Restart of Reactor at Onagawa Nuclear Power Plant: Marking A Step Toward Steady, Stable Supply of Electricity

Editorial

15:09 JST, October 31, 2024

Nuclear power plants are indispensable as a power source to achieve both a stable supply of electricity and decarbonization. It is necessary to steadily promote the resumption of operations for reactors at nuclear power plants in various regions and build up the capacity of the electricity supply.

Tohoku Electric Power Co. has restarted the No. 2 reactor at the Onagawa nuclear power plant in Miyagi Prefecture. This is the first nuclear reactor in eastern Japan to be restarted since the 2011 Great East Japan Earthquake, and is also the first restart of a boiling water reactor in the nation, the same type that caused the accident at Tokyo Electric Power Company Holdings, Inc.’s Fukushima No. 1 nuclear power plant.

It can be said to be a major step forward in making the most of nuclear power plants to ensure a stable energy supply.

Until now, the restart of pressurized water reactors has been happening first. A total of 12 reactors of this type have been restarted in western Japan. As they have larger containment vessels than those of boiling water reactors, they are considered less prone to accidents, and the Nuclear Regulation Authority’s safety screenings for them have progressed relatively quickly.

In western Japan, the resumption of the operations of reactors has proceeded smoothly. But as the resumption has been delayed in eastern Japan and operators have continued to rely on thermal power generation, electricity prices remain high in eastern Japan. It is hoped that reactors will be restarted promptly in eastern Japan as well, and that the disparity between regions will narrow.

The Onagawa plant was closest to the epicenter of the Great East Japan Earthquake and was hit by similar levels of tremors and tsunami as those of the Fukushima No. 1 nuclear power plant. However, because of its elevated location, the plant was not hit directly by tsunami and all of its reactors were safely shut down.

In addition, Tohoku Electric reinforced earthquake resistance for its facilities and piping after the disaster to meet the new regulatory standards that were created after the accident. Seawalls that are 29 meters above sea level were also constructed in anticipation of tsunami of 20 meters or more.

Immediately after the 2011 disaster, the Onagawa plant accepted in the gymnasium on its premises more than 300 residents living nearby who lost their homes due to the tsunami. This aspect, in some respects, may have made it relatively easy to gain the understanding of the local people.

Regarding boiling water reactors, following the Onagawa plant, Chugoku Electric Power Co. plans to restart the No. 2 reactor at its Shimane nuclear power plant in December. It is hoped that Tohoku Electric and Chugoku Electric will place the highest priority on safety and regain public trust in boiling water reactors.

TEPCO’s Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture was initially the first to undergo safety screenings for boiling water reactors, but a spate of inadequacies in anti-terrorism measures and other problems later led to increased distrust of TEPCO in the local communities. The governor of Niigata Prefecture also has not agreed to restarting the reactors, and there are no prospects for restarts there.

In Japan, the construction of state-of-the-art semiconductor factories and data centers, which consume large amounts of electricity, continues, raising concerns about future power shortages. The country must also be prepared for a situation in which the energy supply could be disrupted by a further deterioration of the situation in the Middle East.

The central government and the Niigata prefectural government should take a much broader perspective and cooperate to achieve an early restart of reactors at the Kashiwazaki-Kariwa plant.

(From The Yomiuri Shimbun, Oct. 31, 2024)