７月25日のこと。今になって知る。かなりやばい事故であったようだ。
先ずは、OhmyNewsの記事；
また、
Seven Minutes From Meltdown
On July 25 a short circuit at a Swedish nuclear power plant almost led to disasterAlexander Krabbe (AlexKrabbe)
Published 2006-08-05 13:44 (KST)
Most Europeans will remember July 25 as one of the hottest days since the beginning of regular weather observation. But it also came close to becoming a far more remarkable day. It could have been witness to a second Chernobyl.
It has taken more than a week for some fragments of information about the near-catastrophe at Sweden's Forsmark nuclear power plant to enter the news.
According to Lars-Olov Hoglund -- in the Swedish daily Svenska Dagbladet -- the incident must be regarded as "the most dangerous one since Harrisburg and Chernobyl." For several years, Hoglund was chief of construction in Forsmark.
About 2 p.m. on Tuesday, July 25, maintenance work caused a short circuit, which separated the power plant from the electricity net. A fast shut down of reactor No. 1 was automatically initiated. However, due to the short circuit, all emergency power devices were out of order. So there was nothing left to power the cooler pump systems.
If workers hadn't been able to reactivate two of the generators -- which they did, not as part of a normal procedure, but coincidentally -- a maximum credible accident would have occurred. As it stands, a nuclear meltdown was avoided, but just barely. According to Hoglund, the reactor was only seven minutes away from becoming another Chernobyl.
A Worldwide Problem?
Ingvar Berglund, Forsmark's chief security inspector, criticized the now obvious insufficiency in the technical construction of the emergency power devices. Since not only Finnish and Swedish nuclear power plants use the same generators, Berglund spoke of a possible worldwide problem. A short circuit should be blocked close to where it occurred, and must never be able to cause full-scale shutdowns of various operating systems in a power plant.
A German company, AEG, produced the generators in the early 1990s. As it came out after the Forsmark incident, AEG officials knew about the construction deficiency but didn't feel the need to tell the power plants' engineers about it.
The German daily Tageszeitung (TAZ) quoted Ole Reistad, chief of the office for the protection from radiation in Norway, as saying Forsmark came close to a "catastrophe."
One week after the short circuit in the Forsmark generators, Swedish authorities decided to shut down several other nuclear power plants. Security inspections will now clarify whether there are any more technical problems hidden in the reactors.
Conciliation in Sweden, Indifference in the European Media
Meanwhile, the Swedish office for atomic power, Statens Karnkraftinspektion (SKI), has categorized what happened at Forsmark as a "level 2" incident, on a scale of 1 to 7. In their view, it doesn't rate higher because no radiation escaped.
Both the company running the nuclear power plant and the SKI have refuted Hoglund's claim that a meltdown was close. They are calling the expert's analysis "exaggerated."
The European press has largely ignored the incident, even though had a catastrophe occurred, it could have cost the lives of thousands, if not hundreds of thousands of people. A few scattered reports appeared here and there, and when it did appear, it was quickly forgotten.
A powerful pro-atomic lobby
Germany, followed by Sweden and Belgium, was the first country to decide to abandon the path of producing nuclear energy. By the year 2030 the last nuclear power plant will be shut down in Germany.(*)
Once the decision was made in Germany, influential conservative newspapers attacked the government and the pursuit of alternative sources of energy on their main pages. Conservative politicians demanded an end to such "political nonsense," arguing that too much money was being spent on research into regenerative energies. Over and over, Germans were told that the only reliable alternative to oil is atomic power.
In the face of what happened in Forsmark, the media is now silent.
Nuclear energy now accounts for 30 percent of Western Europe's energy production. Despite the fact that global uranium resources would run out in about 40 years if industrial nations doubled their current nuclear energy production, not to mention the problem of finding somewhere to store all that highly radioactive waste, the majority of Germans support nuclear power as a strategy to secure the nation's energy production.
During the last five decades, billions of euros have been poured into the atomic power industry. More tax money has been spent on the construction and maintenance of nuclear power plants than on any other energy source. Consequentially, the lobby now has enormous political influence, which doesn't leave much space for thinking about alternative ways to produce energy.
This summer the myth of atomic power as a reliable energy source was damaged. In addition to the incident in Sweden, several large German nuclear power plants were ordered to shutdown because of the extraordinary heat Europe is experiencing. The cooling systems were unable to tolerate the high temperatures.
According to the man who was responsible for the construction of the Forsmark power plant, Sweden and the European Union were but seven minutes away from a nuclear disaster. But if no one knows about it, who will complain?
(*) This article has been corrected -- Ed.
The Swedish newspaper The Local reporting on the Forsmark incident.
http://english.ohmynews.com/articleview/article_view.asp?at_code=350796
バックアップ電源の問題は、さらに瑞典の他の原発にも波及している。
Sweden closes nuclear plants over safety fears04-08-2006
"It was pure luck there wasn't a meltdown," said a former director of Forsmark nuclear power plant after a serious incident at that plant last week. Now Sweden has shut down four of its 10 nuclear plants after faults were discovered. And a generator failure like Sweden's could easily happen in the UK.
The closure of the Swedish plants has removed at a stroke roughly 20 percent of Sweden's electricity supply. Emergency power systems to the Forsmark plant failed for 20 minutes during a power cut. If power was not restored there could have been a major incident within hours.
A former director of the Forsmark plant said, "It was pure luck that there was not a meltdown. Since the electricity supply from the network didn't work as it should have, it could have been a catastrophe."
It appears that the fault in the backup power systems originates from new equipment installed in 1993. Not exactly reassuring that faulty equipment, vital for preventing a meltdown, went undetected for 13 years. The same equipment now uncovered to be faulty is also installed on other nuclear power plants in other countries. Germany is already investigating if the same fault affects its nuclear plants. In the UK, a generator failure like Sweden s could easily happen and the result could be a meltdown in the reactor core. Such a meltdown would probably be contained like at Three Mile Island but in a worst case scenario radioactive iodine could be spread throughout Scandianavia, Germany and possibly to other parts of Europe.
Power cuts
Nuclear industry propaganda has been saying that we need nuclear power to prevent future power cuts. But actually current nuclear plants are vulnerable to power cuts. All nuclear plants need power to control them. If mains power is lost, back up power is required to control the reactor. This power is supplied by back up generators but there have been many instances where these generators have been found to be faulty or susceptible to storms or floods. This has caused the temporary closures of nuclear plants in the US and elsewhere.Cut the power to a single wind or solar farm and while they will stop generating electricity for the grid at least it won't threaten to melt down. Nuclear power relies on old, inefficient centralised power grids that are vulnerable to power cuts. Clean renewable energy sources help create more efficient decentralised power where it is generated much closer to where it is used. When the going gets hot, nuclear plants stop running
The problems with Swedish nuclear plants come hot on the heels of problems with nuclear power plants in Europe due to the hot dry summer. Two nuclear plants in Germany recently had to reduce output due to the lack of sufficient water for cooling in rivers. If the drought continues many nuclear plants that rely on rivers for cooling water will have to reduce output or shut down.
Luckily Sweden plans to phase out its nuclear power plants in the coming years. Unfortunately a small minority of other European countries like France, Finland and the UK seem determined to rely on dangerous, dirty and expensive nuclear power that can fail dangerously during a power cut and be shut down by droughts.
Recent events expose industry lies about nuclear being a reliable energy source.
A combination of safe, renewable energy and energy efficiency measures are the only sane solution for power generation.
（以下略）
http://www.greenpeace.org.uk/climate/climate.cfm?CFID=5474390&CFTOKEN=29414827&UCIDParam=20060804135413
８月３日付のGreenpeaceのプレス・リリース；
Near-meltdown incident at Swedish nuclear reactor
Thursday, 3 August 2006, 12:32 pm
Press Release: GreenpeaceCall for immediate closure of Sweden's nuclear reactors following near-meltdown incident.
Greenpeace demands action as Swedish regulator meets to decide on possible shut-downs.
Sweden 2 August 2006. Sweden's nuclear regulator SKI will meet in emergency session tomorrow (3 August) to decide on a possible immediate shut-down of all but one of the country's nuclear power stations supplying up to 50% of Sweden's electricity. Greenpeace has called for the reactors to be shut down following a serious incident last week at Sweden's Forsmark nuclear power station, in which "it was pure luck there wasn't a meltdown" according to a former director of the plant.
The Forsmark incident was caused by the failure of back-up generators following a problem with the main power supply. If the backup system fails after a grid cut-off or a whole blackout, the operator loses instrumentation and control over the reactor leading to an inability to cool the core, which can lead to a meltdown (1). In a report published last year, Greenpeace highlighted the widespread and frequent problems of failing power backup systems of nuclear reactors, which have also been reported in the US and Germany.
Swedish media reported yesterday that a former director of the Forsmark plant said "It was pure luck that there was not a meltdown. Since the electricity supply from the network didn't work as it should have, it could have been a catastrophe." Without power, the temperature would have been too high after 30 minutes and within two hours there could have been a meltdown.
"The Forsmark incident is just another illustration of the nuclear industry and nuclear regulators gambling with the lives of thousands or even millions of people" said Jan Vande Putte of Greenpeace International. "It has proved that a simple power blackout - something which has been happening regularly during the recent heatwaves - can very easily lead to a catastrophic reactor meltdown. This is a prime example of why this technology is inherently dangerous, must be phased out worldwide and never allowed to return. A combination of safe, renewable sources of energy and energy efficiency measures are the only sane solution for power generation."
