Nuclear waste: Leave well alone OF ALL THE difficulties nuclear power is heir to, that of waste has most fired the public imagination. Building power plants that last a century is one thing; creating waste that will be dangerous for 100 times as long is another. For decades America has failed to create a long-term repository for the waste from its civilian reactors at its chosen site, Yucca Mountain in Nevada. Most other countries have similarly failed, so the waste from today's reactors piles up. As it happens, long-term waste disposal is among the more tractable nuclear problems. Temporary storage is a good start. Once fuel has cooled down in spent-fuel pools for a while, it can be moved to "dry cask" storage. Such storage appears robust (dry casks at Fukushima, hit by the tsunami, show no sign of having leaked) and can be maintained indefinitely. It takes space and needs to be guarded, but it can provide an adequate solution for a century or more. That is if you do not want to reprocess the fuel to recover the plutonium inside it. If you are a nuclear engineer you may find reprocessing rather appealing, partly to show that your nuclear programme is as sophisticated as any and partly because it gets around the offensive inefficiency of light-water reactors. If all the uranium in reactor fuel was either split or turned into plutonium which itself was then split, you would get 170 times more energy than you get from just using the fuel once, and would have opened the way to technically intriguing breeder systems. You will not, though, be attracted to reprocessing if you are an accountant. It costs a great deal, and the plutonium produced is for the most part more of a liability than an asset. If you are a plant operator you will also have your doubts. Burning fuel to which plutonium has been added has various drawbacks, one of which is that it is much hotter when it comes out of the reactor, straining the capacity of your spent-fuel pools. Nor will you be that eager if you are concerned about the local environment; reprocessing plants have a bad contamination record. And if you are sceptical about the merits of nuclear proliferation, you will want to keep reprocessing to a minimum. Having avoided reprocessing, in the long term you will want to find a safe deep underground repository for the waste in your dry casks. This need not be too hard. Find a community that may be willing to take on the challenge (one that already has ties to the nuclear industry might be thus predisposed) and that has access to a suitable geological setting. Then have an open discussion of the issues, look at people's concerns and offer ways to lessen them while recompensing the community for its trouble. Set up arrangements by which local people can reassure themselves about any threats to their health, perhaps with free medical treatment and tests. Don't scrimp on investment in the community. Then let them choose. The chances are that they will say yes. This kind of approach seems to be working in Sweden and Finland, and Britain is trying something similar. This is more or less the opposite of what was done at Yucca Mountain. What some now refer to as the Screw Nevada act of 1987 imposed the choice of site and schedule. Nevada politicians objected. Geological surveys threw up some problems. Nevada's caucuses moved up the electoral calendar, meaning that presidential candidates were greatly helped by an anti-Yucca stance. Moreover, the state's senior senator, Harry Reid, became Senate majority leader. President Obama drew a line under the episode by finally abandoning the project in 2010, 12 years after the facility was meant to have entered service. But as well as providing a textbook example of how not to handle long-term storage, America also boasts a success. The Waste Isolation Pilot Plant in the salt caverns of Carlsbad, New Mexico, started taking shipments of waste from the country's military programme in 1999. Throughout the life of the project the local community has been consulted and, on occasion, recompensed. WIPP is not entirely trouble-free, but it has achieved enough social and political stability to make the best of its geological gifts.