South Korea on Monday dedicated two new nuclear reactors that will account for 3 percent of the country's electricity output.

South Korea's 23rd and 24th nuclear reactors, built at a cost of 5.31 trillion won ($4.58 billion), can generate 158 million kilowatt hour of power per year, according to the commerce ministry.

The nuclear reactors -- the Shin-Wolsong 1 and 2 units in Gyeongju, 371 kilometers southeast of Seoul -- can allow the country to push up its electricity reserve ratio by some 3.4 percent, the ministry said. South Korea's power reserves have been slipping in recent years.

Work on the Shin-Wolsong 1 unit was completed in July 31, 2012, with construction on the second unit being finished on July 24 of this year.

According to the Korea Hydro & Nuclear Power Co. that operates the country's nuclear power plants, the two reactors are the last of the modified Optimized Power Reactor-1000 (OPR-1000) models that helped lay the foundation for future reactors designed and built in the country.

The country started building the more updated Advanced Power Reactor-1400 (APR-1400), which is the model being built in the United Arab Emirates.   

The latest APR reactors were wholly developed in South Korea, making it possible for them to be exported with minimum restrictions. Seoul inked a deal to build four such reactors for the UAE in 2009.

At a dedication ceremony, Minister of Trade, Industry and Energy Yoon Sang-jick that the reactors will help the country to cut back on 13 million tons of greenhouse gases from being released into the atmosphere per year.

"The reactors will help the country better meet its obligations to combat climate change as a responsible member of the international community," the policymaker said.

South Korea's first nuclear reactor went online in late 1972. (Yonhap)