Francia e Giappone lottano per ospitare un mega reattore per sperimentare la fusione nucleare.


Decision day for fusion project

Scientists are meeting in Washington to decide where to build the world's first big nuclear fusion reactor.
Nuclear fusion holds out the promise of virtually limitless pollution-free energy - but the reactor will take 10 years to build.

The multi-billion dollar project is likely to be based either in Cadarache in France or in Rokkasho-mura in Japan.

But the US is opposing the French option because of France's opposition to the invasion of Iraq.


Pros and cons

Member countries of the International Thermonuclear Experimental Reactor (Iter) project have been gathering in the US to make a final decision on the location of the project.

The Japanese site has the advantages of proximity to a port, a ground of solid bedrock and a nearby US military base.

The French site offers an existing research facility and a more moderate climate.

The experts are supposed to reach a consensus based on objective criteria, but observers say that the wider political context may play a part.

A French government envoy, Pierre Lellouche, said "very intense" talks were being held at a high-level before the meeting.

The European Union is backing France - but Canada, China, Russia, South Korea, the United States and Tokyo itself are reported to be favouring Japan.

The US, in particular, has raised objections to the French option, citing its opposition to the Iraq invasion.

"We have the structure, scientific and technical environment to ensure that this scheme can start up with competence, expertise and solid safety guarantees," French Research Minister Claudie Haignere said.

"If our site is chosen, Japan will cover the costs that are needed," said Hidekazu Tanaka, a senior official of the Japanese Education, Culture, Sports, Science and Technology ministry.

Self-sustaining

Iter is the boldest nuclear initiative since the Manhattan Project - the effort to build the first atom bomb, says BBC News Online's science editor David Whitehouse
It would also be the world's largest international co-operative research and development project after the International Space Station.

Scientists say it will be the first fusion device to produce thermal energy at the level of an electricity-producing power station.

Its goal will be to produce 500 megawatts of fusion power for 500 seconds or longer during each individual fusion experiment and, in doing so, demonstrate essential technologies for a commercial reactor.

But they are all agreed that taming the power of the Sun will not be easy.

The superhot gas in which the fusion takes place is notoriously difficult to control.

The gas, termed a plasma, has to be kept hot and contained for fusion to take place. So far, no one has achieved a prolonged self-sustaining fusion event.

Advocates of fusion power point out that if they succeed, there is an almost limitless supply of power available because the deuterium atoms on which it would be based can be derived from seawater.