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Nuclear safety issues mount in South Korea

Recent security concerns during inspections have heightened concerns about the safety of South Korea's nuclear reactors, particularly after a recent scandal that involved the use of unverified parts.

By Greg Hale, ISS Source December 11, 2012

Tiny cracks in tunnels at a nuclear plant in South Korea are hiking worries about nuclear safety in the country following a recent scandal involving the use of unverified parts.

The reactor where officials found the cracks will remain offline until regulators investigate the problem, putting extra strain on South Korea’s already stretched power supply going into the winter months.

The utility Korean Hydro and Nuclear Power Co. (KHNP) said it detected microscopic cracks in six control rod tunnels at Unit 3 of its Yonggwang nuclear plant in the southwest of the country. Control rods regulate the speed of nuclear reactions taking place inside reactors.

“The cracks are not serious and there is no risk of radiation leakage,” said Jang Yong-jin, head of the mechanics department at KHNP.

Workers found the problem while the reactor was down for a regular 36-day maintenance period. But it will now stay out of service for a further 47 days as inspectors seek to determine the cause of the cracks, the South Korean Nuclear Safety and Security Commission said.

That deprives the national power grid of another source after operations stopped this month at two other reactors at the same complex to replace thousands of parts forged quality certificates.

Authorities said at the time halting those two reactors, Units 5 and 6, may result in “an unprecedented level” of strain on the nation’s power supply. They account for about 5% of South Korea’s total supply, according to the government.

“Winter here is brutal, and I am now very concerned that the unexpected shutdowns of three nuclear units will cause power shortages,” said Huh Kyun-young, a nuclear engineering professor at Kyung Hee University.

Experts have been warning about insufficient power supplies in South Korea for years, Huh said.

It remains unclear how the power supply will suffer by the extended shutdown of Unit 3, Jang said.

“Relevant departments are mapping contingency plans,” he said.

The cracks themselves are not a serious issue and have been found at reactors in such other countries as the United States and Japan, said Jae Moo-sung, a professor in the nuclear engineering department of Hanyang University.

But Jae warned the news could hurt South Korea’s efforts to export its nuclear power technology to other countries.

The problems at the South Korean reactors come amid increased scrutiny of nuclear power worldwide following the crisis at the Fukushima Dai-ichi nuclear plant in Japan during the aftermath of the earthquake and tsunami that hit the country in March 2011.