Japan Halts Hamaoka Nuclear Reactors Over Falsified Seismic Data

Japan’s Nuclear Regulation Authority has suspended the relicensing process for two reactors at the Hamaoka Nuclear Power Plant due to revelations that the plant’s operator, Chubu Electric Power Co., fabricated seismic hazard data. This decision follows a whistleblower’s report, which alerted regulators to the discrepancies in February 2022. The news comes at a sensitive time, as Japan has been cautiously reactivating its nuclear fleet after the catastrophic Fukushima Daiichi disaster in 2011.

The Hamaoka plant is particularly vulnerable due to its location near an active subduction fault on the east coast of Japan, similar to Fukushima’s situation. The Nuclear Regulation Authority’s action to halt the evaluation process reflects the seriousness of the situation, which could have allowed the reactors to restart.

In a recent press release, Chubu Electric detailed how it manipulated seismic safety data. The company admitted that since 2018, its staff generated large collections of upscaled earthquake scenarios. They selected one scenario while choosing 19 others to create a misleading average that suggested a lower seismic risk. The standard method involves evaluating a group of 20 different upscaled earthquake motions to find the most representative one.

Notably, the company has not clarified how this flawed process impacted risk analysis, but the implications are concerning. Given Japan’s slow and cautious approach to nuclear power reactivation, the decision to misrepresent safety evaluations is particularly striking. The Hamaoka plant’s proximity to the subduction zone raises further alarms, especially regarding the potential for tsunami risks reminiscent of the Fukushima disaster.

In response to the scandal, Chubu Electric has appointed a committee of external lawyers to investigate the matter thoroughly. The Nuclear Regulation Authority’s decision to terminate the safety evaluation process complicates the timeline for any potential restart of the reactors. Currently, it remains uncertain when the evaluation process may resume or when the reactors might be brought back online.

This situation poses additional challenges for the Nuclear Regulation Authority, which has faced scrutiny over regulatory capture and its ability to identify significant safety risks. Just days before the announcement, Bloomberg reported that a staff member at the regulatory agency lost a phone containing classified information while traveling through China, further complicating the agency’s credibility.

As the fallout from this incident unfolds, the implications for Japan’s nuclear energy policy and public trust in regulatory oversight remain to be seen. The ongoing scrutiny highlights the necessity for robust safety measures, especially in a country prone to seismic activity.