The science of nuclear energy
The science of nuclear energy

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

The science of nuclear energy

4.2 Thorium – nuclear fuel of the future?

Download this video clip.Video player: ou_futurelearn_nuclear_energy_vid_1087.mp4
Skip transcript


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.
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.
Here's the opening to the mine.
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.
Thorium. High levels of thorium in this rock, as you can see here.
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.
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.
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.
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.
End transcript
Interactive feature not available in single page view (see it in standard view).

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:

Th 90232 postfix plus n 01 right arrow Th 90233 times right arrow minus minus beta times times decay Pa 91233 right arrow minus minus beta times times decay cap u .92233

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!


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371