Japanese Nuclear Plant Has Ventilation Malfunction, NISA Says

A Japanese nuclear plant had a malfunction in its ventilation system, the country’s atomic regulator said. There was no radiation leakage outside the reprocessing plant northeast of Tokyo.

Three ventilation units failed to restart for about 20 minutes yesterday due to a timer malfunction, the Nuclear and Industrial Safety Agency said in a statement today. The plant in Tokai village in Ibaraki prefecture is operated by the Japan Atomic Energy Agency.

The incident was rated 1, the lowest level, on the seven- step International Nuclear and Radiological Event Scale, the agency known as NISA said.

Tokai was the site of an incident in 1999, when workers at a uranium processing plant started a chain reaction while producing nuclear fuel. Two employees later died from radiation exposure and the event was rated 4 on the INES scale.

The Fukushima accident north of Tokyo, where Tokyo Electric Power Co. is still trying to contain radiation leaks after the March earthquake and tsunami caused three meltdowns, is rated 7 on the INES scale.

An explosion and fire at a French nuclear-waste processing site two days ago killed one person and injured four.

To contact the reporters on this story: Chisaki Watanabe in Tokyo at cwatanabe5@bloomberg.net;

To contact the editor responsible for this story: Peter Langan at plangan@bloomberg.net