Thorium: The forgotten element
The threat of a global energy crisis looms ever larger. With Britain’s power stations struggling to keep up with demand, OFGEM, the UK’s energy regulator, has warned enforced blackouts could be necessary by 2015.
Sometimes known as the “forgotten element”, thorium is increasingly championed as an alternative nuclear fuel. It might not save us from blackouts in the next few years, but could it help provide a longer-term solution?
The task of addressing the world’s future energy needs is one of the major challenges of our age. Scientists and policymakers dream of a “silver bullet” – a sweeping, cure-all solution – but so far the search for answers has appeared decidedly scattergun.
Nothing underlines the lack of consensus more plainly than that most divisive of alternatives, nuclear power. France has embraced it; Germany has abandoned it; and the UK has often seemed to have no idea what to do about it.
The notion that renewables alone will reduce greenhouse gases to the desired levels while at the same time generating all the energy we need is an attractive one. Yet supporters of the nuclear option regard such a scenario as at best highly optimistic and at worst dangerously delusional.
They point out that solar power has still to deliver in earnest, that wave power has not been demonstrated convincingly and that wind power is at the mercy of the most fundamental drawbacks – variability and available space chief among them. Only nuclear energy, they insist, can lend itself to a “green” regime and guard against the startling possibility that countries such as the UK could face compulsory blackouts.
For their part, nuclear power’s detractors are able to couch their case in altogether blunter terms. The spectre of a Fukushima-style disaster can make for a notably persuasive argument.
And so the impasse endures. Carbon budgets remain to be met. The threat of fuel poverty lingers. The rhetoric from both sides continues to be dominated by language that alarms more than it informs. Positions stay firmly entrenched or, in Britain’s case, neither here nor there.
What few people know is that it might all have been so different. And what even fewer appreciate is that it still could be.
Thorium has been described as “the forgotten element”. Baroness Worthington, a leading environmental campaigner, has called it “the fuel that no-one has heard of and that everyone needs to hear of”. The US recently buried thousands of tonnes of it, unable to conceive a more practical fate. Enormous quantities are being excavated in China – but only, ironically enough, as a by-product of efforts to extract the rare earth metals required for manufacturing the magnets for wind turbines.
Its prospects seemed bright enough in the early days of nuclear power generation. It fuelled several plants in the US, as well as Germany’s High-Temperature Gas Reactor and the smaller-scale Dragon Reactor at Winfrith in the UK.
Yet its appeal typically proved short-lived – as was perhaps most starkly illustrated when pioneering nuclear physicist Alvin Weinberg created a prototype molten salt reactor, intended to run on thorium, at America’s Oak Ridge National Laboratory in the 1960s. The result was an inherently safe technical success, but it was active for only a few years and eventually lost out to America’s plutonium-fuelled Fast Breeder programme.
Professors Bob Cywinski and Roger Barlow run the International Institute for Accelerator Applications at the University of Huddersfield. Their research, acknowledged as among the most important of its kind in the world, is dedicated to demonstrating that thorium offers a route to an environmentally acceptable nuclear future.
“The UK has a unique chance to establish and sustain a multi-billion-pound industry,” says Professor Cywinski, whose work on thorium’s behaviour in reactors was presented at an illustrious gathering of experts at CERN, Geneva, home of the European Organisation for Nuclear Research, last year. “It would be based on safe, inexhaustible, low-waste and proliferation-resistant nuclear power generation. It would tick all the boxes and might even satisfy both sides of the debate. We talk about a silver bullet, but this could be a golden mean as well.”
Almost inevitably, a sceptic’s stock response is to ask why thorium’s modern-day advocates should succeed where Weinberg, a scientific giant of the 20th century, was judged to have failed. Technical advances aside, what has changed? One compelling factor, believes Professor Cywinski, is that an attribute that might once have counted against thorium is now very much in its favour.
“Weinberg operated in an era when civil development programmes in this field were inextricably linked with military needs,” he says. “Anecdotal evidence suggests uranium became the nuclear fuel of choice because of its ability to produce plutonium – which is, of course, the raw material for nuclear weapons. The precise truth may well be a little more nuanced, but I always like to recall that even Faraday had to make lenses for the Admiralty before he could go back to working on the electric motor.”
The risk of nuclear proliferation, particularly among rogue states and terrorist groups, means the capacity to generate plutonium is now viewed as a negative. “Weinberg knew all this half a century ago,” says Professor Cywinski. “He just didn’t get the chance to showcase all the advantages.”
Objections to any nuclear programme are usually rooted in fears over safety. Fukushima, Chernobyl and, to a lesser extent, Three-Mile Island are names that have become synonymous with panic and devastation. Professor Cywinski has heard and rebuffed the arguments over and over again.
“It’s not hard to scare people,” he says. “I could just as easily ask whether any parent would want their child to have life-saving surgery in a wind-powered hospital. “The objective truth about Fukushima is that a nuclear power station built using construction principles dating from the 1960s came close to surviving a natural catastrophe that obliterated everything else in its path. That tells you something about the industry’s safety record, which is second to none in relation to other energy industries.”
So what about the legacy of toxic waste? Some heavy actinides may have half-lives of thousands of years. “Thorium has 200 times the energy content of uranium, yet it generates several thousand times less radioactive waste,” says Professor Cywinski. “It’s also comparatively abundant – as commonplace as lead, for instance – which means it could provide a supply of fuel for the next 10,000 years or more. Moreover, with some nuclear reactor designs, legacy and future waste can be mixed with thorium and burnt as fuel, turning a liability into an asset.”
Not everyone is convinced. Critics warn that the technology necessary to fulfil thorium’s potential is decades in the future and that its pursuit represents a costly distraction in the face of the urgent threat posed by global warming. Environmentalists point out that renewable power would now be much more affordable and widespread if it had enjoyed even a fraction of the research funds ploughed into nuclear energy.
Yet the number of high-profile converts is growing. Hans Blix, the UN’s former chief weapons inspector, and Carlo Rubbia, Nobel Laureate and former CERN director, have both become strong advocates. Perhaps most significantly, a new strategy outlining the UK’s future nuclear energy policies, prepared by the government’s chief scientific officer and published last year, called for further research into “the forgotten element”.
“We have to think for the long term,” says Professor Cywinski. “Thorium nuclear power on a commercial scale could happen in 20 years – or we could follow the lead of Thor Energy in Norway and start to develop fuel rods for conventional reactors now. India is working on a thorium nuclear economy, and China promises power stations in less than 15 years. The important thing is that we commit – and that we stay committed.
“There’s a ‘triple burden’ that needs to be met – lowering emissions, preserving output and enhancing public confidence – and it’s difficult to see how a renewables-only approach or a continued focus on uranium could do that. Simple maths alone will show you what’s likely to work and what isn’t. We’ve done the maths, and that’s why we say it’s time to think differently – otherwise there’s a very real possibility the lights will go out.”
Simon Foster, Investment Director, Exeter office