Breeding Ratio, Inventory, and Doubling time in A D-T Fusion Reactor

A simple model is proposed to investigate the relations between breeding, inventory, and doubling time in the blanket of a fusion reactor using the T(D,n)He⁴ reaction. It is assumed that the amount of tritium removed per unit time is proportional to the amount present and the effects of radioactive decay are included. A series of numerical calculations was made using pa rameters appropriate for a 5000-MW(th) reactor. From these calculations it appears that to keep the blanket inventory and the initial inventory for startup to reason able values, the tritium removal system must be de signed to provide a mean tritium residence time in the blanket less than ∼1 day, preferably with the mean residence time approaching 0.1 day. Breeding ratios in the range of 1.02 to 1.1 give acceptable doubling times and, in general, higher breeding ratios are not desirable, especially when considered from a hazards viewpoint.