The U.S. Nuclear Regulatory Commission said it will increase inspections at Duke Energy Corp. (DUK)’s Oconee power plant after finding a flaw deemed to be of “substantial safety significance.”
Faulty circuit breakers may have prevented a back-up shutdown system from operating during fires or storms when other ways to cool the reactors weren’t available, the NRC said today in a statement.
“The facility was vulnerable to core damage if an accident involving a series of unlikely events occurred,” the NRC said in the statement.
The NRC is weighing rules to upgrade safety at 104 commercial U.S. reactors following meltdowns and radiation leaks at Tokyo Electric Power Co. (9501)’s Fukushima Dai-Ichi plant caused by an earthquake and tsunami in March.
A priority for the agency is identifying declines in power- plant performance, such as errors at FirstEnergy Corp.’s Perry plant near Cleveland and Nebraska Public Power District’s Cooper plant near Omaha that almost exposed workers to significant doses of radiation, NRC Chairman Gregory Jaczko told reporters yesterday.
Workers at the three-reactor Oconee plant, about 30 miles (48 kilometers) west of Greenville, South Carolina, detected the electrical breaker failure June 2, and the NRC held a meeting Nov. 16 on the issue, according to the agency. Oconee can generate enough electricity for about 1.9 million homes, according to Duke Energy’s website.
The company “took prompt action to replace the breakers with fuses that were extensively tested and qualified prior to installing them,” Duke Energy spokeswoman Sandra Magee said today in a phone interview. The back-up shutdown system hasn’t been needed since the plant started operating in 1973, she said.
Public safety wasn’t jeopardized because the plant didn’t have an emergency that required the back-up, the NRC said in its statement. The agency is seeking more information “to determine whether the breaker problem represents a current performance issue,” according to the NRC.
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