Thorium is a dense, mildly radioactive silvery metal recovered primarily from thorite and thorianite, although it can also be recovered from monazite sands, where it occurs alongside rare earth elements. Its primary interest is as a novel Nuclear Fuel in the form of TOX, or Thorium Mixed-Oxide Fuel, a mixture of Th-232 and U-233. Thorium-232 can be converted to fissile Uranium-233 in a reactor, and when TOX is used as nuclear fuel, it continually produces more U-233 from its available Th-232 stockpile. Economically viable thorium reactor designs were completed during Project LIBERTY and successfully commercialised by ACME Atomic Industries. Secondary applications include thoriated tungsten electrodes for welding and certain high-temperature ceramics.
