Chubu Electric to Withdraw Hamaoka Restart Applications After Safety Review

Chubu Electric Power said Sept. 14 that it will withdraw applications to restart Units 3 and 4 at the Hamaoka nuclear plant after an external investigation examined inappropriate methods used to evaluate earthquake ground motion. President Kingo Hayashi and Chairperson Satoru Katsuno are scheduled to resign on Sept. 30.

The company received the investigation committee’s report on Sept. 11 and published a partially redacted version three days later. The report concerns seismic-motion evaluations and the formulation of design-basis seismic motion during reviews under Japan’s post-Fukushima regulatory standards.

What the investigation found

The committee said it did not find the conduct appropriate. It also warned against reducing its findings to simple descriptions such as falsification, fabrication, underestimation of seismic motion or data fraud.

That distinction is important. The committee’s report addresses the technical methods, academic questions, decision-making process, internal and external warnings, and the company’s response. Because the public version is partially redacted, it does not necessarily disclose every underlying detail.

Independent reporting by the Associated Press described the case as involving years of manipulated seismic data. Jiji Press, published through Nippon, reported that Chubu Electric submitted selected earthquake-vibration data using a method different from the one it had described to the regulator. Those descriptions should be read alongside the committee’s more qualified assessment rather than treated as a substitute for it.

Corporate and regulatory consequences

Chubu Electric said Hayashi and Katsuno will leave their posts on Sept. 30. The company said it would pursue broad governance and organizational reforms aimed at preventing a recurrence and rebuilding public confidence.

The utility also withdrew its pending applications for Hamaoka Units 3 and 4. That was a company decision, not a formal rejection by the Nuclear Regulation Authority.

According to Jiji Press, an NRA secretariat official said the withdrawal was the first time a nuclear operator had pulled a screening application because of misconduct. The report also said that, if Chubu Electric files again, the screening process would start from the beginning. That is a reported secretariat view, not a formal ruling by the Nuclear Regulation Commission, and no future filing or restart timetable has been decided.

Why Hamaoka matters

Hamaoka is in Shizuoka Prefecture, about 200 kilometers west of Tokyo, in a coastal area exposed to potential Nankai Trough earthquakes. The NRA’s operating-status list identifies Units 3 and 4 as suspended. They were not recently supplying electricity to households, so the withdrawal does not by itself create a new household power interruption.

The larger consequence is institutional. Japan has been working to restore nuclear generation after the 2011 Fukushima disaster, partly to reduce reliance on imported fuel and support electricity supply while pursuing emissions goals. Restart applications depend not only on engineering findings but also on confidence that an operator’s safety information is complete, transparent and reliable.

What happens next

Any future application by Chubu Electric would likely face renewed scrutiny over the seismic analysis, internal controls, governance reforms and the credibility of information provided to regulators. The company has not announced a new filing schedule, and any restart would remain subject to regulatory review and public scrutiny.

For Japan’s nuclear policy, the case is less about an immediate change in household electricity service than about the time, cost and credibility required to bring suspended reactors back into the national power system. The Hamaoka withdrawal tests whether Japan’s post-Fukushima restart program can expand supply while maintaining confidence in the safety-review process.

Sources

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