On the Matching of Fusion Breeders to Heavy-Water Reactors

The matching of D-T fusion breeders to heavy-water CANDU-type reactors has been studied using the transport code ANISN to evaluate the neutron transport and breeding characteristics of a low-power-gain fusion blanket. The fusion blanket consists of a niobium structure, natural lithium coolant, and a graphite reflector with 2- to 6-cm-thick zones of Th, ThO₂, or ThC situated between the first wall and the reflector. Total breeding ratios of 1.40 to 1.50 have been calculated. Using the calculated breeding ratios, a system period of less than 10 years is determined for proposed solid thorium fuels. The reaction rate ratio of fusion to fission is less than unity.