An expert report into the UK's long term nuclear waste storage plans has concluded there are no insurmountable technical barriers to storing nuclear waste deep underground. But the report urges government policy makers to keep the public informed about their plans. 

The advice came after an international workshop held in November 2006, UKlong term nuclear waste management: next steps, identified some key questions the government has yet to answer in its plans to store radioactive waste. 

The UK government announced in October 2006 that high activity radioactive waste was to be stored deep underground, but detailed long-term plans meeting the substantial agreement of learned societies, academia, industry, international experts and the public were still needed, concluded the report. 'We can't let government take a big sigh of relief and think they've ticked that box,' said Charles Curtis, of the Geological Society.

By the summer of 2007, the government hopes to unveil a report explaining how suitable storage sites can be selected. From the granite or crystalline rocks found in Scotland to the clays found through the Midlands and East of England, between a third and two-thirds of the UK is geologically suitable for storing waste some 300-1000 metres deep, Alan Hooper of Nirex UK told reporters at a press conference. 

It remains undecided where repositories should be sited, or how many may be needed. That will depend, for example, on whether different categories of waste can be stored together, and whether spent fuel and separated plutonium and uranium are reprocessed or stored. 

Another question facing the government is whether any repository should stay open for a time - allowing waste to be monitored and perhaps retrieved - or whether it should be instantly sealed. The scientific consensus was that sealing immediately was probably safer, said David Read of the University of Aberdeen.

Wherever nuclear waste ends up being buried, getting public consent will be just as important, experts warned. Even if the process went without a hitch from now on, it would take at least twenty years to complete, said Read. 

Richard Van Noorden