/ 28 June 2005

Scientists expect go-ahead for nuclear fusion reactor

Scientists should on Tuesday finally get the go-ahead to build a prototype nuclear fusion reactor which could offer a clean source of unlimited energy.

Ministers are expected to announce at a meeting in Moscow that a $12-billion experimental reactor, designed to prove the new type of nuclear power is commercially viable, will be built in France. The reactor is intended to produce electricity by harnessing the nuclear reaction at the heart of the sun.

The announcement follows years of often bitter negotiations. The international project — called the International Thermonuclear Experimental Reactor, or Iter — has been deadlocked since December 2003, when the world’s leading scientific powers fell out over where to build it. Russia and China supported the EU’s plan for Cadarache in southern France while the US and South Korea favoured a rival bid from Japan for Rokkasho.

Reports say Japan has been persuaded to drop its claim in return for lucrative construction contracts.

Unlike conventional nuclear power stations that harness the energy released when atoms split, Iter would work by capturing the heat produced when hydrogen isotopes combine to form helium.

Supporters claim such fusion reactors could produce enough electricity to solve the world’s energy demands and, because they would not release carbon dioxide, the problem of global warming. Critics argue that the science is unproven, and say that the promise of nuclear fusion has been 30 years away since the 1960s. Iter will show who is right.

Christopher Llewellyn Smith, director of a fusion research facility called the Joint European Torus (Jet) in Culham, Oxfordshire, said: ”It’s great news because it will enable us to get on with fusion. Iter is the absolutely vital step on the way to building a real fusion power station.”

Experimental reactors such as Jet have proved fusion can work in principle but they have not been able to produce more energy than they use to get the reactions going in the first place. Iter aims to produce 500 megawatts of power, or 10 times its predicted input.

Some problems remain. The US cannot ratify any agreement until Congress looks at complaints from domestic energy researchers that their grants have been slashed to pay the US contribution. – Guardian Unlimited Â