Chubu Electric president and chairman resign over Hamaoka quake data

Chubu Electric Power said on Monday that President Kingo Hayashi and Chairman Satoru Katsuno will resign after an independent panel found the company submitted improper earthquake data in its bid to restart the Hamaoka nuclear plant in Shizuoka Prefecture. The utility, Japan's third-largest by some industry rankings, will withdraw its safety-screening applications for reactors 3 and 4 and try again only after it says it has rebuilt trust.

Hayashi bowed at a news conference in Nagoya. Kyodo reported that director Minoru Yasui, a University of Tokyo graduate who joined the company in 1988, is in line to succeed him. Katsuno was president for about five years from June 2015. The panel said the data problems began around 2012 at the latest and continued through that presidency.

What the 250-page report said

The outside lawyers wrote that Chubu committed what could be called an act of concealment by trying to manufacture data sets that justified the seismic waves chosen for the safety review. Those estimates tell the regulator how hard the site would shake in a set of earthquake scenarios. The Nuclear Regulation Authority uses them to judge whether the plant's design can take the load.

The panel said a management reprimand over delays in the restart review was one factor behind the misconduct. It described an internal culture that treated the manipulation as justified. A whistleblower had raised the issue in 2021 and pointed to an email from three years earlier that showed weaker waves being selected. The company put the accused department in charge of its own fact-finding. The internal hotline later said it found no compliance breach.

The NRA had approved a 1,200 gal peak ground-motion figure for Hamaoka in September 2023. It received a whistleblower tip in February of the following year and suspended the safety review in late December. The utility disclosed in January that it had given regulators data that understated earthquake risk. Last month it also said it had altered documents sent to the decommissioning fund manager for units 1 and 2, which are being dismantled.

Why Hamaoka is a hard site

The plant sits on the Pacific coast of central Japan, in a zone officials have long flagged for a possible megaquake along the Nankai Trough. After the March 2011 Fukushima disaster, Hamaoka was among the plants taken offline. Prime Minister Sanae Takaichi has made nuclear restarts part of a plan to cut power costs and feed AI data centres and factories. Chubu's withdrawal sends that timetable back by years. A fresh application starts the review from scratch.

The Financial Times treated the resignations as a setback for that national pivot. The company must now rewrite how it builds seismic models, how it handles whistleblowers and how it talks to the NRA. Yasui inherits a utility that still runs thermal plants and a nuclear file that the regulator will read with less patience than it did in 2023.

Monday's public record is the report, the two resignations and the withdrawn applications. The NRA has not yet said what enforcement, if any, will follow the panel's language about concealment. That decision sits with the watchdog, not with Chubu's board.