The world’s largest nuclear power plant has commenced operations in Japan, marking the nation’s first reactor restart since the catastrophic 2011 Fukushima disaster forced all reactors offline. Reactor 6 at Kashiwazaki-Kariwa, located northwest of Tokyo, began functioning despite ongoing safety concerns from nearby residents. A technical malfunction delayed the startup by one day, with commercial operations expected to begin next month.
Japan emerged as an early nuclear power adopter due to its heavy dependence on energy imports. However, a devastating earthquake and tsunami in 2011 triggered a meltdown at Fukushima Daiichi, resulting in one of history’s worst nuclear disasters. All 54 reactors were subsequently shut down, and communities experienced radioactive contamination with many residents refusing to return despite government assurances of safety.
The 2011 incident was deemed a man-made disaster caused by inadequate preparation by plant operator Tokyo Electric Power Company and poorly coordinated government response. Public opposition intensified dramatically, with support for nuclear power dropping from 44 percent immediately after the disaster to 70 percent by 2012 wanting reduced reliance on nuclear energy. Recent polling indicates opinion has shifted, with over 50 percent supporting nuclear power if safety measures are guaranteed.
Japan’s nuclear revival remains limited in scope. Since 2015, only 15 of 33 operable reactors have restarted, including this first Tepco-operated facility. The seventh reactor at Kashiwazaki-Kariwa won’t return online until 2030, potentially reducing the plant’s capacity from its previous 8.2 gigawatts. The government aims for nuclear power to provide 20 percent of electricity by 2040, considerably lower than pre-2011 targets of 50 percent.
Safety standards have been substantially strengthened with new regulatory oversight from the Nuclear Regulation Authority established in 2012. Kashiwazaki-Kariwa features 15-metre seawalls and reinforced equipment protection designed to withstand tsunami and earthquake scenarios similar to 2011. However, rising costs from new safety requirements pose significant challenges for plant operators. Nuclear power expenses have surged, creating difficult choices between government subsidies or higher consumer costs—options problematic for leaders historically promoting nuclear energy’s affordability.
Recent security scandals have further eroded public confidence. Employees at Kashiwazaki-Kariwa lost classified documents in 2023 and mishandled confidential materials in November. Separately, the Nuclear Regulation Authority suspended reviews for another facility after discovering manipulated earthquake data from the operator, demonstrating persistent corporate accountability problems within Japan’s nuclear sector.
Expert assessments highlight limitations in current preparedness. While reactors have been hardened against previously experienced disasters, concerns remain about unprecedented climate-related sea-level rise and anticipated megaquakes exceeding historical records. Safety preparations focus on past threats rather than emerging future risks. Some analysts describe Japan’s nuclear revival as incremental, insufficient to reverse broader nuclear power decline in the country.
