The clean-up operation at the Fukushima nuclear plant is entering a new and, dare one say it, critical phase. According to the BBC, 22 fuel rod assemblies are being carefully removed and after that there are another 1,500 to go. Basically, it’s the world’s most dangerous and least enjoyable game of pick-up-sticks.
It’s a relief to know that the new nuclear power station planned for Hinkley Point in Somerset will incorporate ‘passive safety’ features that should mean that what happened in Japan can’t happen to the West Country. Less reassuring, however, is the fact that most nuclear power stations currently under construction around the world don’t incorporate these failsafes.
In a blog post for the Economist, ‘Babbage’ argues that there’s an even more fundamental problem with today’s nuclear technology:
“Passive safety features aside, the new generation of reactors being hawked around the world are still basically old-fashioned light-water reactors with solid-fuel cores that are cooled and moderated by water.”
The light water reactor (LWR) has a several serious disadvantages:
“Producing copious quantities of plutonium is just about the last thing a commercial reactor needs to do. It creates huge handling and storage problems as well as all manner of security and proliferation headaches. On top of that, the LWR’s other drawbacks ensured that commercial reactors would henceforth be more expensive to build and costlier to operate than might otherwise have been the case.
“For instance, the cooling water in an LWR is not only radioactive and corrosive, but also under extremely high pressure. As a consequence, light-water reactors need to be housed in fortress-like containment buildings in case the cooling system fails and radioactive steam is released into the atmosphere.”
This helps explain why power from Hinkley Point C is set to cost us twice the going rate.
But could it be any other way? Aren’t these dangers – and the expensive counter-measures designed to contain them – an inevitable feature of nuclear power? Not necessarily, says Babbage. In the post-war period, the technology could have developed along a different pathway – using thorium instead of uranium as a fuel, and liquid flouride salt instead of water as a coolant:
“One advantage of liquid fuels is that they are not subjected to the radiation damage or structural stresses that cause the fuel rods in conventional reactors to swell and distort. Also, because they use a liquid fluoride salt for a coolant, there is no high-pressure water to deal with. Operating at atmospheric pressure, no containment vessel is therefore needed…
“The spent fuel from a light-water reactor contains radioactive plutonium with a half-life of over 24,000 years. The fuel used in a liquid-fuel reactor is liquid fluoride laced with thorium. The toxicity of what little waste it produces is 10,000 times less than that from a conventional reactor. Overall, the half-life of a liquid-fuel reactor’s byproducts is measured in hundreds rather tens of thousands of years.”
The Americans had a liquid flouride thorium reactor up-and-running in the 1960s, but then the Nixon administration pulled the plug:
“…it produced too little plutonium for making nuclear weapons. Today, that would be seen as a distinct advantage. Without the Cold War, the thorium reactor might well have been the power plant of choice for utilities everywhere.”
So, why can’t we make good this mistake and switch back to thorium-based nuclear power? Well, there are research programmes underway in several countries – with India leading the way. The problem though, is that progress on any nuclear technology is unavoidably slow and cumbersome, requiring a major long-term commitment of resources and the heavy involvement of the state.
For those of us who believe that technological progress comes from free markets and fierce competition, this should not inspire confidence.