Petitioners display banners in front of Osaka District Court in Osaka, western Japan Tuesday, Dec. 20, 2022. A Japanese court ruled Tuesday that a 45-year-old nuclear reactor in central Japan is safe to operate, rejecting demands by local residents that it be suspended because of corrosion and inadequate safety measures -- a decision supportive of the government’s push toward a greater use of nuclear energy amid power crunch concern and decarbonization obligation. The banners read "Unfair decision cannot be permitted. Immediate appeal!," right, and "We'll settle at Osaka Hight Court." Credit: Kyodo News via AP

A Japanese court ruled Tuesday that a 45-year-old nuclear reactor in central Japan can continue to operate, rejecting demands by residents that it be suspended because of safety risks, a decision supportive of the government's push for greater use of nuclear energy because of possible global fuel shortages and the country's pledge to reduce carbon emissions.

The Osaka District Court's decision came just days before Prime Minister Fumio Kishida's Cabinet is expected to approve a new policy that would accelerate restarts of reactors that were idled after the 2011 Fukushima nuclear power plant disaster and extend the operating life of aging reactors.

The Economy and Industry Ministry has drafted a plan to allow extensions every 10 years for reactors after 30 years of operation, while also permitting utilities to subtract offline periods in calculating reactors' operational life beyond the current 60-year limit.

Tuesday's ruling was the first on the of reactors that have operated more than 40 years.

Chief Judge Naoya Inoue said the operator of the Mihama No. 3 , Kansai Electric Power Co., has taken adequate steps to prevent equipment degradation to fulfil the requirements of the Nuclear Regulation Authority and obtain an operational permit. The ruling said the reactor's age doesn't require more stringent than normal.

Nine residents—seven from Fukui prefecture and one each from neighboring Kyoto and Shiga—filed a lawsuit against Kansai Electric in June 2021 demanding the suspension of the Mihama reactor, citing safety risks at the aging facility.

The court also dismissed other safety concerns raised by the plaintiffs, including earthquake resistance and evacuation plans, citing a lack of concrete proof of potential risk.

Lawyers for the plaintiffs said it was obvious that aging increases risks for reactors and said they plan to appeal.

Most nuclear reactors in Japan are more than 30 years old. While four reactors that have operated more than 40 years have cleared the Nuclear Regulation Authority's safety standards and have received permission to operate, the Mihama No. 3 reactor is the only one that is currently in operation.

Anti-nuclear sentiment and safety concerns rose sharply in Japan after the Fukushima disaster, in which a and tsunami damaged reactor cooling systems, causing three to melt and release large amounts of radiation. The government initially planned to phase out but has since reversed that stance.

Kishida said in August that Japan needs to consider all options in its energy mix, including nuclear, to secure a stable energy supply amid potential shortages resulting from Russia's war on Ukraine, while strengthening its "green transformation" to meet greenhouse gas emissions reduction targets. Japan has pledged to reach carbon neutrality by 2050.

While maintaining a 20%-22% target for nuclear energy in its mix for 2030, the government previously insisted it was not planning to build new nuclear plants or replace aging reactors, apparently to avoid triggering criticism from a still wary public.

Under the new nuclear policy to be adopted later this week, the government will seek to develop and construct "new innovative reactors" such as small modular nuclear reactors.

Some experts say extending the operational lifespan of reactors is not desirable because utility operators would need to invest in old equipment to keep it working instead of in new technology or renewables. They also say developing next-generation reactors involves huge costs and uncertain prospects.