Life after death

Nuclear power is clean, but can it overcome its image problem?

The Economist print edition - Jun 19th 2008

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Illustration by Ian Whadcock

IF YOU want to make an environmentalist squirm, mention nuclear power. Atomic energy was the green movement’s darkest nightmare: the child of mass destruction, the spawner of waste that will remain dangerous for millennia, the ultimate victory of pitiless technology over frail humanity. And not even cheap. Well, times change. The followers of Rachel Carson and the Club of Rome in the 1960s and 1970s had not heard of the greenhouse effect, but today’s greens have. And they know that nuclear reactors are the one proven way to make carbon-dioxide-free electricity in large and reliable quantities that does not depend (as hydroelectric and geothermal energy do) on the luck of the geographical draw. What a dilemma for a thoughtful tree-hugger.

Patrick Moore, one of the founders of Greenpeace, faces no such dilemma, though. He is such a convert to the nuclear cause that he now chooses to consult for it. Cynics take him to task for that, but he makes no apology. His view of the world, shared by James Lovelock, the inventor of Gaia (the idea that the Earth itself has some of the characteristics of a living organism), is that nuclear power—which already provides 15% of the world’s electricity—is the only possible way out of climate change. Mr Lovelock thinks it is probably too late anyway, and that Gaia will shake herself and be rid of the plague of humans that now infest her skin. Mr Moore thinks she can be persuaded not to, if nuclear power is applied in even larger doses.

Given the widespread concern about nuclear energy, how can that be done? Partly, the answer comes, by shifting priorities (for today’s youth, climate change is what global nuclear warfare was for the baby-boomers). Partly by the fading of memories: the accident at Three Mile Island, which ended America’s nuclear dreams, took place nearly three decades ago, and even the Soviet disaster at Chernobyl is more than two decades past. And partly by redefining “cheap”. The Electric Power Research Institute, an American industry body, puts the cost of nuclear electricity at 6.5 cents a kWh. Not cheaper than coal’s 5 cents, but cheaper than coal that has had a price put on its carbon emissions. The time, then, is ripe for a rethink.

Ernest Moniz, MIT’s leading energy guru and himself a nuclear physicist, agrees. He thinks that, on the technical side at least, the key to a nuclear revival is to go from a craft-based approach, in which each reactor is a bespoke thing of beauty, to a manufacturing approach, in which modules of components are made in factories and simply bolted together on site.

The other modern desideratum, he believes, is “passive safety”. This seems to be the same as what engineers used to call “fail-safe”, but perhaps the marketing department no longer approves of the word “fail” getting anywhere near a reactor. What it means is that safety measures kick in automatically in an emergency rather than having to be activated. That can be something as simple as configuring the control rods that regulate the speed of a reaction so that they drop by gravity rather than having to be inserted.

Both Dr Moniz’s preconditions are beginning to be met. The world’s three largest nuclear-reactor firms are hoping for sales of reactors whose designs have been upgraded to be more “bolt-together” and passively safe than their predecessors. According to CERA there are plans in America alone to build 14 AP1000 Westinghouse reactors, six General Electric economic simplified boiling-water reactors, two or more GE advanced boiling-water reactors and seven of the French firm Areva’s latest design, the European pressurised reactor.

New generation

Indeed, the idea of modularity can be taken even further. Toshiba, a large Japanese engineering firm, is planning something known as nuclear batteries: factory-made sealed units with an output of 10 megawatts and a lifetime of 15-30 years. When they stop working, you simply send them back to the factory for disposal.

The acme of modular, factory-built, passively safe reactor design, however, is found in South Africa. People there have been experimenting with so-called pebble-bed reactors for decades. They hope to start building one for real in 2010. A pebble-bed reactor is fuelled by small spheres that are, in essence, tiny reactors in their own right. They are made of uranium oxide (the fuel) and graphite (a substance that slows down the flying neutrons that cause nuclear fission). Pile enough pebbles together and a chain reaction will start. Nor is any complicated pipework required to extract the heat. All you need do is run an inert gas such as helium through the pebbles and it will collect the heat for you.

The design also looks like the ultimate in passive safety because a phenomenon called Doppler broadening, which changes the speeds of the neutrons and makes them less likely to cause fission, shuts it down automatically if it overheats—though critics argue that the graphite in the pebbles is a fire hazard, and that helium is so leaky that there is a risk of air getting into the system and starting a fire.

None of these ideas deals with the question of nuclear waste. But that is largely a political problem, not a technical one. Though it sounds like a cop-out, the best answer really is to bury the stuff for the time being. That should be done in places where it can easily be recovered for reprocessing one day when technology has caught up. But it is also worth noting that buried, unprocessed waste cannot be used to make bombs.

Copyright © The Economist Newspaper Limited 2008

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