FUKUOKA (Kyodo) -- Kyushu Electric Power Co. stopped generating and supplying electricity at its nuclear reactor in southwestern Japan on Saturday after detecting a steam leak the previous day.
The utility said there has been no radiation leak and that it will inspect the reactor, which resumed operation only a week ago at the Genkai power plant in Saga Prefecture.
According to Kyushu Electric, staff discovered at around 7 p.m. Friday that steam was leaking from the pipe of a device used for the removal of oxygen and other dissolved gases from the feedwater to steam generators.
The No. 3 reactor at the plant resumed operation on March 23 after being offline for over seven years, amid lingering concerns among residents about how to evacuate from islets near the plant in the event of a serious accident. It restarted power generation two days later.
Following the latest incident, Kyushu Electric's plan to restart the No. 4 reactor in May could be delayed, the utility said.
The No. 3 unit was suspended for a regular inspection in December 2010, three months before a massive earthquake and tsunami sparked a crisis at the Fukushima Daiichi nuclear plant.
It cleared the Nuclear Regulation Authority's safety screening in January 2017 under stricter, post-Fukushima regulations and was later approved for reactivation by the Genkai municipal government and Saga prefectural government.