http://hisz.rsoe.hu/alertmap/index2.phpOfficials with the U.S. Nuclear Regulatory Commission and Progress Energy are looking into an unplanned reactor shutdown that occurred at the H.B. Robinson Nuclear Plant near Hartsville on Monday. "We had an automatic plant trip," said Progress Energy spokesperson Jessica Lambert, who said a faulty electrical relay caused the shutdown. Progress Energy owns and operates the plant. The incident happened at about 11:45 a.m., Lambert said. She said the shutdown occurred when the system that monitors the flow of coolant through the reactor's coolant system indicated a low flow of coolant in the system. Lambert said plant officials have now determined that the incident resulted from a failed electrical relay in the reactor protection system and not from a problem in the coolant system. The reactor was still down on Wednesday, and Lambert said plant personnel are working to make the needed repairs to bring it back into service soon. "Of course, the NRC has on-site
inspectors here, and we are working very closely with them," Lambert said. "It was an automatic shutdown," said NRC Region II spokesman Roger Hannah. "There was nothing complicated about it." Hannah said the reactor system is designed to shut down automatically in the event of a low coolant flow signal. "Everything worked like it was supposed to," he said. "We're following up with our resident inspectors on site." The shutdown occurred just days before the NRC was supposed to close a final deficiency finding related to performance at Robinson and problems resulting in unplanned shutdowns that occurred in 2009 and 2010 that resulted in heightened oversight of the Robinson facility by the regulatory agency. That finding was to have been closed this Friday unless additional findings occurred before then.
"That's something we'll evaluate," Hannah said. "It won't affect what happens on Friday. If we do something, it'll be after Friday. We'll review it and look at how it fits into our overall regulatory oversight." Hannah said it is also unclear how the latest incident will affect Robinson's regulatory status from this point. "We don't know yet. We're looking at that, but it's too early to say at this point," he said. The NRC said in February that it would increase oversight at Robinson in the wake of unplanned reactor shutdowns that occurred on Nov. 6, 2009, and on March 28, Sept. 9 and Oct. 7, 2010. Those incidents included two electrical fires that occurred on March 28, 2010 that damaged the plant's electrical system and other equipment. The NRC also cited problems with an emergency diesel generator. The NRC said poor operator training, failure to follow required procedures and inadequate maintenance all
contributed to the plant's problems. Plant officials say they have taken significant steps to correct the problems identified by the NRC. Those include changes in leadership, improved training, equipment upgrades and improving workplace behavior. In July in a letter and later at a public meeting with Robinson plant officials in Hartsville in August, NRC officials said the steps taken by Progress Energy and Robinson officials to address and correct the problems were appropriate.
The agency said that based on actions taken by Robinson officials, it had closed three "white" inspection findings but would leave one deficiency finding in effect until Sept. 30, when it, too, would be closed unless additional findings occurred before then. The NRC evaluates regulatory performance of commercial nuclear reactors using a color-coded system which classifies findings as green, white, yellow or red in increasing order of safety significance. The agency staff increases its level of oversight and inspection based on that significance and expects the plant's operator to take appropriate corrective actions to address the causes and any underlying issues. The Robinson Steam Electric Plant operates one pressurized-water reactor known as Robinson Unit 2. The reactor went into service in March of 1971 and has been producing electricity ever since. The 719-megawatt Robinson facility was the first commercial nuclear reactor in the southeast. Carolina Power
& Light Co. -- now Progress Energy -- was issued a 40-year license for the plant in 1970. That license was set to expire on July 31, 2010. The NRC, after a nearly two-and-a-half-year review process, renewed the reactor's license and extended it for another 20 years in 2004. The current license expires on July 31, 2030. The NRC regulates 104 nuclear reactors across the U.S. which supply about 20 percent of the nation's electrical power.
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