It must have seemed like a good idea at the time. Take the plutonium produced by nuclear power stations, mix it with uranium and make it into a new fuel for reactors to burn. Call it nuclear recycling, so that it sounds environmentally friendly.
That - or something like it - was the rationale for Tony Blair to give the go-ahead in 2001 to the Sellafield MOX plant (SMP). Costing an eventual £490m to build, this was meant to convert Britain's stockpile of foreign plutonium into a mixed oxide fuel for selling back to foreign customers.
Blair took the decision against the advice of his then environment minister, Michael Meacher and environmental groups. But it was a boost for the flagging nuclear industry and, in retrospect, a foretaste of the government's current enthusiasm for a new nuclear power programme.
Seven years on, what has become of SMP? The answer is instructive. Rising to four floors at the sprawling Sellafield complex on the Cumbrian coast, it is probably one of the biggest technical and economic disasters in the history of the British nuclear industry. For an industry with more than its fair share of mishaps, that is saying something.
The plant was originally meant to process 120 tonnes of MOX fuel a year, but it has yet to manage even three tonnes a year. As the Guardian reported in February, a grand total of only 5.2 tonnes have been produced in the six-year commissioning phase from 2001 to 2007.
Target production was cut to 72 tonnes a year by SMP's former owners, British Nuclear Fuels, in 2001. That was further scaled back to 40 tonnes a year in 2006 by the plant's new owners, the government's Nuclear Decommissioning Authority.
A production rate of 40 tonnes a year is close to the minimum necessary for SMP to cover its running costs, but many experts now think that it will never achieve anything like this. In fact, unless the plant is shut down, it is likely to bleed British taxpayers of
billions of pounds over the next few decades.
In his new book, Nukenomics the former nuclear regulator, Ian Jackson, points out that SMP would cost taxpayers £2.3 billion even if its output is successfully ramped up to 10 tonnes a year. The plant is "hopelessly uneconomic", concludes Jackson, a supporter of nuclear power. He quotes a 2006 report by the government's consultants, Arthur D Little, accepting that SMP's planned improvements may fail "leading eventually to an irrevocable collapse in the business case and closure."
SMP is a "fragile plant with continuous availability problems", says the Little report, only released with sections blacked out in response to requests under freedom of information law. The plant depends on a complex, automated process that has been plagued with up to 37,000 equipment failures a year, starving or blocking production lines for 70% of the time.
In the circumstances, Gordon Brown has two options. He could keep the MOX plant limping on, allowing it to haemorrhage billions of pounds of public money. Or he could lance Blair's boil, and close it down now - and in so doing learn a vital lesson about the nuclear industry's predilection for making false predictions.