The Matsue branch of Hiroshima High Court has dismissed a petition seeking to stop Chugoku Electric Power Co from restarting operations at unit 2 of its Shimane NPP in western Japan. The petition was filed in March 2023 by four residents in the prefectures of Shimane and Tottori, which neighbour each other. It raised concerns over the validity of the design basis earthquake ground motions for the reactor and the effectiveness of evacuation plans.

Judge Yoshiki Matsutani said that it is necessary to take regional characteristics into account in deciding the design basis earthquake ground motions. The residents claimed that the assumed level of ground motions was unreasonable as it was lower than a strong quake that occurred in western Tottori in October 2000 and the Great East Japan Earthquake in March 2011. However, the judge concluded: “It cannot be said that it is reasonable to simply compare numbers.”

He also dismissed the residents’ claim that the evacuation plans were inadequate, saying that the specific risk of a serious accident occurring at the plant in Matsue, the capital of Shimane, was not sufficiently explained.

The Shimane No. 2 reactor is the only reactor in the country located in a prefectural capital. The 820 MWe unit, which started operations in 1989, is a boiling-water reactor, the same type as the reactors at Tokyo Electric Power Company Holdings’ Fukushima Daiichi NPP, which suffered a triple meltdown following the Great East Japan Earthquake. Chugoku Electric plans to reactivate Shimane 2 in December. The unit is slated to become the second of its type to restart, following the planned operation in September of unit 2 at Tohoku Electric Power Co’s Onagawa plant in Miyagi Prefecture.