Paris Physicists have dreamt about it for decades: harnessing the fusion process that powers the sun to make clean, safe and limitless energy. A multinational pact signed Tuesday may bring that dream a step closer to reality.
Seven partners representing half the world's population have agreed to build an experimental fusion reactor in southern France that could revolutionize global energy use for future generations.
Yet it also is just an experiment - a bold, long-awaited, $12.8 billion experiment - and it will be decades before scientists are even sure it works.
New energy source
The International Thermonuclear Experimental Reactor project by the United States, the European Union, China, India, Russia, Japan and South Korea will attempt to combat global warming by offering an alternative to fossil fuels. Controlling climate change and finding new energy sources are urgent goals for a growing global population.
"Worldwide demand for energy is expected to double in the next 25 years, and we need to diversify our energy supply," said U.S. Secretary of Energy Samuel W. Bodman during a tour Tuesday of Princeton University's Plasma Physics Lab.
Experiments on two reactors at the Princeton lab - one in use since 1999 and the other under construction - will be crucial in helping scientists determine how to translate research at the ITER facility into a design for commercial fusion reactors, Bodman said.
French President Jacques Chirac hailed Tuesday's agreement as a victory for humanity - and for France, which widely exports its nuclear energy expertise and beat out Japan in the bidding to host the reactor. The project's director will be Japanese, and Japan will supply the reactor's most complex parts.
"The growing shortage of resources and the battle against global warming demand a revolution in our ways of production and consumption," Chirac said. "We have the duty to start research that will prepare energy solutions for our descendants."
Not immediate solution
Physicists have been trying for half a century to create fusion, which replicates the sun's power source, produces no greenhouse gases and generates relatively little radioactive waste.
The ITER project recognizes that no single country can afford the immense investment needed to move the science forward.
It is expected to take eight years to build the reactor in Cadarache in the southern region of Provence. A demonstration power plant may be ready by 2040, according to project organizers. If the prototype proves viable, it could point the way to designs for commercial power plants.
Officials involved in the project say 10 percent to 20 percent of the world's energy could come from fusion by the end of the century.
Some experts, though, question whether the project can keep all the promises being made on its behalf.
"I would be extremely surprised - pleasantly surprised - if there was a prototype" by 2040, said Matthew Bunn, nuclear expert at Harvard University.
He said "it's an open question" whether the project is even pursuing the right technology. Still, he said Tuesday's signing was seen as a major boost to physicists worldwide - even if the ITER never leads to commercial energy.
"This is big science at its biggest and will keep many people in the plasma physics community with lots of experiments to do for a long time to come," he said. The project is expected to create about 10,000 jobs.
Ivan Oelrich, vice president for strategic security for the Federation of American Scientists, said there is no guarantee the project will lead to designs for commercial reactors. He questioned whether it represented the best investment if the primary goal is to achieve energy independence.
"If you took this money and invested it on things like more efficient insulation and windows and got people to drive smaller cars ... you would come out way ahead on your future energy security than you would by pursuing this right now," he said.
The European Union has agreed to provide about 45 percent of the $12.8 billion cost of building the reactor. The other nations will each contribute 9.1 percent.
Bodman said only 20 percent of the United States' $1.12 billion share will be paid in cash. The rest reflects the value of the equipment and labor to be provided by U.S. scientists and technicians.
Fusion, which powers the sun and other stars, involves confining hydrogen at extreme temperature and pressure to create a highly energetic gas. At 180 million degrees, the gas undergoes nuclear fusion, releasing energy that can be used to generate electricity.
Unlike fossil fuels, which are expected to run short by the end of the century, the supply of the reactor's hydrogen fuel is essentially limitless.
Its backers say one quart of sea water would be able to generate energy equivalent to a quart of oil or two pounds of coal.
The ITER project has been on the drawing boards for years. It stalled amid concerns about financing and reactor design and, at one point, the United States withdrew, leaving scientists warning the U.S. would eventually have to buy the technology from other nations.
The United States never offered to host the project largely because that would require a much larger share of its cost.
The seven partners agreed last year to build the reactor at Cadarache, which houses one of the biggest civil nuclear research centers in Europe. The U.S. has given its final approval, though the other partners still must ratify it.
Environmental activists, who generally oppose nuclear power, have argued the project is too costly and would turn the focus away from efforts to fight global warming.