Thursday, 31 March 2011

Thorium and the Nuclear Future

I had an e-mail from a friend last week recommending that I buy up some of the fast-dwindling world stocks of potassium iodide, to keep in my bathroom cabinet in case levels of radiation in the UK became high enough to threaten our thyroid glands. I replied rather severely (sorry, Eldo!) that I thought this quite unnecessary and indeed unfair to the Japanese, who might actually need some of these stocks for themselves. I've probably lost a friend, but the continuing (and apparently deteriorating) situation at Fukushima, thrust before us in almost every news bulletin, as well as causing panic among some members of the public, has led to qualms among the policymakers, and the question of nuclear safety has become a live issue yet again. The debate seems to be sharply divided into those with a 'green' perspective, who oppose nuclear energy and back 'alternatives' such as wind, wave and solar power, and those with a more pragmatic approach, who back nuclear energy as the only non-fossil-fuel option that can deliver the substantial energy generation that we need for the rest of the century. Both points of view have their merits. There is clearly much to be done to make renewable energy able to deliver sufficient power for today's needs, never mind tomorrow's. Although my solar panels deliver h ot water very effiiciently, I've recently been put off photovoltaic energy and small-scale wind turbines by advice from an expert that both are green but neither are economic. On the other hand, as a longstanding opponent of nuclear energy on the grounds of its inherent dangers, particularly the unresolved issue of how to deal with highly radioactive waste, some of it with a half-life measured in thousands of years, I have not felt able, up to now, to support the commissioning of a new generation of nuclear reactors, whatever the apparent safety precautions built into them. When David Cameron, and others, say that it isn't likely that we will suffer a 9.0 earthquake or a 14m tsunami, we have to say 'yes, that's true, but the Japanese didn't plan for this level of disaster either, and how do we know what may happen with storm surges or geological collapse offshore'. Earlier this week, however, my daughter Christina alerted me to an article in the Daily Telegraph that explained the benefits of a different kind of reactor, one based on thorium salts rather than directly on enriched uranium. Among other things, the article mentioned that the Chinese have already decided to take this route for their new nuclear industry. I did some further research on this matter and have become convinced that thorium liquid-fluoride reactors do indeed provide a real alternative to water-cooled ones. It seems that there are historical reasons why this type of reactor was not developed in the early days of nuclear power, some of them to do with its inability to produce plutonium for nuclear weapons. Since we are now attempting to reduce our reliance on such weapons for security, and encouraging other countries not to develop them at all, it surely makes sense to reassess this choice. Thorium reactors are much safer than water-cooled ones, since the fission process simply stops if bombardment with neutrons ceases. They are also much better able to deal with and re-use waste products. Thorium-based reactors can be used to replace coal- and oil-fired facilities using the same turbines. If you want to know more, go to for more information. I shall certainly be taking part in any campaign to put thorium reactors back on the agenda when the UK commissions new nuclear reactors to replace our ageing ones. I have the nasty suspicion, though, that the momentum built up by more than forty years of solid-core reactors may be too great. After all, the QWERTY keyboard was originally the slowest to use, chosen for manual typewriters because it reduced the number of times keys clashed and tangled, but it is still the one everyone uses today, though modern electronic keyboards don't need it as they don't have a key-clash problem. And everyone knows that the Betamax system was better than VHS, but volumes of trade and the need for compatibility led to the latter's victory in the marketplace. Let's hope that the same phenomenon doesn't work in this case. If nuclear power is the future, let's make it the safest future we can.