Is thorium the future of nuclear energy?

Uranium-fuelled nuclear power stations have enjoyed a somewhat turbulent history, to say the least. With origins steeped in nuclear arms development, and high-profile disasters such as Chernobyl and Fukushima, the cost to benefit ratio of this resource has long since proven divisive amongst politicians and the public alike.

Even so, few would deny the advantages offered by nuclear power. Its ability to generate large quantities of electricity from relatively small amounts of uranium seems to offer one of the only plausible solutions to the ever-growing global demand for low-carbon energy. Fossil fuels cannot offer a long-term solution, and whilst sustainable energy resources are certainly attractive from an environmental perspective, there remain doubts as to whether they can deliver sufficient levels of power to meet demand.

For those who are concerned about the safety of uranium-fuelled nuclear power, but sceptical about the capability of other resources to meet the global energy demand in a sustainable manner, the future might seem bleak. However, Richard Martin, author of Superfuel: Thorium, the Green Energy Source for the future published by Palgrave Macmillan, believes that thorium could provide a solution to both of these problems. I spoke to Martin to find out more about this abundant but overlooked element…

What inspired you to write a book about thorium?
I have been covering energy and technology for about 20 years, and I have come to the conclusion that in many ways, nuclear power is the only solution to global climate change. Whilst I am totally in favour of renewable energy resources such as wind and solar power, they are just not going to scale up fast enough to provide the baseload electricity that we need.

I came across thorium in the blogosphere approximately three years ago, and I ended up writing a story for Wired about the budding thorium movement, as I called it at the time. That grew into a book and it has been very interesting to watch this band of committed outsiders really grow into a dynamic community with several business ventures, government-supported programmes and a handful of interested NGOs as well.

So the landscape of thorium was actually evolving whilst you were writing your book?
It was, and it was a challenge to try to encapsulate it, or to take a snapshot at any given point in time, because things kept changing so rapidly.

You describe thorium as a clean, safe and inexhaustible energy source. If this is the case, why has it been overlooked?
There is a short answer and there is a long answer to that question. The short answer is that thorium is no good for making bombs. As you know, the nuclear power industry grew out of the end of World War II, the Manhattan Project and the use of uranium and plutonium in nuclear warheads.

The long answer is a bit more complicated. We knew how to use uranium; we knew how to make things blow up and so getting it to supply power generation was not that big a leap. The first example of this was the United States Navy’s nuclear submarine programme, which was headed by Admiral Hyman G Rickover. Admiral Rickover had very specific requirements for what he wanted in a nuclear power source, and whilst he possessed many remarkable qualities, tolerance for dissent and a fostering of innovation were not among them. I think that his rigidity of thinking spilled over into the early days of the nuclear power industry, and I think that this has hampered the sector ever since.

When you think about it, not much innovation has occurred within the nuclear power industry over the last 40 years. In fact, the US Nuclear Regulatory Commission (NRC) recently issued the first license for a new nuclear plant in the United States for 34 years. Even this will include conventional, uranium-based reactors; in other words, 40-year-old technology.

We have seen so much innovation in other areas of technology – particularly within the information technology sphere – and the comparison that I like to make with nuclear power is that we are still using Atari 800 computers from 1980.

Could you explain a bit more about the ways in which thorium is safer than uranium?
One thing to keep in mind about thorium is that it’s fertile, not fissile. You cannot cram a bunch of thorium into a small space and have it blow up or create a spontaneous chain reaction. You need to have an external source of neutrons to bombard the thorium, which in turn goes through a decay process and becomes an isotope of uranium – uranium-233. For a variety of chemical reasons, this isotope is far superior to the uranium that we are currently using as a source of energy. This means that you can store, transport and work with thorium in a form that is not very dangerous at all.

Another reason concerns the issue of waste. Thorium reactors create about one tenth or less of the volume of waste that is produced by conventional uranium reactors. Moreover, the waste that they do produce, in terms of its radiotoxicity, is shorter-lived than the waste that the current uranium reactors create, so you would be looking at storing it for 200 years as opposed to 10,000 years.

When considering the third advantage, we should keep in mind that the thorium movement is not only calling for new fuel, but for new machines also. In these machines, known as liquid fuel thorium reactors, the reactions actually occur in a liquid, and so they are inherently safe for a number of reasons. When liquid is heated, it expands, and so the atomic reactions taking place within that expanding liquid are naturally slow. It’s a self-governing reactor. Also, a liquid fuel thorium reactor is built like a bathtub. It has a drain in its bottom that is plugged with a freeze-plug. If anything goes wrong, this plug melts and the fuel drains into a shielded underground container that is virtually impervious to any kind of disturbance.

Finally, this reactor technology operates at an atmospheric pressure, rather than at the very high pressures at which conventional uranium reactors operate. Nuclear accidents usually begin with a steam explosion rather than a core meltdown. Radioactive steam builds up under very high pressures, and it literally blows the top off. This doesn’t happen with thorium reactors.

How does thorium’s capacity to generate power compare with that of uranium?
The most important quality of thorium, in terms of its potential to generate power, is its abundance. Thorium is about four times more abundant than uranium in the ground; it is about as common as lead. If you walked to your local park and scooped up a handful of dirt, you would have about 12 parts per 1,000,000 of thorium in your hand. It is also distributed in such a way that almost every country will contain at least a little thorium. Some countries will have a lot.

India, for instance, depending on whose numbers you are looking at, is thought to possess the largest amount of thorium. I’ve heard it said that if you go to a beach outside Mumbai and scoop up a handful of sand, you will have enough thorium in your hand to power the city for a year. That sounds a bit apocryphal to me, but it gives you an idea of what an abundant and dense source of energy this can be.

You have mentioned the dedicated thorium movement that your book has grown around. Are policymakers beginning to take notice of thorium as a viable source of low-carbon energy?
Yes they are. During my visit to London this week, I travelled to Cambridge for a day and participated in a very interesting roundtable discussion that included policymakers, scientists, analysts and people from Rolls Royce and other private sector companies. One person who has really spearheaded this movement in the United Kingdom is Baroness Bryony Worthington – one of the youngest members of the House of Lords. She has helped to create the Weinberg Foundation, a not-for-profit organisation named after Dr Alvin M Weinberg who was the Director of Oak Ridge National Laboratory (ORNL) during the 1960s. Dr Weinberg really pioneered this technology, and the Foundation is doing some really interesting work to move the policy forwards in terms of renewable energy and climate change. It is also trying to advance research and development within the field of thorium power.

I appreciate that it’s hard to anticipate these matters, but how would you hope to see the global energy landscape evolve over the next decade or so?
There are some very interesting developments taking place in the United States, the United Kingdom and in other Western European countries. However, the thorium revival probably won’t begin in these regions. It is more likely to happen in the booming economies of India and China. Earlier, I mentioned that India contains a lot of thorium and it also has a very well funded, government-supported plan to build dozens of conventional reactors. Over the next 25 years, the use of thorium will be phased in as the primary fuel of these reactors, and India hopes to produce about half of its electricity through nuclear power by approximately 2050. Virtually all of that electricity is to be generated by thorium.

Meanwhile, China arguably has an even more ambitious plan, which is to build liquid fuel thorium reactors, possibly, within the next five years. China is reportedly putting hundreds of millions of dollars into its thorium programme and so it will be very interesting to see what happens there.

If BRIC countries decide to go down the thorium route, do you think that the rest of the world is likely to follow?
The way I put it is that if you liked being dependent on oil from the Middle East, you’ll love being dependent on nuclear technology from China. I say that half-jokingly but I do think that it could be a moment of awakening – a Sputnik moment – when China unveils a liquid fuel thorium reactor that is actually producing power for the grid. That day might not be too far away.

Well thank you very much for taking the time to speak with me today Richard…


Superfuel: Thorium, the Green Energy Source for the future by Richard Martin is published by Palgrave Macmillan, and is available at leading book retailers.