The Hiroshima High Court on Friday revoked a lower court decision and ordered Shikoku Electric Power Co. to suspend its only operable nuclear reactor in Ehime Prefecture because its preparations for a potential eruption of Mount Aso are inadequate.
The high court also said the Nuclear Regulatory Agency’s regulations were unreasonable.
The ruling marks the second time the high court has ordered a halt of the No. 3 reactor at the Ikata nuclear power plant.
The reactor had been shut for regular maintenance work since late December and was likely to restart within a couple of months, but now must remain idled pending an appeal. Shares in the company, which didn’t disclose the court’s reason for issuing the order, plunged on the news, ending the day down 6 percent at ¥957.
Residents near reactors have been filing numerous lawsuits against nuclear power operations in recent years, leading to some temporary closures. Utilities have generally been successful in getting rulings against them overturned on appeal.
The reactor is currently idled for scheduled inspections and the removal of spent mixed-oxide fuel was completed on Wednesday. It is expected to be restarted on April 27.
A previous order forcing a halt in operations was issued by the Hiroshima High Court in December 2017, citing the risk of Mount Aso erupting. The same court then overturned the decision in September 2018 on appeal, and Shikoku Electric restarted the reactor a month later.
Read more at Shikoku Electric again ordered to halt Ikata nuclear reactor over volcano risk