|Prototype's production goal |
is 500 MW (Photo by ITER)
France on June 28 won an 18-month bid against Japan to host a $12-billion international project to prove technology behind clean nuclear power based on abundant hydrogen. After further agreements are signed, procurement could begin for the site near Marseilles next year leading to possible prototype fusion power plant by 2035.
Roughly half the project budget will go into construction of buildings and equipment with the rest allocated for funding 20 years of trial operations. With designs of the International Thermonuclear Experimental Reactor (ITER) taking place in Germany and Japan, the fusion machine will occupy a cylindrical space about 24 m tall and 24 m wide at a new complex at Cadarache.
The Cadarache machine "is not quite a prototype," says Bill Spears, an ITER official at the German design base near Munich. But it aims to at sustained generation of 500 MW of fusion power with output energy exceeding the input by a factor of 10. ITERs trail-blazing predecessor, the U.K.-based Joint European Tours (JET) project, managed generation in bursts of seconds while just achieving breakeven in the energy balance, he adds.
Similar to reactions that power the sun, earthly fusion involves releasing atomic energy by combining hydrogen isotopes at temperatures exceeding 100 million degrees C. In that state, the fuel changes from gas to a plasma of ions. With normal materials unable to bear such temperature, the plasma is held in a magnetic field away from the walls of the donut-shaped containment. The worlds largest "Tokamak" containment, built for the JET project, is about half as big as the one planned for ITER, says Spears.
While the selection of the French site was made at ministerial level, in Moscow on June 28, details must be worked out, treaties signed and funds allocated before work begins. The European Union will provide half of the total budget, with China, Japan, South of Korea, Russia and the U.S. each contributing 10%. Having pulled out of the project in 1999, the U.S. returned two years ago.