South Korea shut down a nuclear reactor Wednesday for what appeared to be problems in an electric generator connected to the reactor, plant operators said. The Unit-3 reactor at Kori Nuclear Power Plant was shut down at 8:36 a.m., according to an official from the Korea Hydro & Nuclear Power Co. \"A problem was detected in the generator, but it will take some time before we learn exactly what the problem is,\" the official said. \"There is no radiation leak or any safety threat.\" The reactor, located 410 kilometers southeast of capital Seoul, went into operation in September 1985. It has a capacity of 950,000 kilowatts. The shutdown came one day after a 1-million kilowatt reactor at a nearby plant in Uljin, 330 kilometers southeast of Seoul, stopped operation for unknown reasons. The stoppage of two nuclear reactors could lower the country\'\'s electricity reserve rate to dangerous levels, especially during the winter peak season. The official from the state-run nuclear power company, however, said there were no immediate dangers of a nationwide blackout due to the shutdown of the reactors. South Korea currently has 21 nuclear reactors that provide about 40 percent of its total electricity needs. (QNA) ST/LY