Japan's "Most Dangerous" Nuclear Plant Operator Admits That It Manipulated Earthquake Safety Data

A power company in Japan has admitted to selectively presenting key safety data in order to clear regulatory inspections for restarting two of its offline nuclear reactors. As per Independent, Chubu Electric Power Co. admitted that it may have intentionally manipulated earthquake safety data for the Hamaoka Nuclear Power Plant in Shizuoka Prefecture.

The company confessed to selecting specific earthquake wave patterns, specifically those closest to a calculated average, to make the projected maximum shaking (seismic motion) appear smaller than it likely would be. The manipulation was reportedly intended to "smooth" and accelerate the rigorous safety screening process required to restart reactors at the site.

"We sincerely apologise for the incident. The actions could potentially shake the foundations of the nuclear power business," Chubu Electric president Kingo Hayashi told a press conference.

The Nuclear Regulation Authority (NRA) first received a tip from a whistleblower in February 2025. A senior agency executive slammed the incident as "unbelievable", saying that the incident would shake trust in Chubu Electric and raise questions about its eligibility.

Japan's Industry Ministry has ordered Chubu Electric to submit a comprehensive report by April 6, 2026, wanting to know what went wrong and how they will prevent it in the future. The company has established an independent panel of legal and technical experts to investigate the misconduct.

Following the disclosure, shares of Chubu Electric fell 8.2%, their steepest drop in nearly a year.

Notably, many seismologists consider Hamaoka the most dangerous nuclear facility in Japan because it sits directly above the Nankai Trough, a major fault zone where a "megaquake" is predicted. Government forecasts predict an 87% chance of a powerful earthquake hitting this specific area.

Professor Katsuhiko Ishibashi, a renowned seismologist, had warned back in 2003 that Hamaoka nuclear power plant was Japan's most perilous due to earthquake risks. He predicted a potential disaster would ravage the Tokyo-Nagoya area, destroying over 200,000 buildings and triggering a massive tsunami. Post-Fukushima, reactors 4 and 5 were shut, and plans to restart reactor 3 were scrapped.