Paris

Site fight: Europe is holding out to build ITER at Cadarache in France. Credit: ITER

The multibillion-dollar ITER fusion reactor was always intended to be an international collaboration, and was billed as a model for ‘big science’ projects. But this week, the model looks in deep trouble.

On 26 November, the European Union (EU) broke ranks with the site selection process, and announced that if agreement isn't reached quickly, it will go it alone to build the reactor in Europe.

ITER aims to prove the principle of generating energy from fusion, by confining a ring of plasma with a magnetic field in a doughnut-shaped vessel and heating it to several million degrees kelvin. But the six-strong collaboration has split over the siting of the facility: China and Russia back the EU's site in Cadarache, France, whereas the United States and South Korea favour Japan's rival site at Rokkasho.

At a meeting in Brussels, research and industry ministers from the EU's 25 member states followed through on a threat that they first aired in September. They authorized the European Commission, the EU's executive arm, to abandon the multilateral site selection process if necessary and build ITER in France, with as many outside partners as it can muster.

EU ministers insist that this option will be a last resort. The Japanese government has yet to respond, but fusion officials there reacted angrily. Satoru Ohtake, director of fusion energy at Japan's science ministry, says the EU move jeopardizes not just ITER but also the ground rules needed for future international collaborations. “By pursuing their own desires, they will be the ones that break international trust,” says Ohtake. “This is divisive; it is not acceptable to us.”

Commission officials counter that the stalled talks needed shock therapy and that the situation was “in complete deadlock”. Political realities make site selection the inevitable crux of any international collaboration, adds one official, and “unless your project is in space, you will have always this problem of choosing the site”.

Europe's most recent offer to Japan, in return for agreeing to the Cadarache site, includes a fusion package that would compensate the country and include support for a major upgrade to its JT60 fusion reactor. Ohtake claims that Japan has offered Europe similar concessions.

Neither offer prevailed, however, at the latest meeting of negotiators on 9 November in Vienna (see Nature 432, 262; 200410.1038/432262b). Japan's position is that both parties should temporarily put aside the siting issue, says Ohtake, and discuss the “role of host and non-host parties”.

Europe's brinkmanship seems partly based on the reckoning that only one ITER will ever be built, and if it can force the deadlock with firm support for a French site, then Japan and the United States will eventually join the only show in town.

This scenario is credible, says Stephen Dean, head of Fusion Power Associates, a Washington-based fusion advocacy group. “I think the EU could get together a package that would work,” he says.

France has already offered to double its support for ITER to $1.12 billion, or 20% of the total bill, and the rest of Europe has committed another 40%. Even if Japan and the United States pulled out, Europe could conceivably make up the shortfall from Russia, China and other partners.

But some European fusion scientists fear that the EU has overplayed its hand — and underestimated Japanese determination to host ITER. “The European Commission badly misread Japan's negotiating positions; it has been convinced that Japan would budge,” says one European scientist close to the negotiations. The big unknown, he says, is whether Japan will call Europe's bluff, and announce that it, too, intends to go it alone.

Additional reporting by Geoff Brumfiel in Washington.