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.