Two senior executives at Japan’s Chubu Electric Power will step down following a scandal involving inaccurate earthquake data submitted during a nuclear safety review.
The company said Monday that President Kingo Hayashi and Chairman Satoru Katsuno will leave their positions. Chubu Electric also announced that it will withdraw applications seeking approval to restart two reactors at its Hamaoka nuclear power plant.
The leadership changes follow revelations that data submitted to Japanese regulators underestimated the potential seismic risks at the facility.
Hamaoka Nuclear Plant Faces Setback
Chubu Electric’s Hamaoka plant is located in central Japan, an area considered vulnerable to a major earthquake. The company had been working through regulatory safety checks as part of plans to restart two reactors.
However, the operator acknowledged in January that it had provided regulators with information that underestimated earthquake risks.
An independent panel released a 250-page report on Monday. It found that management pressure over delays in the restart review contributed to an environment in which misconduct could occur.
According to the report, a management reprimand linked to the delayed review placed pressure on employees. The panel described that pressure as one factor behind the misconduct.
Japanese media had earlier reported that Hayashi and Katsuno were expected to resign. The company was also due to hold a press conference later Monday to explain the decisions.
Earthquake Data Raised Safety Concerns
The maximum seismic ground motion estimate is a critical part of nuclear plant safety planning. Engineers use the figure when designing structures and equipment to withstand earthquakes.
In September 2023, Japan’s Nuclear Regulation Authority approved Chubu Electric’s estimate of 1,200 gal. The unit measures acceleration caused by seismic movement.
However, the regulator later received information from a whistleblower about possible manipulation of the data. The Nuclear Regulation Authority subsequently suspended its safety review of the Hamaoka plant.
The controversy has now put the proposed reactor restarts on hold. Chubu’s decision to withdraw its applications represents a major setback for the company’s plans.
Japan Seeks Nuclear Power Revival
The scandal comes as Japan is trying to expand its use of nuclear energy more than 15 years after the Fukushima disaster.
A massive earthquake and tsunami struck northeastern Japan in 2011. The disaster caused multiple reactor meltdowns at the Fukushima Daiichi nuclear plant.
Japan subsequently moved away from nuclear power. However, the resource-poor country has since sought to bring more reactors back online.
The government sees nuclear energy as a way to reduce reliance on imported fossil fuels. It also wants to reach carbon neutrality by 2050 while meeting rising electricity demand.
Growing energy requirements linked to artificial intelligence and data centres have added to pressure on Japan’s power infrastructure.
Hamaoka Located Near Nankai Trough
Hamaoka’s location makes the safety issue particularly sensitive. The plant sits near a seismic fault zone in Shizuoka prefecture.
The area is associated with the Nankai Trough, where Japanese authorities have long warned about the possibility of a powerful earthquake.
In 2024, the Japan Meteorological Agency issued its first special advisory concerning a possible Nankai Trough megaquake. The warning was lifted about a week later.
Meanwhile, Japan has continued its gradual nuclear restart programme. The Kashiwazaki-Kariwa facility, the world’s largest nuclear power plant, resumed operations earlier this year.
For Chubu Electric, however, the latest data scandal has brought its Hamaoka restart plans back into serious question. The resignations of its top executives are likely to add further pressure as regulators and the public examine how the misconduct occurred.
