Sellafield nuclear decommissioning a 'huge challenge'
Cleaning up the vast amounts of nuclear waste stored at the Sellafield plant is a hazardous and expensive operation.
The government has put more than £67bn aside for the project, but concerns have been raised over increasing costs and delays.
In 2008, the contract was awarded to three companies, which make up Nuclear Management Partners (NMP) and their subsidiary Sellafield Ltd.
A decision will made soon on extending it or awarded elsewhere.'Handled with respect'
Chris Hallewell, from Sellafield Ltd, said that when the plant was built decommissioning was not considered.
"That's given us a massive challenge on how to do it safely and in the environment of an aging facility," he said.
"The stuff is still active so it needs to be handled with the respect and care it deserves, and the site itself is one of the most congested industrial facilities in the world.
"With possibly 10,000 people working here on a daily basis, it's like a small town, so it's a huge challenge in a very, very tight space."
There have been a number of missed deadlines - in one case it was put back for seven years.
Five of the 14 ongoing projects are already over budget, one by £600m.
When an influential group of MPs visited in 2012, they blamed poor management for what they descried as "totally unacceptable" delays.
At the time, Margaret Hodge, chair of the Public Accounts Committee said: "I accept dealing with nuclear waste is a pretty unique problem.
"We want to make sure in this very difficult and hugely important project that the people involved are doing their best and using taxpayers' money to best value."'On track'
In the coming week the government will make the decision on whether the current holders should continue the contract.
Dr Ian Hudson, of Nuclear Management Partners, said they were on track to meet the minimum performance standards.
"We're also on track to deliver around £1bn of savings," he said.
"We've achieved the best safety record at Sellafield since records have started.
"It is my belief we are on track, and we've earned the right for the next five years."
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