NIIGATA, Japan — Japan on Monday restarted the world’s largest nuclear power plant, marking a major milestone in the country’s renewed push toward atomic energy more than a decade after the Fukushima disaster forced a nationwide shutdown of reactors.
The Kashiwazaki-Kariwa nuclear power station in Niigata region was switched back on at 2:00 p.m. local time (0500 GMT), its operator Tokyo Electric Power Company (TEPCO) said, after an earlier restart attempt was suspended due to a minor technical glitch.
The facility, which has a total capacity of more than 8,000 megawatts across seven reactors, has remained offline since 2011, when a massive earthquake and tsunami triggered meltdowns at the Fukushima Daiichi plant and led Japan to halt nuclear power operations amid public outrage and safety concerns.
TEPCO initially attempted to restart one of the reactors at Kashiwazaki-Kariwa on January 21, but shut it down the following day after an alarm in the monitoring system was triggered. The alert detected slight changes in the electrical current of a cable, though officials said the readings were within safety limits.
“The reactor is safe to operate,” TEPCO officials told a press conference last week, adding that the company had adjusted the alarm settings after confirming there was no structural or operational risk.
According to TEPCO, commercial operations will begin on or after March 18, following another comprehensive inspection by regulators.
The restart comes as Japan increasingly turns back to nuclear energy to cut reliance on fossil fuels, curb greenhouse gas emissions, and meet rising electricity demand driven by digitalisation and artificial intelligence.
Japan has committed to achieving carbon neutrality by 2050, a target that has intensified debate over the role of nuclear power in the country’s energy mix. While renewable energy capacity has expanded, officials argue it is insufficient on its own to meet baseload demand.
Conservative Prime Minister Sanae Takaichi, who secured a decisive election victory on Sunday, has been a vocal supporter of nuclear energy, describing it as essential to revitalising the Japanese economy and strengthening energy security.
Under her leadership, the government has moved to ease restrictions on reactor restarts, extend the operating lifespan of existing plants, and accelerate regulatory approvals, while insisting that safety standards remain among the strictest in the world.
However, nuclear power remains deeply controversial in Japan. Residents near Kashiwazaki-Kariwa and anti-nuclear campaigners have repeatedly raised concerns about safety, evacuation planning, and TEPCO’s track record, particularly given the company’s handling of the Fukushima crisis.
Local authorities in Niigata have previously demanded stronger assurances on disaster preparedness and emergency response before allowing full-scale operations to resume.
The Kashiwazaki-Kariwa plant has also faced regulatory scrutiny over security lapses in recent years, including failures in access control systems, which delayed restart approvals.
If fully operational, Kashiwazaki-Kariwa could significantly boost Japan’s power supply and reduce carbon emissions, reinforcing Tokyo’s broader strategy to balance climate commitments with economic growth.
