Japan's Nuclear Regulation Authority has launched an on-site inspection at Chubu Electric Power's headquarters in Nagoya concerning fraudulent earthquake risk data linked to the Hamaoka nuclear power plant. The probe seeks to fully uncover the circumstances and motives behind the misconduct, which may have underestimated seismic ground motions at the facility. Depending on the findings, the authority could impose severe actions, such as disapproving reactor restarts or revoking the plant's installation permit.
On January 26, 2026, Japan's Nuclear Regulation Authority (NRA) initiated an on-site inspection at Chubu Electric Power's headquarters in Nagoya, Aichi Prefecture. The focus is on earthquake risk data fraud connected to the company's Hamaoka nuclear power plant in Shizuoka Prefecture.
During the inspection, the NRA will examine documents and records related to the compilation of the fraudulent data, as well as information used in reactor safety screenings. It will also interview employees implicated in the wrongdoing. The probe, expected to last at least several months, aims to reveal the full circumstances and motives of the misconduct. Based on its outcomes, the authority will decide on potential actions against Chubu Electric.
At its regular meeting on January 14, the NRA considered penalties including the disapproval of a reactor restart at Hamaoka and the revocation of the plant's installation permit. "(The data fraud) is a serious case requiring a study on severe punishment," said NRA chief Shinsuke Yamanaka at a news conference that day.
According to Chubu Electric, the irregularities date back to 2018 or earlier. The company selected representative seismic waves using methods different from those presented during NRA screenings. Around 2018, it began deliberately choosing waves other than average values, potentially underestimating the seismic ground motions the plant could face.
The NRA became aware of the issue through an external tip in February of the previous year. Chubu Electric admitted the misconduct in December and publicly announced it on January 5. Under the nuclear reactor regulation law, the NRA has ordered the company to submit a report on the facts and has halted screenings for reactivating Hamaoka's reactors.
This scandal raises questions about safety oversight and corporate governance in Japan's nuclear sector.
