Top court: nuclear accident ‘could not have been avoided’

By Tatsuro Yasuda/Yomiuri Shimbun Staff Writer

20:00 JST, June 18, 2022

In the lawsuit where residents who were forced to evacuate following the nuclear accident at the Fukushima No. 1 nuclear power plant in 2011 demanded the state to pay damages, the Supreme Court on Friday handed down the first ruling, which denies the responsibility of the central government.

Considering that the tsunami triggered by the Great East Japan Earthquake was one that occurred “beyond expectation” in scale, the ruling concluded that even if the government had made Tokyo Electric Power Company Holdings, Inc. take preventive measures, the accident could not have been avoided.

The top court, however, has drawn out its judgment to exempt the state from responsibility without getting to grips with other major points of contention, prompting experts to criticize the court for not making a thorough examination.

Long-term evaluation

The major point of contention in this lawsuit thus far was whether the arrival of such a massive quake could have been predicted or not.

The Headquarters for Earthquake Research Promotion of the central government released in July 2002 its long-term evaluation of the probability of earthquake occurrence. It presumed that “an 8.2-magnitude earthquake could occur at 20% probability within the next 30 years,” with the epicenter somewhere between the northern part of Sanriku offshore and Boso offshore.

A subsidiary of TEPCO made a provisional calculation in the spring of 2008, on the basis of the long-term evaluation, that a tsunami as high as 15.7 meters could come from the southeast side of the plant.

If the long-term evaluation was the one that should have been relied on, the coming of the tsunami could have been predicted, thus leading to holding the state responsible for failing to order TEPCO to take preventive measures. Because of this, the plaintiff and the state unfolded their assertions and counterarguments over the reliability of the long-term evaluation, with the judgments made at the courts of the first instance and the second instance divided, drawing much attention to what sort of opinions the top court would present.

What the top court focused on, however, was solely whether or not the accident could have been averted as a result.

The Great East Japan Earthquake was a magnitude-9 level quake, the biggest scale on record in Japan. It was far exceeded the long-term evaluation. Regarding the tsunami, the calculation showed that major facilities could be inundated by not more than 2.6 meters, but in reality, they were flooded by 5.5 meters at most. The tsunami hit the plant’s premises on the whole east side, rather than only the southeast side of the plant.

Citing these points, the ruling pointed out that even if a sea wall had been built on the basis of the long-term evaluation and the provisional calculation, the accident could not have been avoided since the scale of both the quake and tsunami were far larger than expected. It then concluded that a large amount of seawater would flood the plant, leading it to lose the power supply and triggering the accident.

While not showing any clear-cut views regarding the reliability of the long-term evaluation and the predictability of a massive tsunami, the top court has denied the responsibility of the state.

Shinsuke Toyonaga, a lawyer well versed in litigation related to nuclear power plants, said, “As opinions were divided among the judges, the ruling may well have been decided within the limits they were able to draw together. But the top court, as the court of last resort, should have given a collective view on major points of contention, including the long-term evaluation.”

Counterarguments

As a matter of fact, opinions to counter its majority opinion were also attached to the ruling.

The Electricity Enterprises Law has stipulated that if there is a “danger of a nuclear power plant to be damaged by a tsunami,” the Economy, Trade and Industry Minister is authorized to order the business operator to conform to appropriate standards.

Mamoru Miura, a justice who was formerly a public prosecutor, noted that this authority is given by considering the gravity of a nuclear plant accident. He then pointed out that even if an occurrence of tsunami is extremely rare, they should respond appropriately as long as there is a possibility of such an occurrence.”

In addition to building a sea wall, if the state had ordered TEPCO to take preventive measures, such as flood-protective work at its major facilities, the accident could have been averted, Miura said. He then criticized the state harshly, saying that it “did not assume its duty of grasping and considering the up-to-date knowledge.”

Hiroyuki Kanno, the chief justice, who joined the majority opinion, also referred to the state’s responsibility in a concurring opinion. Taking into account that the nuclear policy has been advanced as a national policy, he pointed out that “The state should assume more responsibility than power companies for the consequence of an accident, thus the biggest responsibility.” He then proposed that the state should make compensation for a loss incurred by the victims.

Kazuo Kitamura, professor at Ritsumeikan University and scholar on administrative law, criticized the ruling, by saying, “The latest ruling has assessed too strictly whether the consequence could have been avoided or not. Given the risks of a nuclear power plant, there was a possibility of ampler measures than suggested by the provisional calculation was taken. Therefore, I would have to say that the top court has not considered the matter sufficiently.”