Friday, February 24, 2006

British nuclear scientists say waste not a problem

Science News Article

By Jeremy Lovell
SELLAFIELD (Reuters) - Nuclear waste, the spectre haunting the industry, will not pose a problem if Britain decides later this year to build a new generation of nuclear power plants, scientists said on Thursday.
With a lethal life measured in thousands of years, waste from nuclear power stations has a powerful grip on public imagination who fear theft or attack by terrorists or simply that it is an unwanted legacy for generations to come.
"From a technical point of view we can deal with any waste that comes from nuclear plants," Graham Fairhall, chief technology officer at Nexiasolutions, the research arm of the British Nuclear Group, told Reuters.
"And in any case, a new reactor system would produce just 10 percent of the waste volume from the old Magnox reactors," he added during a tour of the Sellafield nuclear site some 300 miles northwest of London.
The British government, facing an electricity shortfall of 20 percent as it closes its aging nuclear power plants, is in the throes of a comprehensive review of how to supply the country's energy needs for coming generations.
Not only is time running out for crucial decisions to be made as the stations are already closing, but Britain also has to meet its international obligations to cut carbon emissions from burning fossil fuels.
British Prime Minister Tony Blair and his energy minister Malcolm Wicks have made it clear that nuclear power -- touted by its supporters as low carbon technology -- must be an option, although they accept that public acceptance could be a problem.
The scientists and engineers at Sellafield -- site of the world's first commercial nuclear electricity plant which opened in 1956 -- are confident they have the problem licked.
"The only question left is disposal or storage of the waste," Fairhall said.
At the sprawling 700-acre (283-hectare) site which employs 11,000 people, spent fuel rods not only from Britain's 11 nuclear reactors but from plants as far away as Japan are taken into a vast shed where they are initially immersed in pure water for six months.
The outer cladding is then stripped off and sent for storage in concrete-filled vats while the inner uranium core is recovered.

Reprocessing into plutonium and uranium leaves a highly radioactive sludge that is first evaporated in a two-stage process that reduces it to a powder.
That is mixed with molten glass at 1,100 degrees Celsius and poured into large stainless steel urns that are cooled, sealed scrubbed and put into a thick outer flasks for final storage.
The process is conducted remotely, with operators manipulating mechanical arms standing behind lead glass windows one meter (3 ft 3 in) thick.
The flasks are put into a giant repository that currently holds nearly 4,000 of them, awaiting a decision on a final solution later this year by a special government committee.
"This high level waste is still very radioactive, but there is no fissile material and when it has been vitrified it is unusable for anything," Fairhall said.
"To access these you would need an industrial set up like we have here. Anything less and the radiation would kill you -- and there would be no point in any case," he added.
The only question remaining, according to Fairhall, is whether to store the high level waste somewhere from which it may be retrieved in a few thousand years after it has lost its lethal potency or bury it forever.
"France has opted for disposal. But the Swedes have chosen copper containers that won't erode for a million years," he said.


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