The government’s revised energy plan now calls for nuclear power to supply 20% of Japan’s electricity by 2040, up from 8.5% in 2024. This follows a dramatic drop after Fukushima, where nuclear once provided 30% of the energy mix. The restart process is expected to continue through 2030, after which attention may turn to building new-generation reactors.

Japan’s turn back to nuclear has been driven by gas market volatility—exacerbated by the war in Ukraine—and rising power demands from AI-related technologies. These factors have disrupted assumptions about Japan’s declining energy needs amid population shrinkage.

New Reactor Technologies And Foreign Partnerships

The government has laid out a roadmap for five types of next-generation reactors, including high-temperature gas-cooled designs and small modular reactors (SMRs). While still in early stages, companies like NuScale and Hitachi are building SMR prototypes abroad with support from Japanese industry partners such as IHI and Chubu Electric.

Experts believe SMRs will be critical to Japan’s long-term energy security, though many caution they are unlikely to come online before 2040. Local resistance remains high, particularly in areas like Kashiwazaki-Kariwa, home to the world’s largest nuclear plant.

Public Skepticism And Legal Pushback

Despite policy momentum, public and legal resistance persists. The Japan Federation of Bar Associations has opposed the shift, arguing nuclear expansion ignores ongoing risks and the unresolved aftermath of Fukushima. Critics advocate for a transition grounded in renewable sources rather than nuclear revival.

Still, policymakers see nuclear energy as vital to cutting fossil fuel dependence—targeting a reduction from 70% to 30–40% of electricity generation by 2040.