A Dream of Clean Energy at ITER

         

A Dream of Clean Energy

   

 SAINT-PAUL-LEZ-DURANCE, France — At a dusty construction site here amid the limestone ridges of Provence, workers scurry around immense slabs of concrete arranged in a ring like a modern-day Stonehenge.

It looks like the beginnings of a large commercial power plant, but it is not. The project, called ITER, is an enormous, and enormously complex and costly, physics experiment. But if it succeeds, it could determine the power plants of the future and make an invaluable contribution to reducing planet-warming emissions.

ITER, short for International Thermonuclear Experimental Reactor (and pronounced EAT-er), is being built to test a long-held dream: that nuclear fusion, the atomic reaction that takes place in the sun and in hydrogen bombs, can be controlled to generate power.

First discussed in 1985 at a United States-Soviet Union summit, the multinational effort, in which the European Union has a 45 percent stake and the United States, Russia, China and three other partners 9 percent each, has long been cited as a crucial step toward a future of near-limitless electric power.

ITER will produce heat, not electricity. But if it works — if it produces more energy than it consumes, which smaller fusion experiments so far have not been able to do — it could lead to plants that generate electricity without the climate-affecting carbon emissions of fossil-fuel plants or most of the hazards of existing nuclear reactors that split atoms rather than join them.

Success, however, has always seemed just a few decades away for ITER. The project has progressed in fits and starts for years, plagued by design and management problems that have led to long delays and ballooning costs.

ITER is moving ahead now, with a director-general, Bernard Bigot, who took over two years ago after an independent analysis that was highly critical of the project. Dr. Bigot, who previously ran France’s atomic energy agency, has earned high marks for resolving management problems and developing a realistic schedule based more on physics and engineering and less on politics.

“I do believe we are moving at full speed and maybe accelerating,” Dr. Bigot said in an interview.

The site here is now studded with tower cranes as crews work on the concrete structures that will support and surround the heart of the experiment, a doughnut-shaped chamber called a tokamak. This is where the fusion reactions will take place, within a plasma, a roiling cloud of ionized atoms so hot that it can be contained only by extremely strong magnetic fields.

Pieces of the tokamak and other components, including giant superconducting electromagnets and a structure that at approximately 100 feet in diameter and 100 feet tall will be the largest stainless-steel vacuum vessel ever made, are being fabricated in the participating countries. Assembly is set to begin next year in a giant hall erected next to the tokamak site.

There are major technical hurdles in a project where the manufacturing and construction are on the scale of shipbuilding but the parts need to fit with the precision of a fine watch.