Japan has approved the restart of unit 6 at Tokyo Electric Power Co’s (Tepco’s) Kashiwazaki-Kariwa NPP, which has been closed for more than a decade since the 2011 Fukushima disaster. Hideyo Hanazumi, governor of Niigata prefecture, where the plant is located, has approved the reactivation of one reactor, clearing the last major hurdle to restarting the plant.
Following the Fukushima accident, Tepco faced heavy criticism for its corporate culture, leading to local opposition to a restart. Hanazumi acknowledged that the future of the Kashiwazaki-Kariwa plant had been a major issue for residents for many years.
“At this moment, it still seems that opinions among the people on whether to restart the plant are divided. But we have decided that, by continuing to provide accurate information about nuclear power and on safety and disaster-prevention measures, public understanding will spread,” he said. A survey conducted by the prefectural government showed that residents opposing a restart of the plant were in the majority in four of the nine surveyed municipalities located within a 30-kilometer radius of the facility.
He added that he would ask the local assembly to decide whether it has confidence in his decision and will allow him to continue in office – a formal step that will confirm the restart. Nuclear power plants are “a truly serious and heavy issue for local communities,” he said. “I’ve spent seven years assessing this. I’d like the local assembly to evaluate my decision and how I approached my work.” He will consult the prefectural assembly on his decision during its regular session in December.
Hanazumi reportedly took the decision based on the central government’s request for approval, as well as survey results by local people and exchanges of views with heads of municipalities in the prefecture. In October, Tepco revealed plans to start considering decommissioning the plant’s unit 1&2 reactors along with a policy to provide the prefecture with funds worth around JPY100bn ($637m) over about 10 years to contribute to improving safety and security in the prefecture and revitalising the local economy. Tepco will also make new business investments in the prefecture to promote local industry and create jobs.
“We will strongly urge the national government and Tepco to demonstrate through their actions and results that they are prioritising safety in the operation of the Kashiwazaki-Kariwa Nuclear Power Plant, which will help restore the trust of the prefecture’s residents,” Hanazumi said. Tepco has already taken some measures to address concerns, including putting a renewed emphasis on biometric security checks at the site after regulators found failures in intrusion detection equipment and the misuse of identity cards.
Although Kashiwazaki-Kariwa was unaffected by the March 2011 earthquake and tsunami all seven of the plant’s reactors had been offline for two to three years following the earlier 2007 Niigata-Chuetsu earthquake, which caused damage to the site. Work has since been carried out to improve the plant’s earthquake resistance. Tepco applied for Nuclear Regulation Authority (NRA) approval of its design and construction plan for Kashiwazaki-Kariwa units 6&7 (1356 MWe advanced boiling water reactors) in September 2013.
Tepco submitted information on safety upgrades across the site and at those units, which began commercial operation in 1996 and 1997 and were the first Japanese boiling water reactors to be considered for restart. NRA cleared safety screenings for the two units in 2017 but security breaches and delays in completing safety upgrades caused delays.
Tepco loaded fuel assemblies into unit 7 in April 2024 in preparation for its restart. However, as the unit cannot be restarted before completion of the antiterrorism facility, which is scheduled for August 2029, the fuel was removed in September. Tepco then prioritised restarting unit 6, where fuel loading was completed in June. The company has until September 2029 to implement similar anti-terrorism safety measures at unit 6, but it can operate until then, pending local approval, which has now been given.
Japan’s chief government spokesman, Minoru Kihara, said the restart was “extremely important from the point of view of lowering electricity prices and securing decarbonised sources of power”.
Prior to the March 2011 accident at the Fukushima Daiichi plant, Japan’s 54 reactors had provided around 30% of total electricity. However, all nuclear units were subsequently closed pending the introduction of more stringent safety regulations. So far only 14 of Japan’s 36 operable reactors have restarted, while older units have been decommissioned. Another four are waiting for local governments to give the green light and eight more are pending regulatory approval.
Japan currently aims to source 20% of its power supply from nuclear energy by 2040, up from about 8.5% now. The aim is to cut fossil fuels from almost 70% of electricity generation in 2023 to 30-40%. Tepco paid out large amounts of compensation following the reactor meltdown in 2011. Restarting one reactor at Kashiwazaki-Kariwa would boost its annual net profit by JPY100bn. The restart would be in line with new Prime Minister Sanae Takaichi’s plans to support more nuclear restarts to strengthen energy security.
