Fire in a Control Panel at the 275-kV Switching Station (Outside the Radiation Control Zone) at the Hamaoka Nuclear Power Plant

On September 15, 2026, in the central control room of Unit 3 at the Hamaoka Nuclear Power Plant, which was undergoing a scheduled inspection, one of our employees (an operator) was performing an engagement operation on a grounding switch (Note 1) located in the 275 kV switchyard (outside the radiation control area) when the grounding switch failed to operate normally. Consequently, upon inspecting the site, we confirmed at 10:42 a.m. that a fire (approximately the size of a palm) had broken out inside the control panel of the grounding switch.
We immediately carried out initial firefighting measures and notified the fire department at 10:51 a.m.
The fire was quickly extinguished through these initial firefighting efforts. Subsequently, the fire department confirmed that the fire was fully extinguished at 11:13 a.m.
This incident did not involve any external radiation exposure, and there were no injuries. Furthermore, there was no impact on other equipment, and there are no implications for nuclear safety.

Regarding this incident, we determined at 10:55 a.m. that it constituted a fire. As this falls under the reporting criteria of "when a fire or other disaster occurs within the power plant premises" as stipulated in the safety agreements (Note 2) with the municipalities surrounding the power plant, we are issuing this notice.

We sincerely apologize for any inconvenience or concern this may have caused. We will investigate the cause and take appropriate measures moving forward.

(Note 1) A grounding switch is a device used during equipment inspection and maintenance to connect equipment or wires to the ground to discharge electricity, thereby preventing electric shock and damage to the equipment.

(Note 2) This refers to the "Agreement Concerning the Ensuring of Safety at the Hamaoka Nuclear Power Plant" concluded between our company and Shizuoka Prefecture, Omaezaki City, Makinohara City, Kakegawa City, and Kikugawa City, as well as the "Agreement Concerning the Ensuring of Safety in the Municipalities Surrounding the Hamaoka Nuclear Power Plant" concluded between our company and Shizuoka Prefecture, Shimada City, Iwata City, Yaizu City, Fujieda City, Fukuroi City, Yoshida Town, and Mori Town.