Thorium is a naturally occurring radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten Thrane Esmark and identified by the Swedish chemist Jöns Jakob Berzelius and named after Thor, the Norse god of thunder.
Thorium, a slightly radioactive metal that occurs in rocks and soils, may hold significant promise as a replacement for uranium in the nuclear energy sector. As global energy consumption increases, thorium is being looked into as a possible alternative to uranium to provide safe and abundant nuclear power at a reasonable cost. 1 gram of thorium is more energy dense than 7,396 gallons of gasoline. This means that 8 grams of the substance could power a thorium turbine motor vehicle for a century.
Canada, China, Germany, India, the Netherlands, the United Kingdom and the United States have experimented with using thorium as a substitute nuclear fuel in nuclear reactors. When compared to uranium, there is a growing interest in thorium-based nuclear power due to its greater safety benefits, absence of non-fertile isotopes and its higher occurrence and availability. India’s three stage nuclear power programme is possibly the most well known and well funded of such efforts.
Thorium is an appealing alternative to uranium to many countries. It is both more cheap and more abundant than uranium, whose price is expected to rise yet more as backlash from the Fukushima disaster dies down, according to Energy and Capital. There are other benefits of thorium as well. During a thorium-powered nuclear reaction, most of the thorium itself is consumed, which leads to less waste, most of which is rendered non-hazardous in 30 years. The most dangerous nuclear waste material currently in use must be stored for 10,000 years, by way of contrast. Furthermore, 1 metric ton of thorium is equal to 250 metric tons in terms of efficiency in a water reactor.
Extraction of thorium would be less expensive per unit of energy than extraction of uranium as well, because it is present in higher concentrations by weight than the other metal, according to Dauvergne. The source also mentions another peculiar trait of thorium: it is nearly impossible to weaponize, as it contains no fissile isotope. This in itself has slowed uranium research, according to a 1997 international scientific symposium on nuclear fuel cycles.
The dangers of uranium – widely publicized in the wake of the Fukushima disaster – often lead analysts and others to consider thorium more seriously. As thorium is not fissile on its own, reactions could be stopped in case of emergency, according to Forbes. The publication suggests thorium could allow countries like Iran and North Korea to benefit from nuclear power without causing concern that they are secretly developing nuclear weapons, as well.
Thorium can also be used together with conventional uranium-based nuclear power generation, meaning a thriving thorium industry would not necessarily make uranium obsolete.
When used in a breeder-like reactor, however, unlike uranium-based light water reactors, thorium requires irradiation and reprocessing before the above-noted advantages of thorium-232 can be realized, which initially makes solid 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 1,000 years.
Where thorium is found
Thorium is present in small quantities in soils and rocks everywhere, and it’s estimated to be about four times more plentiful than uranium. Large reserves, rather than the trace amounts of the metal in the average backyard, exist in China, Australia, the US, Turkey, India and Norway, according to Reuters.
Source : Wikipedia, energyfromthorium.com, http://uraniuminvestingnews.com/, Stuff They Don’t Want You To Know