Experimental Reactor Plans

Representatives from a number of countries, including European Union members, the United States, Japan, Russia, China and South Korea attended the ceremony hosted by French President Jacques Chirac on Tuesday.

"If nothing changes, humanity will have consumed, in 200 years, most of the fossil fuels resources accumulated over hundreds of millions of years," Chirac said.

Depending on how the figures are calculated, the cost of the reactor is estimated at between $5 billion and $12 billion (3.9 billion euros and 9.3 billion euros), making it the second most expensive scientific project after the International Space Station. The EU will be footing about half the bill with the other countries involved picking up the rest.

However, Didier Gambier, the top European official in the ITER consortium, told Deutsche Welle the costs had to be put into perspective. He explained that 5 billion euros was not such a great investment compared with the annual earnings of major energy companies.

It would "not be politically responsible to ignore the potential of nuclear fusion," he added.

The drawbacks of international cooperation

Despite the common consensus about ITER's prospective benefits, the multi-lateral project has not been without its setbacks. The United States temporarily withdrew from the project in 1999, then returned in 2003, while Canada joined in 2001 and left two years later.

There was also some disagreement, especially with Japan, on where the reactor should be built. Finally, the project's EU base in the southern French city of Cadarache, near Marseille, was chosen as the location.

Japan agreed to send some of the 400 scientists needed for the project to France and in exchange for some of the procurement coming from Japan. Germany will provide the expertise necessary for building the inner walls of the fusion chamber.

Potential energy source of the future

If successfully finished, the plant will create energy by replicating the process that takes place inside the sun. Instead of splitting the atom, the project seeks to release energy light atomic nuclei -- the hydrogen isotopes deuterium and tritium -- are fused together to form heavier atomic nuclei.

To use controlled fusion reactions on Earth as an energy source, it is necessary to heat a gas to temperatures exceeding 100 million Celsius - many times hotter than the centre of the sun.

One of the attractions of fusion is the tiny amount of fuel needed. The release of energy from a fusion reaction is 10 million times greater than from a typical chemical reaction, such as burning a fossil fuel.

Chirac said the experimental reactor was "a hand held out to future generations" and predicted that, if it proved successful, "we will be able to derive as much energy from a liter of seawater as from a liter of petrol or a kilo of coal."

Fusion technology questioned

Those in favor of nuclear fusion hope to win over a skeptical public by emphasizing the technology's potential to solve the world's energy problems without producing large amounts of greenhouse gases or nuclear waste. The skeptics, however, point out that similar claims were made about nuclear fission and argue that it could take too much time before a commercially viable reactor is built.

The project has been criticized by environmental groups like Greenpeace, who argue that the enormous cost will suck funds away from other areas of alternative energy research, with no guarantee that an effective method of simulating and harnessing the fusion process will ever be found.

Since the 1950s, scientists have been creating increasingly large experiments that started off as big as a human hand and gradually progressing to a size of about 10 meters (about 33 feet) high, like the Joint European Taurus (JET) in Culham in the United Kingdom, which generates roughly about as much energy as it consumes.

"ITER is twice the size of JET and that step needed to be taken to generate ten times more energy than it consumes," said Mark Tiele Westra, an ITER's spokesman. "We are very confident that this thing will work. We are putting fusion to the test."