Maybe Nuclear Fusion scientists have to stop looking to Fusion Research as a
guarnateed paycheck, without ever having to produce a power source? Probably
a multi-billion dollar prize (after satisfying condions) would drive industry
to attain this needed goal. Maybe you can convince other companies to do the
same for Life Extension, with such a prize?
The heat is on
It's make or break time for the dream of never-ending fusion power
IN A last-ditch bid to realise the 50-year-old dream of making limitless
electricity from the same reactions that power the Sun, physicists last week
presented their final cut-down design for a nuclear fusion reactor. They warn
that unless governments now find the 3.5 billion euros (£2 billion) needed to
build the reactor, the dream will die.
The international fusion project has been in limbo for two years, ever since
funding governments balked at the original price tag of 7 billion euros.
Researchers have since drastically scaled down their ambitions. Speaking at a
fusion conference organised by the International Atomic Energy Agency in
Sorrento last week, Evgenii Velikhov, Russia's leading fusion scientist, says
that if a decision to begin construction is not made soon, "our future is
very bleak". Umberto Finzi, the European Commission's coordinator for energy
and the environment, warns that if governments fail to back the new design,
practical fusion energy research will fade away.
The US, Europe, Japan and the Soviet Union began working together on fusion
in 1986, but by the time the design for the International Thermonuclear
Experimental Reactor (ITER) was finalised in 1998 the political climate was
very different. US support for fusion had dwindled and Russia had little
money to put on the table.
The US pulled out of the project last year, and fusion researchers in Europe,
Japan and Russia have since been reworking the design, cutting the original
capital cost in half. Finzi points out that the cost of building the reactor,
if spread over 10 years, is only 25 per cent of the 1.4 billion euros already
spent on fusion research worldwide every year. Behind the scenes at Sorrento,
Finzi was busy preparing the ground for negotiations next year on a funding
package between Europe and Japan.
The principle of the revamped ITER is the same as before: inside a large
doughnut-shaped vessel known as a "tokamak", powerful magnetic fields contain
a plasma of the hydrogen isotopes deuterium and tritium. When heated to over
100 million degrees, the deuterium and tritium nuclei fuse to form alpha
particles and neutrons. The alpha particles reheat the plasma while the
energy of the neutrons can be extracted.
Many of the key parameters of the new design have shrunk. The amount of power
to be generated has been reduced from 1500 to 500 megawatts, while the volume
of plasma has dropped from 2000 to 837 cubic metres. Crucially, the reactor
is no longer aiming to "ignite" the plasma. Ignition occurs when the alpha
particles provide enough energy to sustain the reaction, and no further input
of heat is needed. The aim now is to provide 67 per cent of the plasma's
energy from alpha particles, a figure that cannot be achieved by any of the
existing small research tokamaks.
Despite the need to input energy, the reduced ITER should produce ten times
as much energy as it consumes. No other tokamak has yet produced surplus
power, though the JET fusion reactor at Culham in Oxfordshire has come close.
Experiments at JET over the past few months have for 5 seconds reached the
levels of plasma pressure, density and confinement required for ITER. "We
have made steady progress on all fronts," says JET's leader, Jerome Pamela.
"I'm sure ITER will work."
Apart from the design, the other burning question for ITER researchers is
where it will be built. Possible sites include Cadarache in southern France
and three locations in Japan. But Canada, an associate ITER member, has
proposed building the reactor next to an existing nuclear complex at
Clarington, west of Toronto. This has the advantage that tritium is already
produced there, and it would also be an acceptable compromise between Europe
and Japan. In addition, ITER scientists hope this location may entice the US
to rejoin the project.
>From New Scientist magazine, 14 October 2000.
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