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(回答先: ”日本原電が事故ことは隠したまま、教育委員会を通じて募集を始めた” 河野太郎の国会日記より 投稿者 外野 日時 2005 年 5 月 28 日 23:38:47)
漏れのある核燃料再処理施設はずっと閉鎖した方が良い、とセラフィールドの所長[Observer]
http://www.asyura2.com/0505/genpatu3/msg/115.html
29 May 2005
Tens of thousands of litres of highly radioactive liquid leaked unnoticed for up to nine months from a ruptured pipe in the controversial Thorp reprocessing plant at Sellafield in what the IoS can reveal was Britain's worst nuclear accident for 13 years.
The leak, detected last month, was the result of a catalogue of human and engineering errors which resulted in a pool of nuclear liquor, half the volume of an Olympic swimming pool, being accidentally discharged. The magnitude of the incident throws the future of the troubled reprocessing plant into doubt this weekend as copies of an internal investigation circulate among senior ministers and officials.
British Nuclear Group, the company that runs the plant, last night admitted that workers failed to respond to "indicators" warning a badly designed pipe had sprung a leak as long ago as last August. The pool of nuclear liquor, 83,000 litres, was eventually discovered on 19 April. The company has ordered a review to check for other potential leaks caused by metal fatigue and an urgent drive against staff "complacency".
But ministers privately concede that Thorp, now owned by a quango, may never re-open as a result of the incident, classified as "serious" by the International Atomic Energy Authority. In a statement released yesterday the Nuclear Decommissioning Agency, the quango that inherited Thorp on 1 April, said it needed time to assess the report's findings before "discussing their implications" with the company and the Government, adding that "safety is the NDA's absolute priority".
The nuclear clean-up agency is thought to be fighting a battle with Downing Street to close the plant for good in a move that would cost taxpayers billions of pounds.
The leak comes just as ministers and nuclear firms are preparing to seek public support for a new generation of nuclear power stations to help meet climate change targets. It explains why Tony Blair and Alan Johnson, the new Secretary of State for Trade, have been so reluctant to start making the nuclear case.
The company has stressed the leak was contained and that the incident did not pose a threat to the public.
The company may yet face a criminal prosecution. A spokesman for the Nuclear Installations Inspectorate (NII) said: "I can confirm we will be seeking to find out what monitors were in place, whether they were working and, if so, why they were not acted on."
Four inspectors have been on the Cumbrian site since the incident happened. In addition to human error, they are concentrating on why engineers failed to modify pipes leading to moveable tanks. Metal fatigue in the pipework was the principal cause of the leak.
It is thought that the investigation will continue for a number of weeks before a decision is made on further action against British Nuclear Group.
A spokeswoman for the Department of Trade and Industry said that Mr Johnson would wait until the completion of the NII probe before deciding on the plant's future.
"It is essential that BNG acts urgently to implement the recommendations to improve operating practice and retrieve the escaped liquid. We are going to wait for advice before taking a decision on the way forward."
29 May 2005
On Friday 19 April, the nation's attention was fixed on the contents of Leo Blair's lunchbox. Journalists, desperate to enliven a dull election campaign, were debating the frequency with which the Prime Minister's son was served chips at his Westminster primary school.
Hundreds of miles away something was happening on the windswept Cumbrian coast that, had it been known at the time, would have blown the campaign wide open.
Managers at the troubled thermal oxide reprocessing plant - Thorp - in Sellafield became aware that they could not account for all the spent fuel, believed to have come from German nuclear power stations, it was supposed to be reprocessing.
Earlier that day they had decided to send a remote-controlled camera into the section of the plant, far too dangerous for human exposure, where the spent fuel is weighed in giant suspended tanks. The images it relayed horrified them. There on the stainless steel floor of the concrete cell housing the tanks lay a huge pool of highly radioactive nuclear liquor.
Altogether 83,000 litres of spent fuel dissolved in concentrated nitric acid shimmered beneath the camera lights. It contained enough plutonium to make 20 nuclear weapons.
The nuclear liquor had been leaking from a badly designed pipe since at least January and possibly from as long ago as last August. The plant is now closed.
How could such a major leak have occurred and why wasn't it detected for up to nine months? These are the subjects of an on-going official inspection that could yet lead to criminal prosecutions.
At the time Barry Sneldon, managing director of the British Nuclear Group, moved quickly to downplay the incident.
"Let me reassure people that the plant is in a safe and stable state," he said in a press release initially reported only in the regional press.
Although the nuclear reprocessing plant's closure was eventually reported in the national press more than two weeks later it failed to achieve widespread coverage as Tony Blair's re-election continued to dominate the news.
In Downing Street and the rest of Whitehall there was near panic, however, as the scale of the incident began to emerge.
An IoS investigation has found that the Nuclear Installations Inspectorate (NII) almost immediately informed Patricia Hewitt, the then Trade Secretary, and Margaret Beckett, the Environment Secretary, that they believed the leak was a significant malfunction.
The regulator also promptly informed the International Atomic Energy Authority which earlier this month classified it as Level 3 - a "serious incident" on the International Nuclear Event Scale. The scale ranges from 0 to 7, with 7 reserved for catastrophes on the scale of Chernobyl and Three Mile Island.
The last Level 3 incident in Britain (also at Sellafield) was in September 1992. There has only been one other incident as serious in the world in the past year. The most recent Level 4 incident led to the deaths from radiation sickness of three workers in a Japanese nuclear plant in 1999. They had been mixing nuclear fuel in a bucket.
Nerves were hardly calmed when the preliminary findings of a Board of Inquiry convened by the British Nuclear Group, formerly BNFL, which runs the plant, began to circulate among a small group of senior ministers and officials.
The company released a copy of that report late on Friday afternoon. It makes devastating reading.
The immediate cause of the leak is blamed on "metal fatigue" arising from a design fault in one of the pipes leading to a suspended tank, known as an accountancy tank. Engineers appear to have overlooked the fact that the tank would rise and fall placing "greater stresses to be exerted on associated pipework than had been anticipated".
Worrying though such a fault is, it is the report's next findings that are the most shocking. "There is some evidence that the pipe may have started to fail in August 2004," it admits, adding that by January of this year "significant amounts of liquor started to be released".
"In the period between January 2005 and 19 April 2005 opportunities... were missed which would have shown that material was escaping. Had these opportunities been taken the quantity of liquid released could have been significantly reduced."
The report stresses that the liquor pooled in a "secondary containment area", which prevented any release to the environment. No personnel were harmed.
In an accompanying statement the company blamed "complacency" for the fact that warning signs were missed.
"I shall be taking action to ensure that any complacency is addressed," said Barry Snelson, who has been at Sellafield since 1 August 2004. He added that the plant was "safe and stable".
Privately, the company knows that Thorp's days may be numbered. Since 1 April, the plant has been owned by a new government quango, the Nuclear Decommissioning Agency (NDA).
The NDA has the unenviable and extremely expensive job of cleaning up after Britain's ageing nuclear installations. Income from Thorp - it was projected to earn around £560m over the next 12 months - is supposed to partially offset the cost, £2.2bn this year, of the clean-up.
Late on Friday night the NDA released a carefully worded statement on its website which gave rise to speculation that Thorp's future was in jeopardy.
The issue of whether to build a new generation of nuclear power stations is one of the most sensitive of Tony Blair's third term.
It had been expected that ministers would aggressively begin to make the case for the carbon-free energy source immediately following the election. That they knew the full scale of the Thorp leak explains why no such exercise was launched.
David Willetts, the shadow Trade Secretary, said he would be calling for ministers to answer an urgent question on the incident when the Commons meets next week.
"This seems like a basic failure of procedure worthy of Homer Simpson. We do need to rationally consider the nuclear case but every incident like this undermines public confidence."
Norman Lamb, the Liberal Democrat trade spokesman, said: "This is staggering, and a timely reminder of why we moved away from nuclear in the first place. The truth is that human error can never be eliminated from this industry."
Mr Lamb urged ministers to give serious consideration to shutting the plant for good.
A DTI spokeswoman said: "It is essential that BNG acts urgently to implement the recommendations of the investigation to improve operating practice and retrieve the escaped liquid.
"Most of Thorp remains closed and the NDA and the regulators are still looking at how best to proceed. We are going to wait for advice before taking a decision on the way forward."
Company sources say there would be huge financial implications in closing the plant. It has £5bn worth of outstanding contracts and hefty penalty payments for non-delivery would have to be met from the public purse. The Government would also have to foot the bill for returning unprocessed spent fuel to customers in countries like Germany, Canada and Japan.
Work began on Monday to pump the highly radioactive liquor back into the system. But the damage to the future of British nuclear energy will take far longer to repair.
* About 3,000 litres of radioactive water leaked on Friday at a Czech nuclear power plant near the border with Austria, it emerged yesterday. An official told AP the water was contained in a tank and did not contaminate the environment.
PAST DISASTERS
Windscale (later renamed Sellafield), UK
1957: Human error during maintenance resulted in a reactor fire, releasing a cloud of radio-isotopes. Thirty years later National Radiological Protection Board estimated 33 premature deaths.
Three Mile Island, USA
1979: Malfunction at Three Mile Island nuclear reactor in Pennsylvania caused near meltdown. Concentrated plume of radioactive smoke exposed local area to radiation.
Chernobyl, Belarus
1986: An early morning explosion at the Chernobyl nuclear plant caused an atomic fire. Ukrainian health authorities estimate the final death toll will be 125,000.
Tokinawa, Japan
1999: Three workers in a nuclear fuel plant caused "criticality accident" by bypassing safety procedure. A chain reaction lasting 17 hours produced large amounts of radiation.
Paks, Hungary
2003: A "design fault" at the Paks nuclear power plant flooded one reactor room with radioactive water 10cm deep, and fuel rods were broken.
Tom Anderson
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