Thorium fuel cycles compared to uranium fuel cycles

This paper compares the material quantities and radioactive properties of t horium fuel cycles for various types of nuclear power plants with similar r esults for uranium fueling. Thorium resources exceed those of uranium. Reac tors can convert thorium to Fissile uranium-233, making breeding possible w ith thermal neutrons. Thorium fuel cycles require a separate fissile source , such as U-235 or Pu-239, to start first-generation thorium breeders or to fuel non-breeding reactors. Thorium-uranium-fueled converter reactors cons ume more uranium than thorium. Toxicity of high-level waste from thorium fu eling can exceed that for uranium fueling.