TEPCO Shuts Down Restarted Reactor at Kashiwazaki-Kariwa Plant; Aims to Resume Operations on Feb. 26

The Yomiuri Shimbun

13:57 JST, January 23, 2026

Tokyo Electric Power Company Holdings, Inc. shut down reactor No. 6 at the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture, shortly after midnight on Friday morning.

The reactor had resrated on Wednesday but was suspended Thursday after an alarm indicating some sort of irregularity sounded in the early hours of the day during the removal of control rods used to suppress nuclear fission.

The shutdown, which completed at 12:03 a.m. Friday, was decided on since it would take time to identify the cause of the incident, TEPCO said.

“We determined it would be necessary to thoroughly investigate the cause of the incident. We will respond to the matter cautiously, prioritizing safety,” plant director Takeyuki Inagaki said at a press conference Thursday evening.

TEPCO aims for the plant to resume commercial operations on Feb. 26. But Inagaki said it is not clear whether it will be able to do so or how long it will take to complete the investigation.

The Nuclear Regulation Agency was informed of the incident through an inspector present during the restart. The NRA is said to have received report of the decision to shut down the reactor before TEPCO’s 4:30 p.m. announcement on Thursday.

“We do not believe the malfunction poses a safety issue,” an NRA official said. The agency will continue to monitor the situation through its on-site inspector.