Characteristics of Plutonium-Topped Thorium Cycles in Heavy-Water-Moderated Pressure Tube Reactors

Thorium cycles in heavy-water-moderated pressure tube reactors are expected to lead to much better nuclear fuel utilization than the current natural uranium once-through fuel cycle. The extent to which various parameters affect fuel cycle economics and uranium requirements during the approach to equilibrium conditions for first-generation plutonium-topped thorium cycle reactors has been studied. The results are compared with systems in which equilibrium has been achieved to elucidate the significant differences between first- and second-generation thorium cycle reactors.