Following the 2011 Fukushima disaster, Japan shuttered its entire fleet of over 50 nuclear reactors, causing nuclear power's share of electricity generation to collapse from ~30% to under 10%. The resulting baseload void was filled with imported LNG and thermal coal, costing the national economy tens of billions of dollars annually for over a decade and rendering Japanese electric utilities structurally disadvantaged. That dynamic has decisively reversed: Japan's 7th Strategic Energy Plan removed past language regarding 'reducing reliance on nuclear energy', set a target of ~20% nuclear generation by 2040, and opened the path for next-generation reactor construction, backed by the most pro-nuclear administration in decades.
A transformative catalyst unfolded in late 2025: the Niigata prefectural government approved the restart of Kashiwazaki-Kariwa-the world's largest nuclear power station (seven units, ~8 GW capacity), idle for over a decade. Unit 6 is already fuel-loaded, representing TEPCO's first commercial reactor restart post-Fukushima. The financial economics are compelling: these capital assets are fully depreciated, meaning each restarted unit substitutes costly imported LNG with electricity generated at virtually zero incremental fuel cost. TEPCO estimates that two operational units alone boost annual ordinary profit by ~100 billion yen. This represents a structural, permanent step-change in utility cost structures rather than a cyclical rebound. Additional units are lined up across the nation, notably Tomari Unit 3 in Hokkaido following safety clearance.