The Tokyo High Court has overturned a lower court ruling dismissing a claim by plaintiffs that former Tokyo Electric Power Company (Tepco) executives should pay damages to the utility over the 2011 nuclear accident at the Fukushima Daiichi NPP.
The plaintiffs, 42 shareholders of Tepco, had filed the lawsuit against five people in top managerial posts at the company arguing that the accident occurred because of poor safety measures at the plant. The five defendants were: Tsunehisa Katsumata, a former chairman who died in 2024; Masataka Shimizu, a former president; two former vice presidents, Ichiro Takekuro and Sakae Muto; and a former managing director, Akio Komori.
The plaintiffs demanded that the defendants pay damages to Tepco worth over JPY23,000bn ($160bn), to cover the costs the company incurred in compensating local residents who had to evacuate, decommissioning the plant and conducting decontamination efforts.
In an earlier ruling in 2022, the Tokyo District Court had ordered four of the defendants to pay the utility a total of JPY13,300bn in compensation. The amount of damages is believed to be the highest ever ordered by a court in Japan. These were the same defendants but without Komori.
The focal point of the trial was whether the management’s inaction regarding tsunami countermeasures was acceptable after a Tepco unit estimated in 2008 that a tsunami of up to 15.7 metres could hit the plant based on the government’s long-term earthquake assessment made public in 2002. The lower court ruling said the assessment was scientifically reliable making it obligatory for the company’s managers to take measures against tsunami.
However, Tokyo High Court Presiding Judge Kino Toshikazu said that while Tepco should have respected the assessment, it cannot necessarily be judged that the company had been legally liable to take anti-tsunami measures. He said the government’s assessment did not provide a sufficient basis for the utility to swiftly conduct construction work to protect against a huge tsunami and that the massive tsunami that destroyed the NPP was “not foreseeable”.
In a separate criminal trial of Katsumata, Takekuro and Muto for their alleged professional negligence resulting in death and injury over the nuclear accident, they were acquitted in March this year. The charges against Katsumata had been dismissed after his death in October 2024. However, Katsumata’s heirs succeeded him in the latest lawsuit.
Hiroyuki Kawai, lawyer for the shareholders seeking the damages, criticised the ruling as “fundamentally flawed”, expressing his intention to appeal the latest decision. “This is an extremely unjust and logically contradictory verdict,” he said. “It allows a recurrence of the nuclear accident, and we will pursue the flaws in this decision at the Supreme Court.”
