IT'S ELEMENTAL!
THORIUM SETH H. GRAE, THORIUM POWER
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H O R I U M WAS DISCOVERED BY
the Swedish chemist Jons J. Berzelius in 1828. He named it after Thor, the Norse god of thunder and war, because of its power. Thorium is the most efficient nuclear reactor fuel, so there have been many attempts to produce reactor fuel from thorium, including current unrelated efforts by Thorium Power and by institutes in India. Thorium oxide has the highest melting point of all oxides, which can provide a safety benefit as a nuclear reactor fuel. Thorium is estimated to be three times as abundant as uranium, holding more untapped energy than all oil, coal, natural gas, and uranium combined, with vast reserves in the U.S., Australia, India, Canada, and many other countries. Thorium is also responsi-
CLEANER REACTORS In a reactor with thorium fuel, some neutrons are absorbed by thorium-232 atoms, which become uranium-233. Uranium-233 is a more efficient nuclear fuel than uranium-235 or plutonium, with a high fission cross-section, a high number of neutrons released per fission (which makes it easier to sustain a critical reaction), and a high ratio of fission-to-parasitic capture. For these reasons, the thorium/uranium233 cycle has been studied since the earliest days of nuclear power, and it has been implemented in several water- and gas-cooled reactor systems.
D I V I N E J U S T I C E Thor wields his mighty hammer, Mjollnir. HTTP://WWW.CEN-ONLINE.ORG
THORIUM AT A GLANCE Name: Named for Thor, the Norse god of thunder. Atomic mass: 23204. History: Discovered in 1828 by Swedish chemist Jons Jakob Berzelius. Occurrence: Occurs naturally as a weakly radioactive isotope. Much of Earth's internal heat has been attributed to thorium and uranium decay. Thorium is primarily obtained from the minerals thorite and thorianite. Appearance: Silvery white metal. Behavior: Radioactive with a high melting point. The powdered metal is a fire hazard. The pure metal resists corrosion but tarnishes in air when contaminated with the oxide. Uses: Used in fabricating portable gas lamps, filament wire, breeder reactor fuel, gaslight mantles, and crucibles. Thorium oxide is used as a catalyst in the production of sulfuric acid and the conversion of ammonia to nitric acid.
ble for most of the internal heating of Earth. Thorium is stockpiled around the world. When rare-earth elements are separated from monazite sands for use as a fuel-cracking catalyst in the petroleum industry, a by-product is thorium. Although hundreds of tons of thorium are stockpiled from this process, only small amounts are used in commercial processes and products. In the U.S., a commercial use of thorium was small quantities in the wicks of camping lanterns. I have been told that Coleman stopped this use when it found out that people were testing Geiger counters on the wicks. In addition, small quantities ofvarious forms of thorium have been produced for nonenergy uses such as ceramics, magnesiumthorium alloys, and welding electrodes. I first heard of thorium in 1992 from a reactor than any other method, and curAlvin Radkowsky who designed the thorium fuel that Thorium Power is now develrent estimates are that the costs will prove to be significantly less than any other oping. Alvin was the original chief scientist for the U.S. Naval Reactors Program for method. In addition, fuels that burn pluAdm. Hyman G. Rickover, and he also tonium without thorium actually produce headed the design team for the first nuclear large quantities of new weapons-suitable power plant on land, at Shippingport, Pa. plutonium in the spent fuel; this is not the That reactor used thorium in its first core case with thorium fuel. The fuel also results and was the first reactor under former presin dramatically less toxic spent fuel, with much less spent fuel for the same ident Dwight D. Eisenhower's Atoms for Peace program, which amount of electricity generated. began 50 years ago. Reps. Jim Gibbons (R-Nev.) and Curt Weldon (R-Pa.) have W h e n Radkowsky's former taken up the cause of thorium professor, Edward Teller, asked fuel for plutonium disposition in him in 1986 if he could come up Russia. They have traveled to with a fuel design to address proMoscow to speak with scientists liferation concerns, Radkowsky and engineers and witnessed the turned back to thorium as the anCELEBRATING thorium fuel ampules in a test reC&EN'S swer. Radkowsky passed away last 80TH actor in Moscow. These conyear, but his work led to the fuel ANNIVERSARY gressmen are leading the effort design now being developed and to secure government funding tested in Russia to dispose of for the project. weapons-grade plutonium and to stop the production of new weapons-suitable pluPromising new thorium fuel technolotonium. Radkowsky spent most ofhis career gies eventually may lead governments and in the U.S. Navy program during the Cold the nuclear power industry to uncover the War and was amused by how times change; untapped energy potential of thorium for his technology is being tested in Russia to peaceful energy uses. dispose of plutonium from warheads. Seth H. Grae ispresident ofThorium Power, The project has been headed in Russia a Washington, D. C-basedcompany developingnuby academician Nikolai N . Ponomarevclearfuel designs to stop theproduction of weaponsStepnoi, vice president of the Kurchatov Institute, where the first Soviet atomic grade plutonium and eliminate plutonium stockbomb was developed. The work in Russia piles. He holds a BA. from Brandeis University, aJ.D.fromAmerican University, andanL.L.M. has determined that the thorium fuel design andM.B.A. from Georgetown University. will dispose of more plutonium per year in C & E N / S E P T E M B E R 8, 2003
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