Themes > Science > Chemistry > Nuclear Chemistry > Transuranium Element > Uses of Thorium

Thorium is currently important as a potential atomic-fuel source, because bombardment of thorium-232 by slow neutrons yields the fissile isotope uranium-233. This process is comparable to the process by which fast neutrons "breed" fissile plutonium-239 from nonfissile uranium-238. The thorium-uranium fuel cycle is being studied by scientists as an alternative to the uranium-plutonium fuel cycle. Two types of reactors, the molten-salt breeder reactor and the light-water breeder reactor, are being considered. These programs may make available for power production the United States thorium-fuel reserves, which represent a source of energy many times greater than the known coal, oil, and natural-gas reserves of the country. Thorium metal is used in magnesium alloys and as a stabilizing component of electronic tubes. Thorium oxide is used in light filaments and electrodes and also as a catalyst.