The nuclear safety commission halted the operation of two nuclear reactors Tuesday, while also suspending the scheduled operation of two other reactors for substandard parts used in the reactors.

Neither the shutdown of the reactors nor the substandard parts used in them posed immediate threats to public safety, according to the Nuclear Safety and Security Commission.

The commission said it has shut down two reactors -- the Shin Kori Reactor 2 and Shin Wolsong Reactor 1 -- after learning that substandard parts supplied under fake quality warranties had been used in building them.

The commission has also suspended the scheduled resumption of operation of the Shin Kori Reactor 1, which had been undergoing regular maintenance.

In addition, the new Shin Wolsong Reactor 2, which is currently under a review for the start of its commercial operation, will not be allowed to begin operation until all substandard parts have been replaced, it said.

There was no danger of a radiation leak, but the shutdown of two nuclear reactors that are currently in operation posed a serious problem for the supply of electricity, especially ahead of the summer season when electricity consumption usually surges to an annual high.

The country currently operates 23 reactors, supplying about 30 percent of its total electricity consumption. Shutting down two nuclear reactors that are currently generating electricity meant a significant drop in the country's power reserve levels.

The shutdown of the reactors follows a corruption scandal that erupted late last year, involving more than 13,000 substandard parts supplied under fake quality warranties for over 10 years.

The commission had shut down two reactors at the Yeonggwang Nuclear Power Plant, located 330 kilometers south of Seoul, saying nearly 99 percent of all substandard parts had been used in the two Yeonggwang reactors.

The commission did not specify whether the two incidents were related, saying only control cables with fake warranties had been used in the two reactors at the Wolsong Nuclear Power Plant, located some 400 kilometers southeast of Seoul, and the two reactors at the Kori Nuclear Power Plant, located about 450 kilometers from the capital and near Busan. (Yonhap News)