Yes, you can have a cheaper and safer form of nuclear energy. Whats the problem with that. Well, you can’t use the fuel for nuclear weapons. The original purpose of nuclear reactors was to create fuel for weapons and not for energy. 

With uranium and thorium, the key similarity is that both can absorb neutrons and transmute into fissile elements.

That means thorium could be used to fuel nuclear reactors, just like uranium. And as proponents of the underdog fuel will happily tell you, thorium is more abundant in nature than uranium, is not fissile on its own (which means reactions can be stopped when necessary), produces waste products that are less radioactive, and generates more energy per ton.

So why on earth are we using uranium? As you may recall, research into the mechanization of nuclear reactions was initially driven not by the desire to make energy, but by the desire to make bombs. The $2-billion Manhattan Project that produced the atomic bomb sparked a worldwide surge in nuclear research, most of it funded by governments embroiled in the Cold War. And here we come to it: Thorium reactors do not produce plutonium, which is what you need to make a nuke.

How ironic. The fact that thorium reactors could not produce fuel for nuclear weapons meant the better reactor fuel got short shrift, yet today we would love to be able to clearly differentiate a country’s nuclear reactors from its weapons program.

How safe is Thorium?

Then there’s the safety side of thorium reactions. Unlike U235, thorium is not fissile. That means no matter how many thorium nuclei you pack together, they will not on their own start splitting apart and exploding. If you want to make thorium nuclei split apart, though, it’s easy: you simply start throwing neutrons at them. Then, when you need the reaction to stop, simply turn off the source of neutrons and the whole process shuts down, simple as pie.

India and China have long term plans to use Thorium.

Researchers have studied thorium-based fuel cycles for 50 years, but India leads the pack when it comes to commercialization. As home to a quarter of the world’s known thorium reserves and notably lacking in uranium resources, it’s no surprise that India envisions meeting 30% of its electricity demand through thorium-based reactors by 2050.

In 2002, India’s nuclear regulatory agency issued approval to start construction of a 500-megawatts electric prototype fast breeder reactor, which should be completed this year. In the next decade, construction will begin on six more of these fast breeder reactors, which “breed” U233 and plutonium from thorium and uranium.

Design work is also largely complete for India’s first Advanced Heavy Water Reactor (AHWR), which will involve a reactor fueled primarily by thorium that has gone through a series of tests in full-scale replica. The biggest holdup at present is finding a suitable location for the plant, which will generate 300 MW of electricity. Indian officials say they are aiming to have the plant operational by the end of the decade.

China is the other nation with a firm commitment to develop thorium power. In early 2011, China’s Academy of Sciences launched a major research and development program on Liquid Fluoride Thorium Reactor (LFTR) technology, which utilizes U233 that has been bred in a liquid thorium salt blanket. This molten salt blanket becomes less dense as temperatures rise, slowing the reaction down in a sort of built-in safety catch. This kind of thorium reactor gets the most attention in the thorium world; China’s research program is in a race with similar though smaller programs in Japan, Russia, France, and the US.

There are at least seven types of reactors that can use thorium as a nuclear fuel, five of which have entered into operation at some point. Several were abandoned not for technical reasons but because of a lack of interest or research funding (blame the Cold War again). So proven designs for thorium-based reactors exist and need but for some support.

A bit more research is needed.

Thorium is three times more abundant in nature than uranium. All but a trace of the world’s thorium exists as the useful isotope, which means it does not require enrichment. Thorium-based reactors are safer because the reaction can easily be stopped and because the operation does not have to take place under extreme pressures. Compared to uranium reactors, thorium reactors produce far less waste and the waste that is generated is much less radioactive and much shorter-lived.

To top it all off, thorium would also be the ideal solution for allowing countries like Iran or North Korea to have nuclear power without worrying whether their nuclear programs are a cover for developing weapons… a worry with which we are all too familiar at present.

So, should we run out and invest in thorium? Unfortunately, no. For one, there are very few investment vehicles. Most thorium research and development is conducted by national research groups. There is one publicly traded company working to develop thorium-based fuels, called Lightbridge Corp. (Nasdaq: LTBR). Lightbridge has the advantage of being a first mover in the area, but on the flip side the scarcity of competitors is a good sign that it’s simply too early.

Had it not been for mankind’s seemingly insatiable desire to fight, thorium would have been the world’s nuclear fuel of choice. Unfortunately, the Cold War pushed nuclear research toward uranium; and the momentum gained in those years has kept uranium far ahead of its lighter, more controllable, more abundant brother to date. History is replete with examples of an inferior technology beating out a superior competitor for market share, whether because of marketing or geopolitics, and once that stage is set it is near impossible for the runner-up to make a comeback. Remember Beta VCRs, anyone? On a technical front they beat VHS hands down, but VHS’s marketing machine won the race and Beta slid into oblivion. Thorium reactors aren’t quite the Beta VCRs of the nuclear world, but the challenge they face is pretty similar: it’s damn hard to unseat the reigning champ.

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