South Korea saw its already-dwindling power reserves dip Wednesday afternoon as another reactor shut down unexpectedly.
Yonhap News reported that safety systems tripped a reactor at Korea Electric Power Co.'s Yeonggwang plant. KEPCO said it will take up to a week to determine the cause of the shutdown but added it did not pose a threat to public safety.
The afternoon incident briefly pushed the country's power reserves below 4,000 megawatts, prompting KEPCO to ask its customers to conserve energy. South Korean grid operators normally keep reserves above 5,000 megawatts, but hot weather and power plant outages have caused reserves to fall below that level multiple times this summer.
South Korea relies on 23 reactors to supply about one-third of its electricity. In May, though, the government forced shutdowns at two units amid a scandal involving quality control documentation for plant cabling. Four more are offline for maintenance and inspections.