On the 7th, the Oita District Court ruled on the 7th in a lawsuit in which residents of Oita Prefecture, on the opposite coast of the Ikata Nuclear Power Plant in Ehime Prefecture, requested the suspension of operation, claiming that measures against earthquakes and eruptions were inadequate. I will pass the verdict.



This is the first judgment in a series of class action lawsuits, and the judicial decisions regarding safety measures at nuclear power plants are attracting attention.

Regarding Shikoku Electric Power's Ikata Nuclear Power Plant Unit 3 in Ehime Prefecture, 569 residents of Oita Prefecture, on the opposite shore, are demanding that Shikoku Electric Power suspend operations, claiming that measures against earthquakes and eruptions are inadequate.



In previous lawsuits,


the residents said, ``Despite the fact that there is a possibility that there are other active faults near the nuclear power plant, in addition to the ``Median Tectonic Line Fault Zone,'' which is one of the largest in Japan, we do not have a detailed understanding of the underground structure.''


▼In response, Shikoku Electric Power

claimed that ``three-dimensional exploration'' was not carried out, which violates the new regulatory standards established by the Nuclear Regulation Authority after the accident at the Fukushima Daiichi Nuclear Power Plant.

He stated that it was not necessary, but insisted that ``safety is ensured based on the latest knowledge.''



In addition


, residents argued that measures to prepare for a huge eruption of Mt. Aso in Kumamoto Prefecture are necessary but insufficient, but


Shikoku Electric Power Co. said that a huge eruption could occur at Mt. Aso during the operating period of the nuclear power plant. I objected that the sex was small enough.



Regarding the Ikata Nuclear Power Plant Unit 3, the Hiroshima High Court twice issued provisional injunctions not allowing operation, pointing out the risks of earthquakes and eruptions, but the decision was later rescinded, and judgments were divided.



This is the first ruling in a series of class action lawsuits filed in Ehime, Hiroshima, and Yamaguchi, and is also attracting attention as a judicial decision regarding safety measures for nuclear power plants after the Noto Peninsula earthquake.



The verdict will be handed down at Oita District Court from 2pm on the 7th.

What is Shikoku Electric Power Ikata Nuclear Power Plant?

Shikoku Electric Power's Ikata Nuclear Power Plant is located on the Sadamisaki Peninsula in Ikata Town, Ehime Prefecture, about 70 kilometers from the center of Oita City on the opposite shore.



Initially, the Ikata Nuclear Power Plant had Units 1 to 3 in operation, but it has been decided that Units 1 and 2 will be decommissioned, and only Unit 3 is currently in operation.



Following the accident at Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Plant, concerns about the safety of nuclear power plants have increased, and a class action lawsuit has been filed by residents of Ehime Prefecture, where the nuclear power plant is located, as well as Hiroshima, Yamaguchi, and Oita Prefectures.



There have been a number of different judicial decisions regarding the safety of Unit 3 at the Ikata Nuclear Power Plant, and operations have been repeatedly halted and restarted.



▽In December 2017, the Hiroshima High Court issued a decision ordering the suspension of operation, pointing out the risk of volcanic eruption, in response to a petition for a provisional disposition by Hiroshima Prefecture residents and others requesting suspension of operation.



However, Shikoku Electric Power filed an objection, and in September 2018, a different presiding judge at the Hiroshima High Court reversed the decision and allowed operation.



Additionally


, in January 2020, the Hiroshima High Court issued a decision not to allow drivers to drive again, citing a ``risk of serious damage caused by an earthquake or volcanic eruption'' in response to a request for a provisional disposition by a resident of Yamaguchi Prefecture. However, this decision was also reversed the following year.



After that, Ikata Nuclear Power Plant Unit 3 had to be shut down at times due to a series of troubles such as a temporary loss of power and violations of nuclear power plant safety regulations, but it is currently continuing to operate after explanations to the local community and periodic inspections. Masu.

History of class action lawsuit demanding shutdown of Ikata nuclear power plant

A movement to halt the operation of Ikata Nuclear Power Plant Unit 3 began eight years ago in Oita Prefecture.



Eight years ago, as aftershocks from the Kumamoto earthquake that occurred in April of this year continued to occur in Oita Prefecture, a group of residents called for a review of the impact of the earthquake on the safety of the Ikata Nuclear Power Plant in Ehime Prefecture on the opposite shore. We filed a petition with the Oita District Court for a provisional disposition to suspend driving.



In September, while the preliminary disposition was being heard, 264 residents of Oita Prefecture filed a class action lawsuit demanding that the operation of Unit 3 of the Ikata Nuclear Power Plant be halted.



Oita is the third class action lawsuit filed in the Ikata Nuclear Power Plant Unit 3, following Matsuyama District Court and Hiroshima District Court.



After that, three additional lawsuits were filed in May 2017, May 2018, and July 2019, bringing the number of plaintiffs to 569.



While the trial and the hearing on the provisional disposition proceeded simultaneously, the Oita District Court ruled in September 2018, ``There are irrational points in the Nuclear Regulation Authority's determination that measures against earthquakes and volcanoes comply with new regulatory standards.'' The court rejected the request for a provisional injunction to stop the operation, stating, "There is no specific danger to the lives or bodies of residents."



After that, the remaining trials involved questioning experts and other witnesses, and all hearings concluded in June of last year, about seven years after the lawsuit was filed.



In order to avoid prolonging the trial and preventing the issues from becoming too technical, the residents have narrowed the issue to safety measures against earthquakes and volcanic eruptions, and have limited the number of witnesses to one expert. is.

The main issue in this trial is

The main issue in this trial was whether the measures taken at Unit 3 of the Ikata Nuclear Power Plant to deal with earthquakes and volcanic eruptions were sufficient.



First of all, with regard to earthquakes


, residents are concerned about the need to understand the underground structure in detail, even though there is a possibility that there are other active faults in addition to Japan's largest ``Median Tectonic Line Fault Zone'' near the nuclear power plant. They argued that the company had not carried out "three-dimensional exploration," which violated the new regulatory standards established by the Nuclear Regulation Authority after the Fukushima Daiichi nuclear power plant accident, and that safety evaluations were insufficient without "three-dimensional exploration." .



On the other hand, Shikoku Electric Power stated that the new regulatory standards require a three-dimensional understanding of the underground structure and do not require ``three-dimensional exploration,'' but that it has used previous boring surveys and seismic waves. He argued that it was clear that the geological boundary was not an active fault due to the method used to generate it.



Regarding the second point of contention, the eruption,


residents argue


that countermeasures to anticipate a huge eruption are needed at Mt. Aso in Kumamoto Prefecture, located approximately 130 kilometers west of the Ikata Nuclear Power Plant, but are insufficient, and that a


huge eruption has occurred. It was argued that there was a risk of pyroclastic flows reaching the nuclear power plant premises.



On the other hand,


Shikoku Electric Power argued


that the possibility of a huge eruption occurring at Mt. Aso during the operating period of the nuclear power plant is sufficiently small,


and that even if a huge eruption were to occur, pyroclastic flows would not reach the site based on field survey results.

Litigation over nuclear power plants: Judicial decisions to date

To date, there have been 11 judicial decisions that have allowed complaints by residents to stop the operation of nuclear power plants or cancel installation permits. An increasing number of judgments are recognizing this.



Lawsuits demanding the shutdown of nuclear power plants have been filed in courts around the country since the 1970s, but before the 2011 nuclear power plant accident, lawsuits were dismissed on grounds such as ``there is no specific danger.'' In most cases, it was.



Around this time, the lawsuit by the residents was accepted


in the court case regarding Fukui Prefecture's Monju fast breeder reactor, and in 2003 the Kanazawa branch of the Nagoya High Court invalidated the government's construction permit, and


in 2006. These two cases are based on the Kanazawa District Court's ruling ordering the shutdown of the No. 2 reactor at the Shiga Nuclear Power Plant in Ishikawa Prefecture.



Both lawsuits were subsequently dismissed, and the residents' defeat was confirmed.



On the other hand, after the nuclear power plant accident, there were nine cases in which complaints by residents were approved, and in some cases, electric power companies were forced to take action.



The breakdown is


: 2 at the Oi Nuclear Power Plant in Fukui Prefecture


, 3 at the Takahama Nuclear


Power Plant, 2 at the Ikata Nuclear Power Plant in Ehime Prefecture


, 1 at the Tokai Daini Nuclear Power Plant in Ibaraki Prefecture,


and 1 at the Tomari Nuclear Power Plant in Hokkaido.



Of these, the Fukui District Court in 2015 and the Otsu District Court in 2016 twice issued provisional dispositions ordering the suspension of operations at Takahama Nuclear Power Plant Units 3 and 4.



In response to the Otsu District Court's decision, Kansai Electric Power Company shut down the No. 3 nuclear reactor that was in operation, making this the first case in which an operating nuclear power plant was shut down by a judicial decision.



After that, the decision to suspend operations was rescinded, and Takahama Nuclear Power Plant Units 3 and 4 have resumed operation.



In addition, regarding the Ikata Nuclear Power Plant Unit 3, which is the subject of this lawsuit, the Hiroshima High Court issued provisional disposition orders ordering the suspension of operations in 2017 and 2020.



It was not operational at the time, undergoing routine inspections, and remained in a state of being unable to operate until the decision was reversed.

Changes in the points that courts emphasize

There are also changes in the points that courts place emphasis on.



The Osaka District Court's ruling in 2020 revoking the permission for the installation of Units 3 and 4 at the Oi Nuclear Power Plant pointed out flaws in the Nuclear Regulation Authority's review process.



▽In 2021, the Mito District Court pointed out the flaws in the evacuation plan for the Tokai Daini Nuclear Power Plant and decided not to allow it to restart.



In addition to the safety of nuclear power plants themselves, the regulations required efforts to ensure the safety of residents in the event of an accident, making the content very difficult for operators.



These two cases are still being heard at the High Court.