The decision to halt the reactors followed the recent controversy over the components used amid the increased security checkups at nuclear power plants in a worldwide effort to avoid disasters like the Fukushima Daiichi crisis in Japan in the aftermath of the earthquake and tsunami that hit the country in March 2011.
The two affected units at the Yeonggwang nuclear complex in the southwest is likely to remain nonfunctional until early January, as more than 5,000 fuses, cooling fans and other parts for which suppliers had provided fake quality certificates, need to be replaced, the AFP reported.
The two reactors account for about 5 percent of South Korea's national power supply, according to the government.
Knowledge Economy Minister Hong Suk-woo said these were "non-core" parts that didn’t pose a safety threat.
"We deeply regret the fact that such an incident took place, but again I point out the fact that this has no direct link to the safety of nuclear reactors," Hong was quoted as saying by Yonhap news agency.
"It's inevitable that we will experience unprecedented power shortage during the coming winter with the two reactors shut," he added.
The plant operator, Korean Hydro and Nuclear Power Co., found that eight suppliers had sold it a total of 7,682 items with forged quality certificates between 2003 and 2012, CNN reported citing the data from the South Korean government. The products were worth around 820 million won ($750,000).
South Korea has been aiming at energy security and minimal dependence on energy imports and runs 23 reactors which meet one third of the nation’s electricity needs.
The incident was likely to seriously undermine confidence over the safety of South Korean reactors, also denting the country's efforts to export nuclear power plants, Yonhap said in a report.
"The government plans to further increase its efforts to export nuclear reactors. In this regard, the government will quickly provide all necessary and accurate facts to prospective foreign buyers to make sure there is not a single shred of doubt left over the safety of the country's nuclear reactors," Hong said.