BY Jorn Madslien
Business reporter, BBC News, Sellafield
**The first shipment of highly radioactive waste from the UK is leaving the Sellafield nuclear complex later, destined for Japan.**The waste is being repatriated after nuclear fuel spent by Japanese reactors was sent to the UK for reprocessing during the 1980s and 1990s.
Over the next decade, high-level waste will also be returned to European countries.
Campaigners say the shipments are unnecessary and dangerous.
However, they are also critical about it being stored at the Sellafield site.
For security reasons, the exact route of the shipment remains a secret until after it has taken place.
Profitable shipment
Returning waste to countries that have benefited from nuclear energy production is in line with both global agreements and UK government policy.
For Sellafield, it is also a source of revenue, as the company - which runs the site under a contract with the [Nuclear Decommissioning Authority](http://Decommissioning Authority) - is being paid by the government for meeting targets set as part of a complex contract that involves the decommissioning, reprocessing and waste management at the site.
“This is a performance-based milestone,” Mike Johnson, executive director, waste and effluent disposition, Sellafield Ltd, told BBC News in an exclusive interview.
“This is one of the ways we earn our fees.” Sellafield declined to reveal the payment details.
Revenue loss
Sellafield’s high-level nuclear waste storage is one of the most concentrated sources of radioactivity anywhere in the world.
When measured by volume, 65% of Britain’s total waste mountain is stored there, though it accounts for about 95% of the waste when measured by radioactivity.
It is also widely seen as the most complex nuclear facility in the world, because its waste is derived from a broad range of weapons and energy production - in the UK and abroad - during a period in history when the focus was more on quick solutions than on how to deal with their aftermath.
For the UK, the shipment goes one step towards reversing the country’s reputation as the nuclear dustbin of the world - although, over time, it will also lead to a fall in revenue from nations currently paying for their nuclear waste to be stored at Sellafield in Cumbria.
Domestic challenge
In about 10 years, high-level nuclear waste equivalent to the waste created by the nuclear fuel received will have been returned to all Sellafield’s foreign customers.
Afterwards, the UK will nevertheless be left with waste from decades of weapons programmes, research and energy production, which means the repatriation of waste will do little to provide a solution to the waste management challenge facing the UK.
Current nuclear waste storage facilities have evolved during the last 50 years, though they are still defined as temporary solutions.
Plans for the construction of an underground repository have been discussed for decades, but as yet, no firm decisions have been made.
In the meantime, the nuclear shipments will clear up space in the current storage facilities, which have been designed to cope with much more high-level waste than is currently there.
Made in the UK
Only two countries, the UK and France, have been engaged in the reprocessing of spent nuclear fuel from power stations.
In simple terms, nuclear reprocessing involves cutting up spent nuclear fuel rods into small bits that are dissolved in acid.
Uranium and plutonium is extracted from the mix, and this can be reused to make new nuclear fuel, which is then returned to nuclear power plants.
The remainder is then waste in a liquid form.
This is kept in evaporation ponds for long periods, eventually being reduced to a powdery substance that is then dissolved in liquid glass heated to some 1,100C.
This cocktail is then poured into steel canisters that resemble milk churns.
In turn, in the case of Sellafield, the high-level waste canisters are stored in a massive building that looks like an ordinary warehouse from the outside.
Inside, the canisters are stacked on top of each other and the radioactivity is contained by about 10ft (3m) of concrete shielding and 2-m thick concrete lids.
In the future, the plan is to start treating spent fuel from nuclear power plants as waste, rather than trying to extract and reuse the plutonium and uranium to create new fuel.
Many in the nuclear industry seem convinced that this is not a sustainable way of working, given anticipated shortages of both these valuable chemical elements.