Questions concerning accountability for the unprecedented accident at the Fukushima No. 1 nuclear power plant, characterized by a Diet fact-finding committee as a “man-made disaster,” remain unanswered.

This sorry state of affairs arises from yet another baffling court ruling that has further compounded the problem by acquitting three former top executives of Tokyo Electric Power Co. (TEPCO), the operator of the crippled plant, of criminal liability for the catastrophic triple meltdown.

The Tokyo High Court on Jan. 18 found the three former executives not guilty of criminal negligence resulting in deaths and injuries related to the 2011 disaster, upholding a lower court ruling.

The court’s decision was based on the so-called nuclear safety myth that prevailed for decades in Japan, courtesy of a campaign by the nuclear establishment, including the utility and the government, to convince the Japanese public of the safety of nuclear power. The ruling underscored a lack of accountability for the mistake.

The focus of the trial was on whether the three former executives could have foreseen a situation in which towering tsunami of 10 meters or higher would ever engulf the facility, thereby necessitating drastic action on their part.

Although the ruling cited a long-term earthquake forecast published by the central government in 2002 that said a massive earthquake could occur anywhere in wide offshore areas of the Pacific coastline in northern parts of Japan, it said the report was not so definitive as to impose a legal obligation on the defendants to halt the operation of the reactors.

The ruling also acknowledged that the trio were unaware of the realistic possibility of a maximum tsunami of 15.7 meters striking the Fukushima plant, as estimated in 2008 by a TEPCO subsidiary. The court also pointed out that there was no evidence to suggest the accident could have been averted if safety measures had been taken in line with the warning.

Ironically, the top executives’ failure to recognize the risk justified the company’s failure to take action.

In criminal cases, claims must be proved more rigorously than in civil cases due to the presumption of innocence. In a civil case concerning the accident, the Tokyo District Court last year ordered four former TEPCO executives, including the three defendants, to pay a total of 13.3 trillion yen ($103 billion) in compensation to the company for failing to take measures that could have prevented the 2011 triple meltdown. They have appealed the ruling. This indicates the acquittal of the three former executives does not exonerate the utility from responsibility for the disaster.

The Tokyo District Public Prosecutors Office initially decided not to indict the former executives, citing insufficient evidence. Nevertheless, criminal proceedings went ahead after the court decision was reviewed by a prosecution inquest panel, which ruled twice that the three must stand trial.

The panel’s verdict was based on the common sense view that the three men had a shared obligation to provide the highest level of safety. This view is supported by the accepted sense of justice and norms that prevail in society. The question, therefore, comes down to whether the trial responded adequately to this argument.

No new witnesses were questioned during the high court trial. Neither the district nor the high court carried out on-site inspection by judges. Had this happened, it could have given the judges other viewpoints in assessing the forecasts of tsunami and the effectiveness of measures taken to protect the reactors and other facilities. In some civil cases related to the accident, courts carried out on-site inspections by judges.

The trial in a case that will forever be part of world history will only be convincing if all the related issues have been scrutinized from all angles.

Still, the criminal trial was meaningful in that it uncovered many important matters not cited in any of the reports by fact-finding panels.

The trial disclosed key points about how TEPCO dealt with the earthquake and tsunami risks that had been pointed out and how it postponed taking appropriate safety measures. These revelations have been used in civil trials filed by victims.

The findings should lead to effective efforts to identify the core factors behind the disaster to ensure that a nuclear accident never occurs again.

--The Asahi Shimbun, Jan. 20