South Korea's nuclear watchdog said Wednesday it will strengthen its ability to fight cyberattacks and expand the size of its cybersecurity staff to deal with safety concerns following recent hackings.

In an annual policy briefing to the president, the Nuclear Safety and Security Commission said it will form a task force against such attacks and increase the number of people on its cybersecurity staff from the current three to 30.

"We will establish an anti-nuclear disaster training system to strengthen emergency preparedness and form a task force to counter cyberattacks on nuclear reactors," the commission said in a release.

An unidentified hacker group last month posted partial blueprints of the nation's two nuclear plants online and threatened to release other confidential files unless the plants were closed by Christmas. There were no incidents linked to the threats.

Nuclear officials said the information released by the group were noncritical data, but their laid-back response raised fears that hackers, including those with possible North Korean links, could target the nation's key infrastructure. 

South Korea has 23 nuclear reactors in operation, from which it gets about 30 percent of its electricity supply, and is building several more.

The commission also said it will establish legal frameworks covering all processes ranging from design to shutdown of a nuclear reactor to prepare for closing of aging reactors in the future.

A nuclear security revision bill was passed by the parliament in December, but it has not yet gone into force.

Under the law, new nuclear reactors must have a decommissioning plan in order to get an operation approval, and nuclear facilities currently operating need to submit such a plan within three years.

Old reactors face growing pressure to shut down in the next decade, while nuclear officials try to extend their lifespan to meet the country's energy demand.

The NSSC last week delayed a decision on whether to extend the operation of a 32-year-old nuclear reactor amid strong opposition from residents and civic groups over its safety, with the upcoming meeting scheduled for next month.

The commission said it will set up 20 more radioactive detectors at the nation's ports to toughen control over imported cargo and to require importers of recycled steel to submit safety check certificates.

In August, South Korea returned some steel scrap imported from Japan due to radiation contamination, the first such action since Seoul heightened nuclear safety monitoring in 2012 after the Fukushima nuclear disaster in 2011.

As part of efforts to root out corruption in the nuclear industry, the watchdog plans to adopt a special investigatior system to better monitor parts suppliers and officials.

"To prevent corruption such as fake certificates for nuclear parts, (officials) should be able to conduct on-site investigations," Kim Yong-hwan, a senior commission official, said. "(The commission) will adopt the special investigation system to step up monitoring activities." 

Some 100 officials in the local nuclear energy industry were charged with corruption in 2013 after they were found to have issued safety guarantee certificates for substandard parts that were used in nuclear reactors. (Yonhap)