Hamaoka restart will likely face significant delays after Chubu Electric submitted improper seismic data, undermining ongoing safety reviews. Furthermore, Hamaoka restart has prompted concerns among local communities and regulators about the reliability of the plant’s screening process.
The issue emerged on Monday when Chubu Electric provided data to the Nuclear Regulation Authority that may underestimate earthquake tremors. Consequently, the planned resumption of the plant’s reactors appears increasingly uncertain as scrutiny intensifies.
Chubu Electric officials addressed the situation during a press conference at their Nagoya headquarters Monday afternoon. President Kingo Hayashi avoided giving a specific timeline, explaining that the company plans to restructure its nuclear division. Additionally, he noted that reviewing corporate governance and the relationship between executives and the nuclear division may be necessary.
The company has faced previous administrative misconduct in safety procedures, increasing pressure to resolve recurring problems. Meanwhile, the Hamaoka plant sits within the projected focal zone of a potential Nankai Trough earthquake, raising safety concerns further. Reactors 3, 4, and 5 were shut down after the 2011 Great East Japan Earthquake, while units 1 and 2 have already been decommissioned.
Chubu Electric filed safety review applications for reactor 4 in 2014 and reactor 3 in 2015, aiming to resume operations. The NRA approved the design basis ground motion in September 2023 and the design basis tsunami standards in October 2024. The company initially intended to complete facility screenings and geological fault investigations by spring 2026. However, the improper data raises doubts about the credibility of the restart plan.
Prof. Hiroshi Yamagata of Nagaoka University explained that internal oversight failures likely allowed the data misconduct. He emphasized that Chubu Electric must reform its organizational culture and resubmit technically correct data before reviews can proceed.
Local officials reacted strongly to the news, highlighting public safety and trust in the utility. Shizuoka Governor Yasutomo Suzuki urged strict government supervision and guidance to ensure the plant undergoes proper screening. Omaezaki Mayor Masaru Shimomura described the issue as serious, warning it could undermine safety evaluations. Neighboring Kakegawa Mayor Takashi Kubota demanded a thorough investigation and transparent explanations to the local community.
Looking ahead, Hamaoka restart will likely face prolonged delays as regulators impose stricter scrutiny. Chubu Electric must resolve internal weaknesses and rebuild public confidence to continue any reactor operations. Ultimately, Hamaoka restart demonstrates the challenges of safely resuming nuclear energy in earthquake-prone areas. The situation also underscores the importance of accurate data, strong regulatory oversight, and corporate accountability in Japan’s energy sector.
