Japan moved closer on Monday to restarting the world’s largest nuclear power plant after a local assembly approved a confidence motion backing a governor who supports the plan, marking a pivotal shift nearly 15 years after the Fukushima disaster forced a nationwide suspension of nuclear power.
The Niigata prefectural assembly voted to support Governor Hideyo Hanazumi, whose consent is required to restart the Kashiwazaki-Kariwa nuclear power station operated by Tokyo Electric Power Company (TEPCO). Hanazumi is expected to formally notify the central government of Niigata’s approval, completing the remaining local administrative procedures.
TEPCO reportedly is considering restarting one of the plant’s seven reactors – likely Unit 6 – as early as 20 January 2026. Located on the Niigata coast, Kashiwazaki-Kariwa has a total generation capacity of about 8.2 gigawatts (GW), making it the world’s largest single nuclear power station. Restarting one reactor would increase electricity supply to the Tokyo region by about 2 per cent.
If restarted, Kashiwazaki-Kariwa would become the first nuclear plant operated directly by TEPCO since the 2011 Fukushima Daiichi disaster, in which the company was criticised for safety failures and its crisis response. TEPCO said it had strengthened safety measures and was committed to preventing a repeat of the accident.
The Fukushima disaster was triggered when a powerful earthquake and tsunami knocked out power and cooling systems at the Fukushima Daiichi plant, causing reactor meltdowns, radioactive releases and the evacuation of tens of thousands of residents. The accident – the world’s worst nuclear crisis since Chernobyl – led Japan to suspend its nuclear reactor fleet and overhaul safety regulations.
Public opposition to the restart remains strong. About 300 protesters gathered outside the Niigata prefectural assembly on Monday, chanting slogans such as “No restart” and “Don’t forget Fukushima”.
A prefectural survey released in October showed that 60 per cent of Niigata residents said conditions for restarting the plant had not been met, while 70 per cent said they were concerned about TEPCO’s ability to operate the facility safely. To ease resistance, TEPCO has pledged to invest 100 billion yen (US$641 million) in Niigata over the next decade.
Craig Peacock, chief adviser at Kujaku Japan Advisory and a former Western Australian commissioner for Japan, said Japan’s return to nuclear power should be seen as the re-emergence of a long-standing strategic position rather than a political reversal.
“What we are seeing now is the gradual alignment of energy security realities, decarbonisation imperatives and industrial policy with planning assumptions that were never fully abandoned,” Peacock said, adding that Tokyo never dismantled the institutional, regulatory or industrial foundations of its nuclear sector despite years of public caution and regulatory stringency after Fukushima.
“Japan’s energy system is highly constrained by geography, import dependence, and grid structure, and nuclear has long been embedded in how policymakers think about resilience, baseload stability and emissions reduction over multi-decade time frames,” Peacock told Eco-Business.
The country relies on fossil fuels for about 60 to 70 per cent of its electricity generation and spent roughly 10.7 trillion yen (US$68.3 billion) last year on imports of liquefied natural gas and coal, about one-tenth of its total imports.
“Japan’s approach to energy policy is fundamentally institutional and long-horizon in nature, and the renewed role of nuclear power is consistent with that planning culture rather than a departure from it,” he added.
Prime Minister Sanae Takaichi, who took office two months ago, has backed nuclear power as central to Japan’s energy security strategy, arguing it is needed to cut fuel import costs and meet rising electricity demand driven by the expansion of AI data centres.
Studies estimate that data centres currently account for about 1 to 2 per cent of Japan’s electricity consumption, but demand from the sector could triple by the early 2030s, with peak load rising to around 6 to 8 GW – comparable to the output of several large power plants.
Under government plans, nuclear power’s share of the energy mix is set to rise to around 20 per cent by 2040. Of the 54 reactors operating before Fukushima, only 14 have since resumed operations.
