'Japan was totally unprepared for Fukushima'

Japanese agencies were thoroughly "unprepared" for the earthquake and tsunami that struck Japan on March 11 last year, says an independent investigation coming a year after the disastrous event that also shut down the Daiichi nuclear power plant.

A public myth of "absolute safety", nurtured by nuclear power proponents over decades, contributed to the lack of adequate preparation. The public was also ill-informed about the meaning of reported radiation levels, according to the probe.

The Rebuild Japan Initiative Foundation established an independent investigation panel to review how the government, the Tokyo Electric Power Company (Tepco), and other key actors responded during the disaster, the journal Bulletin of the Atomic Scientists reported.

The foundation's chairman, Yoichi Funabashi and staff director of the investigation panel, Kay Kitazawa, explained the reasons behind the lack of disaster preparation; their findings are based on interviews with nearly 300 people involved in the accident, including then Prime Minister Naoto Kan, according to a statement of the Rebuild Japan Foundation.

Their article highlights how Kan secretly instructed Shunsuke Kondo, chairman of the Japan Atomic Energy Commission (AEC), to draw up a "worst case scenario" for the nuclear accident as the crisis deepened -- that is, six increasingly drastic scenarios, that would play out as various systems at the nuclear plant failed.

The most extreme scenario would have involved evacuation of all residents living within 170 km or more of the Fukushima plant and, depending on the wind direction, could have meant evacuating the 30 million residents in the Tokyo metropolitan area.

Tepco's own nuclear energy division understood the risk, but the company dismissed these probabilities as "academic".

Regulatory authorities also encouraged the company to incorporate new findings into its safety plans, but did not make these measures mandatory.

Many human errors were made at Fukushima, illustrating the dangers of building multiple nuclear reactor units close together.

Masao Yoshida, the director of the Fukushima Daiichi Nuclear Power Station at the time of the accident, had to cope simultaneously with core meltdowns at three reactors and exposed fuel pools at four units.

The errors were not the fault of one individual, but were systemic: When on-site workers referred to the severe accident manual, the answers were not there.

The authors write that Tepco bears the primary responsibility for incompetent handling of the disaster's aftermath. The organisation failed to make rapid decisions, losing government trust in the process.