Operation and safety

Japan's safety response

20 December 2006

Changes to Japan’s nuclear safety culture after known accidents have not convinced everyone there is sufficient open scrutiny to prevent another mishap. By Julian Ryall

On 21 September 2006, Kansai Electric Power commenced test operations at Mihama 3 in Fukui prefecture, on the north coast of central Japan. The facility had been shut down in August 2004 when a badly corroded coolant pipe ruptured and released superheated steam onto a team of 11 workers. Four men were killed immediately, a fifth died in hospital later and the remaining six sustained serious injuries. In a meeting with Kansai Electric Power president Hiroshi Morimoto, before the test operations began, relatives of the dead men asked the company to be honest and tell them the truth if a fault was identified. Another person said he did not think the reactor was ready to go back into service.

Others agree that Japan’s nuclear industry is overconfident of its own abilities and point to the deaths of two JCO employees in the town of Tokai, Ibaraki prefecture, after they triggered a criticality accident on 30 September 1999, in a conversion and fuel fabrication facility. The workers set off a self sustaining chain reaction, which lasted for 20 hours before it could be stopped, by ignoring procedures and using a bucket to add too much enriched uranium. Instead of enriching the uranium to between 3% and 5%, appropriate for use in commercial light water reactors, the short cut increased the mixture to 18.8% of uranium-235.

Monju sodium incident

But if the accidents at Mihama and Tokai shocked Japan, it was nothing to what happened at the Monju fast breeder reactor, in the town of Tsuruga, Fukui prefecture. Nobody was killed on 8 December 1995, when several hundred kilogrammes of sodium leaked from a coolant pipe. The liquid sodium ignited when it came into contact with air, filling the room with poisonous fumes and producing temperatures as high as 1500°C. The leak was in the plant’s secondary cooling system and the sodium was not radioactive, but the real public fury broke upon Power Reactor and Nuclear Fuel Development Corporation (PNC) when it was discovered the operator had tried to cover up the scale of the accident by falsifying reports, issuing gag orders to staff and judiciously editing videotape images of the scene of the accident.

“That came as a real shock to everybody,” said Tatsujiro Suzuki, a professor at the Graduate School of Public Policy at the University of Tokyo and adviser to the nuclear industry. “Technically it was a relatively minor accident, but when the truth came out it was clear that a decline in the institutional culture of safety in the industry had begun in Japan in the early 1990s.

“Before that, we had looked at Japan’s nuclear industry as the best example in the world and the industry itself had stressed a ‘zero defect’ philosophy,” he said. That meant that components were replaced at the nation’s nuclear facilities before they were worn out and quality control came from the bottom up, with people onsite identifying potential problems and informing their managers.

“The problem was that once the system had been set up, people got used to it and were no longer required to pay so much attention,” said Suzuki. “And we also stopped learning from other countries because we thought that we were the best. We told communities where we built plants that there was no danger of an accident. We put all this pressure on ourselves. And then when we had an accident, like Monju, we tried to hide it because we were meant to be the best.”


Technically, Japan’s nuclear industry does have a low incidence of faults, but it is the culture of tending not to inform senior officials or anyone outside the company when a failure does occur that can exacerbate the problem. And while the desire to keep bad news within the corporation is a very Japanese trait, Suzuki said that when it comes to nuclear power, operators need to be more open.

But that is a hard transition for companies that for years were unable to even have the word ‘risk’ in their vocabulary; power firms here did not carry out ‘risk assessments’, they preferred ‘safety assessments,’ he pointed out. After the Monju and Tokai incidents, however, ‘risk’ was no longer taboo and the impact of a major accident, such as a core meltdown, began to be considered.

“In the wake of the Tokai accident, the government conducted a thorough review of the principles of the industry and made many changes to the Reactor Regulation Law that regulates operators,” said Satoshi Ito, director of the Nuclear Safety Public Relations and Training Division at the Nuclear and Industrial Safety Agency, a division of Japan’s Ministry of Economy, Trade and Industry.


High on the list of amendments to the reactor law were the clarification of the requirement to educate employees, the placement of nuclear safety inspectors at sites, the introduction of safety inspections and the establishment of the ‘allegation system’, whereby whistleblowers were encouraged to come forward without concern for their jobs.

“By reviewing the mistakes that had been made previously, we also realised that despite beefing up the emergency systems, we were not reacting to problems quickly enough,” said Ito.

The Special Law of Emergency Preparedness for Nuclear Disaster was proclaimed in December 1999 and contains provisions for improving alliances between national and local government and introduces offsite emergency centres. Failure by operators to adhere to the law can result in plants being ordered to suspend operations or, in an extreme case, an operator’s licence being revoked.

The culture of concealing a problem is taking longer to eradicate, however, as in August 2002, Tokyo Electric Power (Tepco) was found to have excluded a 1.4m-long crack in a welded section of a core shroud at the Fukushima Daiichi nuclear power station from an inspection report. The operator was aware of the problem but, as it was not considered critical to operational safety and would have required paperwork and repairs, it was not reported. Finally revealed by an engineer from the USA, it proved costly to Tepco; all 17 of its plants were shut down for inspections and the minister had to apologise to the governor of Fukushima prefecture.

Yet Ito believes the fact that the problem was revealed by a company insider is a vindication of the new policies.

“Since May 2004, we have witnessed ten violations of the Nuclear Safety Programme, four of which were reported by safety inspectors and the rest were reported in-house,” he said. “We believe that the regulations on nuclear safety have been steadily improved. We know that we cannot be sure that an accident won’t happen again, but we have learned from our mistakes, particularly in the area of industry oversight and management skills. We are aware those areas were direct causes of the accidents at Mihama and Tokai and we knew we needed to make changes to the whole system.”

Hidden embarrassment

But not everybody is convinced that the nuclear industry really has put its house in order.

“The nuclear power industry is the Frankenstein’s monster of ‘Japan Inc’,” believes Eric Johnston, a reporter for The Japan Times who has covered the nation’s nuclear power industry for more than a decade and is writing a book on the subject. “It’s the very antithesis of the world famous ‘Japan Inc’, an embarrassment that official Japan, in particular, is desperately hiding in places like the bleak, sparsely populated Japan Sea coast or the mountains, well away from the major urban – and media – centres.

“Sony, Toyota, the bullet train – those represent Japan at its technological and organisational best. The nuclear power industry represents technological embarrassment and organisational failure due to greed, secrecy, corruption, shoddy technological practices, bureaucratic incompetence and an emphasis on production at the expense of safety – and common sense.”

And given what Johnston believes are problems at both the individual plant level and revelations of cover ups at the institutional level, he said it was just a matter of time before Japan suffered a major nuclear accident.

“Given the poor quality of education of the workers, the corporate and institutional culture which encouraged cutting corners and saving costs, and management incompetence and corruption, an accident of the Tokai type was inevitable,” he said. “I think you have high profile plants like Tokai and a few others that anti-nuclear activists and the public are keeping an eye on; these plants are probably following regulations to the letter. But Japan has 55 nuclear power plants. What about those plants that, to date, have had no problems and are out of the public eye?”

Fortunately for the industry, the anti-nuclear movement in Japan is relatively small and lacks the resources and political support to mount an effective campaign against atomic power. Its opposition is further weakened by the vast amount of funds provided by power companies and the national government to towns and villages that agree to host nuclear facilities. One of the groups that provides the most resistance is the Citizens’ Nuclear Information Centre (CNIC), based in Tokyo, which believes that three of the most serious recent incidents, Tokai, the Tepco cover-up and the Mihama accident, had their own unique characteristics, according to co-director Hideyuki Ban. He added: “But the common denominator was that procedures were not followed, warning signs were not heeded and economic considerations were prioritised over safety.”

Ban continued: “The underlying cause is institutional at several levels. There is the culture of each company, of the research agencies and of the nuclear bureaucracy. Collectively these might be referred to as the ‘nuclear club’.

“The club’s first instinct is to be defensive, to deny rather than confront problems. These days, they are much more willing to provide information about accidents, leaks and other incidents. They realise that the damage from covering up incidents is often greater than the damage from admitting them. But despite the formal improvements and the rhetoric, it is hard to see that anything has changed at a deeper level. Because of severe competition in the electricity market, utilities try to achieve a capacity factor for their nuclear power plant of more than 90%,” he pointed out.

“They aim to achieve this by shortening the time spent on annual inspections and/or expanding operation time. Adherence to policies established years ago and maintaining profits are consistently prioritised over safety.”

Ban disputed the industry’s claim that Japan needs nuclear energy, saying: “CNIC has no doubt that Japan can meet its energy needs without nuclear power and has participated in projects that researched alternative energy scenarios. However, the nuclear lobby repeats ad nauseam phrases along the lines of ‘resource poor Japan’. Phrases like this have been repeated so often that the general public is now utterly convinced that Japan is indeed ‘resource poor’. This has led to a kind of mental paralysis when it comes to thinking of alternatives.”

The aftermath

One of the measures introduced in the aftermath of the Tokai accident was the creation of an organisation titled the Nuclear Safety Network, which was to oversee and evaluate power plants. Japan’s version, however, did not have an auditing function and because of its open nature was uncritical of areas of concern. What some termed a ‘friendly organisation’ was swallowed up by the Japan Nuclear Technology Institute, based on the US Institute of Nuclear Power Operations, in 2005, after the Mihama accident, an improvement on its predecessor because it has its own technical staff.

Yet drawbacks remain, according to Suzuki. In the quest for full transparency and the release of more data, the industry is reluctant to reveal its full hand. And the industry still does not have an independent, self-regulatory function.

“We need more independence in the regulatory functions in Japan, both politically and technically,” he said. “The entire system of safety regulations is relatively dependent on the industry and the agency that oversees safety is still under the Ministry of Economy, Trade and Industry – whose job is to promote nuclear power. That’s not independence.”

The International Atomic Energy Agency (IAEA) carries out inspections of safety at Japanese nuclear plants. After a recent visit to Japan, an IAEA official in an aside said that Japan’s nuclear industry is so confident of its own abilities that it ignores the agency’s advice. If that attitude and complacency genuinely still exist within the operators and regulators, then another Monju, Tokai or Mihama may just be a matter of time.

Mihama 3 ruptured pipe Mihama 3 ruptured pipe

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