FUKUOKA (Kyodo) -- Kyushu Electric Power Co. said Sunday that it found a one centimeter-size hole in a pipe that is believed to have caused a small steam leak at its recently reactivated nuclear reactor in southwestern Japan on Friday.
The steam leak at the Genkai plant's No. 3 reactor in Saga Prefecture occurred in part of a system to produce steam for electricity generation and did not cause any radiation leakages. The utility is currently checking the reactor without taking it offline.
The hole was spotted in an air vent pipe in a device used for the removal of oxygen and other gases that goes to a steam generator, according to Kyushu Electric Power. The generator is located inside the reactor's primary containment vessel.
The No. 3 reactor had resumed operation on March 23 after a seven-year hiatus, as it took time to clear a set of new safety requirements introduced after the 2011 Fukushima Daiichi nuclear power plant disaster.
The reactor was expected to enter into commercial operation on April 24, but the plan has hit a snag due to the latest incident. The utility's plan to restart the No. 4 reactor in May is also likely to see a delay.