Japanese Nuclear Plant Operator Faces Fallout Over Falsified Data

Japan’s Nuclear Regulation Authority announced on September 27, 2023, that it is halting the relicensing process for two reactors at the Hamaoka plant after discovering that the operator, Chubu Electric Power Co., fabricated seismic hazard data. This revelation comes at a critical time as Japan gradually seeks to reactivate its nuclear power plants, which were shut down following the Fukushima Daiichi disaster in 2011.

The Hamaoka plant is particularly concerning due to its location on the coast near an active subduction fault. The plant’s proximity to this seismic zone raises alarms, especially given Japan’s history with powerful earthquakes and tsunamis. A whistleblower alerted the Nuclear Regulation Authority to potential issues in February 2022, but the public only became aware of the situation this week when regulators announced the suspension of the evaluation process necessary for a reactor restart.

In a press release, Chubu Electric Power Co. detailed how its team manipulated seismic safety data. According to the company’s report, seismic risks were inaccurately assessed by scaling up ground motion data derived from smaller earthquakes. The standard procedure involves generating a set of 20 different upscaled earthquake scenarios and selecting the one that best represents the average. The company now admits that since 2018, its staff has been improperly selecting one scenario and then adjusting the remaining 19 to ensure the average appeared favorable.

While the company has not clarified the specific impact of this methodology on risk analysis, the adjustments seem designed to downplay actual risks. Given the slow and cautious approach Japan has taken in reactivating its nuclear fleet, the decision to compromise safety evaluations is particularly striking.

The Hamaoka plant’s location on Japan’s east coast places it at significant risk of the same catastrophic events that led to the Fukushima meltdown. Although the falsified data does not directly involve tsunami risks, it raises concerns about the operator’s commitment to safety. In light of these revelations, Chubu Electric has appointed a committee of external lawyers to investigate the matter thoroughly.

The Nuclear Regulation Authority’s decision to halt the safety evaluation process complicates the timeline for any potential restart of the Hamaoka reactors. The agency, which is striving to restore public trust following accusations of regulatory capture, faces additional scrutiny after a staff member reportedly lost a phone containing classified information while traveling in China just days before this announcement.

As Japan navigates the complexities of nuclear energy and public safety, the fallout from this incident underscores the urgent need for transparency and accountability in the industry. The future of the Hamaoka plant, and potentially others in the country, remains uncertain as investigations continue and stakeholders await further developments.