Tokyo Electric Power Company (TEPCO) said on January 22 that it has decided to shut down Unit 6 at the Kashiwazaki-Kariwa nuclear power plant, which had been restarted the previous night.

According to TEPCO, an alarm sounded at 12:28 a.m. on January 22 during a control rod withdrawal operation involving one control rod, prompting the company to suspend the procedure. 

While the investigation is ongoing, TEPCO said determining the cause will take time.

The company therefore decided to carry out a planned shutdown of the plant on January 22 for inspections.

TEPCO said it will hold a news conference from 7 p.m. on the same day to explain the shutdown of Unit 6.