Court Approves Safety Assessment of Ikata Nuclear Plant

Oita District Court decided that the risk assessment of Shikoku Electric Power Company (Yonden) for its Reactor #3 of Ikata Nuclear Power Plant in case of major earthquake of eruption of volcano was rational and dismissed the suit of plaintiffs requiring to stop the operation. The court concluded that actual danger for the plaintiffs’ lives could not be recognized. The plaintiffs appealed to the high court immediately. 

Ikata Nuclear Power Plant is located on the base of Sadamisaki Peninsula in the west end of Shikoku Island. Hiroshima High Court decided to stop Yonden’s operation, recognizing that the measures against earthquake or volcanic eruption was insufficient in 2017 and 2020. Yonden later disputed and the court later overturned its previous decision. The reactor of the Ikata plant resumed its operation in December, 2021.

 

While Hiroshima is on northern opposite side of Ikata beyond Seto Inland Sea, Oita is on the western opposite. 569 residents in Oita prefecture filed a lawsuit to Oita District Court in 2016, demanding Ikata plant’s stop. They argued that the faults underground and volcano in Kyusyu Island might affect the safety of the Ikata plant.

 

The plaintiffs argued that Yonden cannot accurately assess the location of faults, because it did not exercise “three dimensional test” which enables precise research of faults. They also claimed that the assessment of volcanic eruption in Kyushu was too insufficient to avoid possible damages by volcanic ashes flying toward Ikata.

 

The Oita District Court found that three dimensional test was not necessarily be required for the assessment of Ikata plant, recognizing new regulation standard made by Nuclear Regulatory Commission after the severe accident in Fukushima as sufficient for the research of underground geological structure. It found Yonden’s assessment to be rational when it concluded that there had been no active fault around the site based on the sound wave examination from the sea surface.

 

The court also approved the assessment of Yonden on Aso volcanic mountain in Kumamoto. Yonden evaluated that the situation of magma inside Aso mountain was not close to major eruption. The court regarded it as endorsed by scientifically rational reasons.

 

The court made that decision, mostly standing on the side of Yonden. The plaintiffs argued that the decision was drawn for supporting prepared conclusion. Yonden supported the court decision as approving their argument that the reactor #3 was safe.

 

Geographical characteristic of the location of Ikata plant can be paralleled with Shika Nuclear Power Plant of Hokuriku Electric Power Company. Located on the base of Noto Peninsula, where a major earthquake occurred in January, Shika plant revealed problems in evacuation in case the roads were destroyed by earthquake. Not only the people in Oita or Hiroshima, but the people living in the Sadamisaki Peninsula are worried about possible accident in Ikata plant.

 

The government of Japan plans to reactivate a reactor in Shimane plant in August and another in Onagawa, Miyagi, in September. People around those nuclear power plants embraces the same anxiety on where should they go in the time of nuclear accident.