Comparison of activation of ceramic and ferritic structural materials with D-T and D-3He fuel cycles

Neutron-activation-induced radioactivity is a major source of radiological hazards of a fusion reactor. In a conventional D-T-fueled, ferritic-steel-structure fusion reactor, the induced radiological hazards may be comparable with those of typical fission reactors. The activation radioactivity can be reduced by utilizing low-activation materials or low-neutron-yield fusion fuel cycles. The authors study the merits of these two approaches by comparing the resulting activation radiological hazards of a low-activation silicon carbide ceramic composite D-T-fueled reactor design and a ferritic steel D-³He-fueled reactor design. They use as examples ARIES-type 1000-MW electric power reactors as their point-of-departure designs. They follow the ESECOM scheme in evaluating the critical, chronic, contact, and intruder doses for assessing the accident, occupation, and waste disposal radiological hazards. The study indicates that the silicon carbide design has a better environmental and safety performance than the D-³He design