The government’s nuclear watchdog was aware of the vulnerability of some of Japan's reactors a year before disaster struck the Fukushima No. 1 nuclear power plant, but it did not take action.
The government’s nuclear watchdog was aware of the vulnerability of some of Japan's reactors a year before disaster struck the Fukushima No. 1 nuclear power plant, but it did not take action.
Specifically, it chose not to seek a revision of laws requiring operators of plants to draw up additional safeguards against a severe accident, according to records obtained by The Asahi Shimbun.
The Nuclear and Industrial Safety Agency shied away from tougher regulations, concerned that it could pave the way for lawsuits disputing the soundness of the design of some reactors.
The documents, created in April 2010, showed that the NISA concluded that any decision to add more safety precautions against a possible severe accident should be left to each operator of nuclear plants.
The records were obtained under the Information Disclosure Law.
Experts say the accident at the Fukushima No. 1 nuclear plant last year could have been less severe if Tokyo Electric Power Co., the plant operator, had been required to install safety steps stipulated by law.
A government special panel looking into the Fukushima disaster pointed out in an interim report last December that TEPCO’s voluntary efforts alone were not sufficient in terms of preparing for a severe accident.
As a lesson learned from the Fukushima crisis, the government plans to revise the law requiring plant operators to better deal with accidents.
The documents showed that the NISA and the Japan Nuclear Energy Safety Organization, a government-affiliated body, discussed efforts to improve preparedness at nuclear plants for a severe accident.
They looked at amending the nuclear reactor regulation law and other relevant legislation.
One proposal discussed was to require operators to strengthen containment vessels, install equipment to contain nuclear fuel in the case of a meltdown and beef up the ability of emergency equipment to withstand major earthquakes.
But the NISA was reluctant to push it due to fears the revision could give rise to lawsuits over design failings of some reactors that had been permitted to operate.
“It is important that plant operators take proactive countermeasures,” said one of the documents. “But how that should be sought under regulation is a question (that will have to be worked out.)”
The NISA took up the discussion to toughen the regulations again and was supposed to release details in March last year, but that plan was derailed by the Great East Japan Earthquake that struck that month, triggering the Fukushima nuclear disaster.
An official at the NISA’s Nuclear Safety Regulatory Standard Division acknowledged that the agency was extremely wary of possible lawsuits at that time.
“As a result, drawing up new regulations was delayed,” the official said.