The Sapporo District Court has issued a ruling granting a request for an injunction against the operation of the three-unit Tomari nuclear power plant on Japan's northern Hokkaido island. Operator Hokkaido Electric Power Company said it will appeal against the decision.

The Tomari plant (Image: Mugu-shisai/Wikipedia)

In November 2011, a lawsuit was filed with the Sapporo District Court by about 1200 plaintiffs, including local residents. They claimed the plant has insufficient countermeasures against earthquakes and tsunamis and called for it to be decommissioned.

The plaintiffs argued that there is an active fault near the Tomari plant, which Hokkaido EPC had not taken into consideration in the plant's earthquake protection measures. They also claimed soil liquefaction could occur around sea walls near the plant in the event of an earthquake and the utility has not taken sufficient measures to protect against tsunamis.

Hokkaido EPC has stressed that there are no active faults near the plant and the possibility of soil liquefaction around the sea walls is low.

The court ruled in the plaintiffs' favour on 31 May, with presiding judge Tetsuya Taniguchi saying that the Tomari plant does not meet required safety standards against tsunami and ordered Hokkaido EPC not to operate the plant. However, it rejected their request for the plant to be decommissioned.

"Since the lawsuit was filed with the Sapporo District Court in November 2011, we have repeatedly explained the safety of the Tomari nuclear power plant from a scientific and technical point of view, based on the latest knowledge, so that the court can understand it," Hokkaido EPC said in a statement.

It added: "Today's decision is regrettable ... and we cannot accept it at all, so we will promptly proceed with the appeal."

The Tomari plant comprises two 550 MWe pressurised water reactors (PWRs) (units 1 and 2) and a 912 MWe PWR (unit 3). All three units have been offline since unit 3 stopped power generation for regular inspection in 2012. Hokkaido EPC is seeking regulatory approval to restart all three reactors.

Researched and written by World Nuclear News