South Korea has resumed operations of a nuclear reactor six days after the reactor was automatically shut down due to the malfunctioning of its power supply unit, authorities said Sunday, according to a report of "YONHAP" news agency. The Reactor-6 at the Younggwang Nuclear Power Plant, located some 330 kilometers southwest of Seoul, began operations at 8:40 a.m., the state-run Korea Hydro & Nuclear Power Co. said, noting the Nuclear Safety and Security Commission approved the resumption of the operation of the reactor on Saturday.