The earthquake that occurred late on the 17th was the first to record a seismic intensity of lower 6 in Shikoku. Shikoku Electric Power’s Ikata nuclear power plant in Ehime Prefecture continues to operate, but generator output has decreased by 2%. At a typical nuclear power plant on a peninsula, the evacuation risk that emerged in the Noto Peninsula earthquake has resurfaced. In addition to the Nankai Trough mega-earthquake, which falls within the assumed epicenter area, there are many other earthquake risks. If a major earthquake hits, will you really be able to escape? How are local residents and surrounding parties taking it? (Shintaro Soda, Yuichiro Yamada)
Shikoku Electric Power Ikata Nuclear Power PlantIt is located in Ikata Town, Ehime Prefecture, on the Seto Inland Sea side of the Sadamisaki Peninsula, which extends toward Kyushu. All are pressurized water reactors, and Unit 1 began commercial operation in 1977, Unit 2 in 1982, and Unit 3 in 1994. Currently, Units 1 and 2 are being decommissioned. Unit 3 (output: 890,000 kilowatts) had been shut down for regular inspections since December 2019, but restarted in December 2021.
Ikata Nuclear Power Plant has many facilities on its premises.Units 1, 2, and 3 from left = March 2020
◆“Terrible shaking, is the nuclear power plant okay?”
“It was a huge lateral tremor, and it was the scariest earthquake I’ve ever experienced. At the same time, I was worried about whether the nuclear power plant would be okay.”
Noriko Kondo (69), a representative of the Association to Eliminate Nuclear Power from Ikata, who lives in Yawatahama City, Ehime Prefecture, about 10 kilometers east of the Ikata Nuclear Power Plant, looks back at the time of the earthquake. The city’s seismic intensity was lower than 5. The elevator in her apartment complex stopped working, and she said she felt a tremor stronger than the 2014 earthquake that hit Seiyo City in the same prefecture, registering a seismic intensity of 5 or above.
The Noto Peninsula earthquake in January highlighted the risk of evacuation from nuclear power plants on the peninsula. Approximately 110,000 people live within a 30km radius of the Ikata Nuclear Power Plant on the Sadamisaki Peninsula, which requires an evacuation plan. In the event of an accident, the prefecture and other local governments are considering evacuating by land or by boat from a port to places like Oita Prefecture.
◆“If we try to escape all at once, there will be a huge traffic jam.”
However, Kondo expresses concern, saying, “This area is in a mountainous area.During the heavy rains in western Japan, landslides occurred and roads were closed.If a bigger earthquake were to occur, the roads would be cut off and there would be no place to escape.” . During evacuation drills simulating a nuclear power plant accident, strong winds sometimes made it impossible for helicopters to land or ships to dock. “Considering the possibility of a tsunami, evacuation by boat is not realistic. There are few roads, so if everyone tried to escape at once, it would cause huge traffic jams and confusion.”
Kenichiro Kamata (76), who runs a fishing industry in a village facing the Seto Inland Sea in Yawatahama City, about 6 kilometers from the nuclear power plant, said, “There is only one evacuation route nearby.If the road is blocked by a landslide or the sea gets rough due to a tsunami, we will be worried.” We can’t escape by boat. I don’t think the evacuation plan will go as planned.”
This time, Ikata Town, where the nuclear power plant is located, experienced a seismic intensity of 4. Shikoku Electric Power Co. announced on the 18th that a valve in the heater tank that removes moisture from the steam sent to the turbine at Ikata Nuclear Power Plant Unit 3 malfunctioned, reducing thermal efficiency and reducing generator output by approximately 2%. The train continues to operate, saying there are “no safety issues.”
People raise their voices against the restart of the No. 3 reactor at Shikoku Electric Power’s Ikata Nuclear Power Plant in Nagatacho, Tokyo, August 2016.
◆ “I want dangerous nuclear power plants to stop.”
Still, Mr. Kamata expressed his concerns, saying, “If an earthquake with an intensity of 4 can have an impact, what will happen if an earthquake with an intensity of 7 occurs?If a tsunami were to come, unimaginable damage would occur.” She says, “As people who depend on the sea for sustenance, what should I do if I can’t return to my hometown due to a nuclear accident like in Fukushima?I want dangerous nuclear power plants to stop, and they need to be eliminated as soon as possible.”
Lawyer Nobuo Komoda, who is the head of the legal team in the lawsuit to halt the operation of the Ikata nuclear power plant, said that given the local situation, where villages are scattered on a long, narrow peninsula and there is only one main evacuation road, “Ikata is even more isolated than Noto. “Settlements will occur.” “The village is a depopulated area, and most of the people are elderly (who need support during evacuation).The evacuation plan is not effective.It is clear that if an earthquake and nuclear power plant accident were to occur, it would be a catastrophe, and Ikata originally built a nuclear power plant. “It’s located in a place where it shouldn’t be.”
◆Two major earthquakes at the end of the Edo period
Historically, large earthquakes have occurred in this region. In 1854, at the end of the Edo period, the Ansei Nankai earthquake with a magnitude (M) of 8.4 occurred. Two days later, an M7.4 earthquake occurred on the Sadamisaki Peninsula near the epicenter.
There are risks other than the Nankai Trough mega-earthquake. The Median Tectonic Line, a fault zone that runs from eastern Japan to Kyushu, runs north of the nuclear power plant. Nuclear power plant lawsuits have been occurring one after another not only locally but also in Oita, Hiroshima, and Yamaguchi.
“Last night there was a lot of shaking, and when I watched the TV, I saw that the epicenter was near the Ikata nuclear power plant, which made me feel scared,” said a shiitake farmer in Kitsuki City, Oita Prefecture, and co-leader of the plaintiff group in the lawsuit to stop operations in Oita. Satsuki Nakayamada (69), who serves as During the Fukushima nuclear power plant accident in 2011, the price of shiitake mushrooms produced in Oita Prefecture fell. She is concerned that, “If an accident were to occur in Ikata, it would not only be damage to our reputation, but also a major blow, making it impossible for us to live.”
Hokuriku Electric Power’s Shiga Nuclear Power Plant = January 2024 (from the headquarters helicopter “Manazuru”)
◆High court ruling that the location is inappropriate
The lawsuit alleges that Shiden’s risk assessment against earthquakes and volcanoes was insufficient, but the Oita District Court dismissed the request in a ruling in March this year, stating that there was “no concrete danger.” In response to the recent earthquake, he said, “There is a plan for residents of the Sadamisaki Peninsula to evacuate to Oita by ferry, but it is absolutely impossible.”
In 2017, the Hiroshima High Court ruled that Shikoku Electric Power’s assumptions about the Aso caldera, 130 kilometers from the Ikata nuclear power plant, were understated and ordered a suspension of operation of Unit 3. It was pointed out that the possibility of volcanic activity was “sufficiently small and cannot be determined,” and the possibility that pyroclastic flows from past eruptions reached the nuclear power plant site was considered “unsuitable.” However, Shikoku Electric Power filed an objection. It was covered in 2018.
In 2020, the same high court ordered an injunction on the basis that the fault investigation was insufficient, but it was rescinded after receiving objections. Currently, a lawsuit is being filed in the Hiroshima District Court by 350 people, including about 20 atomic bomb survivors, seeking an injunction to stop them from driving.
◆Inside the hypocenter area of the Nankai Trough mega-earthquake
Isaac Tetsuno (75), a member of the plaintiffs’ office, is concerned that the epicenter of this earthquake occurred within the assumed epicenter area of the Nankai Trough mega-earthquake. “In the Noto Peninsula earthquake, there was unexpected interlocking of active faults.We don’t know when or where an earthquake will occur, but nuclear operators are pretending that what they don’t know is “not happening.” Although Hiroshima is about 100 kilometers away from the Ikata nuclear power plant, he says, “If an accident occurs, there is still the fear of internal radiation exposure.Hiroshima, the site of the atomic bombing, must not be exposed to radiation again.”
A village in Nie-cho, Suzu City, Ishikawa Prefecture, isolated due to a large-scale landslide (January 2024, from the headquarters helicopter “Wakazuru”)
In Kaminoseki Town, Yamaguchi Prefecture, residents opposed the construction of the Chugoku Electric Power Company’s Kaminoseki nuclear power plant, and plans have been suspended. Toshiyasu Shimizu (69), representative of the Iwaishima Islanders’ Association to Prevent the Construction of the Kaminoseki Nuclear Power Plant, said, “If the sea breaks out, how do we evacuate from the remote island? “I’ll run out,” he says.
◆Pushing risks on remote areas
Evacuation from the peninsula is once again seen as an issue. Kenichi Oshima, a professor of environmental economics at Ryukoku University, said, “Nuclear power plants are often located on peninsulas or in remote areas. This is because the government’s guidelines require that the area around the site be a low-population area. “We have selected areas that are inadequate and difficult to escape from, and imposed risks in a discriminatory manner,” he says, pointing out the structural problems of nuclear power policy.
“If you look at the reality of the Noto Peninsula earthquake, the evacuation plan is nothing more than a ‘picture-filled cake’.The same is true of other places, Ikata cannot be called safe in its current state.As the population continues to decline, evacuation plans are becoming increasingly safer. We need to shut down the nuclear power plant and verify whether an effective evacuation is possible.”
◆Desk memo
In the wake of the Great East Japan Earthquake, the “Comb Teeth Strategy” was said to have been a success, first restoring the main inland roads and then connecting roads to the coast. Even so, the Fukushima nuclear power plant accident caused many people to evacuate from place to place, resulting in many related deaths. Does this weakened country have the capacity to deal with both a major earthquake and a nuclear disaster? (Book)