IF SCIENTISTS ever succeed in building working fusion reactors, the
technology could help make nuclear waste safer, say Chinese and American
scientists. They think that fast neutrons released by fusion could smash the
waste into substances with much shorter half-lives.
Lijian Qiu from the Institute of Plasma Physics at the Chinese Academy of
Sciences in Hefei is proposing a hybrid fusion and fission reactor. This would
split atoms of plutonium and other radionuclides that last hundreds of thousands
of years into isotopes that only last hundreds of years. After 30 years of
operation, more than 96 per cent of the radioactivity would vanish, he told last
week鈥檚 International Atomic Energy Agency fusion conference in Sorrento,
Italy.
Qiu鈥檚 plan is to surround a spherical tokamak fusion reactor with a blanket
of fission waste which would gradually be destroyed, producing additional heat.
Though tokamaks are still experimental, Qiu says such a hybrid could generate
100 megawatts of power and destroy waste from 10 of today鈥檚 pressurised water
reactors. A hybrid would be easier and cheaper to build than a fully fledged
fusion reactor, says Qiu.
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General Atomics in San Diego, California, is also considering a
spherical tokamak for producing electricity and burning nuclear waste. Ron
Parker of the Massachusetts Institute of Technology is researching the concept,
which he describes as 鈥減romising鈥�. But he points out that some fusion scientists
are worried about the politics of mingling 鈥渃lean鈥� fusion with 鈥渄irty鈥� fission.