4.2 Thorium – nuclear fuel of the future?
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Transcript
FIONA BRUCE
Do we need a new kind of nuclear fuel? Some of the world's top physicists are gathered in Geneva to discuss the merits of the radioactive element thorium. Although it's lagging way behind the standard fuel uranium in its development, potentially it has some major advantages. Thorium is three times more plentiful than uranium. It's estimated to produce 10 times less waste than uranium.
And unlike uranium, its byproducts can't be made into a nuclear bomb. Our environment analyst Roger Harrabin reports from a thorium test site in southern Norway, partially funded by the UK government.
ROGER HARRABIN
The gentle hills of southern Norway, forged 600 million years ago from the fire and ash of a supervolcano. It left a hidden bounty for mankind.
GUIDE
Here's the opening to the mine.
ROGER HARRABIN
Centuries of iron have been hewn from this rock, but a guide with a Geiger counter shows that the walls inside are also peppered with a radioactive element.
GUIDE
Thorium. High levels of thorium in this rock, as you can see here.
ROGER HARRABIN
So if it's radioactive, could thorium be used as a nuclear fuel, instead of its volatile cousin uranium? Scientists are trying to find out. Tests are going on under this hill. There's a nuclear reactor in the belly of the mountain. It's like a Bond movie. A private firm's being helped by the British government to trial thorium here.
I'm standing now right on top of the reactor itself. If I look down the hole, I can see the top of the reactor down there below me. It's turned off now for maintenance, so I'm safe. Down there is where the thorium has been tested, and the firms say so far the experiments are going well. Similar tests are being carried out in India, China, and Japan, as several nations assess the potential of thorium.
OYSTEIN APSHJELL
There's lots of thorium in the world. Very well distributed all over the globe. In operations, in a reactor, it has some chemical and physical properties that make it really superior over uranium as well. On the waste side, we don't generate new long-lived waste.
ROGER HARRABIN
There's a potential safety benefit, too. When the tsunami hit the uranium-fueled Fukushima nuclear plant two years ago, the reaction spun out of control. Scientists in Norway say that wouldn't have happened with thorium. But critics say developing thorium will be expensive, and won't produce clean energy for decades.
DR. NILS BOHMER
The advantage of thorium is purely theoretical. The technology's development is decades in the future. Instead, I think we should focus on developing renewable technology - for example, offshore wind technology, which I think there's a huge potential to develop.
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So far, the course has considered only uranium and plutonium as nuclear fuels.
However, thorium has been suggested as an alternative fuel because it is more abundant than uranium and has some advantages regarding safety.
The transformation of thorium-232 into a fissile isotope follows two β-decays:
Many research groups are actively pursuing thorium as a fuel. It is of particular interest to countries such as Norway and India which have large natural reserves of thorium.
The next sections consider a more radical change in nuclear fuel!