Onagawa Nuclear Plant Reactor Resumes Operations; First Eastern Japan Plant to Restart Since 2011 Disaster (UPDATE 1)

The Yomiuri Shimbun

15:56 JST, October 29, 2024 (updated at 19:20 JST)

Tohoku Electric Power Co. restarted the Onagawa nuclear power plant’s No. 2 reactor in Miyagi Prefecture on Tuesday. The company conducted final inspections of the facilities ahead of the reactivation of the reactor earlier on the day.

This was the first time since the 2011 Great East Japan Earthquake that a nuclear power plant located in eastern Japan resumed operations. It was also the first restart for a boiling water reactor (BWR), the same type used at Tokyo Electric Power Company Holdings, Inc.’s disaster-hit Fukushima No. 1 nuclear power plant.

BWRs have a simple structure and can be easily downsized, but accidents are said to develop rapidly when the reactor core is damaged.

At a press conference following a Cabinet meeting on Tuesday morning, Economy, Trade and Industry Minister Yoji Muto said, “It is extremely important to restart the nuclear power plants in eastern Japan,” in view of the expected increase in electricity demand and other factors.

The No. 2 reactor at the plant, which straddles Onagawa and Ishinomaki in the prefecture, has an output capacity of 825,000 kilowatts.

The company has taken safety measures such as building a seawall measuring 29 meters above sea level and 800 meters in total length. It is designed to withstand a tsunami of up to 23.1 meters. The reactor also has a venting system with filters to reduce pressure inside the primary containment vessel while minimizing the leakage of radioactive materials.

Upon reactivation of the reactor, a daily report on its operations will be released, and any problems will be disclosed appropriately according to the level of importance. Tohoku Electric President Kojiro Higuchi said: “There is no end to safety measures. We want to restart the reactors so that they can be trusted by the local community.”

Domestic demand for electric power is expected to increase due to the spread of artificial intelligence and data centers. To achieve both a stable supply of electricity and decarbonization, the government has announced a policy of promoting the development and construction of next-generation nuclear power plants with enhanced safety features, in addition to restarting existing nuclear power plants.

Seventeen nuclear power reactors nationwide have passed safety inspections under the new regulatory standards, and 13 have been restarted so far. After Onagawa nuclear power plant, Chugoku Electric Power Co.’s No. 2 reactor at Shimane nuclear power plant in Matsue is scheduled to restart operations in early December.

In contrast, the Nos. 6 and 7 reactors at the Kashiwazaki-Kariwa nuclear power plant run by TEPCO in Niigata Prefecture and Japan Atomic Power Co.’s Tokai No. 2 nuclear power plant in Ibaraki Prefecture, which have passed safety inspections, face difficulties in obtaining the consent of local municipalities, which is necessary for reactivation.

Some have called for further evacuation measures following the Noto Peninsula Earthquake in January.