A single uranium fuel pellet is the size of your fingertip It contains as much energy as 481 cubic metres of natural gas, 677 litres of oil or 807 kilograms of coal

Moreover, it is cleaner than all of them The USA gets nearly one fifth of its electricity from nuclear power Every plant uses uranium This rare element is only found in a few places on Earth, requires a complex 16-step process to generate power, and its byproducts are tremendously radioactive This is not to mention the financial, environmental and human costs of a meltdown

Two places to the left of uranium on the periodic table is thorium It too can be used as nuclear fuel It is easier to find, safer to use and yields more energy So why does the world not use thorium power? If you haven’t heard of thorium, don't worry, you're not alone Particle physicist Victor J

Stenger first heard of it in 2012 He said, “It came as a surprise to me to learn recently that such an alternative has been available to us since World War II” Back then, nuclear energy was such a new, complex, dangerous and expensive technology to develop that it could only be done by national governments The Manhattan Project spent $2 billion figuring out how to split the atom controllably, and it took three more decades before nuclear energy was ready to become an industry Uranium isotope 235 is the industry standard fuel

This is not cheap to find Ninety percent of the world's natural uranium comes from only seven countries, none of them the USA Yet only 07% of the world’s natural uranium is U-235 The other 99

3% is U-238, which does not undergo fission So the uranium that is mined must be enriched, but no more than 5% of enriched uranium fuel is the useful isotope U-235 And once the U-235 has burned down, the fuel is spent In the meantime, the U-238 has been breaking down into other radioactive isotopes This radioactive waste cannot be used for fuel and is very dangerous

It has to be housed, separate from people and the environment, for up to 10,000 years Thorium is three times more abundant in nature than uranium It does not require enrichment – 9998% of naturally occurring thorium is useful as fuel It generates more energy per ton

It produces one to ten thousand times less waste than uranium, and that waste needs to be stored for 500 years Furthermore, thorium is more stable than uranium The nuclear reaction that releases energy can be stopped, so there is no danger of a meltdown, unlike with uranium John Kutsch, president of Whole World Engineering and executive director of the Thorium Energy Alliance, says that if we used thorium power, disasters like Fukushima and Three Mile Island would never have happened Thorium is easy to find, too

It’s everywhere, and is often buried amongst the waste from uranium mines It's less expensive and environmentally damaging to extract Some of the largest reserves of thorium are in Idaho Former NASA scientist Kirk Sorensen says that if the US used thorium, it could probably have achieved energy independence by around the year 2000 In all, the nuclear energy available in the world's thorium supply is estimated to be greater than the available energy from all of the world’s oil, coal and uranium combined

But in 1973, the US government discontinued research into thorium power Its official reasons were that uranium reactors were more efficient, that thorium was insufficient to support a commercial nuclear industry, and the research into thorium was unproven However, this last claim is untrue In 1964, the Department of Energy’s Oak Ridge National Laboratory built an experimental reactor, designed for thorium

Between 1965 to 1969, the reactor operated for around 15,000 hours As a result of this experiment, Glenn Seaborg, the discoverer of plutonium, told the Atomic Energy Commission that the thorium-based reactor had been successfully developed and tested The experimental thorium reactor was developed under nuclear physicist Alvin Weinberg He was director of the Oak Ridge National Laboratory and pioneered the reactor designs widely used today He supported the use of thorium in reactors because it would have zero risk of meltdown

As a result, in 1973 he lost his job The government told him, ""Alvin, if you are concerned about the safety of reactors, then I think it may be time for you to leave nuclear energy"" Overall, there are seven types of thorium reactors Five have entered into operation at some point in the past Therefore, proven designs exist

They were simply not supported by the government, and therefore not by private industry A 1997 international scientific symposium on nuclear fuel cycles concluded that the real reason thorium had been shut down was that its ore contains no fissile isotope Uranium, on the other hand, produces plutonium This is a key ingredient in nuclear warheads As Victor Stenger succinctly puts it, “[Thorium was] not pursued because it lacked weapons applications

” On the other hand, a 2003 paper by nuclear scientists Ralph W Moir and Edward Teller concluded that the government’s decision in 1973 was made by comparing the two types of reactor their scientists had built at the time, one uranium and one thorium The uranium reactor, benefiting from years’ more research, was simply better Moir and Teller argue that the decision to stop researching thorium power in 1973 was not a sinister conspiracy, but “an excusable mistake” America was not alone in its decision: Russia favoured uranium ore for its reactors, not just because of its military applications, but because Russia boasts uranium as a natural resource, and could therefore become energy independent

Thorium may have a future India has one quarter of the world’s known thorium reserves It lacks its own uranium resources, and therefore aims to provide 30% of its electricity needs through thorium reactors by 2050 In 2011, China’s Academy of Science began a major research and development program on a Liquid Fluoride Thorium Reactor Germany and the UK have conducted similar research in the past, and Japan, Russia, France and America have projects underway

Unfortunately, making thorium fuel pellets is expensive It needs to reach 3,300 degrees Celcius to melt Ironically, the nuclear reaction that provides energy needs to be kick-started by another element – either uranium or plutonium The science and technology behind uranium fuel is far too advanced and useful to be abandoned overnight Thorium power needs a lot more research and development by governments around the world before it provides the answers to all our problems

India, for instance, still has 20 uranium based reactors in operation, another 6 under construction, 17 planned and 40 proposed However, there is no escaping the fact that our energy industry could be far more efficient, cleaner and safer than we ever imagined, if it weren’t for a small-minded decision made 45 years ago