Whilst many see nuclear as the only viable means of meeting our future energy needs few can doubt the risks, especially following the recent disaster at Japan’s Fukushima power plant. Also uranium, the usual fuel for nuclear power stations, is itself a finite resource and so will at some time run out. On the other hand the present “renewable” alternatives, wind, solar, biomass etc, all have their drawbacks and at their present rate of introduction will not come anywhere near meeting our predicted energy needs.
One possible answer to the dilemma is thorium: a naturally occurring radioactive element, four times more abundant than uranium in the earth’s crust and with other potential advantages over uranium including:
– It is claimed that it produces 10 to 10,000 times less long-lived radioactive waste;
– The thorium cycle uses 100% of the isotope as coming out of the ground (whereas the uranium cycle uses only the 0.7% fissile U-235 of the natural uranium).
– Thorium cannot sustain a chain reaction without priming, so fission stops by default. (Basically, it “fails safe”)Also, and a cynic might say this is why it has not been developed in the past, weapons-grade fissionable material is harder to retrieve from a thorium reactor.
Indeed thorium reactors have been around since the 1960’s but have generally been discounted as not commercially viable. That may be about to change. India, a country with 25% of the world’s reserves of thorium, is embarking on a major investment in thorium fuelled reactors. Ratan Kumar Sinha, the director of the Bhabha Atomic Research Centre in Mumbai, says that the basic physics and engineering of a thorium-fuelled reactor are in place, and the design is ready. A search for a suitable site is now underway and the plant is expected to be operational within 6 years. However not everyone is convinced. Jean McSorley of Greenpeace was quoted earlier this year as saying ‘Even if thorium technology does progress to the point where it might be commercially viable, it will face the same problems as conventional nuclear: it is not renewable or sustainable and cannot effectively connect to smart grids. The technology is not tried and tested, and none of the main players are interested. Thorium reactors are no more than a distraction.’
Others word their objections even more strongly, with Peter Karamoskos of the International Campaign to Abolish Nuclear Weapons (ICAN) quoted as stating: ‘Without exception, have never been commercially viable, nor do any of the intended new designs even remotely seem to be viable. Like all nuclear power production they rely on extensive taxpayer subsidies; the only difference is that with thorium and other breeder reactors these are of an order of magnitude greater, which is why no government has ever continued their funding’
For both sides of this debate see: India plans ‘safer’ nuclear plant powered by thorium and Don’t believe the spin on thorium being a greener nuclear option