Thorium as a nuclear fuel:Benefits and challenges

Thorium as well as uranium and plutonium can be used as fuel in a nuclear reactor and it is a fertile material which allows it to be used to produce nuclear fuel in a breeder reactor. In 1997 the U.S. Energy Department underwrote research into thorium fuel and research was also begun in 1996 by the International Atomic Energy Agency (IAEA) to study the use of thorium reactors. Nuclear scientist Alvin Radkowsky of Tel Aviv University in Israel founded a consortium to develop thorium reactors which included
other companies: Raytheon Nuclear Inc. Brookhaven National Laboratory and the Kurchatov Institute in Moscow. Radkowsky was chief scientist in the U.S. nuclear submarine program directed by Admiral Hyman Rickover and later headed the design team which built the USA’s first civilian nuclear power
plant at Shippingport Pennsylvania which was a scaled-up version of the first naval reactor. Some countries including India are now investing in research to build thorium-based nuclear reactors. A 2005 report by the International Atomic Energy Agency discusses potential benefits along with
the challenges of thorium reactors. India has also made thorium based nuclear reactors a priority with its focus on developing fast breeder technology.
Some benefits of thorium fuel when compared with uranium were summarized as
follows:
* Weapons-grade fissionable material (233U) is harder to retrieve safely and clandestinely from a thorium reactor;
* Thorium produces 10 to 10000 times less long-lived radioactive waste;
* Thorium comes out of the ground as a 100% pure usable isotope which does not require enrichment whereas natural uranium contains only 0.7% fissionable U-235;
* Thorium cannot sustain a nuclear chain reaction without priming so fission stops by default.
However unlike uranium-based breeder reactors thorium requires irradiation and reprocessing before the above-noted advantages of thorium-232 can be realized which makes thorium fuels more expensive than uranium fuels.
But experts note that “the second thorium reactor may activate a third thorium reactor. This could continue in a chain of reactors for a millennium if we so choose.” They add that because of thorium’s abundance it will not be exhausted in 1000 years.
The Thorium Energy Alliance (TEA) an educational advocacy organization emphasizes that “there is enough thorium in the United States alone to power the country at its current energy level for over 1000 years.” Reducing coal as an energy source according to science expert Lester R. Brown of The
Earth Policy Institute in Washington DC would significantly reduce medical costs from breathing coal pollutants. The Institute estimates that coal-related deaths and diseases are currently costing the U.S. up to $160 billion annually.