A big bet on small

摘要

One of the cliches of nuclear-power research is that a commercial fusion reactor is only 30 years away, and always will be. Hence a flurry of interest-and not a little incredulity-when in October news emerged that Lockheed Martin, a big American engineering and defence company, has a new design for a fusion reactor that it believes could be up and running within a decade. A team at Lockheed's renowned Skunk Works, where its wilder (and often secret) ideas are developed, reckons fusion is ripe for a rethink. Attempts to harness the types of reaction that power the sun and hydrogen bombs in order to generate electricity go back to the 1950s. The latest, a device called iter, is under construction in France. Fusion is attractive in principle. It does not generate the same amount of nasty, long-lived radioactive waste that its cousin nuclear fission does. Its principal fuel is deuterium, an isotope of hydrogen that is found in water and is thus in limitless supply. And a fusion reactor would be incapable of having a meltdown. But it is hard in practice. Reactors like iter, known as tokamaks, are huge and temperamental undertakings. Even when they work as prototypes, they do not look the stuff of commercial power generation.