A series of breakdowns of the nation’s nuclear power plants have rekindled the debate over whether to shut down old reactors or extend their operation.

A top government official fanned the controversy when he hinted at a possible shutdown of another reactor whose design lifetime has expired.

“Whether to extend operation of the 30-year-old first reactor at the Wolseong complex will be decided based on the agreement of the public,” said Lee Eun-chul, new head of the nation’s Nuclear Safely and Security Commission.

Industry watchers said Lee’s remark is likely to put the brakes on efforts made by Korea Hydro & Nuclear Power, the state-run operator of the nation’s 23 nuclear power plants, to renew the license for the reactor from the NSSC within the first half of this year.

Wolseong unit 1, near the coast in Gyeongju, North Gyeongsang Province, stopped operations once its 30 year-long design life expired last year. It had produced about 678,000 kilowatts of electricity, fulfilling about 0.8 percent of the nation’s power consumption.

“Whether to extend operation of an old nuclear power plant whose design life expires should be decided depending on results of a safety evaluation rather than age,” a KHNP official said.

“As part of efforts to prove the safety of Wolseong unit 1, we are planning to conduct a European stress test for the unit following the safety review from the International Atomic Energy Agency.”

The EU stress test evaluates whether a nuclear power plant can withstand extreme natural disasters such as earthquakes.

Despite KHNP’s continued efforts, civic groups, especially environment-related nongovernmental organizations, have raised questions over the credibility of KHNP’s safety review processes for Wolseong unit 1.

“We found out that KHNP used outdated IAEA’s inspection criteria to review the safety of Wolseong unit 1,” an official from the Korea Federation of Environment Movement said, urging the government to reconsider the license renewal for the reactor.

Civic groups also oppose the extended use of the first reactor at the Kori nuclear power plant complex in Busan. The nation’s oldest nuclear reactor, which was built in 1977, was given a 10-year operational extension in 2007. The KHNP is trying to gain approval for another operational extension for the reactor through the tighter safety assessment.

“A series of breakdowns of nuclear power plants and the 2011 Fukushima accident fanned safety concerns of the public over the nation’s old nuclear power plants,” Lee said.

“The NSSC will increase investments to take preventive measures to prevent nuclear power plants from breaking down,” Lee said.

By Seo Jee-yeon  (jyseo@heraldcorp.com)