How far away is fusion?

Right now, the site of the ITER experimental nuclear fusion plant is literally just a bare spot on the ground in the south of France. But the grand energy vision is gradually taking shape on the computers and whiteboards at the ITER organization's temporary quarters nearby - and Gary Johnson is already worried about getting everything ready in time for the big reveal in 2016.

"A 10-year cycle to do all this is very tight from our standpoint," Johnson told me in his very temporary office, set up in a prefab building at CEA Cadarache, one of France's nuclear research centers.

"All this" refers to the long list of tasks that Johnson, one of the top-ranking Americans in ITER's hierarchy, will have to oversee. During this week's visit to Cadarache, I saw firsthand how the international effort to develop commercially viable fusion reactors is only now beginning to gather critical mass.

ITER is an acronym for International Thermonuclear Experimental Reactor, but it also refers to the Latin word for "the way." ITER's seven partners, or "parties" - China, Europe, India, Japan, Russia, South Korea and the United States - believe the effort will show the way toward the long-held but elusive dream of harnessing the power behind the sun's glow and an H-bomb's blast. Agreement on the ITER framework was announced two years ago today, and the treaty setting up the organization was signed last November.

Scheduled for startup in 2016, ITER's 15-story-tall facility would combine two isotopes of hydrogen, deuterium and tritium, amid temperatures of tens of millions of degrees to create helium and a neutron - releasing a burst of energy in the process. The chief challenge will be to contain all that power inside a doughnut-shaped magnetic field, generated by a superconducting contraption called a tokamak.

As one of ITER's seven acting deputy directors-general, Johnson is in charge of building the tokamak, in cooperation with all the parties backing the effort.

"It's definitely a big challenge," said Johnson, a veteran of nuclear research programs at the Oak Ridge and Lawrence Livermore national labs. "We're going to have bumps in the road, but I go to a lot of meetings with various parties, and they're motivated just as much as we are to make this successful."

Kaname Ikeda, ITER's acting director-general (and Johnson's boss), is convinced that his nascent organization is taking the right way. "I feel quite comfortable," Ikeda told me. "It's just a question of investment and commitment by the parties. ... It's not something you can do alone."

If ITER is successful, the project could open the way to a new source of power - one that is arguably safer and cleaner than nuclear fission, potentially better for large-scale power generation than wind or solar, and less problematic than fossil fuels when it comes to the issue of global warming.

"Not to argue the impact, but I do think that nuclear energy is very essential to solve the living quality of the environment, and also to save many communities from the question of resources, and also to raise the supply of energy," Ikeda said.

Exploring all the inner workings of nuclear fusion research in general - and ITER in particular - will have to wait for a later time. It's just too much information to digest at once, even during this month's Big Science Tour.

For now, I'll just list some of the reasons why 2016 doesn't look that far away for Johnson. They aren't the reasons that you might think would apply. Sure, some people are doubtful whether ITER will actually show the way - but not Johnson. He believes commercial fusion is at least theoretically possible, even though it may take until 2040 to get all the way there.

"Basically, we know how to design this machine," he told me. "It's just a complicated, integrated package with a lot of different players, that's what makes it challenging for us."

The first challenge is to ramp up the ITER organization, while at the same time respecting the contributions of the seven parties. Although ITER has been decades in the making, the legal and administrative foundation for operations is only now being established.

ITER has to lay out the specifications for all of the facility's components, which are to be supplied by the parties under the terms of a complicated procurement formula. All this will take years to thrash out. Then, under the watchful eye of French nuclear regulators, ITER will be charged with making sure that the components do the job safely and according to the specs.

"It's going to be quite an interesting time when these things start coming in," Johnson said.

Materials science will be a big issue for the ITER facility. The cryogenically cooled tokamak will have to weather the radiation thrown off by the fusion plasma, as well as electromagnetic loads created by the magnetic containment system. All this will likely require the use of exotic metals such as beryllium, niobium and tungsten.

"In some cases, we're going to put a big dent in the world supply of some of these things," Johnson said. "We're going to be buying 23,000 tons of some high-tech stuff."

ITER's reactor will have to use radioactive tritium, and that means the components will degrade over time. The best workers for the job of maintaining the reactor will be robots, operating autonomously as well as under remote control, Johnson said. All this will require rock-solid systems for the remote handling of radioactive materials.

"We're going to actually test those out during our assembly activities," Johnson said.

Every day brings new issues to deal with. On Wednesday, the day we spoke, Johnson had at least three major meetings to attend - focusing on the plans for the tokamak's vacuum vessel, the superconducting coils and the building plans. France hasn't yet signed off on the permits for the actual fusion facility, so crews have just been clearing the trees off the main site and working on secondary buildings (like the prefab office space). Plant construction is due to begin in earnest in 2009.

Plenty of organizational matters as well as engineering challenges still have to be addressed. For example, Europe's procurement agency, Fusion for Energy, was inaugurated just today in Barcelona - and the agency's director has yet to be named. (The designated U.S. procurement agency is hosted by the Oak Ridge National Laboratory in partnership with the Princeton Plasma Physics Laboratory and the Savannah River National Laboratory.) These domestic agencies will play a key role in making sure Johnson and other ITER officials have the hardware they'll need to make the reactor a reality.

And then there's the issue of public sentiment, which is often tinged with suspicion of all things nuclear. ITER officials have been conducting a series of public forums to reassure local residents in Provence about the facility's safety, and they say the project has been well-received. But not everyone is convinced. One sign painted on a hillside along the road to ITER's headquarters proclaims in French: "Non a ITER."

Check out the ITER Web site and review this discussion of ITER's pros and cons on the journal Nature's Weblog. Then put on your thinking cap and let me know whether you vote "oui" or "non" by adding your comments below. You can also register your opinion and find out what others think by taking this unscientific Live Vote.

I'm heading back home from Europe today, but I'll start passing along what you have to say as soon as I touch down in Seattle.

Previously from the Big Science Tour:The science behind the tour ... Living in the Web's cradle ... Inside the big-bang machine ... Toiling in the fields of physics ... Inside the antimatter factory... First, the Web ... now, the Grid ... Suspense on a subatomic scale ... Inside fusion's fortress.