Wednesday, March 21, 2012


NUCLEAR CRISIS: HOW IT HAPPENED / Kan's visit 'wasted time'
Nearly three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending any time soon.
This is the first installment in a series that looks into what has given rise to the unprecedented crisis, dealing a fatal blow to the myth of safety at nuclear power plants in this country.
Shortly after 1 a.m. on March 12--about 10 hours after the massive earthquake and tsunami struck--Prime Minister Naoto Kan was becoming increasingly exasperated.
Kan, 64, told his aides at the Prime Minister's Office that he wanted to go and visit the Fukushima No. 1 nuclear power plant to grasp the situation in person. But Chief Cabinet Secretary Yukio Edano, 47, tried to dissuade him from doing so, saying, "If you leave the Prime Minister's Office at this moment, you'll come under fierce criticism."
Kan shouted in anger. "You idiot! Which is more important, ending this situation or thinking about the risk of drawing fire?"
Pressure in the No. 1 reactor's containment vessel shot up to a level nearly double its designed strength. Given the situation, plant operator Tokyo Electric Power Co. came to the conclusion that venting radioactive steam from the reactor was needed to prevent an explosion. Such a measure had never before been taken in this country.
TEPCO workers called a situation that required venting the worst-case scenario. And the company was hit by more unexpected trouble--loss of all power. That hampered preparations for the venting.
At 6:14 a.m. Kan headed for the plant in a Self-Defense Forces helicopter and arrived there at 7:11 a.m.
"Has the venting been done yet?" he shouted in a meeting room in a strongly earthquake-resistant building used as a base for the restoration work.
At that moment, more than five hours had passed since the government had told TEPCO to vent steam from the reactor.
Kan regained his composure as Masao Yoshida, 56, head of the plant, told him, "We'll form a suicide squad to do it."
As soon as Kan left the crippled power plant after 8 a.m., Yoshida immediately instructed his men to carry out the venting. It was as if he had been waiting until the prime minister's departure to do so.
Work to prepare for the venting at the No. 1 reactor started at 9:15 a.m.
Workers headed for the reactor building, carrying nitrogen cylinders and batteries over their shoulders. They called the mission their "last service."
In a severe working environment where they were exposed at one point to more than 106 millisieverts of radiation, a level that exceeded the limit permitted for workers at nuclear power plants, three teams of two people took turns venting steam from the reactor. At about 2 p.m., the venting was deemed a success.
However about 1-1/2 hours later, there was a hydrogen explosion at the reactor.
TEPCO has cited slowness in the evacuation of residents in neighboring areas as a reason for its delay in carrying out the venting. But the government-ordered evacuation of people living within three kilometers of the plant was completed by 12:30 a.m. on March 12.
It remains unknown why Yoshida waited for hours to order workers to conduct the venting.
A photograph provided by TEPCO showed that updates of the situation on the site were given on a whiteboard in the No. 1 reactor's central control room. But from 6:29 a.m., shortly after Kan departed the Prime Minister's Office, to 9:04 a.m., an hour after he left the plant, there was nothing written on the board. Speculation has arisen that work to fight the crisis was stalled during the missing 2-1/2 hours.
"The director had to accompany the prime minister. I'm not sure if the hydrogen explosion could have been prevented, but I'm sure [Kan's visit] wasted our time," a senior TEPCO official said.
Meanwhile, Kan has apparently viewed TEPCO's handling of the crisis as problematic, saying they failed to respond promptly to the government's instruction to carry out the venting.
(Jun. 9, 2011)

NUCLEAR CRISIS: HOW IT HAPPENED / Hydrogen blasts at plant surprised experts
Nearly three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending any time soon.
This is the second installment in a series that looks into what has given rise to the unprecedented crisis, dealing a fatal blow to the myth of safety at nuclear power plants in this country.
"An explosion was heard at the Fukushima No. 1 nuclear power plant."
At 3:36 p.m. March 12, this information was conveyed from the Fukushima prefectural police via the National Police Agency to the government's crisis management center, located in the basement of the Prime Minister's Office.
But officials of the Nuclear and Industrial Safety Agency and Tokyo Electric Power Co. who were at the Prime Minister's Office at the time refused to accept the information, some of them repeatedly saying, "That's not possible."
It was not until five hours later that the government acknowledged that a hydrogen explosion had occurred at reactor No. 1. Such an explosion had not been factored into their scenarios, and it took some time for officials to analyze the situation.
At 8:40 p.m., Chief Cabinet Secretary Yukio Edano held a press conference. "The explosion destroyed the reactor building, but the containment vessel [housing the reactor] has not been damaged," he said, stressing that the reactor was safe.
Meanwhile, TEPCO, the plant operator, had only made an announcement that it was analyzing the incident.
"No expert had predicted that a hydrogen explosion would occur at the reactor building," said Goshi Hosono, special adviser to Prime Minister Naoto Kan.
Haruki Madarame, chairman of the Nuclear Safety Commission, had said, "The containment vessel has been refilled with nitrogen, so a hydrogen explosion won't happen." Kan accepted the explanation.
Nuclear experts, including Madarame, overlooked the risk of a hydrogen explosion because they were shackled with what was considered common sense among many nuclear experts. Instead it turned out to be more like excessive self-confidence.
The 2002 report, compiled by TEPCO and five other power companies, on response measures to be taken in the event of core meltdowns and other severe nuclear accidents, stated, "There is no need to take a hydrogen explosion into consideration." This belief came from the common knowledge that such an explosion would not occur if the containment vessel was filled with nitrogen, which would keep the concentration level of hydrogen low.
The government's safety screening was based on similar beliefs.
Tomoho Yamada, director of the NISA's Nuclear Power Licensing Division, said, "[The reactor] was designed to keep hydrogen from leaking out of the containment vessel into the reactor building."
"In the safety screening, we assumed that a hydrogen explosion would not occur in the reactor building," Yamada added, admitting that due to this assumption, measures to prevent a hydrogen explosion in the reactor building were not included in the list of safety measure evaluations.
But according to an analysis by TEPCO, after all of the nuclear fuel at the No. 1 reactor melted 16 hours after the massive earthquake and tsunami on March 11, the pressure and the containment vessels became damaged.    
Hydrogen, which was generated from the reaction between the zirconium cladding of the fuel rods and oxygen, leaked out and began accumulating in the reactor building.
A former TEPCO executive said: "I'd never have thought such a large amount of hydrogen would be generated after the nuclear fuel was exposed. We must accept that we were overly confident."
TEPCO attempted to ventilate other reactor buildings at the power plant, but workers struggled with high radiation levels, and failed to prevent a hydrogen explosion at the No. 3 reactor on March 14.
The hydrogen explosion at the No. 1 reactor was indeed a critical point leading to delays in responses to the nuclear accident.
When nuclear reactors are in operation, hydrogen tends to be generated by the radiolytic decomposition of water and other chemical reactions. But hydrogen generation was not the cause of most past explosions at nuclear plants, so close attention was not initially paid to the phenomenon during the Fukushima crisis.
In the 1979 accident in which a cooling malfunction crippled the Three Mile Island nuclear power station in the United States, a hydrogen explosion took place inside a containment vessel about 10 hours after the malfunction began. But the reactor building and containment vessel stood intact despite the blast. Several hours later, the cooling system was restored.
But it took four days until the threat of immediate catastrophe was declared to be over after hydrogen was eliminated.
An explosion that occurred at Chubu Electric Power Co.'s Hamaoka nuclear power plant in Shizuoka Prefecture in November 2001 was due to hydrogen combustion inside a pipe used for the emergency cooling of a reactor core.
Reactor design a factor
The Fukushima No. 1 plant suffered a series of explosions because the design of its reactors made it prone to hydrogen blasts, but this risk was overlooked, according to some experts.
At the plant, the Nos. 1-5 reactors are the Mark-1 model developed by General Electric Co. of the United States in the 1960s. The Mark-1 is one of the oldest light-water reactor models. Construction of Fukushima's No. 1 reactor dates back to 44 years ago.
"[The Mark-1] containment vessels are relatively small and pressure fluctuates greatly, so its operation is difficult," said a former senior TEPCO official who worked at the Fukushima plant. "As hydrogen accumulates easily, I felt a potential risk."
In the United States, among 104 reactors in use at 65 nuclear power plants, the Mark-1 model accounts for 23 reactors at 16 plants, a major subject of criticism among antinuclear activists.
In the 1970s, U.S. nuclear regulators considered a ban on the use of the Mark-1 model out of concern that its containment vessels could be vulnerable to serious accidents. But as the model was already being widely used, authorities stopped short of forbidding its use.
However after the 1970s, experts pointed to the need for measures to prevent rapid hydrogen buildup. As a result, plant operators have since taken steps such as installing equipment that regenerates water from hydrogen in turbine buildings and injects nitrogen into containment vessels.
Such measures have also been taken at the Fukushima plant.
But in the 1980s, a senior official of the U.S. Nuclear Regulatory Commission named Harold Denton pressed the argument that Mark-1 reactors had a 90 percent probability of suffering an explosion if fuel rods overheated and melted in an accident.
In the late 1980s, GE attempted to help the model survive such criticism by equipping it with improved devices such as a venting system to reduce pressure in the containment vessel.
NRC Chairman Gregory Jaczko has said all existing reactors in the United States, including Mark-1 reactors, are operating safely.
But regarding the Mark-1 model and its 40-year history, a senior official of a nuclear reactor manufacturer said, "The biggest problem is we lacked knowledge of the workings of devices that were vulnerable to a loss of power."
Even the device to regenerate water from hydrogen cannot work if power is lost.
"Unexpectedly, nuclear engineers aren't so familiar with electric systems," a TEPCO official said.
TEPCO uses Mark-2 reactors at its Fukushima No. 2 nuclear power plant. Immediately after the March 11 disaster, the cooling system temporarily halted at the plant's three reactors, but a hydrogen blast did not occur there.
In Japan, the Mark-1 model also has been used at the Nos. 1 and 2 reactors at the Hamaoka plant. Nuclear plants in Onagawacho, Miyagi Prefecture; Matsue, Shimane Prefecture; and Tsuruga, Fukui Prefecture, each have one Mark-1 reactor.
In a report prepared for the International Atomic Energy Agency, the government has included the installation of equipment to eliminate hydrogen from reactor buildings as a measure to prevent hydrogen explosions.

 Government radiation data disclosure--too little, too late
Three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending any time soon.
This is the third installment in a series that looks into what has given rise to the unprecedented crisis, dealing a fatal blow to myth of safety at nuclear power plants in this country.
On June 3, the Nuclear and Industrial Safety Agency released a shocking, but very belated, report about what happened around the Fukushima No. 1 nuclear plant immediately after the March 11 earthquake and tsunami.
At 8:39 a.m. on March 12, about 18 hours after the earthquake, radioactive tellurium-132 was detected in Namiemachi, Fukushima Prefecture, six kilometers from Tokyo Electric Power Co.'s damaged plant, according to the report from the agency.
The detection of Te-132 meant the temperature of nuclear fuel at the plant had shot up to more than 1,000 C. It also meant nuclear fuel pellets in the reactor cores had been damaged and nuclear material had leaked into the environment.
Seven hours later, a massive hydrogen explosion rocked the plant's No. 1 reactor.
Attempting to explain the delay in making the information public, agency spokesman Hidehiko Nishiyama said later, "We never meant to conceal the information, but it never occurred to us to make it public."
SPEEDI data unused
Throughout the ups and downs of the nuclear crisis, the government's transparency record has been consistently atrocious.
At 5:44 a.m. on March 12, the government expanded the evacuation area around the plant to 10 kilometers from three kilometers. Namiemachi authorities moved residents by bus to the Tsushima district in the western part of the town.
Meanwhile, the System for Prediction of Environmental Emergency Dose Information (SPEEDI) had been pumping out estimates of radiation doses once every hour since 4 p.m. on March 11.
SPEEDI--a system used to make forecasts of radiation diffusion patterns--had been showing that the Tsushima district was being hit with high radiation doses. This crucial information, however, was not passed on to town authorities.
Mayor Tamotsu Baba said later, "We weren't told anything important."
According to the government's basic nuclear disaster plan, SPEEDI should be used to help make evacuation recommendations. The system cost more than 11 billion yen in taxpayer money to install. When Prime Minister Naoto Kan directed a disaster response drill at Chubu Electric Power Co.'s Hamaoka nuclear power plant in Shizuoka Prefecture last year, SPEEDI simulations were used to set evacuation areas.
However, the March 11 calamity severed power at the Fukushima plant, meaning SPEEDI data could not be transmitted. The government said it did not make forecasts from the system public because "accurate predictions could not be made."
Despite the information blackout on radiation levels, SPEEDI continued to churn out useful data about radiation emissions immediately after the earthquake and tsunami by inputting provisional readings.
The system's estimates on radiation pollution for the afternoon of March 12 show high contamination in areas eerily similar to those the government eventually designated as "planned evacuation areas" in April.
"Although the system was supposed to be used to deal with a crisis, we weren't fully prepared to actually use it." said one senior education ministry official. "There were no ideas or discussions about if the [SPEEDI] data should be made public," he said, essentially admitting the ministry wasted the system.
On May 2, Goshi Hosono, special adviser to the prime minister on the Fukushima crisis, made public about 5,000 SPEEDI radiation-prediction images. Explaining why the disclosure had been so late, Hosono said the government had been "afraid of triggering a panic."
Commenting on the matter, Hirotada Hirose, professor emeritus of Tokyo Women's Christian University and specialist in risk psychology, said, "In a fast-changing crisis situation, delays in releasing information to try to ensure accuracy often aggravates people's suspicions and unease."
"Even if information is only about possible developments, data obtained through scientific methods should be disclosed," he said. "In the initial phase of the Fukushima crisis, scientifically valid forecasts should have been made public, with the understanding that the information would be modified immediately if the situation changed."
Numbers, but no analysis
In addition to the problems with transparency, the Fukushima nuclear crisis has also highlighted issues with the arrangements the government has made for measuring radiation from the nuclear power plant and how the data are evaluated.
The government's basic disaster response plan assumes the task of measuring radiation levels around a nuclear plant in the event of an accident would be done by the prefectural government involved. The education ministry's role is only "supplementary" to the duties of the prefectural government.
In this crisis, however, the Fukushima prefectural government was unable to handle the task of making radiation measurements on its own.
Therefore, on March 16, Chief Cabinet Secretary Yukio Edano instructed the education ministry to cooperate with the prefectural government in analyzing and announcing radiation dosage data.
The ministry then brought observation vehicles and robots to construct 13 observation networks in April to measure air, sea and soil radiation levels. Findings were subsequently posted on the ministry's Web site.
Since the networks were only makeshift and there was no way to digitally transmit the data to the ministry, trips to the observation stations were a cumbersome necessity. The readings were sometimes even called in over public pay phones. The result was chaos--wrong data were sometimes made public, while information that had been gathered and reported sometimes was not released.
Looking back at the situation, senior vice minister of the education ministry Ryuzo Sasaki said, "Both personnel and equipment were sorely lacking, as there was no proper plan in place for the central government to take the initiative in addressing the situation."
Data, no matter how much effort was expended to collect it, does not serve people's needs unless it is combined with expert evaluation and analysis. Organs in charge of making evaluations, however, failed to do their jobs.
On March 16, Yasutaka Moriguchi, deputy minister of the education ministry, announced that radiation doses of 330 microsieverts had been measured about 20 kilometers from the crippled nuclear plant. When asked about possible health hazards, Moriguchi only said, "Our duty is confined to providing the public with data."

'No comment'
The observation point Moriguchi was reporting on was in an area where residents had not been evacuated but were currently being told to stay indoors.
The data alone would likely have fanned anxiety among residents near the nuclear facility, but Moriguchi, when pressed over why he was only reporting the data, told the press conference, "We have been instructed by the chief cabinet secretary not to make any comments on the data."
Around that time, Chief Cabinet Secretary Edano had issued an order that evaluations of radiation data could only be done by the Nuclear Safety Commission.
Chief of the commission Haruki Madarame, however, was tied up advising Kan and other government leaders. For a full week after Edano's order, no evaluation of the radiation data was announced by the commission, the nation's expert body on the matter.
Instead, Edano repeated in press conference after press conference that radiation levels would not cause any "immediate" health damage.
On March 23, Madarame finally held his first press conference. In it, he apologized. "We are very sorry, but we cannot make any [radiation evaluations] because we are very understaffed."

Government, TEPCO brushed off warnings from all sides
The Yomiuri Shimbun
Three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending anytime soon.
This is the fourth installment in a series that examines what caused the unprecedented crisis, which has dealt a fatal blow to the myth of the safety of nuclear power plants in this country.
"The lands of Mutsunokuni were severely jolted. The sea covered dozens, hundreds of blocks of land. About 1,000 people drowned."
This is a description of the massive Jogan Earthquake and tsunami that hit the Tohoku region about 1,150 years ago. It is contained in "Nihon Sandai Jitsuroku" (The official history of three reigns of Japan), which was compiled during the early Heian Period (794-1192).
Mutsunokuni is the name of the region that covered most of the present-day prefectures in the Tohoku region.
It is now clear the government and Tokyo Electric Power Co. did not learn from history.
Since 1990, Tohoku Electric Power Co., Tohoku University and the National Institute of Advanced Industrial Science and Technology have researched the traces left by the Jogan Earthquake. Their studies have shown that the ancient tsunami was on the same scale as that caused by the March 11 earthquake.
According to a report submitted by the national institute to the government in the spring of last year, the Jogan Earthquake occurred off Miyagi and Fukushima prefectures and is estimated to have had a magnitude of about 8.3 or 8.4.
The Jogan Earthquake tsunami penetrated more than four kilometers inland in the Sendai plain in Miyagi Prefecture, and about 1.5 kilometers inland in an area where Minami-Soma, Fukushima Prefecture, is currently located, the report said.
According to a recent study conducted by Tohoku University, two tsunami equivalent to the size of the Jogan Earthquake tsunami have hit the Sendai plain in the past 3,000 years.
Before March 11, scholars had repeatedly warned at academic conferences and other occasions that a massive tsunami could hit the Tohoku region in the future.
However, the government's Central Disaster Management Council and TEPCO never factored such studies into their estimates of the damage that earthquakes and tsunami could cause to nuclear power plants.
TEPCO said there was not much evidence of the damage caused by the Jogan Earthquake. It was more appropriate, the utility said, to reference the Shioyazaki-oki Earthquake--a magnitude-7.9 temblor that hit Fukushima Prefecture in 1938 and caused much smaller tsunami than the March 11 earthquake--when estimating the damage earthquakes and tsunami could cause at the Fukushima No. 1 power plant.
Robert Geller, a professor at the University of Tokyo and an expert in seismology, said that if TEPCO and the government had referred to the study of the National Institute of Advanced Industrial Science and Technology, they might have increased the size of tsunami they thought the Fukushima plant might encounter. The government and TEPCO should have taken the risk of tsunami more seriously, he added.
"This crisis at the power plant is not a natural disaster. It is a man-made disaster," Geller said.
According to Geller, four earthquakes measuring magnitude-9 or stronger occurred in the 60 years to 2009.
"In 2004, there was the Indian Ocean earthquake. [The government and TEPCO] should have been aware that similar earthquakes could occur anywhere," Geller said.
The government plays an enormous role in the safety of nuclear power plants, checking reports submitted by power companies regarding the quake-resistance measures implemented at each of their nuclear plants.
However, it takes time for the government to factor new studies into its evaluation of the reports. In addition, both the government and power companies have focused more on measures against earthquakes than tsunami.
According to sources, people who tried to raise the alarm about the risks of tsunami were in the minority at TEPCO. Many thought it was enough to arm against earthquakes equivalent to the size of the Shioyazaki-oki Earthquake, they said.
A former TEPCO executive once said: "Tsunami are a threat to ria coasts, such as the Sanriku coast. However, they're not a threat to straight coasts, such as the one where the Fukushima No. 1 power plant is located."
There are other examples of risks regarding earthquakes and tsunami being ignored.
In its annual reports, which have been made public since 2008, the Japan Nuclear Energy Safety Organization (JNES) has predicted possible damage tsunami could cause to Mark-1 nuclear reactors that are about the same size as the Nos. 2 and 3 reactors at the Fukushima plant.
One report said if a breakwater that extended up to 13 meters above sea level was hit by a 15-meter-high tsunami, all power sources would be knocked out--including outside electricity and emergency power generators. In such a situation, the report said, cooling functions would be lost and the reactor's core would be 100 percent damaged--a meltdown, in other words.
The breakwater at the Fukushima No. 1 plant was about 5.5 meters high, less than half the assumed height in the JNES report.
TEPCO assumed the tsunami hitting the plant would be 5.4 meters to 5.7 meters high. But the wave that struck on March 11 was 14 meters to 15 meters high.
Another report by the organization released last year predicted that if all power sources were lost due to an earthquake, fuel rods will begin melting after only 100 minutes. This report said a reactor's containment vessel would be damaged after about seven hours and a large amount of radioactive material would be released into the air.
According to an analysis by the government's Nuclear and Industrial Safety Agency, damage to the core of the Fukushima plant's No. 1 reactor started about two hours after the tsunami and its pressure vessel was damaged in about four hours--very close to what JNES had predicted.
Both entities are under the Economy, Trade and Industry Ministry and are in charge of safety regulations at the nation's nuclear power plants. Findings by JNES are often reflected in safety measures adopted by plant operators. But one TEPCO official said, "We prioritized preparing for high-probability incidents, so we couldn't respond to everything."
Wataru Sugiyama, a lecturer on nuclear power safety at Kinki University's Atomic Energy Research Institute, said, "From a cost-performance perspective, it's difficult to prepare for low-probability disasters and prevent all accidents.
"But by thinking about things after an accident, it's possible to prevent worse situations," he said.
His words were proved true by Japan Atomic Power Co.'s Tokai No. 2 nuclear plant in Tokaimura, Ibaraki Prefecture, which was also hit by the disaster but managed to avoid a serious accident.
After the Kashiwazaki-Kariwa nuclear plant was hit by the Niigata Prefecture Chuetsu Offshore Earthquake in July 2007, Japan Atomic Power decided to build anti-tsunami walls at the Tokai No. 2 plant. The walls were built to withstand a tsunami 5.7-meters high, up from about four meters.
Construction had not been completed by the time the March 11 tsunami struck, but a finished section on the south side of the Tokai plant protected a seawater-intake pump needed to cool an emergency diesel power generator, which prevented a complete loss of power at the plant.
Economic factors are not the only reason why power utilities were reluctant to take action on safety measures. The firms also wanted to avoid losing the trust of local residents.
Many cases of cover-ups or altered data have been unveiled since 2002, including some at the Fukushima No. 1 plant. TEPCO believed that launching repairs to solve these problems would make their explanations about the safety of nuclear power to local residents ring false.
Another issue was that the voices of workers at the plant did not reach the higher-ups.
"Workers at the plant thought from before the quake that there was a risk all power could be lost if a tsunami flooded the emergency power generators," according to one TEPCO employee who has worked as an operator at the Fukushima No. 1 plant.
But a former TEPCO executive who is now an adviser to the firm said, "If there was a risk of losing all power, why didn't workers present their views at board meetings? It's really too bad."
When asked why the government failed to act on tsunami warnings, industry minister Banri Kaieda said his ministry had blindly believed Japan's nuclear plants "were the safest in the world."

NUCLEAR CRISIS: HOW IT HAPPENED / Safety vows forgotten, 'safety myth' created
Three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending anytime soon.
This is the fifth installment in a series that examines what caused the unprecedented crisis, which has dealt a fatal blow to the myth of the safety of nuclear power plants in this country.
A former employee of Tokyo Electric Power Co. still remembers the enthusiasm of the early days of atomic energy when he was sent across the Pacific Ocean to be trained to operate a nuclear power plant.
The 76-year-old former employee was involved in operating the Fukushima No. 1 nuclear power plant from when its No. 1 reactor went on-line in 1971 until he became a top executive at the plant in the 1990s.
In spring of 1969, TEPCO sent 16 workers in their 30s and 40s to the Dresden nuclear power plant southwest of Chicago, Ill. They underwent intensive training by General Electric Co. engineers, including on a nuclear plant simulator. "We really felt it was our mission to bring back nuclear power know-how and help it take root in Japan," he recalled.
After returning home, they translated GE's operation manuals and other resources into Japanese, eventually filling about 10 telephone book-sized volumes.
Whenever he entered the central control room for the No. 1 reactor, he said he made a vow to operate it safely. "We always felt a sense of urgency that any mistake could lead to an accident," he said.
He said TEPCO also stressed safety. The utility was proactive about adopting operators' suggestions for improvements, such as by installing a different type of emergency light in better locations. Improving safety was always top priority, according to the former employee.
While learning from their experiences, domestic engineers aggressively adopted technology from overseas. Over time, Japan's nuclear industry changed from student to teacher.
From 1992 to 2001 the Japanese government accepted about 1,000 trainees from nations of the former Soviet Union and eastern Europe. The program was designed to spread a culture of safety at nuclear power plants around the world.
"We believed Japan's nuclear plants were top class. But there was probably a bit of overconfidence there," said a former top TEPCO official, 68, who was in charge of developing new plants.
According to government opinion polls from the 1980s and '90s, however, more than half of respondents continued to express "worry over nuclear plants," likely reinforced by the Chernobyl accident in 1986 and the criticality accident at JCO Co.'s facility in Tokaimura, Ibaraki Prefecture, in 1999.
Shunichi Tanaka, former acting chairman of the Atomic Energy Commission, said people in the nuclear industry were always on guard.
"If we even mentioned there was a slight possibility that nuclear plants were dangerous, antinuclear advocates pushed for shutting every plant down," he said. "So, we just kept on declaring the plants were safe."
This combination of overconfidence and trapping themselves with their own words gradually built up the "safety myth" of nuclear power plants.
"You can take all kinds of possible situations into consideration, but something 'beyond imagination' is bound to take place, like the March 11 tsunami," said the former plant operator. "The possibility of a worst-case scenario should have been assumed, and there should have been a reliable system in place with proper training to keep damage to a minimum."
The United States, which has provided Japan with nuclear technology and currency has 104 reactors, began a secret program called "B5b" in the wake of the Sept. 11, 2001, terrorist attacks to prepare for a possible loss of power to reactors.
The program was designed to prevent serious radiation leakage even if an aircraft crashed into a nuclear plant, and also to ensure plants could withstand natural disasters like floods or tornados.
A senior official of the U.S. Nuclear Regulatory Commission, which was in charge of planning the program, said confidently there was "no possibility" that any U.S. nuclear facility could lose all its cooling functions, as occurred at the Fukushima plant.
The San Onofre nuclear power plant on the Pacific Coast in California houses its four backup generators in a reinforced concrete building, separate from the power plant and designed to withstand being hit by a tsunami.
Sin of complacency
Japan, in fact, had ample opportunity to bolster disaster-prevention measures at domestic nuclear facilities.  The first opportunity came after the 1979 accident at the Three Mile Island nuclear facility in Pennsylvania, in which the world witnessed the first core meltdown of a nuclear reactor. But it was not until 13 years later that Japan's Nuclear Safety Commission revised its position that no serious accident could take place as long as its safety guidelines were followed.
Based on lessons learned from the Three Mile Island accident, in which mechanical troubles were compounded by operation errors by workers, the NSC asked electric utilities to come up with countermeasures for a "severe accident" beyond the specifications their reactors were designed to withstand.
In written instructions issued in May 1992, the NSC said the new guidelines for severe accidents would surely reduce the risk of such accidents from an already low level.
In 1994, TEPCO adopted a new policy to enhance safety at its nuclear plants. It decided to increase the number of emergency power sources by installing additional backup diesel generators and other means.  At the Fukushima No. 1 facility, the utility equipped the Nos. 2, 4 and 6 reactors with air-cooled backup generators from 1997 to 1999, in addition to 10 water-cooled generators already at the six-reactor complex.
The March 11 earthquake and tsunami, however, painfully exposed the insufficiency of these measures, which were meant to ensure emergency power would not be lost.
In the calamity, only one of the air-cooled generators for the No. 6 reactor, which sat 13 meters above sea level, was still operable after the tsunami. The generator barely got the Nos. 5 and 6 reactors into a state of stable cooling.
The other air-cooled generators at the Nos. 2 and 4 reactors--even though they were 10 meters above sea level--were rendered useless when the tsunami submerged their switchboards. All 10 of the plant's water-cooled emergency generators were also inundated.
"We took it for granted that the quake-resistant design of our Fukushima and other nuclear plants was fail-safe," one former TEPCO executive said. "But I now doubt how serious we were about preparing for a severe disaster."
"If only we'd put the backup generators on even higher ground away from the reactors, the Nos. 1 to 4 reactors might not have been damaged," he said.
Guidelines sat unchanged
The "safety myth" of the nation's nuclear plants lay behind this failure to fully implement preparations for severe accidents.   Safety inspection guidelines the NSC revised in 1990 said, "We do not need to take into account the danger of a long-term power severance, as we could anticipate recovery of power transmission lines and emergency generators in a short period of time."  The first sentence of a TEPCO report from March 1994 on action to be taken in the event of a serious accident said, "Our country's nuclear power plants have attained a high degree of safety from a global point of view."
The report emphasized, "It is inconceivable that a severe accident could actually occur." The report seemed to imply that efforts to prevent an "inconceivable" accident would be a waste of time and energy.   "The NSC's guidelines for coping with a severe accident were left unchanged since they were set in 1992, and no additional steps were taken," said a preliminary government report on the Fukushima crisis submitted June 7 to the International Atomic Energy Agency.

NUCLEAR CRISIS: HOW IT HAPPENED / 'Nuclear power village' a cozy, closed community
Three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending anytime soon.
This is the sixth installment in a series that examines what caused the unprecedented crisis, which has dealt a fatal blow to the myth of the safety of nuclear power plants in this country.
"The 'nuclear power village'--the promoters of atomic energy--was behind both the cause and expansion of the crisis at the Fukushima No. 1 plant," said Tetsunari Iida, head of the nonprofit Institute for Sustainable Energy Policies.
"They lack sufficient knowledge and technology, and the safety inspections they conduct are totally inadequate," Iida added.
The nuclear power village is the nickname for a tight circle of government entities, utilities, manufacturers and others involved in the promotion of nuclear power who believe nuclear plants are safe and reject out of hand any opposing views. Iida used the term "genshiryoku mura" (nuclear power village) in a magazine opinion piece in 1997, and it has now entered the vernacular. Mura means village, but also refers to a small, closed community.
The 52-year-old executive director said he realized the nature of the cozy ties among the members of the nuclear power village more than two decades ago.
At the time, he worked in the private sector as an engineer in charge of radiation safety evaluations at the Fukushima No. 1 plant. Plant operator Tokyo Electric Power Co. had commissioned Toshiba Corp. to do the job, and Toshiba subcontracted it to Iida's firm.
His company's safety analyses were submitted to Toshiba, then to TEPCO and finally to the then International Trade and Industry Ministry.
Iida recalled being shocked when he once saw a safety assessment released by the ministry. The report's cover had been changed, but the contents were almost identical to one prepared by Iida and his fellow engineers. "They didn't do their own checks of our analyses or confirm whether things were really safe. No wonder accidents happen," Iida said.
The nuclear village has thrived under the government's treatment of nuclear energy as "national policy run by the private sector." The central government promotes nuclear power with subsidies and other support, and private utilities handle the building and operating of nuclear facilities. The nuclear-related portion of the national budget amounts to about 430 billion yen a year, and utilities invest 2 trillion yen every year in nuclear power.
The nuclear village really started to grow after the 1973 oil crisis. Since then, the planning and construction of nuclear plants across the nation was promoted under the banner of "energy security."
After the 1974 accident in which radiation leaked from the nuclear-powered ship Mutsu, the government established the Nuclear Safety Commission in 1978 to oversee the then Science and Technology Agency, which conducted basic research and development on nuclear power and the nation's nuclear policy. The science agency also contained a bureau that was in charge of nuclear safety regulations at the time.
However, the 2001 restructuring of government ministries and agencies scaled back such regulatory bodies. The Natural Resources and Energy Agency that promotes nuclear power and industry regulator Nuclear and Industrial Safety Agency were both placed under the Economy, Trade and Industry Ministry, the successor of MITI.
This only encouraged a tighter relationship between two bodies with conflicting tasks.
The parts of the science agency that had led nuclear power development were divided and merged into the Education, Culture, Sports, Science and Technology Ministry, the revamped Nuclear Safety Commission and other entities.
"The Science and Technology Agency was small and powerless, so it wasn't very dependable," a senior official of a heavy industries company said.
Integrating the nuclear industry's safety regulators into the industry ministry was apparently carried out with the full approval of the nuclear power village.
This system of having promoters and regulators under the same roof has been criticized for years, but prior to the Fukushima crisis, no administration had been keen to separate them.
At a October 2007 House of Councillors Budget Committee session, then industry minister Akira Amari of the Liberal Democratic Party, rebuffed calls for splitting the bodies up. "We'll promote nuclear power while stepping on the brakes at the same time. Double checks can be done by the Nuclear Safety Commission," he said.
The Democratic Party of Japan, while it was in the opposition, called for the creation of a "nuclear safety regulatory committee" by separating NISA from the industry ministry and integrating the agency with the Nuclear Safety Commission. But after the DPJ took power, it shifted to a more "realistic stance" and seemed to forget its earlier demands.
Responding to both domestic and international criticism, Prime Minister Naoto Kan on May 18 finally advocated allowing the Nuclear Incident Investigation and Verification Committee looking into the Fukushima fiasco to consider separating NISA from the industry ministry.
On June 1, the International Atomic Energy Agency urged the government to reform its regulatory authorities, saying it was necessary to ensure the independence of regulatory bodies and clarify their roles.
Tatsuru Uchida, critic and professor emeritus at Kobe College, said, "Both NISA and the NSC are part of the system that promotes nuclear power, which is national policy, even though they call themselves regulators."
"The state and politicians bear an extremely heavy responsibility for not fixing this unreasonable system that overestimated safety and underestimated risks," Uchida added.
But destroying the nuclear village is no easy task. The community involves heavy back-scratching and complex personnel relationships.
NISA was formed in the streamlining of the government. Although the agency was once headed by a former Science and Technology Agency official, its top posts are usually filled by former MITI bureaucrats--nuclear power promoters--including current agency head Nobuaki Terasaka. Also, NISA has accepted 80 on-loan employees of power utilities and other nuclear-related firms. One former Toshiba Corp. employee even served as a safety inspector at the Fukushima No. 1 plant, which uses Toshiba-made reactors.
Former NSC Chairman Atsuyuki Suzuki, who worked as a regulator at the troubled prototype fast-breeder reactor Monju in Tsuruga, Fukui Prefecture, last year became head of the Japan Atomic Energy Agency, the operator of Monju.
Electric power firms have deepened relations with the bureaucracy by temporarily dispatching employees to government bodies and giving cushy jobs to retired bureaucrats in the so-called amakudari (descending from heaven) practice.
Since 2000, power companies have sent at least 100 employees to central government bodies for on-loan postings, according to the government. These government bodies include the NSC and other offices involved in safety at nuclear plants. TEPCO, which has sent 32 workers to the government, had de facto reserved seats at several posts, sources said.
Meanwhile, 68 former industry ministry officials have parachuted into postretirement jobs as executive board members or advisers at 12 of the nation's power companies over the past five decades, according to the industry ministry.
Toru Ishida, former director general of the Natural Resources and Energy Agency, an industry ministry-related body, became an adviser at TEPCO in January. He left his post at the utility at the end of April after his amakudari move was heavily criticized in the wake of the Fukushima crisis. He was seen as likely to become a TEPCO vice president.
As of May 2, there were still 13 former industry ministry officials working at TEPCO and 10 other power companies.
To cut these cozy ties, former NSC Chairman Shojiro Matsuura said the members of the nuclear power village "must reflect on their actions as academics in terms of ethics and safety consciousness."
"They need to stop being a closed clique and turn themselves into a group of trusted professionals," Matsuura said.

NUCLEAR CRISIS: HOW IT HAPPENED / Time needed for fresh start of N-power policy
Three months have passed since the Great East Japan Earthquake triggered a nuclear crisis that shows little sign of ending anytime soon.
This is the seventh and final installment in a series that examines what caused the unprecedented crisis, which has dealt a fatal blow to the myth of the safety of nuclear power plants in this country.
On May 19, about two months after the Great East Japan Earthquake, plaintiff lawyer Hiroyuki Kawai firmly delivered his opening argument in a lawsuit seeking to have Electric Power Development Co. suspend the building of a nuclear power facility in Omamachi, Aomori Prefecture.
"Referred to as the 'boy who cried wolf,' we were accused of discussing something that didn't exist. But it's now clear we were right [to be concerned about the dangers posed by nuclear power plants]," he said during a hearing at the Hakodate District Court.
The 67-year-old lawyer also headed the legal counsel for plaintiffs in an older lawsuit over Chubu Electric Power Co.'s Hamaoka nuclear power plant in Shizuoka Prefecture. In that suit, he referred to the risk of all power at the plant being lost if its two emergency diesel generators were flooded in a tsunami.
However, Nuclear Safety Commission Chairman Haruki Madarame, 63, who at that time was a University of Tokyo professor, denied this possibility. He appeared as a witness for Chubu Electric at the Shizuoka District Court in February 2007.
"Both [generators] won't disengage at the same time. These remarks are just an opinion," he said.
In October 2007, the district court ruled against the plaintiffs, saying it was infeasible for both generators to malfunction simultaneously.
The plaintiffs appealed the ruling to the Tokyo High Court, and the case is still in litigation.
The massive tsunami that struck Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant on March 11 disabled 12 of 13 emergency generators.
Itsuo Sonobe, a 82-year-old former Supreme Court justice, said the ongoing nuclear crisis in Fukushima Prefecture will affect future nuclear power-related lawsuits.
"Now that 'unforeseeable accidents' have occurred, judges will be skeptical why they couldn't be anticipated," Sonobe said. "Judicial reviews will become stricter."
Kawai and other lawyers plan to form a nationwide legal counsel on July 16 and start preparations for filing lawsuits against nuclear power plants across the nation.
Out of the nation's 54 reactors, 37, including those at the Hamaoka plant, are currently not in use due to the disaster or regular inspections.
Prospects of reactivating the plants remain uncertain. Seventeen of the reactors currently operating are scheduled to be suspended for inspections by next spring.
According to an estimate released by the Japan Center for Economic Research on Tuesday, if all the nation's nuclear reactors halt operations, the nation's gross domestic product will fall an average 1.2 percent a year, or 7.2 trillion yen, from fiscal 2012 to 2020.
Some business circle figures are alarmed.
"As companies can't draw up business plans, industries could bottom out," said Yasuchika Hasegawa, 64, chairman of the Japan Association of Corporate Executives. "We want the government to take charge and reactivate [the reactors]."
Yet the government's basic energy plan has been scrapped in the wake of the nuclear crisis. Approved by Cabinet in June last year, it aimed to protect the environment and promote economic growth. The plan called for at least 14 nuclear power plants to be built during the next two decades and to raise the ratio of nuclear power to more than 50 percent of the nation's total power generation.
European angle
In the wake of the nuclear crisis at the Fukushima plant, antinuclear movements have strengthened in Europe.
On Tuesday, Italy held a referendum to ask its people whether operations at nuclear power plants should resume. With 94 percent of voters opposing such a move, Italian Prime Minister Silvio Berlusconi said Italy has no choice but to drop its existing plans for nuclear power.
On June 6, Germany decided to close all 17 reactors there by late 2022. Nuclear power makes up 23 percent of Germany's power generation. Switzerland, where nuclear power generates 39 percent of the country's power, followed suit by announcing a plan to shut down all its nuclear plants.
However, replacing nuclear power with natural energy is no easy task.
In France, nuclear power accounts for 75 percent of domestic power generation. French President Nicolas Sarkozy has called the nuclear power industry an asset to the French economy because it boosts employment, competitiveness and energy independence.
Sarkozy has seen business opportunities in neighboring countries' change of policy. Both Germany and Italy plan to import electricity from France to cover their power shortages.
Japan launches probe into crisis
In Japan, the Nuclear Incident Investigation and Verification Committee held its first meeting on June 7, launching a probe into how the nuclear crisis happened. None of the panel members appointed by Prime Minister Naoto Kan is versed in nuclear power engineering. Kan apparently aimed at ensuring neutrality in the 10-member panel by excluding people associated with the so-called nuclear power village--a closed community of people promoting nuclear power.
However, Kan's selection has been met with criticism.
"Will they be able to understand what's happened from a technical point of view?" asked Hisaji Shimizu, a professor emeritus of Yokohama National University specializing in safety engineering.
As the panel looks into the government's handling of the nuclear crisis, the results of its probe could affect the issue of compensation to be paid by Tokyo Electric Power Co. The panel may meet resistance when it tries to find out how the crisis developed.
After the 1979 nuclear accident on Three Mile Island in the United States, an investigative committee was authorized to summon witnesses forcibly. Witnesses who made false statements could be prosecuted for perjury. About 150 people were questioned at public hearings, and a report the panel compiled six months later blasted the U.S. Nuclear Regulatory Commission for facilitating the plant operator's business activities rather than securing its safety. The report called on the NRC to review its practices.
Japan's Transport Safety Board investigates aircraft, railway and marine accidents and can impose fines of less than 300,000 yen on people who make false reports and refuse to submit documents in cases. But as the nuclear incident investigative panel does not have the legal authority to enforce its decisions, it lacks investigative clout.
Even worse, the panel appears to be divided over how the investigation should proceed because of its members' differing backgrounds.
During the panel's first meeting, Chairman Yotaro Hatamura, a University of Tokyo professor emeritus known for his study of learning from failure, recommended the panel proceed with the investigation according to his suggestions.
"The panel should not carry out an investigation that attempts to find out who should be blamed [for the crisis]," the 70-year-old said.
However, some panel members have challenged Hatamura's stance. One said, "We have to check thoroughly whether any rules were violated."
Restart dates unknown
Meanwhile, it remains unclear as to when reactors currently out of action can restart. The government initially had high hopes that Kyushu Electric Power Co.'s Genkai plant in Saga Prefecture and Hokkaido Electric Power Co.'s Tomari plant could resume operations soon, as neighboring residents had good relationships with the companies.
However, local leaders have become cautious about the resumption of the reactors.
Saga Gov. Yasushi Furukawa, 52, said, "We don't have the necessary information to decide [on this matter]."
Hokkaido Gov. Harumi Takahashi, 57, stated a similar view, saying, "We're still a long way from even being able to consider safety."
To make a fresh start of the nation's nuclear power policy, securing safety and recovering public trust is essential. This requires a thorough investigation into the nuclear crisis.