US rejoins fusion reactor project

The US government has indicated that it wants to play as large a role as possible in the £3bn International Thermonuclear Reactor (ITER) programme to build the world’s first fusion reactor.

The US rejoined the project last month after a three-year absence. But it said this week that it was likely to seek a much greater stake in the programme than the 10 per cent it originally announced. This comes in advance of crucial negotiations on where the reactor will be built and how much each partner should contribute.

The project envisages an operational experimental fusion reactor by 2014. If successful this could lead to the development of the first commercial reactor to produce an abundant and relatively clean source of energy.

ITER was founded by the US, Canada, Japan, Russia and the European Union in 1992. But the Clinton administration pulled out in 1999 because of concerns about costs, which were predicted to reach $12.5bn (£8bn).

Since then the technology has undergone a redesign, with costs halved. A subsequent report by the US National Academy of Science, entitled Burning Plasma Physics Assessment, recommended that the country rejoin as the next step in its own fusion research activities.

The announcement that the US again intends to contribute to the project will reduce the costs faced by the other partner nations. But speaking to The Engineer, the head of the US ITER team, Dr James Decker, who is deputy director of the US department of energy’s office of science, said the administration’s position was not to gain just 10 per cent of the contract work. ‘We want a proportion of the work that is as beneficial as possible to the US and to the project.’

Decker indicated that areas of particular interest for contract work, where the US believes it has specialist knowledge, were simulation, diagnostics and heating technologies.

Fusion involves the fusing of fuel atoms under intense pressure and a temperature in excess of 100million degrees C. The resulting plasma, an ionised gas, is held in mid-air by magnetic fields because it is so hot that it would damage the walls of the reactor.

The US’s aggressive negotiating position reflects the stage the project has reached. After years of technical preparations the partners will now engage in a prolonged political fight over the siting of the reactor and the contract work for the completed design.

As well as the US decision to join, China also became a member at the February meeting in St Petersburg. The developing nation had been in discussions to join for many years and finally announced its intention in January.

Dr Robert Aymar has been director of the ITER project since 1994. He welcomed the decision of the US and China to join and hoped that other members would not delay the decision-making process, with everything agreed by this summer.

‘These new members are a political benefit,’ he said. ‘The project becomes worldwide. It is a large investment and this increases the cost-to-benefit ratio for everyone. It will need the heads of states to agree a final site. We would like a decision this year but you can’t tell governments when they should decide by.’

Representatives will attempt to finalise the siting of the reactor at the next negotiators’ meeting in Vienna in May. The four proposed locations are in Canada, France, Japan and Spain, but none of these has been singled out for recommendation in the ITER site report. It will be up to the 20 member nations to decide.

The US missed the chance to bid for the reactor to be built on its soil when it pulled out in 1999. However, it is expected to push for Canada to host the project because this means ITER would be built near Toronto and close to the US border.

The UK representative on the ITER site assessment team is Franc Briscoe, director of the Culham Science Centre in Oxfordshire, where Europe’s fusion project JET is centred. He said ITER was at a similar stage to JET in 1978. ‘In the early days there were three or four sites and I think technically Culham was the least favoured but still came out in the end.’

Bizarrely the UK is said to have won the fight to host JET because of help the British Army’s Special Air Service regiment gave to German anti-terrorist operations during a plane hijacking. This led to German government support for the UK bid and that secured Culham’s success. ‘Who knows what it will be that causes the ITER decision, but that’s very much the situation I think we’re now entering,’ said Briscoe.

Previously The Engineer reported that sources close to the project considered Canada favourite to win as its bid was ‘wholly commercial’, with no government involvement.

Wherever it is built ITER will be the same type of magnetic confinement torus, or ‘doughnut- shaped’, reactor as JET but will be twice its size. Its goal is to produce 500MW for 500 seconds or longer. It would use tritium and deuterium as fuel, with 1kg of this combination producing energy equivalent to 10,000 tonnes of fossil fuel.

The researchers hope that with tritium-deuterium fuel the reactor will generate 10 times as much energy as is required to initiate and sustain the process. Although such a success would lead the way to commercial use the ITER machine will not be fitted with technology to distribute energy to a national grid. Research at the ITER reactor could last up to 20 years before commercial stations are built.

Although fusion is said to be environmentally friendly reactors will still be radioactive and will have to be entombed at the end of a power station’s life. The process will also produce radioactive waste, which will have to be disposed of like fission nuclear waste. But the amount will be much smaller.