YAMAGUCHI - A district court on Friday rejected a plea by residents to halt a reactor at the Ikata nuclear power plant in Ehime Prefecture.
The decision by the Iwakuni branch of the Yamaguchi District Court is in line with rulings made by other regional courts and allows the No. 3 reactor to continue operating. The plant is managed by Shikoku Electric Power Co.
Unit No. 3, the sole remaining reactor at the plant, passed the state safety screening process that was revamped in the wake of the 2011 Fukushima nuclear crisis. But concerns remain about its safety, which led residents to turn to the courts to seek an injunction.
Of the more than 30 reactors in Japan, excluding those set to be decommissioned, only a few are in operation.
A previous order forcing a halt in operations was issued by the Hiroshima High Court in December 2017, citing the risk of an eruption at the caldera of Mount Aso about 130 kilometers away. The decision was overturned in September 2018 and the utility company restarted the unit a month later.
The Yamaguchi court considered whether the utility and the Nuclear Regulation Authority’s estimates of risks from eruptions at the volcano in Kumamoto Prefecture were reasonable. It also looked at the potential size of a quake anticipated by scientists in seismically active areas off the central and western coasts, a key factor in a reactor’s quake-resistance, when ruling.
In the decision, the presiding judge, Akira Onose, said the possibility that a large eruption might occur during the reactor’s operating life is low and the regulatory authority’s safety standards are adequate.
The No. 3 reactor at Ikata began operations in 1994.
The plaintiffs pointed out that pyroclastic flows from possible catastrophic eruptions could reach the plant.
They also said the utility underestimated the fact that the reactor sits on the median tectonic line, a massive fault zone, as well as the potential damage from a massive earthquake off the Pacific coast of central and western Japan.
“We find the decision appropriate. We will ensure safe and stable operation while keeping in mind that there is no end to efforts to improve safety,” Shikoku Electric said in a statement.
The Ikata No. 3 reactor was temporarily halted in April 2011 for a periodic inspection and was restarted in August 2016.
Separate demands to halt the reactor had been turned down by regional courts in Matsuyama, Ehime Prefecture, and Oita.