A nuclear reactor in northeastern Japan will be halted just days after becoming the first one to restart in the region since the 2011 earthquake and tsunami disaster, the plant operator said Sunday, citing the need for checkups.
Tohoku Electric Power Co. said it has not confirmed any abnormalities in the No. 2 reactor at the Onagawa plant in Miyagi Prefecture. The latest decision stemmed from a problem in sending in a device necessary to confirm the reactor’s condition.
The No. 2 unit on Tuesday joined a dozen reactors in the country that have been rebooted after meeting more stringent safety standards in the wake of the Fukushima Daiichi nuclear power plant accident, triggered by the quake-tsunami disaster that devastated coastal areas including in Miyagi Prefecture.
Tohoku Electric Power was planning to restart power generation and transmission on Sunday but decided to postpone it after failing to place the device to adjust the readings of a neutron detector inside the reactor.
The device was manually pulled out and recovered inside a shielded container.
The utility said it will investigate the cause of the incident and decide when to resume power generation. It was not immediately clear how long the postponement will be.
The restart of the Onagawa reactor also marked the first time in Japan that a boiling water reactor — the same type as the Fukushima Daiichi reactors that suffered fuel meltdowns — has been brought online since the 2011 disaster.
The Onagawa plant, located closest to the epicenter of the magnitude 9.0 earthquake on March 11, 2011, was struck by tsunami waves around 13 meters high.
The No. 2 reactor cleared safety screening in February 2020 under tougher post-Fukushima crisis safety standards and gained local consent to resume operations. The No. 1 unit will be decommissioned.
