South Korea's plans to boost nuclear power face increasing resistance from civic and environmental groups, post Fukushima, the Japanese reactor site hit by an earthquake and tsunami last year.

South Korea relies on nuclear energy for about 30 percent of its electricity needs, supplied by 21 active nuclear reactors. The government aims to increase that share to 40 percent by 2040.

Even after Japan's magnitude-9 earthquake and tsunami last March 11 led to a meltdown at the Fukushima nuclear power plant, a South Korean government official was quoted by The Korea Herald newspaper as saying "the (nuclear) plan has not changed."

And the South Korean government has been trying to recruit top nuclear experts from Tokyo Electric Power Company, operator of the Fukushima plant, to work in South Korea's nuclear power sector, reports Japan's Mainichi Shimbun newspaper.

Meanwhile in Gyeongju, 230 miles southeast of Seoul, the No. 1 reactor at the Wolseong nuclear power plant was shut down last month after a temperature sensor on one of its four reactor coolant pumps malfunctioned.

That incident came six months after the reactor was restarted following more than two years of maintenance.

The Wolseong plant, which features four pressurized heavy water reactors, generates about 5 percent of South Korea's electricity.

Korea Hydro and Nuclear Power Co. Ltd., operator of the plant, and the Ministry of Knowledge Economy maintain that no radiation leaked from the No. 1 reactor.

"The temperature did not actually rise; it was simply a component abnormality," a ministry official said, Japanese newspaper The Hankyoreh reports.

The Wolseong No. 1 reactor, which began commercial operation in 1983, is the second oldest in Korea. Its 30-year design life comes to a close in 2013 but the Nuclear Safety and Security Commission is assessing the possibility of an extension.

"They give 10-year extensions in other countries, too, after conducting safety inspections according to set procedures," a ministry official said.

However, local residents and environmental groups are concerned about the reactor's safety, given its track record. Not including last month's shutdown, the reactor has had 51 malfunctions since it went online, "due to flaws in machinery and components, including radiation leaks, coolant leaks and reactor shutdowns," says the Korea Federation of Environmental Movements.

"Because the Wolseong No. 1 reactor has reached the end of its 30-year design life and is worn out, it is expected to keep malfunctioning from now on. There is a high possibility that a small accident could quickly turn into a large-scale one," warned Lee Sang-hong, director of a Gyeongju alliance for nuclear safety, Hankyoreh reports.