Japan Nuclear Restart Delays Widen 2040 Generation Gap
BloombergNEF cuts its forecast for Japanese reactor restarts after regulatory scandals and safety failures at Chubu and Hokkaido utilities, leaving a significant gap in the country's 2040 energy targets.
Japan’s efforts to expand nuclear power generation have stalled as regulatory scandals and safety accidents have delayed critical reactor restarts. These setbacks threaten the nation’s strategy to reduce reliance on expensive imported fossil fuels, particularly as electricity demand rises from the artificial intelligence sector. The delays force the country to maintain higher exposure to volatile liquefied natural gas and coal markets, complicating its energy security posture.
BloombergNEF now expects only nine reactors totaling 9.6 gigawatts to restart by 2040, a reduction from its previous outlook of eleven units. This downward revision leaves Japan at least 11.7 gigawatts short of its goal to generate 35 gigawatts from nuclear sources by 2040. The shortfall undermines the government’s aim to raise nuclear’s share of the power mix to 20 percent, up from the current 9 percent, while still falling below pre-Fukushima levels.
Regulatory failures at Chubu and Hokkaido
Chubu Electric Power withdrew applications to restart two units at its Hamaoka plant in Shizuoka Prefecture after accusations of fabricating seismic data. This move directly impacts the utility’s ability to contribute to the national grid. Meanwhile, Hokkaido Electric Power faces delays at its Tomari plant following a fatal construction accident and regulatory rejection of proposed safety measures.
BloombergNEF has pushed the forecast for the restart of Tomari No. 3 back one year to 2028 due to these operational and regulatory hurdles. The Tomari unit is the only operable nuclear facility in Hokkaido, and its delayed return to service jeopardizes the region’s plan to become a major data center hub. The Organization for Cross-regional Coordination of Transmission Operators forecasts that electricity demand in Hokkaido will grow faster than in any other part of Japan.
Demand surge strains power supply
Nationwide spot electricity prices have reached their highest levels since 2022, driven by global supply disruptions in the Strait of Hormuz. Robert Liew of Wood Mackenzie notes that Japan’s data center power demand is expected to double by 2030. Without nuclear capacity, the country must rely on increased coal or LNG imports to meet this baseload demand, exposing it to further price volatility.
Currently, only 15 of Japan’s 33 operable reactors are online due to strict regulations and local opposition. The Tomari No. 3 unit could meet up to a third of Hokkaido’s power demand if restarted, according to BloombergNEF. The government aims to replace up to 14 retiring reactors with new units by the 2050s, but the current delays complicate the transition toward a more stable and domestic energy supply.
