Fuel-Cycle Analysis of Molten-Salt Breeder Reactors

Thermal- and intermediate-energy molten-salt breeder reactors appear capable of fuel doubling times less than 20 years and fuel-cycle costs under 0.4 mill/kWh. These reactors are fueled with circulating molten salts consisting of the fluorides of thorium, uranium, lithium, and beryllium.Three reactor concepts were analyzed; the first two were graphite-moderated thermal breeders. In the first of these, the fissile and fertile materials were kept separated by graphite tubes in the core; in the second, the fissile and fertile materials were included in a single salt stream. In the third concept, an intermediate-energy breeder, the core was an unmoderated salt containing both fissile and fertile materials. The reactors were optimized for minimum fuel-cycle cost and maximum annual fuel yield. The results showed that each concept was capable of a low fuel-cycle cost and a short doubling time; however, the major development problems are different for each concept.