Sunday, August 21, 2005

Fusion - The Economist


A step towards commercial fusion power. PerhapsTHIS week, an international project to build a nuclear-fusion reactor came astep closer to reality when politicians agreed it should be constructed inFrance rather than in Japan, the other country lobbying to host it. Theestimated cost is $12 billion, making it one of the most expensivescientific projects around—comparable financially with the InternationalSpace Station. It is scheduled to run for 30 years, which is handy since,for the past half century, fusion advocates have claimed that achievingcommercial nuclear fusion is 30 years away.The International Thermonuclear Experimental Reactor (ITER), as the projectis known, is intended to be the final proving step before a commercialfusion reactor is built. It would demonstrate that power can be generatedusing the energy released when two light atomic nuclei are brought togetherto make a heavier one—a process similar to the one that powers the sun andother stars.Advocates of fusion point to its alleged advantages over other forms ofpower generation. It is efficient, so only small quantities of fuel areneeded. Unlike existing nuclear reactors, which produce nasty long-livedradioactive waste, the radioactive processes involved with fusion arerelatively short-lived and the waste products benign. Unlike fossil-fuelplants, there are no carbon-dioxide emissions. And the principal fuel, aheavy isotope of hydrogen called deuterium, is present in ordinary water, ofwhich there is no shortage.The challenges of achieving fusion should not be underestimated. A largevolume of gas must be heated to a temperature above that found at the centreof the sun. At the same time, that gas must be prevented from touching thewalls of the reactor by confining it in a powerful magnetic field known as amagnetic bottle. The energy released in fusion is carried mostly byneutrons, a type of subatomic particle that has no electric charge and hencecannot be confined by the magnetic bottle. Ensuring that the reactor wallcan cope with being bombarded by these neutrons presents a furtherchallenge.The costs involved are immense. The budget for ITER involves spending $5billion on construction, $5 billion on operating costs over 20 years andmore than $1 billion on decommissioning. Yet the reason why taxpayers shouldspend such sums is unclear. The world is not short of energy. Climate changecan be addressed without recourse to generating power from fusion sincethere are already many alternatives to fossil-fuel power plants. And $12billion could buy an awful lot of research into those alternatives.Part of the reason why commercial fusion reactors have always been 30 yearsaway is that increasing the size of the reactors to something big enough tobe a power plant proved harder than foreseen. But fusion aficionados alsoblame a lack of urgency for the slow progress, claiming that at least 15years have been lost because of delays in decision-making and what theyregard as inadequate funding.There is some truth in this argument. ITER is a joint project betweenAmerica, most of the European Union, Japan, China, Russia and South Korea.For the past 18 months, work was at a standstill while the member stateswrangled over where to site the reactor in what was generally recognised asa proxy for the debate over the war in Iraq. America was thought to supportthe placing of ITER in Japan in return for Japan's support in that war.Meanwhile, the Russians and Chinese were supporting France which, like them,opposed the American-led invasion. That France was eventually chosen owesmuch to the fact that the European Union promised to support a suitableJapanese candidate as the next director general of ITER.Like the International Space Station, ITER had its origins in the superpowerpolitics of the 1980s that brought the cold war to its end as Russia and theWest groped around for things they could collaborate on. Like theInternational Space Station, therefore, ITER is at bottom a politicalanimal. And, like the International Space Station, the scientific reasonsfor developing it are almost non-existent. They cannot justify the price.


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