Chubu Electric Power said on September 11, 2026 that it has received the findings of an independent committee that spent eight months investigating how the utility evaluated ground motion at its Hamaoka Nuclear Power Station. The committee, made up solely of outside experts with no ties to the company, was examining an assessment of the reference earthquake motion for Hamaoka Units 3 and 4 that Chubu Electric itself disclosed had been carried out using an improper method.
Chubu Electric carried out the flawed evaluation during the Nuclear Regulation Authority's conformity review of the two reactors under the Reactor Regulation Act. The company disclosed the improper evaluation on January 5, 2026, and set up the external panel the same day to establish the facts, identify the causes, and work out how to prevent a repeat, with a mandate framed around transparency and independence from the company.
That committee has now handed in its report, but the public will have to wait to read it. Chubu Electric says it will publish the document only after partial redactions, citing the need to protect the privacy of people involved and to limit any impact on them. No release date has been set. The company apologized to residents near the plant and to the broader public for the concern the matter has caused and for what it called strong distrust from society.
The financial stakes are still an open question. Chubu Electric filed a same-day extraordinary report with the Kanto Local Finance Bureau under the Financial Instruments and Exchange Act, the kind of filing required when an event could materially affect a listed company's financial position, results, or cash flow. In it, the utility states plainly that the effect of the seismic-evaluation matter on both the current and future consolidated results is undetermined at this time.
The paperwork trail extends further: Chubu Electric also filed an amended shelf registration statement the same day, folding the extraordinary report into the reference documents attached to its bond program. That shelf registration, originally filed in October 2024, covers up to ¥500bn in bonds, of which roughly ¥413.3bn remains available to issue before the registration expires in October 2026. The amendment itself changes nothing about the bond terms; it exists only to formally attach the disclosure about the seismic finding to a debt program still open for business.