TOKYO — A Japanese nuclear reactor which survived a massive 2011 earthquake and tsunami that badly damaged the nearby Fukushima nuclear power plant was restarted Tuesday for the first time since the disaster after a safety upgrade, as the government pursues a renewed expansion of nuclear energy to provide stable power and reduce carbon emissions.
The No. 2 reactor at the Onagawa nuclear power plant on Japan’s northern coast was put back online and is expected to start generating power in early November, operator Tohoku Electric Power Co. said.
The reactor is one of the three at the Onagawa plant, which is 100 kilometers (62 miles) north of the Fukushima Daiichi plant where three reactors melted following a magnitude 9.0 earthquake and tsunami in March 2011, releasing large amounts of radiation.
The Onagawa plant was hit by a 13-meter (42-foot) tsunami but was able to keep its crucial cooling systems functioning in all three reactors and achieve their safe shutdowns.
All of Japan’s 54 commercial nuclear power plants were shut down after the Fukushima disaster for safety checks and upgrades. Onagawa No. 2 is the 13th of the 33 still useable reactors to return to operation. It is also the first restart in Japan of the same type of reactor damaged in Fukushima.
Tohoku Electric President Kojiro Higuchi said the reactor’s restart highlights the area’s recovery from the disaster.
Last year, Japan’s government adopted a plan to maximize use of nuclear energy, including accelerating restarts of closed reactors, extending the operational life of aging plants, and developing next-generation reactors, as the country struggles to secure a stable energy supply and meet its pledge to reach carbon neutrality by 2050.
“Nuclear energy, along with renewables, is an important power source for decarbonization,” Chief Cabinet Secretary Yoshimasa Hayashi said Tuesday. “We will maximize its use while ensuring safety.”
Restarting nuclear reactors is also increasingly important for Japan’s economic growth, Hayashi said.
Concern about the government’s revived push for nuclear energy grew after a magnitude 7.5 earthquake hit Japan’s Noto Peninsula on Jan. 1, 2024, killing more than 400 people and damaging more than 100,000 structures. Minor damage was reported at two nuclear facilities and evacuation plans for the region were found to be inadequate.
For the Onagawa No. 2 reactor, Tohoku Electric in 2013 began upgrading its safety, including tsunami risk estimates and anti-quake measures. It also built an anti-tsunami wall extending up to 29 meters (95 feet) above sea level, and obtained safety approval from regulators in 2020.
Twenty-one of Japan’s nuclear reactors, including six at Fukushima Daiichi and one at Onagawa, are currently being decommissioned because their operators chose to scrap them instead of investing large amounts for additional safety equipment required under the much-stricter post-Fukushima safety standards.