South Korea has no option but to expand its nuclear power plant programme despite growing public concern over safety in the wake of Japan's Fukushima disaster in 2011 and a series of scares that closed two reactors last year.
The proportion of South Koreans who considered nuclear power safe fell to 34.8 percent in a survey conducted in November and published on Tuesday, down from 40 percent in April 2011 and 71 percent in January 2010, the Ministry of Knowledge Economy said.
The ministry has been sharply criticised for its role as regulator and operator of the country's nuclear power plants, and one of its subsidiaries was accused of suppressing negative public opinion after the Fukushima disaster by not publishing polls.
A fake parts scandal closed two reactors last year and the industry suppressed details of the closure of the Kori No.1 reactor early in 2012.
"It is an urgent priority to recover people's trust and the safety of reactors just as it is unavoidable to maintain nuclear at a certain percentage of the total power supply, considering the power supply and demand situation," the ministry said.
The two troubled reactors were fully restarted last week, easing fears over winter power shortages.
Three others are offline for maintenance and operational approval, but power supplies remain a concern amid peak winter demand expected until the end of next month.
Asia's fourth-largest economy, which depends heavily on oil and gas imports, plans to add 11 reactors by 2024 on top of its existing 23 reactors which supply a third of the country's total power.
An earthquake and tsunami in Japan in March 2011 killed nearly 20,000 people and triggered the world's worst nuclear crisis in 25 years when the Fukushima-Daiichi nuclear plant was destroyed, leaking radiation into the sea and air.