Tepco Says It Will Delay Commercial Start Of Kashiwazaki: Kariwa nuclear reactor (updated)

Tokyo Electric Power Holdings

13/03/2026 11:17

Recasts with company confirmation, adds details

TOKYO, March 13 (Reuters) - Tokyo Electric Power 9501.T said on Friday it will likely delay the start of commercial operations at the Kashiwazaki-Kariwa nuclear power plant because of a minor electricity leak that will temporarily suspend power transmission.

TEPCO said it had decided on the suspension from the plant's No. 6 reactor after an alarm detected the electricity leak from the generator.

The utility had planned the commercial restart on March 18 but needs time to investigate the cause of the issue, a company spokesperson said, adding it remains unclear how long the delay would last.

    The reactor shows no abnormalities and continues nuclear operations safely, the spokesperson said.

When the reactor is disconnected from the power transmission system, its output will be reduced to about 20% but the reactor will remain in operation, TEPCO said.

Once reduced to 20%, the output takes about a week to return to 100%, the spokesperson said.

Kashiwazaki-Kariwa, the world's biggest nuclear power plant, earlier this year became TEPCO's first reactor to restart since the Fukushima disaster in 2011.

 (Reporting by Yuka Obayashi and Kantaro Komiya
Editing by Chang-Ran Kim)

 ((kantaro.komiya@thomsonreuters.com; X: @kantarokomiya;))