Jiji Press IWAKUNI, Yamaguchi (Jiji Press) — A district court branch on Friday dismissed a petition seeking an injunction to halt operations at the No. 3 reactor of Shikoku Electric Power Co.’s Ikata nuclear power plant in Ehime Prefecture.
The petition was filed by three residents of nearby Yamaguchi Prefecture with the Iwakuni branch of the Yamaguchi District Court in March 2017. The petitioners cited safety concerns about the nuclear reactor.
Key issues in the legal battle were how the court branch would assess Shikoku Electric’s estimate of maximum ground motions from possible earthquakes and the likelihood of a catastrophic volcanic eruption occurring at Mount Aso in Kumamoto Prefecture, located some 130 kilometers from the reactor.
Presiding Judge Akira Onose concluded that there is nothing unreasonable in the ground motion estimate, saying it takes sufficient account of possible movements of faults running near the plant.
Onose added that a devastating eruption is very unlikely to occur during the reactor’s operational period.
In the petition, the Yamaguchi Prefecture residents claimed that the nuclear plant stands close to active faults of great length and that Shikoku Electric has underestimated the strength of ground motions in the event of earthquakes.
They argued that the operations of the No. 3 reactor should be halted, citing experts’ view that a pyroclastic flow, or a mix of high-temperature fragments of volcanic origin such as molten rocks, from a past eruption of the volcano had reached the site of the plant.
Shikoku Electric rejected this, saying that the possible ground motions have not been underestimated and that the company has installed adequate measures to protect the reactor from potential Mount Aso eruptions.
In December 2017, Hiroshima High Court ordered Shikoku Electric not to reactivate the Ikata No. 3 reactor, after it was suspended in October that year for routine checkups.
In September 2018, however, the same high court canceled the order, upholding an appeal filed by Shikoku Electric. The 890,000-kilowatt reactor went back online the following month.
A petition for a halt to the reactor has also been filed with Fukuoka High Court. The case is still ongoing.
Commercial operations of the No. 3 reactor started in 1994. The two other reactors at the Ikata plant—the No. 1 and No. 2 units — are set to be scrapped, and their operations have already been ended.Speech