An appeals court on Wednesday upheld an acquittal of three former executives of Tokyo Electric Power Company Holdings Inc. who were accused of failing to prevent the 2011 disaster at the Fukushima Daiichi nuclear plant in northeastern Japan.

The Tokyo High Court decision followed a Tokyo District Court ruling in 2019 that found former TEPCO Chairman Tsunehisa Katsumata, 82, along with Ichiro Takekuro, 76, and Sakae Muto, 72, both former vice presidents, could not have predicted the massive tsunami that crippled the power plant and led to core meltdowns.

Tsunehisa Katsumata, former chairman of Tokyo Electric Power Company Holdings Inc. (Kyodo)

The ruling cleared the defendants of professional negligence resulting in deaths and injuries.

"There was no foreseeability that tsunamis higher than 10-meters would strike," Presiding Judge Keisuke Hosoda said. "The district court's ruling, which did not recognize that duty of care should be given, is appropriate."

The trial focused on whether the former executives should have foreseen the massive tsunami and prevented the accident, given that a TEPCO unit had estimated in 2008 that tsunami waves of up to 15.7 meters could strike the Fukushima plant based on the government's earlier long-term evaluation of quake risks released in 2002.

The high court ruling admitted that the government estimate "carried weight that could not be overlooked." But it pointed out that some experts disputed its reliability.

It is utterly unacceptable, court-appointed lawyers acting as prosecutors said during a press conference in the capital, adding that they may consider appealing the decision.

Combined photo shows Ichiro Takekuro (L) and Sakae Muto, both former vice presidents of Tokyo Electric Power Company Holdings Inc., entering the Tokyo High Court on Jan. 18, 2023. (Pool photo)(Kyodo)

The verdict was met with anger and disbelief from a crowd of people, including those affected by the disaster, who had been waiting outside the courthouse for the ruling.

"A not guilty decision is unthinkable. If we don't clarify who is responsible, it's likely to affect the future," said Yoshiko Furukawa, who had evacuated from Tomioka, Fukushima Prefecture, to Yokohama.

The 59-year-old said she had observed the trial and was under the impression that the executives had been aware of the potential danger of a nuclear accident.

File photo shows Fukushima Daiichi nuclear complex on Feb. 9, 2022. From left, No. 4, No. 3, No. 2 and No. 1 reactors. (Kyodo)

The three former TEPCO executives were indicted in 2016 for allegedly failing to implement tsunami countermeasures, resulting in the deaths of 44 people -- including patients at a hospital in Fukushima Prefecture -- after they were forced to endure long-term evacuations.

Prosecutors had decided not to pursue criminal charges against the three, but that decision was ultimately superseded by a committee for the inquest of prosecution made up of members of the general public who reviewed the case and called for indictments.

The court-appointed lawyers acting as prosecutors demanded each of the three men be given a five-year prison sentence, while the defendants denied any wrongdoing.

In September 2019, the Tokyo District Court found the three not guilty. It denied the credibility of the government's long-term evaluation, saying the former executives "could not have logically predicted tsunami waves over 10 meters tall."

Although prosecutors alleged the defendants failed to implement the construction of a seawall and flood prevention work to core facilities, the lower court ruled that a temporary shutdown was the only guaranteed way to avoid an accident.

There have also been civil cases focusing on whether a tsunami could have been anticipated, with courts coming to different decisions.

In June last year, the Supreme Court's Second Petty Bench absolved the government of responsibility for the Fukushima crisis in a lawsuit filed by evacuees, saying it would not have been able to prevent an accident.

Meanwhile, in a shareholder lawsuit, the Tokyo District Court in July last year ordered four former company executives, including Katsumata, Takekuro and Muto, to pay 13.3 trillion yen ($103 billion) in damages for failing to prevent the crisis.

In appeal trials, the high court was required to make a decision based on similar testimony and evidence submitted to the lower court.

On March 11, 2011, the six-reactor plant on the Pacific coast was flooded by tsunami waves exceeding 10 meters triggered by the magnitude 9.0 quake, causing the reactor cooling systems to lose their power supply.

The Nos. 1 to 3 reactors subsequently suffered core meltdowns, while hydrogen explosions damaged the building housing the Nos. 1, 3 and 4 units.


Related coverage:

Japan's top court rules state not liable for Fukushima disaster

Court orders TEPCO to pay 73.5 million yen over Fukushima crisis

Japan's top court orders TEPCO to pay damages over Fukushima nuclear crisis