Japan’s Hiroshima high court on 18 March reversed its earlier order to shut down unit 3 at Shikoku Electric Power Co’s Ikata NPP in Ehime Prefecture after an ongoing periodic inspection is completed later this year. In 2017, three residents of Yamaguchi Prefecture living near the Ikata plant filed a request to suspend the plant with the Iwakuni branch of the Yamaguchi District Court, which rejected it in March 2019.
However, in response to the residents' appeal, the Hiroshima High Court in January 2020 ordered the utility to suspend the reactor, saying the operator's risk estimates and research were insufficient and the Nuclear Regulation Authority's (NRA’s) judgement to permit the operation was incorrect. The suspension order was to be in place until a separate civil lawsuit demanding the halt of the Ikata plant at the Iwakuni branch concluded, and this is still awaited. In the meantime, Shikoku Electric filed an objection in February 2020 resulting in the latest decision handed down by a different High Court judge.
In the wake of this ruling, Shikoku Electric will speed up anti-terror upgrades at the plant in order to restart the reactor at the end of October as originally planned. Key issues in the lawsuit were a potential active fault near the plant and risks linked to volcanic ash from a possible eruption at Mount Aso's caldera in Kumamoto Prefecture, some 130 kilometres from the plant.
Presiding Judge Kunihiko Yokomizo ruled that "there is nothing unreasonable in Shikoku Electric's claim that its detailed sonic probe has found no active faults near the plant”. He rejected the argument that the probe was inaccurate and its result incorrect. He also dismissed the petitioners' complaint about volcanic ash, saying, "It cannot be acknowledged based on current scientific knowledge that the possibility of an eruption is specifically high."
Shikoku President and CEO Keisuke Nagai said in a statement that the company had "carefully insisted and proved" to the court that the Ikata plant has sufficient safety against risks posed by earthquakes and volcanoes. "This decision is based on our previous assertion that the safety of Ikata nuclear power plant unit 3 is ensured," Nagai said. "It was approved by the court and we believe that we have received a reasonable decision." He noted Ikata 3 is "a core power source that supports stable and inexpensive power supply".
The same day, Mito District Court's barred the restart of unit 2 at Japan Atomic Power Co’s (JAPC’s) Tokai NPP in Ibaraki prefecture. The facility is currently offline, and in any event will not be ready to restart until at least December 2022 when it completes its required upgrades. The court cited a lack of evacuation plans despite persisting safety concerns.
In handing down the ruling, Presiding Judge Eiko Maeda said it is not possible to say that "attainable evacuation plans and a disaster risk reduction system are in place”. The plaintiffs, who live in Ibaraki and surrounding prefecture,s have expressed concerns, as around 940,000 people live within a 30-kilometre radius of the plant. Maeda noted that only five of the 14 municipalities within the radius have formulated regional evacuation plans in the event of a disaster, and that those need improvement. The current situation "poses a concrete danger that could infringe on personal rights" of local residents, he said. On the other hand, the court did not find any problems with the plant's earthquake and tsunami estimates or with the quake resistance of its building.
Tokai 2, which started commercial operation in 1978, has remained offline while JAPC undertakes work required to meet stricter safety regulations set after the 2011 Fukushima disaster. JAPC said it will appeal against the ruling. It has been seeking to restart the plant, after gaining approval from NRA in November 2018 for the extension of its operations beyond the preliminary 40-year limit. This was the second case of a court ordering the suspension of a reactor. In December 2020, the Osaka District Court had revoked government approval of the operation of units 3&4 of Kansai Electric Power Co's Ohi NPP in Fukui Prefecture.