An international consortium today formally signed an agreement to build the ITER experimental nuclear fusion reactor in France.

China, the European Union, India, Japan, the Republic of Korea, the Russian Federation and the U.S. have signed an agreement to build the international fusion energy project known as ITER, an acronym for International Thermonuclear Experimental Reactor (and, conveniently, Latin for "the way".)

ITER will be constructed at Cadarache, France and is expected to be completed in 2015, next to the main research center of the French Atomic Energy Commission, and cost the equivalent of at least $13 billion U.S. dollars, making it the world's second most costly scientific project after the International Space Station.

The EU, as the host, will provide 45 percent of the construction phase funding, with other countries participating at roughly 9 percent each.

"The energy that powers the stars is moving closer to becoming a new source of energy for the Earth through the technology represented by ITER," U.S. Secretary of Energy Samuel W. Bodman said, noting that the ITER members represent over half of the world's population.

Fusion energy, created when light atomic nuclei are fused together at temperatures greater than those of the interior of stars and far above the melting point of any solid container, could provide for the world's electricity needs without greenhouse gas emissions and also generate hydrogen.

Advocates say fusion power has the following advantages:

• Clean: It produces negligible atmospheric emissions and zero greenhouse gas emissions.
• Safe: Reactors cannot "melt down," and do not generate the high-level, long-lasting radioactive waste associated with nuclear fission.
• Renewable: Commercial fusion reactors would use lithium and deuterium, both readily available natural resources.

Critics disagree. Greenpeace has called the project "madness" and "a dangerous toy." Spokesperson Bridget Woodman said, "Nuclear fusion has all the problems of nuclear power, including producing nuclear waste and the risks of a nuclear accident." Proponents call this criticism uneducated, and maintain that the experiments are not inherently dangerous.

The ITER project actually began two decades ago, but became bogged down in bickering over where to put the reactor's design team. A compromise split the team between Japan, the United States and Germany. Then, in 2001, arguments began over where to build the project.