The Outside Gamble

Fusion is the turtle in the race to develop sustainable energy; it is the outside gamble that just might win.

In November, seven of the largest and richest nations in the world (China, India, the U.S., the E.U., Russia, Japan, and South Korea) will sign the final agreement to begin work on the $12 billion international thermonuclear experimental reactor, ITER. (Incidentally, the acronym no longer officially stands for anything: apparently, they decided "thermonuclear" was bad marketing.) You can find descriptions of ITER from the official ITER website, from the AAAS, and from Wikipedia.

First proposed in 1985, the giant tokomak in Cadarache, France will take 10 years to build, assuming the project stays on schedule. Second only to the International Space Station, ITER will be the most expensive international experimental collaboration in history. If ITER succeeds, its successor (oddly dubbed DEMO) should be a commercial fusion power plant up and running by 2040. The catch is that nobody knows for sure if ITER will work. It's not called "experimental" for nothing.

So far, no tokomak has ever generated more power than it consumes, but the bigger the plasma chamber, the more efficient it has become. The working assumption therefore is that if you just build one big enough, you'll get a working fusion reactor. The largest tokomak currently in existence, JET, has a plasma volume of about 40 cubic meters and produces at best 16 MW of power, only 70% of what it takes to run. ITER will have a plasma volume of over 800 cubic meters and is predicted to produce 500 MW of excess power--a tenfold amplifcation of the input power.

There are a number of physicists who believe this is the wrong approach. They worry that instabilities in the plasma field will inhibit power production; they worry about safety. They believe that the attempt to make the equivalent of a toroidal stellar core is not the way to go: instead, they believe a fundamental breakthrough in thinking--such as perhaps extremely high-powered lasers pummeling puffs of gas--might permit tabletop fusion. (Anyone remember "Mr. Fusion" from Back to the Future?)

Still, the scientific community has decided to back the horse they know best and have pushed hard for two decades to get the consortium of seven nations to pony up the billions needed for the ambitious experiment. It is astonishing to me that so few people know of this vast undertaking. Turtle though it may be, fusion is the only power source that has potential to up-end geopolitics and re-write the rules of global climate change. If ITER succeeds, November 2006 may go down in history as the beginning of the end of the era of fossil fuels. Of course, ITER will require sustained political will to see it through to its planned operational date of 2017.

Let's just hope "Cadarache" is not French for "Waxahachie."