 6/Li enriched material is used. A subsequent 3-D analysis of the optimized blanket demonstrated that a TBR of unity is achievable in the 6 m-height outboard blanket. By adding the breeder in the top and bottom zones of the reactor, the TBR can be as large as 1.2