Tohoku Electric to Decommission Onagawa N-Plant Reactor

October 26, 2018

Sendai, Miyagi Pref.- Tohoku Electric Power Co. said Thursday it will decommission the aging No. 1 reactor at its Onagawa nuclear power plant in Miyagi Prefecture, northeastern Japan.

It will be the first time for Tohoku Electric to scrap a reactor.

In a meeting on Thursday afternoon, Tohoku Electric President Hiroya Harada told Miyagi Governor Yoshihiro Murai that his company has decided to decommission the No. 1 reactor, which started operations in June 1984.

The reactor is the oldest among the four reactors operated by Tohoku Electric.

The company concluded that it is not worth spending a huge amount of money to strengthen safety measures needed to reactivate the reactor.

"We decided on the decommissioning after comprehensively examining various issues, including technical problems related to work on safety measures required for a restart and the output of the reactor as well as the reactor's operational life after reactivation," Harada said in the meeting.

"We'll proceed with decommissioning work by putting top priority on safety," he said.

Murai said he respects the decommissioning decision while calling on the company to make all-out efforts to ensure stable power supplies.

Of its other three reactors, Tohoku Electric has applied for the Nuclear Regulation Authority's safety screenings for the No. 2 reactor at the Onagawa plant and the reactor at the Higashidori plant in Aomori Prefecture, northeastern Japan.

The company also plans to apply for safety screening for the No. 3 reactor at the Onagawa plant.

It is estimated to take 30 to 40 years to scrap the Onagawa No. 1 reactor. Decommissioning costs were estimated at 43.2 billion yen as of fiscal 2017.

At a press conference on Thursday, Harada said that his company will invest its management resources in the Onagawa No. 2 and other reactors in order to improve their safety, showing the power supplier's hope to resume nuclear power generation at an early date.

The 524,000-kilowatt Onagawa No. 1 reactor is a boiling-water reactor, the same type as the reactors at Tokyo Electric Power Company Holdings Inc.'s Fukushima No. 1 plant, which suffered triple meltdowns due to damage from the March 2011 earthquake and tsunami.

The Onagawa plant, straddling the city of Ishinomaki and the town of Onagawa, has been idle since it automatically halted its operations due to the impact of the March 2011 disaster. Jiji Press