But looking beyond the immediate crisis, it has also raised doubts about whether plutonium really is what the industry has always dreamt it to be - the fuel of the future. "Today, if you had tonnes of plutonium to offer for free," says Klaus Janberg, general manager of the German nuclear waste company GNS, "no one would take it."

So, if the highly toxic metal that first came to fame as a nuclear explosive doesn't have a future in fuelling reactors, what on earth is to be done with it ?

The plutonium shipped to Japan had been extracted from fuel burnt in Japanese reactors, blended with uranium and made into mixed oxide (MOX) fuel at the Sellafield nuclear plant in Cumbria. The consignment and others like it were meant to pave the way for an expansion of the multimillion-pound business exporting MOX fuel to foreign customers. But while the shipment was still en route, "The Independent", a British newspaper, reported that quality control checks on the size of the fuel pellets made at Sellafield's pilot MOX fabrication plant had been faked. Instead of laboriously measuring hundreds of pellets by hand, workers had simply "cut and pasted" data from previous checks. Although BNFL admitted that data had been falsified and has since sacked five workers, it initially insisted that the problem is limited and did not extend to the eight MOX fuel assemblies on their way to Japan.

Unfortunately, subsequent investigations by Britain's Nuclear Installations Inspectorate have revealed that the scale of the deception was far worse. Last Friday, in its most recent report, the NII blamed a "systematic failure"dating back to 1996, suggesting MOX with falsified safety data was sent to Germany, too. Kansai Electric Power, the Japanese company that had ordered the plutonium for its nuclear plant at Takahama, is furious. The company has refused to take the fuel, is demanding that it be returned to Britain and has barred BNFL from supplying any more.

"We are losing trust in BNFL," declared Japan's industry minister, Takashi Fukiai. BNFL made an abject apology and launched a major damage limitation exercise aimed at winning back the confidence of its biggest overseas customer - so far to no avail. But apart from alienating important customers, the scandal has again called into question the wisdom of reprocessing. Jack Harris, formerly a senior scientist at the Central Electricity Generating Board's Berkeley Nuclear Laboratories, in Gloucestershire, has revealed that he has been arguing within the industry against reprocessing since the 1970s. The MOX fuel cycle is "spherically daft", he says. "It is ridiculous from whichever direction it is viewed."

MOX is a "desperate attempt by the reprocessing industry to stay in existence long after the need for it has ceased", he claims in the latest issue of " Science and Public Affairs." "Reprocessing of spent civil fuel is expensive, polluting and carries with it nuclear proliferation risks, and should be stopped forthwith."

For BNFL, the MOX quality-control scandal and renewed questions about investing in the fuel could hardly have come at a worse time. For the past two years it has been awaiting government approval to start up its pounds 300 million MOX fabrication plant at Sellafield. It was also being prepared for partial privatisation. But last week the Trade and Industry Secretary, Stephen Byers, said there was a "fundamental flaw" in the management at BNFL.

Part-privatisation plans have been shelved. Reprocessing, the technique central to making MOX, dates back to the 1950s, when it was developed to separate plutonium from spent fuel for weapons manufacture. Reprocessed fuel was also meant to power a new generation of fast-breeder reactors, but these died a slow economic death in the 1980s and 1990s. As a result, Sellafield has amassed one of the world's largest stockpiles of separated plutonium: 66 tonnes, of which 9 tonnes belongs to overseas customers.

MOX, which is made by France, Belgium and Britain for some 40 reactors in Europe and Japan, was conceived as the best way of using the plutonium. But according to industry sources, the cost of making MOX has risen eightfold since the 1970s, while the price of its main competitor, plain uranium fuel, has plummeted. Harold Bolter, BNFL's company secretary for 10 years until 1993, argues that the only attraction of MOX is as a way of getting rid of plutonium.

Japan and Germany accepted it as a result of BNFL's hard-sell technique. But he believes these countries probably regret the deals they've made. "It is certainly more expensive than ordinary fuel, so why bother ?" Some countries are considering abandoning the reprocessing cycle and simply putting their plutonium out of harm's way.

German government advisers have suggested turning some of its plutonium, due to be returned from Sellafield and the French reprocessing plant at La Hague in Normandy, into poor-quality MOX, mixing it with radioactive spent fuel and then storing it as waste. The Americans are considering "immobilisation". This involves incorporating plutonium into a ceramic, then surrounding it with molten glass containing high-level radioactive waste to render it inaccessible to terrorists. Allison Macfarlane, a nuclear policy analyst from the Kennedy School of Government at Harvard University, argues that this technique should be adapted to work in Europe. Environmentalists in Britain and Japan, and 50 British MPs, also back the idea.

Surprisingly, BNFL has not ruled out the latter strategy. But its favourite course is to carry on making MOX. Despite the expense, it maintains that this is what its customers want - or at least that's what the contracts say. BNFL says it even has contracts in Europe for reprocessing MOX fuel after it has been burnt in reactors, though this will not happen until after 2004 - and it's being rather coy about the details of such agreements. But Sellafield's 10 000 workers are less sanguine about their prospects. Serious question marks over MOX would threaten the future of the plant's core business - reprocessing - which in turn would threaten jobs. "It's the worst crisis BNFL has ever faced," says one of the plant's trade union leaders, John Kane. In reality, though, it is the Sellafield site rather than BNFL itself that stands to lose the most as a result of the current crisis.

Observers note that BNFL is not as wedded to reprocessing as it used to be. As well as taking over responsibility for running Britain's first generation Magnox reactors, it has been expanding its radioactive clean-up business in the US and Russia. Within the past year it has bought two of the world's largest nuclear fuel fabrication companies: Westinghouse in the US for dollar 11 billion and ABB in Sweden for dollar 485 million. This has dramatically changed the shape of BNFL's business. Just six years ago, reprocessing at Sellafield accounted for half of the company's annual turnover: this has now shrunk to 25 per cent. "While customers want recycling and MOX fuel, we will make it," says one senior BNFL executive. "And if they don't, we will exit the market."

Not all the current top brass might be there to see this happen, however. Largely as a result of the MOX fiasco, the government expects senior heads to roll. And despite BNFL's assertions to the contrary, at least one boardroom sacking is not out of the question - especially after the publication of another NII report last Friday that slated management standards across the Sellafield site.

In Japan, meanwhile, arguments over the fate of the plutonium dispatched from Britain last year have produced some unlikely bedfellows. Environmentalists led by Greenpeace find themselves in agreement with BNFL that, because of the cost and dangers, it would be foolish to accede to Kansai Electric Power's demand to ship it back. Whatever the future of MOX, it seems this consignment of plutonium is in Japan to stay.

• Return to Nix MOX Bulletin Board
  
• Go to Nix MOX Bulletin Board Index