Japan Onagawa Nuclear Reactor Restart Halted Due to Equipment Issues After 13-Year Shutdown

However, Tohoku Electric Power Company reported that a malfunction in a neutron data-related instrument inside the reactor forced its shutdown just five days after it was restarted. The utility confirmed that the reactor was functioning normally and posed no radiation threat to the environment. In light of safety concerns raised by local residents, Tohoku Electric decided to halt operations to conduct a thorough re-evaluation of the equipment. No new date for the reactor’s restart has been provided.

The Onagawa plant is located approximately 100 kilometers (62 miles) north of the Fukushima Daiichi Nuclear Power Plant, where a 9.0 magnitude earthquake and subsequent tsunami in March 2011 led to the meltdown of three reactors and the release of significant radiation. Despite the tsunami reaching heights of 13 meters (42 feet) and impacting the Onagawa plant, it successfully maintained crucial cooling systems in its three reactors, enabling a safe shutdown.

Following the Fukushima disaster, Japan’s 54 commercial nuclear power plants were taken offline for safety inspections and upgrades. The Onagawa No. 2 reactor is the 13th of the 33 reactors deemed operable to be restarted.

Last year, the Japanese government adopted a plan to maximize the use of nuclear energy, emphasizing the need to accelerate the restart of reactors to ensure a stable energy supply and meet its commitment to achieve carbon neutrality by 2050.

Concerns regarding the government’s revitalized push for nuclear energy have intensified following a 7.5 magnitude earthquake that struck the Noto Peninsula on January 1, 2024, resulting in over 400 fatalities and damage to more than 100,000 structures. The earthquake caused minor damage to two nearby nuclear facilities, revealing inadequate evacuation plans for the region.