In the wake of the Fukushima nuclear disaster, the most extraordinary thing is the lack of public discussion and the disturbing policy silence – here and worldwide – over safe nuclear energy.
Yes, it does exist.
There is a type of nuclear reactor which cannot melt down or blow up, and does not produce intractable waste, or supply the nuclear weapons cycle. It's called a thorium reactor or sometimes, a molten salt reactor – and it is a promising approach to providing clean, reliable electricity wherever it is needed.
It is safe from earthquake, tsunami, volcano, landslide, flood, act of war, act of terrorism, or operator error. None of the situations prevailing at Fukushima, Chernobyl or Three Mile Island could render a thorium reactor dangerous. Furthermore thorium reactors are cheap to run, far more efficient at producing electricity, easier and quicker to build and don't produce weapons grade material.
The first thorium reactor was built in 1954, a larger one ran at Oak Ridge, USA, from 1964-69, and a commercial-scale plant in the 1980s – so we are not talking about radical new technology here. Molten salt reactors have been well understood by nuclear engineers for two generations.
They use thorium as their primary fuel source, an element four times more abundant in the Earth's crust than uranium, and in which Australia in particular is richly-endowed. Large quantities of thorium are currently being thrown away worldwide as a waste byproduct of sand mining for rare earths, making it very cheap as a fuel source.
Unlike Fukushima, these reactors don't rely on large volumes of cooling water which may be cut off by natural disaster, error or sabotage. They have a passive (molten salt) cooling system which cools naturally if the reactor shuts down. There is no steam pressure, so the reactor cannot explode like Chernobyl did or vent radioactivity like Fukushima. The salts are not soluble and are easily contained, away from the environment and public. This design makes thorium reactors inherently safe, whereas the world's 442 uranium reactors are inherently risky (although the industry insists the risks are very low).
They produce a tenth the waste of conventional uranium reactors, and it is much less dirty, only having to be stored for three centuries or so, instead of tens of thousands of years.
Furthermore, they do not produce plutonium and it is much more difficult and dangerous to make weapons from their fuel than from uranium reactors.
An attractive feature is that thorium reactors are 'scalable', meaning they can be made small enough to power an aeroplane or large enough to power a city, and mass produced for almost any situation.
Above all, they produce no more carbon emissions than are required to build them or extract their thorium fuel. They are, in other words, a major potential source of green electricity.
According to researcher Benjamin Sovacool, there have been 99 accidents in the world's nuclear power plants from 1952-2009. 19 of these have taken human life or caused over $100m in property damage. Such statistics suggest than mishaps with uranium power plants are unavoidable, even though they are comparatively rare. (And, it must be added, far fewer people die from nuclear accidents than die from gas-fired, hydroelectric or coal-fired power generation.)
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