AI
Wednesday, March 30, 2011 3:28:29 AM
Japan nuclear: Fukushima seawater radioactivity rises
Nuclear safety agency official Hidehiko Nishiyama briefed journalists
Seawater near Japan's quake-hit Fukushima Daiichi nuclear plant has a much higher level of radiation than previously reported, officials say.
30 March 2011 Last updated at 02:03 ET
In one section, radioactive iodine stood at 3,355 times the legal limit, said Japan's nuclear safety agency.
However, an official said the iodine would have deteriorated considerably by the time it reached people.
Meanwhile, the president of the Fukushima nuclear plant operator Tepco has been admitted to hospital.
Masataka Shimizu is being treated for high blood pressure and dizziness, a Tepco spokesperson said.
Mr Shimizu has barely been seen in public since the earthquake and tsunami on 11 March which damaged the Fukushima plant.
Engineers are battling to restore power and restart the cooling systems at the plant.
Tepco has been accused of a lack of transparency and failing to provide information more promptly. It was also heavily criticised for issuing erroneous radiation readings at the weekend.
Tepco officials have announced a news conference for 1500 local time (0600 GMT).
'Unpredictable'
Earlier samples had put the iodine level in the sea at 1,850 times the legal limit.
The new readings were near reactor No 1 - 300m from the shore.
Much lower - but still elevated levels - of the same radioactive element have been found in seawater as far as 16km to the south.
The BBC's Mark Worthington in Tokyo says the discovery is the strongest indication so far that highly radioactive water is leaking into the sea.
Tepco and the safety agency say the exact source of the leak is unknown.
"Iodine 131 has a half-life of eight days, and even considering its concentration in marine life, it will have deteriorated considerably by the time it reaches people," Hidehiko Nishiyama, deputy director-general of Japan's nuclear safety agency told a news conference.
Radioactive materials are measured by scientists in half-lives, or the time it takes to halve the radiation through natural decay.
Iodine 131 was blamed for the high incidence of thyroid cancer among children exposed to fallout from the Chernobyl nuclear disaster in 1986.
Japanese Prime Minister Naoto Kan discussed the crisis at Fukushima with US President Barack Obama.
Mr Obama also pledged to help the people affected by the earthquake which damaged the Fukushima plant earlier this month, the Jiji news agency reported.
Workers at Japan's quake-hit nuclear plant are trying to prevent radioactive water from seeping into the sea.
Highly radioactive liquid has been found inside and outside several reactor buildings.
Small amounts of plutonium have also been detected in soil at the plant - the latest indication that one of the reactors suffered a partial meltdown.
But, like the discovery of plutonium, the high levels of radiation found inside and outside reactor buildings are likely to have come from melted fuel rods.
Theories for the leak centre on two possibilities: steam is flowing from the core into the reactor housing and escaping through cracks, or the contaminated material is leaking from the damaged walls of the water-filled pressure control pool beneath the No 2 reactor.
The plutonium - used in the fuel mix in the No 3 reactor - is not at levels that threaten human health, officials said.
BBC © MMXI
http://www.bbc.co.uk/news/world-asia-pacific-12903072
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Japan's Edano: Can't say when nuclear plant will be under control
TOKYO | Wed Mar 30, 2011 1:03am EDT
(Reuters) - Japanese Chief Cabinet Secretary Yukio Edano told reporters on Wednesday that he could not say when conditions at the crippled Fukushima Daiichi nuclear complex would be under control, referring to the world's worst atomic crisis since Chernobyl in 1986.
"We have been considering various measures, but at this stage we are not in a situation where we can say we will have this under control by a certain period," Edano told a news conference.
(Reporting by Yoko Kubota; Editing by Chris Gallagher.)
© Copyright 2011 Thomson Reuters
http://www.reuters.com/article/2011/03/30/us-japan-edano-idUSTRE72T0BV20110330 [with comments]
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Japan mulls new steps to contain radiation leakage
By V. Phani Kumar
March 29, 2011, 10:52 p.m. EDT
HONG KONG (MarketWatch) -- The Japanese government is considering new measures to prevent radiation leakage from the Fukushima Daiichi nuclear-power facility from spreading further, according to a Kyodo News report Wednesday. The government and experts have been mulling the feasibility of new measures, such as blanketing the reactor with special cloth to reduce the amount of radioactive leakage, and using a big tanker to collect the contaminated water at the facility, Kyodo cited media reports as saying. Japan's Chief Cabinet Secretary Yukio Edano reportedly said the government and nuclear experts are considering every possibility, including those that have been reported in the media. The remarks came as radioactivity in and around the nuclear plant remained at elevated levels. Traces of radioactive iodone found in seawater near the earthquake-damaged Fukushima facility in northeastern Japan were 3,355 times the legal limit, a separate report in Kyodo said Wednesday.
Copyright © 2011 MarketWatch, Inc.
http://www.marketwatch.com/story/japan-mulls-new-steps-to-contain-radiation-leakage-2011-03-29 [with comments]
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Stricken nuclear plant faces staffing difficulties
2011/03/30
Editor's note: We will update our earthquake news as frequently as possible on AJW's Facebook page: http://www.facebook.com/AJW.Asahi . Please check the latest developments in this disaster. From Toshio Jo, managing editor, International Division, The Asahi Shimbun.
* * *
The prolonged crisis at the quake-stricken nuclear power plant in Fukushima Prefecture is increasingly wearing down front-line workers, as the exhausting and dangerous work shows no signs of letting up.
Companies supplying the workers say safety fears have grown, particularly since three workers were exposed to high levels of radiation last Thursday from leaked water at the No. 3 reactor of the Fukushima No. 1 nuclear power plant.
Although some workers continue to return to the plant to avert a catastrophe, others willing to help cool down the reactors acknowledge they are more concerned about their next paycheck.
"We have become very nervous," said a senior official of a company with business ties to Tokyo Electric Power Co. (TEPCO), operator of the plant.
The official said the company is checking to ensure that TEPCO was not forcing workers to engage in too difficult a task.
Wearing protective gear, workers at the plant are toiling under stressful conditions amid the ever-present danger of radiation exposure.
Those who need to stay within the compound sleep on the floor of a tightly sealed room. They are given emergency rations twice a day.
Machinery maker IHI Corp., electric facility engineering firm Kandenko Co., reactor makers Hitachi Ltd. and Toshiba Corp., and general contractors are among those supplying workers to help TEPCO repair the plant battered by the March 11 earthquake and tsunami.
Highly radioactive water flooding the basement of turbine buildings, which injured the three workers last week, is hampering work to restore systems to cool the reactor cores.
Hitachi has assigned 170 workers, including those from subcontractors, to help restore power at the reactors.
"Workers with expertise are limited, and they can't be easily replaced," said a Hitachi official. "We are managing to somehow get by while carefully watching radiation levels."
The company has gradually increased the number of workers in an effort to reduce their burden.
Another company with ties to TEPCO has set a radiation limit lower than the government's standard of 250 millisieverts to make frequent replacements. Some of the workers have already reached the company-set limit.
"The work environment is becoming more and more risky, so it seems not many employees are willing to go," said a senior official. "We cannot force them to go. It's been such a headache."
According to TEPCO, 381 of its employees and 69 from "partner" companies entered the plant compound Monday. Most of the latter worked to restore electricity and repair equipment.
Kandenko and related firms have sent more than 200 workers, including the three workers exposed to high levels of radiation. All three have been discharged from hospital.
"Because there are dangerous places, we are taking the utmost caution," a Kandenko official said. "We must bring the situation under control while putting priority on safety."
Toshiba has assigned more than 100 engineers, including those from affiliates, to the Fukushima No. 1 and No. 2 plants. The company says it will send more if requested.
IHI dispatched about 30 to the No. 1 plant, including those from subcontractors, to help repair pipes for cooling systems. But it says rubble from explosions is also a source of concern to worker safety.
The current situation poses a difficult choice to those working for TEPCO's subcontractors, most of them neighborhood residents.
Many are staying at shelters after residents within a 20-kilometer radius from the plant were told to evacuate, but some are considering a return to the plant if asked because they must "make a living."
A man in his 30s who is at a shelter within the prefecture once declined a request from the president of his company in mid-March to help lay cables at the plant. He said he couldn't go because gasoline was not available at that time.
Having worked in the field for five years, the man confided that "nuclear power is scary because we can't tell what's happening." But he said he is proud of having worked for Japan's electricity supply and would accept the next request.
"We are in a position to get work from a subcontractor to TEPCO," he said. "If we gain a reputation that 'they didn't come' under these circumstances, what do you think will become of our job in the future?"
His daily wage is between 10,000 yen ($122) and 20,000 yen.
Another evacuee, who has accepted a request to return to work for a subcontractor, said: "We were given work from TEPCO for all 365 days. To get additional work, we must go even if it means having to work in a restricted area with risks of radiation exposure."
Another man in his 40s, who works for a sub-subcontractor to TEPCO, was born and raised in an area near the plant site.
At a shelter, the man has been waiting for a call from his employer "because there is no place to work here except at a nuclear power plant."
(This article was written by Kenichi Iwasaki and Tsuyoshi Shimoji.)
Copyright ©2011 The Asahi Shimbun Company
http://www.asahi.com/english/TKY201103290168.html
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Japan pay 'suicide squads' fortunes to work in stricken nuclear plant as 'battle is lost for reactor two'
'Suicide squads': The workers have been offered between 80,000 and 100,000 yen a day - around £608 to £760
Too little too late? A water pump is lifted onto a U.S. military boat, bound for the power plant - but some are warning that the battle to save the nuclear reactor has been lost
Battle lost: It is not thought that there will be a Chernobyl-style disaster
By Richard Hartley-parkinson
Last updated at 2:00 AM on 30th March 2011
A man who helped install reactors into the Fukushima reactor has claimed that the race to save the facility has been lost.
His grim assessment comes as it has been revealed that workers at the plant are being paid huge amounts of money to tackle the problem.
Their efforts, however, may be in vain as the former General Electric employee pointed out.
Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian [first item three back at http://investorshub.advfn.com/boards/read_msg.aspx?message_id=61492314 ] that workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe.
He added: 'The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the dry well.
'I hope I am wrong, but that is certainly what the evidence is pointing towards.'
The major worry is that the lava-like radioactive core will react with the concrete floor in Unit Two, sending radioactive gasses into the atmosphere.
Fortunately, though, the plant is flooded with seawater which will cool the material quicker than normal, reducing the amount of gas released.
According to the Independent newspaper, subcontractors have been offered 80,000 to 100,000 yen a day to take part.
Former worker Shingo Kanno said: 'They know it's dangerous so they have to pay up to 20 times what they usually do.'
The seasonal farmer and construction worker turned down offers of work. 'My wife and family are against it because it's so dangerous.'
A new evacuation zone is now being considered by the Tokyo Electric Power Company which could mean another 130,000 people have to evacuate.
© Associated Newspapers Ltd.
http://www.dailymail.co.uk/news/article-1371375/Japan-nuclear-suicide-squads-paid-huge-amounts-claims-battle-lost.html [no comments yet]
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Special Report: Japan engineers knew tsunami could overrun plant
By Kevin Krolicki, Scott DiSavino and Taro Fuse
TOKYO | Wed Mar 30, 2011 4:46am BST
TOKYO (Reuters) - Over the past two weeks, Japanese government officials and Tokyo Electric Power executives have repeatedly described the deadly combination of the most powerful quake in Japan's history and the massive tsunami that followed as "soteigai," or beyond expectations.
When Tokyo Electric President Masataka Shimizu apologised to the people of Japan for the continuing crisis at the Fukushima Daiichi nuclear plant he called the double disaster "marvels of nature … that we have never experienced before".
But a review of company and regulatory records shows that Japan and its largest utility repeatedly downplayed dangers and ignored warnings -- including a 2007 tsunami study from Tokyo Electric Power Co's senior safety engineer.
"We still have the possibilities that the tsunami height exceeds the determined design height due to the uncertainties regarding the tsunami phenomenon," Tokyo Electric researchers said in a report reviewed by Reuters.
The research paper concluded that there was a roughly 10 percent chance that a tsunami could test or overrun the defenses of the Fukushima Daiichi nuclear power plant within a 50-year span based on the most conservative assumptions.
But Tokyo Electric did nothing to change its safety planning based on that study, which was presented at a nuclear engineering conference in Miami in July 2007.
Meanwhile, Japanese nuclear regulators clung to a model that left crucial safety decisions in the hands of the utility that ran the plant, according to regulatory records, officials and outside experts.
Among examples of the failed opportunities to prepare for disaster, Japanese nuclear regulators never demanded that Tokyo Electric reassess its fundamental assumptions about earthquake and tsunami risk for a nuclear plant built more than four decades ago. In the 1990s, officials urged but did not require that Tokyo Electric and other utilities shore up their system of plant monitoring in the event of a crisis, the record shows.
Even though Japan's Nuclear and Industrial Safety Agency, (NISA) one of the three government bodies charged with nuclear safety, catalogued the damage to nuclear plant vent systems from an earlier earthquake, it did not require those to be protected against future disasters or hardened against explosions.
That marked a sharp break with safety practices put in place in the United States in the 1980s after Three Mile Island, even though Japan modelled its regulation on U.S. precedents and even allowed utilities to use American disaster manuals in some cases.
Ultimately, when the wave was crashing in, everything came down to the ability of Tokyo Electric's front-line workers to carry out disaster plans under intense pressure.
But even in normal operations, the regulatory record shows Tokyo Electric had been cited for more dangerous operator errors over the past five years than any other utility. In a separate 2008 case, it admitted that a 17-year-old worker had been hired illegally as part of a safety inspection at Fukushima Daiichi.
"It's a bit strange for me that we have officials saying this was outside expectations," said Hideaki Shiroyama, a professor at the University of Tokyo who has studied nuclear safety policy. "Unexpected things can happen. That's the world we live in."
He added: "Both the regulators and TEPCO are trying to avoid responsibility."
Najmedin Meshkati, a professor of civil and environmental engineering at the University of Southern California, said the government's approach of relying heavily on Tokyo Electric to do the right thing largely on its own had clearly failed.
"The Japanese government is receiving some advice, but they are relying on the already badly stretched resources of TEPCO to handle this," said Meshkati, a researcher of the Chernobyl disaster who has been critical of the company's safety record before. "Time is not on our side."
The revelation that Tokyo Electric had put a number to the possibility of a tsunami beyond the designed strength of its Fukushima nuclear plant comes at a time when investor confidence in the utility is in fast retreat.
Shares in the world's largest private utility have lost almost three-fourth of their value -- $30 billion -- since the March 11 earthquake pushed the Fukushima Daiichi nuclear plant into crisis. Analysts see a chance the utility will be nationalized by the Japanese government in the face of mounting liability claims and growing public frustration.
AN 'EXTREMELY LOW' RISK
The tsunami research presented by a Tokyo Electric team led by Toshiaki Sakai came on the first day of a three-day conference in July 2007 organized by the International Conference on Nuclear Engineering.
It represented the product of several years of work at Japan's top utility, prompted by the 2004 earthquake off the coast of Sumatra that had shaken the industry's accepted wisdom. In that disaster, the tsunami that hit Indonesia and a dozen other countries around the Indian Ocean also flooded a nuclear power plant in southern India. That raised concerns in Tokyo about the risk to Japan's 55 nuclear plants, many exposed to the dangerous coast in order to have quick access to water for cooling.
Tokyo Electric's Fukushima Daiichi plant, some 240 km (150 miles) northeast of Tokyo, was a particular concern.
The 40-year-old nuclear complex was built near a quake zone in the Pacific that had produced earthquakes of magnitude 8 or higher four times in the past 400 years -- in 1896, 1793, 1677 and then in 1611, Tokyo Electric researchers had come to understand.
Based on that history, Sakai, a senior safety manager at Tokyo Electric, and his research team applied new science to a simple question: What was the chance that an earthquake-generated wave would hit Fukushima? More pressing, what were the odds that it would be larger than the roughly 6-metre (20 feet) wall of water the plant had been designed to handle?
The tsunami that crashed through the Fukushima plant on March 11 was 14 meters high.
Sakai's team determined the Fukushima plant was dead certain to be hit by a tsunami of one or two meters in a 50-year period. They put the risk of a wave of 6 metres or more at around 10 percent over the same time span.
In other words, Tokyo Electric scientists realised as early as 2007 that it was quite possible a giant wave would overwhelm the sea walls and other defenses at Fukushima by surpassing engineering assumptions behind the plant's design that date back to the 1960s.
Company Vice President Sakae Muto said the utility had built its Fukushima nuclear power plant "with a margin for error" based on its assessment of the largest waves to hit the site in the past.
That would have included the magnitude 9.5 Chile earthquake in 1960 that killed 140 in Japan and generated a wave estimated at near 6 meters, roughly in line with the plans for Fukushima Daiichi a decade later.
"It's been pointed out by some that there could be a bigger tsunami than we had planned for, but my understanding of the situation is that there was no consensus among the experts," Muto said in response to a question from Reuters.
Despite the projection by its own safety engineers that the older assumptions might be mistaken, Tokyo Electric was not breaking any Japanese nuclear safety regulation by its failure to use its new research to fortify Fukushima Daiichi, which was built on the rural Pacific coast to give it quick access to sea water and keep it away from population centres.
"There are no legal requirements to re-evaluate site related (safety) features periodically," the Japanese government said in a response to questions from the United Nations nuclear watchdog, the International Atomic Energy Agency, in 2008.
In fact, in safety guidelines issued over the past 20 years, Japanese nuclear safety regulators had all but written off the risk of a severe accident that would test the vaunted safety standards of one of their 55 nuclear reactors, a key pillar of the nation's energy and export policies.
That has left planning for a strategy to head off runaway meltdown in the worst case scenarios to Tokyo Electric in the belief that the utility was best placed to handle any such crisis, according to published regulations.
In December 2010, for example, Japan's Nuclear Safety Commission said the risk for a severe accident was "extremely low" at reactors like those in operation at Fukushima. The question of how to prepare for those scenarios would be left to utilities, the commission said.
A 1992 policy guideline by the NSC also concluded core damage at one of Japan's reactors severe enough to release radiation would be an event with a probability of once in 185 years. So with such a limited risk of happening, the best policy, the guidelines say, is to leave emergency response planning to Tokyo electric and other plant operators.
PREVENTION NOT CURE
Over the past 20 years, nuclear operators and regulators in Europe and the United States have taken a new approach to managing risk. Rather than simple defenses against failures, researchers have examined worst-case outcomes to test their assumptions, and then required plants to make changes.
They have looked especially at the chance that a single calamity could wipe out an operator's main defence and its backup, just as the earthquake and tsunami did when the double disaster took out the main power and backup electricity to Fukushima Daiichi.
Japanese nuclear safety regulators have been slow to embrace those changes.
Japan's Nuclear and Industrial Safety Agency (NISA), one of three government bodies with responsibility for safety policy and inspections, had published guidelines in 2005 and 2006 based on the advances in regulation elsewhere but did not insist on their application.
"Since, in Japanese safety regulation, the application of risk information is scarce in experience ? (the) guidelines are in trial use," the NISA said.
Japanese regulators and Tokyo Electric instead put more emphasis on regular maintenance and programs designed to catch flaws in the components of their ageing plants.
That was the thinking behind extending the life of the No. 1 reactor at Fukushima Daiichi, which had been scheduled to go out of commission in February after a 40-year run.
But shutting down the reactor would have made it much more difficult for Japan to reach its target of deriving half of its total generation of electricity from nuclear power by 2030 -- or almost double its share in 2007.
The Ministry of Economy, Trade and Industry (METI) figured it could reach the target by building at least 14 new nuclear plants, and running existing plants harder and longer. Fukushima's No. 1 reactor was given a 10-year extension after Tokyo Electric submitted a maintenance plan.
Safety regulators, who also belong to METI, did not require Tokyo Electric to rethink the fundamental safety assumptions behind the plant. The utility only had to insure the reactor's component parts were not being worn down dangerously, according to a 2009 presentation by the utility's senior maintenance engineer.
That kind of thinking -- looking at potential problems with components without seeing the risk to the overall plant -- was evident in the way that Japanese officials responded to trouble with backup generators at a nuclear reactor even before the tsunami.
On four occasions over the past four years, safety inspectors from Japan and the International Atomic Energy Agency (IAEA) were called in to review failures with backup diesel generators at nuclear plants.
In June 2007, an inspector was dispatched to Fukushima's No. 4 reactor, where the backup generator had caught fire after a circuit breaker was installed improperly, according to the inspector's report.
"There is no need of providing feedback to other plants for the reason that no similar event could occur," the June 2007 inspection concluded.
The installation had met its safety target. Nothing in that report or any other shows safety inspectors questioned the placement of the generators on low ground near the shore where they proved to be at highest risk for tsunami damage at Fukushima Daiichi.
"GET OUT, GET OUT"
Japanese nuclear regulators have handed primary responsibility for dealing with nuclear plant emergencies to the utilities themselves. But that hinges on their ability to carry them out in an actual crisis, and the record shows that working in a nuclear reactor has been a dangerous and stressful job in Japan even under routine conditions.
Inspectors with Japan's Nuclear Energy Safety Organisation have recorded 18 safety lapses at Tokyo Electric's 17 nuclear plants since 2005. Ten of them were attributed to mistakes by staff and repairmen.
They included failures to follow established maintenance procedures and failures to perform prescribed safety checks. Even so, Toyko Electric was left on its own to set standards for nuclear plant staff certification, a position some IAEA officials had questioned in 2008.
In March 2004, two workers in Tokyo Electric's Fukushima Daini plant passed out when the oxygen masks they were using - originally designed for use on an airplane - began leaking and allowed nitrogen to seep into their air supply.
The risks also appear to have made it hard to hire for key positions. In 2008, Toshiba admitted it had illegally used six employees under the age of 18 as part of a series of inspections of nuclear power plants at Tokyo Electric and Tohoku Electric. One of those minors, then aged 17, had participated in an inspection of the Fukushima Daiichi No. 5 reactor, Tokyo Electric said then.
The magnitude 9.0 quake struck on Friday afternoon of March 11 -- the most powerful in Japan's long history of them -- pushed workers at the Fukushima plant to the breaking point as injuries mounted and panic took hold.
Hiroyuki Nishi, a subcontractor who had been moving scaffolding inside Reactor No. 3 when the quake hit, described a scene of chaos as a massive hook came crashing down next to him. "People were shouting 'Get out, get out!'" Nishi said. "Everyone was screaming."
In the pandemonium, workers pleaded to be let out, knowing a tsunami was soon to come. But Tokyo Electric supervisors appealed for calm, saying each worker had to be tested first for radiation exposure. Eventually, the supervisors relented, threw open the doors to the plant and the contractors scrambled for high ground just ahead of the tsunami.
After the wave receded, two employee were missing, apparently washed away while working on unit No. 4. Two contractors were treated for leg fractures and two others were treated for slight injuries. A ninth worker was being treated for a stroke.
In the chaos of the early response, workers did not notice when the diesel pumps at No. 2 ran out of fuel, allowing water levels to fall and fuel to become exposed and overheat. When the Fukushima plant suffered its second hydrogen blast in three days the following Monday, Tokyo electric executives only notified the prime minister's office an hour later. Seven workers had been injured in the explosion along with four soldiers.
An enraged Prime Minister Naoto Kan pulled up to Tokyo Electric's headquarters the next morning before dawn. "What the hell is going on?" reporters outside the closed-door discussion reported hearing Kan demand angrily of senior executives.
Errors of judgement by workers in the hot zone and errors of calculation by plant managers hampered the emergency response a full week later as some 600 soldiers and workers struggled to contain the spread of radiation.
On Thursday, two workers at Fukushima were shuttled to the hospital to be treated for potential radiation burns after wading in water in the turbine building of reactor No. 3. The workers had ignored their radiation alarms thinking they were broken.
Then Tokyo electric officials pulled workers back from an effort to pump water out of the No. 2 reactor and reported that radiation readings were 10 million times normal. They later apologized, saying that reading was wrong. The actual reading was still 100,000 times normal, Tokyo Electric said.
The government's chief spokesman was withering in his assessment. "The radiation readings are an important part of a number of important steps we're taking to protect safety," Chief Cabinet Secretary Yukio Edano told reporters. "There is no excuse for getting them wrong."
VENTS AND GAUGES
Although U.S. nuclear plant operators were required to install "hardened" vent systems in the 1980s after the Three Mile Island incident, Japan's Nuclear Safety Commission rejected the need to require such systems in 1992, saying that should be left to the plant operators to decide.
A nuclear power plant's vent represents one of the last resorts for operators struggling to keep a reactor from pressure that could to blow the building that houses it apart and spread radiation, which is what happened at Chernobyl 25 years ago. A hardened vent in a U.S. plant is designed to behave like the barrel on a rifle, strong enough to withstand an explosive force from within.
The U.S. Nuclear Regulatory Commission concluded in the late 1980s that the General Electric designed Mark I reactors, like those used at Fukushima, required safety modifications.
The risks they flagged, and that Tokyo did not heed, would come back to haunt Japan in the Fukushima crisis.
First, U.S. researchers concluded that a loss of power at one of the nuclear plants would be one of the "dominant contributors" to the most severe accidents. Flooding of the reactor building would worsen the risks. The NRC also required U.S. plants to install "hard pipe" after concluding the sheet-metal ducts used in Japan could make things much worse.
"Venting via a sheet metal duct system could result in a reactor building hydrogen burn," researchers said in a report published in November 1988.
In the current crisis, the failure of the more vulnerable duct vents in Fukushima's No. 1 and No. 3 reactors may have contributed to the hydrogen explosions that blew the roof off the first and left the second a tangled hulk of steel beams in the first three days of the crisis.
The plant vents, which connect to the big smokestack-like towers, appear to have been damaged in the quake or the tsunami, one NISA official said.
Even without damage, opening the vulnerable vents in the presence of a build-up of hydrogen gas was a known danger. In the case of Fukushima, opening the vents to relieve pressure was like turning on an acetylene torch and then watching the flame "shoot back into the fuel tank," said one expert with knowledge of Fukushima who asked not to be identified because of his commercial ties in Japan.
Tokyo Electric began venting the No. 1 reactor on March 12 just after 10 a.m. An hour earlier the pressure in the reactor was twice its designed limit. Six hours later the reactor exploded.
The same pattern held with reactor No. 3. Venting to relieve a dangerous build-up of pressure in the reactor began on March 13. A day later, the outer building - a concrete and steel shell known as the "secondary containment" -- exploded.
Toshiaki Sakai, the Tokyo Electric researcher who worked on tsunami risk, also sat on a panel in 2008 that reviewed the damage to the Kashiwazaki-Kariwa nuclear plant. In that case, Tokyo Electric safely shut down the plant, which survived a quake 2.5 times stronger than it had been designed to handle.
Sakai and the other panellists agreed that despite the successful outcome the way the ground sank and broke underground pipes needed for firefighting equipment had to be considered "a failure to fulfil expected performance".
Japanese regulators also knew a major earthquake could damage exhaust ducts. A September 2007 review of damage at the same Tokyo Electric nuclear plant by NISA Deputy Director Akira Fukushima showed two spots where the exhaust ducts had broken.
No new standard was put in place requiring vents to be shored up against potential damage, records show.
Masashi Goto, a former nuclear engineer who has turned critical of the industry, said he believed Tokyo Electric and regulators wrongly focussed on the parts of the plant that performed well in the 2007 quake, rather than the weaknesses it exposed. "I think they drew the wrong lesson," Goto said.
The March 11 quake not only damaged the vents but also the gauges in the Fukushima Daiichi complex, which meant that Tokyo Electric was without much of the instrumentation it needed to assess the situation on the ground during the crisis.
"The data we're getting is very sketchy and makes it impossible for us to do the analysis," said David Lochbaum, a nuclear expert and analyst with the Union of Concerned Scientists. "It's hard to connect the dots when there are so few dots."
In fact, Japan's NSC had concluded in 1992 that it was important for nuclear plant operators to have access to key gauges and instruments even in the kind of crisis that had not happened then. But it left plans on how to implement that policy entirely to the plant operators.
In the Fukushima accident, most meters and gauges were taken out by the loss of power in the early days of the crisis.
That left a pair of workers in a white Prius to race into the plant to get radiation readings with a handheld device in the early days of the crisis, according to Tokyo Electric.
They could have used robots to go in.
Immediately after the tsunami, a French firm with nuclear expertise shipped robots for use in Fukushima, a European nuclear expert said. The robots are built to withstand high radiation.
But Japan, arguably the country with the most advanced robotics industry, stopped them from arriving in Fukishima, saying such help could only come through government channels, said the expert who asked not to be identified so as not to appear critical of Japan in a moment of crisis.
(Scott DiSavino was reporting from New York; Additional reporting by Kentaro Sugiayama in Tokyo, Bernie Woodall in Detroit, Eileen O'Grady in New York, Roberta Rampton in Washington; Editing by Bill Tarrant)
© Thomson Reuters 2011
http://uk.reuters.com/article/2011/03/30/uk-japa-nuclear-risks-idUKTRE72S5PW20110330 [no comments yet] [as a pdf with various images/infographics http://graphics.thomsonreuters.com/AS/pdf/tepcomarch29dk.pdf ]
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Records Show 56 Safety Violations at U.S. Nuclear Power Plants in Past 4 Years
Mishandled Radioactive Material and Failing Backup Generators Among the Violations
By PIERRE THOMAS, JACK CLOHERTY AND ANDREW DUBBINS
March 29, 2011
Among the litany of violations at U.S. nuclear power plants are missing or mishandled nuclear material, inadequate emergency plans, faulty backup power generators [ http://abcnews.go.com/US/wireStory?id=13244299 (fifth item four back at http://investorshub.advfn.com/boards/read_msg.aspx?message_id=61457583 )], corroded cooling pipes and even marijuana use inside a nuclear plant, according to an ABC News review of four years of Nuclear Regulatory Commission safety records.
And perhaps most troubling of all [ http://abcnews.go.com/Technology/wireStory?id=13213010 ], critics say, the commission has failed to correct the violations in a timely fashion.
"The Nuclear Regulatory Commission has very good safety regulations but they have very bad enforcement of those regulations," said David Lochbaum, a nuclear scientist with the nonprofit Union of Concerned Scientists.
There are 104 U.S. nuclear power plants.
Lochbaum and the Union of Concerned Scientists found 14 "near misses" at nuclear plants in 2010. And there were 56 serious violations at nuclear power plants [ http://abcnews.go.com/GMA/video/us-fault-lines-nuke-plants-spotlight-13165063 ] from 2007 to 2011, according the ABC News review of NRC records.
At the Dresden Nuclear Power Plant in Illinois, for instance, which is located within 50 miles of the 7 million people who live in and around Chicago, nuclear material went missing in 2007. The Nuclear Regulatory Commission fined the operator -- Exelon Corp. -- after discovering the facility had failed to "keep complete records showing the inventory [and] disposal of all special nuclear material in its possession."
As a result, two fuel pellets and equipment with nuclear material could not be accounted for.
Exelon did not contest the violation and paid the fine, a company spokesman said. "We took the learnings from that violation with respect to ways we can improve our spent-fuel practices," Marshall Murphy said.
Two years later, federal regulators cited Dresden for allowing unlicensed operators to work with radioactive control rods. The workers allowed three control rods to be moved out of the core. When alarms went off, workers initially ignored them.
Murphy said the company concurred with the NRC's determination. " We have also taken a number of steps to ensure a similar event would not occur at any of our sites and shared the lessons from that with the industry," he said.
"In both violations, neither employees or the public were ever jeopardized, but we take them seriously, we always look to learn from them, and we do that going forward.
Still, Lochbaum of the Union of Concerned Scientists said, "This event is disturbing. In August 1997, the NRC issued information … about a reactivity mismanagement problem at Exelon's Zion nuclear plant," which was retired the following year.
"It was an epoch event in the industry in that other plants owners noted it and took steps to address [the issue]. Yet, a decade later, Exelon's Dresden plant experiences an eerily similar repetition of the control-room operator problems."
The lost material was almost certainly shipped to a licensed, low-level waste disposal site, Lochbaum said.
At the Indian Point nuclear plant just outside New York City, the NRC found that an earthquake safety device has been leaking for 18 years.
In the event of an earthquake, Lochbaum said, the faulty safety device would not help prevent water from leaking out of the reactor. A lack of water to cool the fuel rods has been the most critical problem at the Fukushima plant in Japan after the recent earthquake and tsunami.
"The NRC has known it's been leaking since 1993," Lochbaum said, "but they've done nothing to fix it."
While declining to address specific violations, Roger Hanna, a spokesman for the NRC, said "we do require plant to comply, and we do follow up for corrections" when violations are discovered.
But NRC records examined by ABC News show that such incidents are not uncommon: In June 2009, at the Southern Nuclear Operating Co. Inc. in Birmingham, Ala., the emergency diesel generator -- which would be used in the event of a disaster -- was deemed inoperable, after years of neglect.
"Cracks in the glands of the emergency diesel generator couplings had been observed since 1988, but the licensee did not recognize the cracking was an indication of coupling deterioration," according to the NRC report. On April 19, 2010, the NRC cited the Tennessee Valley Authority Browns Ferry nuclear plant near Decatur for failing to provide "fire protection features capable of limiting fire damage."
The NRC fire protection regulations in effect today were developed as a direct result of the Browns Ferry fire on March 22, 1975.
In June 2010, Duke Energy, operators of the William McGuire nuclear plant in Mecklenburg County, N.C., was cited by the NRC after a contract employee was caught using marijuana inside the protected area.
NRC safety records show that inadequate emergency planning was a recurring problem in the industry from 2007 to 2011. Violations included unapproved emergency plans and plan changes, inadequate fire planning and precautions, falsified "fire watch" certification sheets," inadequate flooding precautions, an insufficient tone alert radio system to notify the populace in a potential emergency and faulty assessment of containment barrier thresholds.
Corroded water pipes and cooling problems were also recurring issues.
Copyright © 2011 ABC News Internet Ventures
http://abcnews.go.com/Politics/us-nuclear-power-plants-safe/story?id=13246490 [with comments]
Nuclear safety agency official Hidehiko Nishiyama briefed journalists
Seawater near Japan's quake-hit Fukushima Daiichi nuclear plant has a much higher level of radiation than previously reported, officials say.
30 March 2011 Last updated at 02:03 ET
In one section, radioactive iodine stood at 3,355 times the legal limit, said Japan's nuclear safety agency.
However, an official said the iodine would have deteriorated considerably by the time it reached people.
Meanwhile, the president of the Fukushima nuclear plant operator Tepco has been admitted to hospital.
Masataka Shimizu is being treated for high blood pressure and dizziness, a Tepco spokesperson said.
Mr Shimizu has barely been seen in public since the earthquake and tsunami on 11 March which damaged the Fukushima plant.
Engineers are battling to restore power and restart the cooling systems at the plant.
Tepco has been accused of a lack of transparency and failing to provide information more promptly. It was also heavily criticised for issuing erroneous radiation readings at the weekend.
Tepco officials have announced a news conference for 1500 local time (0600 GMT).
'Unpredictable'
Earlier samples had put the iodine level in the sea at 1,850 times the legal limit.
The new readings were near reactor No 1 - 300m from the shore.
Much lower - but still elevated levels - of the same radioactive element have been found in seawater as far as 16km to the south.
The BBC's Mark Worthington in Tokyo says the discovery is the strongest indication so far that highly radioactive water is leaking into the sea.
Tepco and the safety agency say the exact source of the leak is unknown.
"Iodine 131 has a half-life of eight days, and even considering its concentration in marine life, it will have deteriorated considerably by the time it reaches people," Hidehiko Nishiyama, deputy director-general of Japan's nuclear safety agency told a news conference.
Radioactive materials are measured by scientists in half-lives, or the time it takes to halve the radiation through natural decay.
Iodine 131 was blamed for the high incidence of thyroid cancer among children exposed to fallout from the Chernobyl nuclear disaster in 1986.
Japanese Prime Minister Naoto Kan discussed the crisis at Fukushima with US President Barack Obama.
Mr Obama also pledged to help the people affected by the earthquake which damaged the Fukushima plant earlier this month, the Jiji news agency reported.
Workers at Japan's quake-hit nuclear plant are trying to prevent radioactive water from seeping into the sea.
Highly radioactive liquid has been found inside and outside several reactor buildings.
Small amounts of plutonium have also been detected in soil at the plant - the latest indication that one of the reactors suffered a partial meltdown.
But, like the discovery of plutonium, the high levels of radiation found inside and outside reactor buildings are likely to have come from melted fuel rods.
Theories for the leak centre on two possibilities: steam is flowing from the core into the reactor housing and escaping through cracks, or the contaminated material is leaking from the damaged walls of the water-filled pressure control pool beneath the No 2 reactor.
The plutonium - used in the fuel mix in the No 3 reactor - is not at levels that threaten human health, officials said.
BBC © MMXI
http://www.bbc.co.uk/news/world-asia-pacific-12903072
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Japan's Edano: Can't say when nuclear plant will be under control
TOKYO | Wed Mar 30, 2011 1:03am EDT
(Reuters) - Japanese Chief Cabinet Secretary Yukio Edano told reporters on Wednesday that he could not say when conditions at the crippled Fukushima Daiichi nuclear complex would be under control, referring to the world's worst atomic crisis since Chernobyl in 1986.
"We have been considering various measures, but at this stage we are not in a situation where we can say we will have this under control by a certain period," Edano told a news conference.
(Reporting by Yoko Kubota; Editing by Chris Gallagher.)
© Copyright 2011 Thomson Reuters
http://www.reuters.com/article/2011/03/30/us-japan-edano-idUSTRE72T0BV20110330 [with comments]
===
Japan mulls new steps to contain radiation leakage
By V. Phani Kumar
March 29, 2011, 10:52 p.m. EDT
HONG KONG (MarketWatch) -- The Japanese government is considering new measures to prevent radiation leakage from the Fukushima Daiichi nuclear-power facility from spreading further, according to a Kyodo News report Wednesday. The government and experts have been mulling the feasibility of new measures, such as blanketing the reactor with special cloth to reduce the amount of radioactive leakage, and using a big tanker to collect the contaminated water at the facility, Kyodo cited media reports as saying. Japan's Chief Cabinet Secretary Yukio Edano reportedly said the government and nuclear experts are considering every possibility, including those that have been reported in the media. The remarks came as radioactivity in and around the nuclear plant remained at elevated levels. Traces of radioactive iodone found in seawater near the earthquake-damaged Fukushima facility in northeastern Japan were 3,355 times the legal limit, a separate report in Kyodo said Wednesday.
Copyright © 2011 MarketWatch, Inc.
http://www.marketwatch.com/story/japan-mulls-new-steps-to-contain-radiation-leakage-2011-03-29 [with comments]
===
Stricken nuclear plant faces staffing difficulties
2011/03/30
Editor's note: We will update our earthquake news as frequently as possible on AJW's Facebook page: http://www.facebook.com/AJW.Asahi . Please check the latest developments in this disaster. From Toshio Jo, managing editor, International Division, The Asahi Shimbun.
* * *
The prolonged crisis at the quake-stricken nuclear power plant in Fukushima Prefecture is increasingly wearing down front-line workers, as the exhausting and dangerous work shows no signs of letting up.
Companies supplying the workers say safety fears have grown, particularly since three workers were exposed to high levels of radiation last Thursday from leaked water at the No. 3 reactor of the Fukushima No. 1 nuclear power plant.
Although some workers continue to return to the plant to avert a catastrophe, others willing to help cool down the reactors acknowledge they are more concerned about their next paycheck.
"We have become very nervous," said a senior official of a company with business ties to Tokyo Electric Power Co. (TEPCO), operator of the plant.
The official said the company is checking to ensure that TEPCO was not forcing workers to engage in too difficult a task.
Wearing protective gear, workers at the plant are toiling under stressful conditions amid the ever-present danger of radiation exposure.
Those who need to stay within the compound sleep on the floor of a tightly sealed room. They are given emergency rations twice a day.
Machinery maker IHI Corp., electric facility engineering firm Kandenko Co., reactor makers Hitachi Ltd. and Toshiba Corp., and general contractors are among those supplying workers to help TEPCO repair the plant battered by the March 11 earthquake and tsunami.
Highly radioactive water flooding the basement of turbine buildings, which injured the three workers last week, is hampering work to restore systems to cool the reactor cores.
Hitachi has assigned 170 workers, including those from subcontractors, to help restore power at the reactors.
"Workers with expertise are limited, and they can't be easily replaced," said a Hitachi official. "We are managing to somehow get by while carefully watching radiation levels."
The company has gradually increased the number of workers in an effort to reduce their burden.
Another company with ties to TEPCO has set a radiation limit lower than the government's standard of 250 millisieverts to make frequent replacements. Some of the workers have already reached the company-set limit.
"The work environment is becoming more and more risky, so it seems not many employees are willing to go," said a senior official. "We cannot force them to go. It's been such a headache."
According to TEPCO, 381 of its employees and 69 from "partner" companies entered the plant compound Monday. Most of the latter worked to restore electricity and repair equipment.
Kandenko and related firms have sent more than 200 workers, including the three workers exposed to high levels of radiation. All three have been discharged from hospital.
"Because there are dangerous places, we are taking the utmost caution," a Kandenko official said. "We must bring the situation under control while putting priority on safety."
Toshiba has assigned more than 100 engineers, including those from affiliates, to the Fukushima No. 1 and No. 2 plants. The company says it will send more if requested.
IHI dispatched about 30 to the No. 1 plant, including those from subcontractors, to help repair pipes for cooling systems. But it says rubble from explosions is also a source of concern to worker safety.
The current situation poses a difficult choice to those working for TEPCO's subcontractors, most of them neighborhood residents.
Many are staying at shelters after residents within a 20-kilometer radius from the plant were told to evacuate, but some are considering a return to the plant if asked because they must "make a living."
A man in his 30s who is at a shelter within the prefecture once declined a request from the president of his company in mid-March to help lay cables at the plant. He said he couldn't go because gasoline was not available at that time.
Having worked in the field for five years, the man confided that "nuclear power is scary because we can't tell what's happening." But he said he is proud of having worked for Japan's electricity supply and would accept the next request.
"We are in a position to get work from a subcontractor to TEPCO," he said. "If we gain a reputation that 'they didn't come' under these circumstances, what do you think will become of our job in the future?"
His daily wage is between 10,000 yen ($122) and 20,000 yen.
Another evacuee, who has accepted a request to return to work for a subcontractor, said: "We were given work from TEPCO for all 365 days. To get additional work, we must go even if it means having to work in a restricted area with risks of radiation exposure."
Another man in his 40s, who works for a sub-subcontractor to TEPCO, was born and raised in an area near the plant site.
At a shelter, the man has been waiting for a call from his employer "because there is no place to work here except at a nuclear power plant."
(This article was written by Kenichi Iwasaki and Tsuyoshi Shimoji.)
Copyright ©2011 The Asahi Shimbun Company
http://www.asahi.com/english/TKY201103290168.html
===
Japan pay 'suicide squads' fortunes to work in stricken nuclear plant as 'battle is lost for reactor two'
'Suicide squads': The workers have been offered between 80,000 and 100,000 yen a day - around £608 to £760
Too little too late? A water pump is lifted onto a U.S. military boat, bound for the power plant - but some are warning that the battle to save the nuclear reactor has been lost
Battle lost: It is not thought that there will be a Chernobyl-style disaster
By Richard Hartley-parkinson
Last updated at 2:00 AM on 30th March 2011
A man who helped install reactors into the Fukushima reactor has claimed that the race to save the facility has been lost.
His grim assessment comes as it has been revealed that workers at the plant are being paid huge amounts of money to tackle the problem.
Their efforts, however, may be in vain as the former General Electric employee pointed out.
Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian [first item three back at http://investorshub.advfn.com/boards/read_msg.aspx?message_id=61492314 ] that workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe.
He added: 'The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the dry well.
'I hope I am wrong, but that is certainly what the evidence is pointing towards.'
The major worry is that the lava-like radioactive core will react with the concrete floor in Unit Two, sending radioactive gasses into the atmosphere.
Fortunately, though, the plant is flooded with seawater which will cool the material quicker than normal, reducing the amount of gas released.
According to the Independent newspaper, subcontractors have been offered 80,000 to 100,000 yen a day to take part.
Former worker Shingo Kanno said: 'They know it's dangerous so they have to pay up to 20 times what they usually do.'
The seasonal farmer and construction worker turned down offers of work. 'My wife and family are against it because it's so dangerous.'
A new evacuation zone is now being considered by the Tokyo Electric Power Company which could mean another 130,000 people have to evacuate.
© Associated Newspapers Ltd.
http://www.dailymail.co.uk/news/article-1371375/Japan-nuclear-suicide-squads-paid-huge-amounts-claims-battle-lost.html [no comments yet]
===
Special Report: Japan engineers knew tsunami could overrun plant
By Kevin Krolicki, Scott DiSavino and Taro Fuse
TOKYO | Wed Mar 30, 2011 4:46am BST
TOKYO (Reuters) - Over the past two weeks, Japanese government officials and Tokyo Electric Power executives have repeatedly described the deadly combination of the most powerful quake in Japan's history and the massive tsunami that followed as "soteigai," or beyond expectations.
When Tokyo Electric President Masataka Shimizu apologised to the people of Japan for the continuing crisis at the Fukushima Daiichi nuclear plant he called the double disaster "marvels of nature … that we have never experienced before".
But a review of company and regulatory records shows that Japan and its largest utility repeatedly downplayed dangers and ignored warnings -- including a 2007 tsunami study from Tokyo Electric Power Co's senior safety engineer.
"We still have the possibilities that the tsunami height exceeds the determined design height due to the uncertainties regarding the tsunami phenomenon," Tokyo Electric researchers said in a report reviewed by Reuters.
The research paper concluded that there was a roughly 10 percent chance that a tsunami could test or overrun the defenses of the Fukushima Daiichi nuclear power plant within a 50-year span based on the most conservative assumptions.
But Tokyo Electric did nothing to change its safety planning based on that study, which was presented at a nuclear engineering conference in Miami in July 2007.
Meanwhile, Japanese nuclear regulators clung to a model that left crucial safety decisions in the hands of the utility that ran the plant, according to regulatory records, officials and outside experts.
Among examples of the failed opportunities to prepare for disaster, Japanese nuclear regulators never demanded that Tokyo Electric reassess its fundamental assumptions about earthquake and tsunami risk for a nuclear plant built more than four decades ago. In the 1990s, officials urged but did not require that Tokyo Electric and other utilities shore up their system of plant monitoring in the event of a crisis, the record shows.
Even though Japan's Nuclear and Industrial Safety Agency, (NISA) one of the three government bodies charged with nuclear safety, catalogued the damage to nuclear plant vent systems from an earlier earthquake, it did not require those to be protected against future disasters or hardened against explosions.
That marked a sharp break with safety practices put in place in the United States in the 1980s after Three Mile Island, even though Japan modelled its regulation on U.S. precedents and even allowed utilities to use American disaster manuals in some cases.
Ultimately, when the wave was crashing in, everything came down to the ability of Tokyo Electric's front-line workers to carry out disaster plans under intense pressure.
But even in normal operations, the regulatory record shows Tokyo Electric had been cited for more dangerous operator errors over the past five years than any other utility. In a separate 2008 case, it admitted that a 17-year-old worker had been hired illegally as part of a safety inspection at Fukushima Daiichi.
"It's a bit strange for me that we have officials saying this was outside expectations," said Hideaki Shiroyama, a professor at the University of Tokyo who has studied nuclear safety policy. "Unexpected things can happen. That's the world we live in."
He added: "Both the regulators and TEPCO are trying to avoid responsibility."
Najmedin Meshkati, a professor of civil and environmental engineering at the University of Southern California, said the government's approach of relying heavily on Tokyo Electric to do the right thing largely on its own had clearly failed.
"The Japanese government is receiving some advice, but they are relying on the already badly stretched resources of TEPCO to handle this," said Meshkati, a researcher of the Chernobyl disaster who has been critical of the company's safety record before. "Time is not on our side."
The revelation that Tokyo Electric had put a number to the possibility of a tsunami beyond the designed strength of its Fukushima nuclear plant comes at a time when investor confidence in the utility is in fast retreat.
Shares in the world's largest private utility have lost almost three-fourth of their value -- $30 billion -- since the March 11 earthquake pushed the Fukushima Daiichi nuclear plant into crisis. Analysts see a chance the utility will be nationalized by the Japanese government in the face of mounting liability claims and growing public frustration.
AN 'EXTREMELY LOW' RISK
The tsunami research presented by a Tokyo Electric team led by Toshiaki Sakai came on the first day of a three-day conference in July 2007 organized by the International Conference on Nuclear Engineering.
It represented the product of several years of work at Japan's top utility, prompted by the 2004 earthquake off the coast of Sumatra that had shaken the industry's accepted wisdom. In that disaster, the tsunami that hit Indonesia and a dozen other countries around the Indian Ocean also flooded a nuclear power plant in southern India. That raised concerns in Tokyo about the risk to Japan's 55 nuclear plants, many exposed to the dangerous coast in order to have quick access to water for cooling.
Tokyo Electric's Fukushima Daiichi plant, some 240 km (150 miles) northeast of Tokyo, was a particular concern.
The 40-year-old nuclear complex was built near a quake zone in the Pacific that had produced earthquakes of magnitude 8 or higher four times in the past 400 years -- in 1896, 1793, 1677 and then in 1611, Tokyo Electric researchers had come to understand.
Based on that history, Sakai, a senior safety manager at Tokyo Electric, and his research team applied new science to a simple question: What was the chance that an earthquake-generated wave would hit Fukushima? More pressing, what were the odds that it would be larger than the roughly 6-metre (20 feet) wall of water the plant had been designed to handle?
The tsunami that crashed through the Fukushima plant on March 11 was 14 meters high.
Sakai's team determined the Fukushima plant was dead certain to be hit by a tsunami of one or two meters in a 50-year period. They put the risk of a wave of 6 metres or more at around 10 percent over the same time span.
In other words, Tokyo Electric scientists realised as early as 2007 that it was quite possible a giant wave would overwhelm the sea walls and other defenses at Fukushima by surpassing engineering assumptions behind the plant's design that date back to the 1960s.
Company Vice President Sakae Muto said the utility had built its Fukushima nuclear power plant "with a margin for error" based on its assessment of the largest waves to hit the site in the past.
That would have included the magnitude 9.5 Chile earthquake in 1960 that killed 140 in Japan and generated a wave estimated at near 6 meters, roughly in line with the plans for Fukushima Daiichi a decade later.
"It's been pointed out by some that there could be a bigger tsunami than we had planned for, but my understanding of the situation is that there was no consensus among the experts," Muto said in response to a question from Reuters.
Despite the projection by its own safety engineers that the older assumptions might be mistaken, Tokyo Electric was not breaking any Japanese nuclear safety regulation by its failure to use its new research to fortify Fukushima Daiichi, which was built on the rural Pacific coast to give it quick access to sea water and keep it away from population centres.
"There are no legal requirements to re-evaluate site related (safety) features periodically," the Japanese government said in a response to questions from the United Nations nuclear watchdog, the International Atomic Energy Agency, in 2008.
In fact, in safety guidelines issued over the past 20 years, Japanese nuclear safety regulators had all but written off the risk of a severe accident that would test the vaunted safety standards of one of their 55 nuclear reactors, a key pillar of the nation's energy and export policies.
That has left planning for a strategy to head off runaway meltdown in the worst case scenarios to Tokyo Electric in the belief that the utility was best placed to handle any such crisis, according to published regulations.
In December 2010, for example, Japan's Nuclear Safety Commission said the risk for a severe accident was "extremely low" at reactors like those in operation at Fukushima. The question of how to prepare for those scenarios would be left to utilities, the commission said.
A 1992 policy guideline by the NSC also concluded core damage at one of Japan's reactors severe enough to release radiation would be an event with a probability of once in 185 years. So with such a limited risk of happening, the best policy, the guidelines say, is to leave emergency response planning to Tokyo electric and other plant operators.
PREVENTION NOT CURE
Over the past 20 years, nuclear operators and regulators in Europe and the United States have taken a new approach to managing risk. Rather than simple defenses against failures, researchers have examined worst-case outcomes to test their assumptions, and then required plants to make changes.
They have looked especially at the chance that a single calamity could wipe out an operator's main defence and its backup, just as the earthquake and tsunami did when the double disaster took out the main power and backup electricity to Fukushima Daiichi.
Japanese nuclear safety regulators have been slow to embrace those changes.
Japan's Nuclear and Industrial Safety Agency (NISA), one of three government bodies with responsibility for safety policy and inspections, had published guidelines in 2005 and 2006 based on the advances in regulation elsewhere but did not insist on their application.
"Since, in Japanese safety regulation, the application of risk information is scarce in experience ? (the) guidelines are in trial use," the NISA said.
Japanese regulators and Tokyo Electric instead put more emphasis on regular maintenance and programs designed to catch flaws in the components of their ageing plants.
That was the thinking behind extending the life of the No. 1 reactor at Fukushima Daiichi, which had been scheduled to go out of commission in February after a 40-year run.
But shutting down the reactor would have made it much more difficult for Japan to reach its target of deriving half of its total generation of electricity from nuclear power by 2030 -- or almost double its share in 2007.
The Ministry of Economy, Trade and Industry (METI) figured it could reach the target by building at least 14 new nuclear plants, and running existing plants harder and longer. Fukushima's No. 1 reactor was given a 10-year extension after Tokyo Electric submitted a maintenance plan.
Safety regulators, who also belong to METI, did not require Tokyo Electric to rethink the fundamental safety assumptions behind the plant. The utility only had to insure the reactor's component parts were not being worn down dangerously, according to a 2009 presentation by the utility's senior maintenance engineer.
That kind of thinking -- looking at potential problems with components without seeing the risk to the overall plant -- was evident in the way that Japanese officials responded to trouble with backup generators at a nuclear reactor even before the tsunami.
On four occasions over the past four years, safety inspectors from Japan and the International Atomic Energy Agency (IAEA) were called in to review failures with backup diesel generators at nuclear plants.
In June 2007, an inspector was dispatched to Fukushima's No. 4 reactor, where the backup generator had caught fire after a circuit breaker was installed improperly, according to the inspector's report.
"There is no need of providing feedback to other plants for the reason that no similar event could occur," the June 2007 inspection concluded.
The installation had met its safety target. Nothing in that report or any other shows safety inspectors questioned the placement of the generators on low ground near the shore where they proved to be at highest risk for tsunami damage at Fukushima Daiichi.
"GET OUT, GET OUT"
Japanese nuclear regulators have handed primary responsibility for dealing with nuclear plant emergencies to the utilities themselves. But that hinges on their ability to carry them out in an actual crisis, and the record shows that working in a nuclear reactor has been a dangerous and stressful job in Japan even under routine conditions.
Inspectors with Japan's Nuclear Energy Safety Organisation have recorded 18 safety lapses at Tokyo Electric's 17 nuclear plants since 2005. Ten of them were attributed to mistakes by staff and repairmen.
They included failures to follow established maintenance procedures and failures to perform prescribed safety checks. Even so, Toyko Electric was left on its own to set standards for nuclear plant staff certification, a position some IAEA officials had questioned in 2008.
In March 2004, two workers in Tokyo Electric's Fukushima Daini plant passed out when the oxygen masks they were using - originally designed for use on an airplane - began leaking and allowed nitrogen to seep into their air supply.
The risks also appear to have made it hard to hire for key positions. In 2008, Toshiba admitted it had illegally used six employees under the age of 18 as part of a series of inspections of nuclear power plants at Tokyo Electric and Tohoku Electric. One of those minors, then aged 17, had participated in an inspection of the Fukushima Daiichi No. 5 reactor, Tokyo Electric said then.
The magnitude 9.0 quake struck on Friday afternoon of March 11 -- the most powerful in Japan's long history of them -- pushed workers at the Fukushima plant to the breaking point as injuries mounted and panic took hold.
Hiroyuki Nishi, a subcontractor who had been moving scaffolding inside Reactor No. 3 when the quake hit, described a scene of chaos as a massive hook came crashing down next to him. "People were shouting 'Get out, get out!'" Nishi said. "Everyone was screaming."
In the pandemonium, workers pleaded to be let out, knowing a tsunami was soon to come. But Tokyo Electric supervisors appealed for calm, saying each worker had to be tested first for radiation exposure. Eventually, the supervisors relented, threw open the doors to the plant and the contractors scrambled for high ground just ahead of the tsunami.
After the wave receded, two employee were missing, apparently washed away while working on unit No. 4. Two contractors were treated for leg fractures and two others were treated for slight injuries. A ninth worker was being treated for a stroke.
In the chaos of the early response, workers did not notice when the diesel pumps at No. 2 ran out of fuel, allowing water levels to fall and fuel to become exposed and overheat. When the Fukushima plant suffered its second hydrogen blast in three days the following Monday, Tokyo electric executives only notified the prime minister's office an hour later. Seven workers had been injured in the explosion along with four soldiers.
An enraged Prime Minister Naoto Kan pulled up to Tokyo Electric's headquarters the next morning before dawn. "What the hell is going on?" reporters outside the closed-door discussion reported hearing Kan demand angrily of senior executives.
Errors of judgement by workers in the hot zone and errors of calculation by plant managers hampered the emergency response a full week later as some 600 soldiers and workers struggled to contain the spread of radiation.
On Thursday, two workers at Fukushima were shuttled to the hospital to be treated for potential radiation burns after wading in water in the turbine building of reactor No. 3. The workers had ignored their radiation alarms thinking they were broken.
Then Tokyo electric officials pulled workers back from an effort to pump water out of the No. 2 reactor and reported that radiation readings were 10 million times normal. They later apologized, saying that reading was wrong. The actual reading was still 100,000 times normal, Tokyo Electric said.
The government's chief spokesman was withering in his assessment. "The radiation readings are an important part of a number of important steps we're taking to protect safety," Chief Cabinet Secretary Yukio Edano told reporters. "There is no excuse for getting them wrong."
VENTS AND GAUGES
Although U.S. nuclear plant operators were required to install "hardened" vent systems in the 1980s after the Three Mile Island incident, Japan's Nuclear Safety Commission rejected the need to require such systems in 1992, saying that should be left to the plant operators to decide.
A nuclear power plant's vent represents one of the last resorts for operators struggling to keep a reactor from pressure that could to blow the building that houses it apart and spread radiation, which is what happened at Chernobyl 25 years ago. A hardened vent in a U.S. plant is designed to behave like the barrel on a rifle, strong enough to withstand an explosive force from within.
The U.S. Nuclear Regulatory Commission concluded in the late 1980s that the General Electric designed Mark I reactors, like those used at Fukushima, required safety modifications.
The risks they flagged, and that Tokyo did not heed, would come back to haunt Japan in the Fukushima crisis.
First, U.S. researchers concluded that a loss of power at one of the nuclear plants would be one of the "dominant contributors" to the most severe accidents. Flooding of the reactor building would worsen the risks. The NRC also required U.S. plants to install "hard pipe" after concluding the sheet-metal ducts used in Japan could make things much worse.
"Venting via a sheet metal duct system could result in a reactor building hydrogen burn," researchers said in a report published in November 1988.
In the current crisis, the failure of the more vulnerable duct vents in Fukushima's No. 1 and No. 3 reactors may have contributed to the hydrogen explosions that blew the roof off the first and left the second a tangled hulk of steel beams in the first three days of the crisis.
The plant vents, which connect to the big smokestack-like towers, appear to have been damaged in the quake or the tsunami, one NISA official said.
Even without damage, opening the vulnerable vents in the presence of a build-up of hydrogen gas was a known danger. In the case of Fukushima, opening the vents to relieve pressure was like turning on an acetylene torch and then watching the flame "shoot back into the fuel tank," said one expert with knowledge of Fukushima who asked not to be identified because of his commercial ties in Japan.
Tokyo Electric began venting the No. 1 reactor on March 12 just after 10 a.m. An hour earlier the pressure in the reactor was twice its designed limit. Six hours later the reactor exploded.
The same pattern held with reactor No. 3. Venting to relieve a dangerous build-up of pressure in the reactor began on March 13. A day later, the outer building - a concrete and steel shell known as the "secondary containment" -- exploded.
Toshiaki Sakai, the Tokyo Electric researcher who worked on tsunami risk, also sat on a panel in 2008 that reviewed the damage to the Kashiwazaki-Kariwa nuclear plant. In that case, Tokyo Electric safely shut down the plant, which survived a quake 2.5 times stronger than it had been designed to handle.
Sakai and the other panellists agreed that despite the successful outcome the way the ground sank and broke underground pipes needed for firefighting equipment had to be considered "a failure to fulfil expected performance".
Japanese regulators also knew a major earthquake could damage exhaust ducts. A September 2007 review of damage at the same Tokyo Electric nuclear plant by NISA Deputy Director Akira Fukushima showed two spots where the exhaust ducts had broken.
No new standard was put in place requiring vents to be shored up against potential damage, records show.
Masashi Goto, a former nuclear engineer who has turned critical of the industry, said he believed Tokyo Electric and regulators wrongly focussed on the parts of the plant that performed well in the 2007 quake, rather than the weaknesses it exposed. "I think they drew the wrong lesson," Goto said.
The March 11 quake not only damaged the vents but also the gauges in the Fukushima Daiichi complex, which meant that Tokyo Electric was without much of the instrumentation it needed to assess the situation on the ground during the crisis.
"The data we're getting is very sketchy and makes it impossible for us to do the analysis," said David Lochbaum, a nuclear expert and analyst with the Union of Concerned Scientists. "It's hard to connect the dots when there are so few dots."
In fact, Japan's NSC had concluded in 1992 that it was important for nuclear plant operators to have access to key gauges and instruments even in the kind of crisis that had not happened then. But it left plans on how to implement that policy entirely to the plant operators.
In the Fukushima accident, most meters and gauges were taken out by the loss of power in the early days of the crisis.
That left a pair of workers in a white Prius to race into the plant to get radiation readings with a handheld device in the early days of the crisis, according to Tokyo Electric.
They could have used robots to go in.
Immediately after the tsunami, a French firm with nuclear expertise shipped robots for use in Fukushima, a European nuclear expert said. The robots are built to withstand high radiation.
But Japan, arguably the country with the most advanced robotics industry, stopped them from arriving in Fukishima, saying such help could only come through government channels, said the expert who asked not to be identified so as not to appear critical of Japan in a moment of crisis.
(Scott DiSavino was reporting from New York; Additional reporting by Kentaro Sugiayama in Tokyo, Bernie Woodall in Detroit, Eileen O'Grady in New York, Roberta Rampton in Washington; Editing by Bill Tarrant)
© Thomson Reuters 2011
http://uk.reuters.com/article/2011/03/30/uk-japa-nuclear-risks-idUKTRE72S5PW20110330 [no comments yet] [as a pdf with various images/infographics http://graphics.thomsonreuters.com/AS/pdf/tepcomarch29dk.pdf ]
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Records Show 56 Safety Violations at U.S. Nuclear Power Plants in Past 4 Years
Mishandled Radioactive Material and Failing Backup Generators Among the Violations
By PIERRE THOMAS, JACK CLOHERTY AND ANDREW DUBBINS
March 29, 2011
Among the litany of violations at U.S. nuclear power plants are missing or mishandled nuclear material, inadequate emergency plans, faulty backup power generators [ http://abcnews.go.com/US/wireStory?id=13244299 (fifth item four back at http://investorshub.advfn.com/boards/read_msg.aspx?message_id=61457583 )], corroded cooling pipes and even marijuana use inside a nuclear plant, according to an ABC News review of four years of Nuclear Regulatory Commission safety records.
And perhaps most troubling of all [ http://abcnews.go.com/Technology/wireStory?id=13213010 ], critics say, the commission has failed to correct the violations in a timely fashion.
"The Nuclear Regulatory Commission has very good safety regulations but they have very bad enforcement of those regulations," said David Lochbaum, a nuclear scientist with the nonprofit Union of Concerned Scientists.
There are 104 U.S. nuclear power plants.
Lochbaum and the Union of Concerned Scientists found 14 "near misses" at nuclear plants in 2010. And there were 56 serious violations at nuclear power plants [ http://abcnews.go.com/GMA/video/us-fault-lines-nuke-plants-spotlight-13165063 ] from 2007 to 2011, according the ABC News review of NRC records.
At the Dresden Nuclear Power Plant in Illinois, for instance, which is located within 50 miles of the 7 million people who live in and around Chicago, nuclear material went missing in 2007. The Nuclear Regulatory Commission fined the operator -- Exelon Corp. -- after discovering the facility had failed to "keep complete records showing the inventory [and] disposal of all special nuclear material in its possession."
As a result, two fuel pellets and equipment with nuclear material could not be accounted for.
Exelon did not contest the violation and paid the fine, a company spokesman said. "We took the learnings from that violation with respect to ways we can improve our spent-fuel practices," Marshall Murphy said.
Two years later, federal regulators cited Dresden for allowing unlicensed operators to work with radioactive control rods. The workers allowed three control rods to be moved out of the core. When alarms went off, workers initially ignored them.
Murphy said the company concurred with the NRC's determination. " We have also taken a number of steps to ensure a similar event would not occur at any of our sites and shared the lessons from that with the industry," he said.
"In both violations, neither employees or the public were ever jeopardized, but we take them seriously, we always look to learn from them, and we do that going forward.
Still, Lochbaum of the Union of Concerned Scientists said, "This event is disturbing. In August 1997, the NRC issued information … about a reactivity mismanagement problem at Exelon's Zion nuclear plant," which was retired the following year.
"It was an epoch event in the industry in that other plants owners noted it and took steps to address [the issue]. Yet, a decade later, Exelon's Dresden plant experiences an eerily similar repetition of the control-room operator problems."
The lost material was almost certainly shipped to a licensed, low-level waste disposal site, Lochbaum said.
At the Indian Point nuclear plant just outside New York City, the NRC found that an earthquake safety device has been leaking for 18 years.
In the event of an earthquake, Lochbaum said, the faulty safety device would not help prevent water from leaking out of the reactor. A lack of water to cool the fuel rods has been the most critical problem at the Fukushima plant in Japan after the recent earthquake and tsunami.
"The NRC has known it's been leaking since 1993," Lochbaum said, "but they've done nothing to fix it."
While declining to address specific violations, Roger Hanna, a spokesman for the NRC, said "we do require plant to comply, and we do follow up for corrections" when violations are discovered.
But NRC records examined by ABC News show that such incidents are not uncommon: In June 2009, at the Southern Nuclear Operating Co. Inc. in Birmingham, Ala., the emergency diesel generator -- which would be used in the event of a disaster -- was deemed inoperable, after years of neglect.
"Cracks in the glands of the emergency diesel generator couplings had been observed since 1988, but the licensee did not recognize the cracking was an indication of coupling deterioration," according to the NRC report. On April 19, 2010, the NRC cited the Tennessee Valley Authority Browns Ferry nuclear plant near Decatur for failing to provide "fire protection features capable of limiting fire damage."
The NRC fire protection regulations in effect today were developed as a direct result of the Browns Ferry fire on March 22, 1975.
In June 2010, Duke Energy, operators of the William McGuire nuclear plant in Mecklenburg County, N.C., was cited by the NRC after a contract employee was caught using marijuana inside the protected area.
NRC safety records show that inadequate emergency planning was a recurring problem in the industry from 2007 to 2011. Violations included unapproved emergency plans and plan changes, inadequate fire planning and precautions, falsified "fire watch" certification sheets," inadequate flooding precautions, an insufficient tone alert radio system to notify the populace in a potential emergency and faulty assessment of containment barrier thresholds.
Corroded water pipes and cooling problems were also recurring issues.
Copyright © 2011 ABC News Internet Ventures
http://abcnews.go.com/Politics/us-nuclear-power-plants-safe/story?id=13246490 [with comments]
Greensburg, KS - 5/4/07
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upon the Right of Election, 1790
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