The ruling said the four defendants–Tsunehisa Katsumata, a former chairman; Masataka Shimizu, a former president; and two former vice presidents, Ichiro Takekuro and Sakae Muto–“fundamentally lacked an awareness of the need for safety and a sense of responsibility that is asked of executives of an operator of a nuclear plant.”
The ruling said that instead of taking the required measures to deal with a possible tsunami, the four put off making decisions on the matter.
A nuclear accident “could lead to the collapse of our nation because the damage would extend over a wide land area and cause enormous damage to the entire population,” the ruling said.
Faced with such a possibility, the ruling said operators of nuclear plants had a social and public interest obligation to prevent an accident even if the possibility was remote.
A major point in the lawsuit was the long-term assessment of the probability of major earthquakes released by the government’s Headquarters for Earthquake Research Promotion in July 2002.
The district court said that assessment had “a considerable scientific reliability” since it was compiled by the nation’s top researchers in earthquakes and tsunami.
The court came to a similar conclusion regarding the estimate made in 2008 by a TEPCO subsidiary about a maximum tsunami of 15.7 meters striking the Fukushima plant.
The district court noted that Muto was deputy chief of TEPCO’s Nuclear Power and Plant Siting Division. His decision in July 2008 to ask the Japan Society of Civil Engineers to look into the appropriateness of the tsunami estimate rather than implement measures constituted a “failure to take action,” the court said.
The court called Muto’s decision “unforgivable because of the extreme irrationality of delaying the implementation of anti-tsunami measures.”
The court then turned its attention to Takekuro, who headed the Nuclear Power and Plant Siting Division, and ruled that his decision in August 2008 gave consent to Muto’s failure to take action the previous month.
Although Muto and Takekuro were the top officials in charge of nuclear plant operations, the court also found Katsumata and Shimizu equally responsible for the lack of action.
Katsumata and Shimizu attended a meeting in February 2009 and were told a tsunami of about 14 meters could hit the Fukushima plant.
The court found that Katsumata and Shimizu shirked their responsibility to confirm any irrational points in the decision made by the Nuclear Power and Plant Siting Division the previous year.
The district court even said the nuclear accident could have been avoided if measures were taken to make watertight the main buildings and equipment at the Fukushima plant.
Those measures could have been completed in about two years, the court said.
The four former executives’ failure to take action for more than two years before the March 2011 triple meltdown at the Fukushima plant was a major cause of the accident, according to the ruling.
The court pointed out that steps to make rooms watertight had been taken in some parts of the Fukushima plant as well as at other nuclear plants operated by different utilities.
The ruling “was filled with anger toward the TEPCO executives for failing to take anti-tsunami measures,” said Hiroyuki Kawai, one of the lawyers for the 48 shareholders who took part in the lawsuit, at a news conference.
Another lawyer, Yuichi Kaido, pointed out the strong wording in the ruling may have stemmed from a visit to the Fukushima plant site in October 2021 by Presiding Judge Yoshihide Asakura and others as part of court proceedings.
Asakura was the first judge involved in any of the various criminal and civil cases related to the Fukushima disaster to visit the plant site.