A nuclear reactor at one of South Korea's nuclear power plants stopped generating power due to malfunctions on Sunday, plant operators said.

A turbine and a generator of the Wolsong 1 reactor in Gyeongju stopped at 4:51 p.m. due to the malfunction of a device that supplies exiting currents to the generator, according to an official from the state-run Korea Hydro & Nuclear Power Co., Ltd.

The reactor located some 371 kilometers southeast of Seoul is still in operation, but cannot produce electricity, the official said.

An investigation is currently underway to confirm the exact cause of the malfunctioning.

There is no danger, however, of a radiation leak from the reactor, the official added.

The power generation will resume after the ongoing investigation finds the exact problem and the malfunctioning device is repaired, the official said.

The 678,000 kilowatt nuclear reactor went into full operation in April 1983 and government permission for the operation is due to expire in November this year. The government is conducting a screening to determine whether to extend the permission.

South Korea currently operates 23 nuclear reactors, which supply about 30 percent of its total electricity consumption. (Yonhap News)