Reactor halted at Japan’s Mihama NPP after steam leak

Operator Kansai Electric Power said it halted a reactor at its Mihama Nuclear Power Plant in central Japan on Friday morning, May 8, after detecting a steam leak near a high-pressure turbine.

The company, quoted by Japanese media, said the steam did not contain radioactive material, and there was no impact on the external environment. It added that it cannot yet say when operations at the No. 3 reactor will resume.

The leak was identified at approximately 4:10 a.m., and workers manually shut down the reactor about 15 minutes later, according to the operator.

The No. 3 unit, which began operations in 1976, became in 2021 the first nuclear reactor in Japan to continue operating beyond 40 years under regulatory changes introduced after the Fukushima Daiichi nuclear disaster. Under those rules, reactors are generally limited to a 40-year service life, though extensions of up to 20 years may be granted with regulatory approval.

At the Mihama facility, decommissioning work is currently underway for the plant’s two other ageing reactors.

By Tamilla Hasanova