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Browns Ferry Nuclear Power Plant  (Source: svsnowgoose.com)
A valve on its residual heat removal system was stuck shut, which prompted in-depth inspections by the NRC

Nuclear power has received a lot of criticism lately due to the 9.0-magnitude earthquake that rocked Japan on March 11. U.S. Senators urged the Nuclear Regulatory Commission (NRC) to repeat the inspection of nuclear power in the United States after it was already deemed safe, and French President Nicolas Sarkozy called for a global nuclear review after visiting Japan.

Despite all of these negative reviews, there are also many advocates who see the benefits of cheap, clean and reliable nuclear power as an alternative energy source. U.S. President Barack Obama even embraced nuclear energy in last year's State of the Union address

No matter which side you're on, many can agree that safety comes first, and now, federal regulators are concerned about the safety of an Alabama nuclear plant after its emergency cooling system failed. 

The Browns Ferry nuclear power plant is located near Athens, Alabama and is run by the Tennessee Valley Authority. A valve on its residual heat removal system was stuck shut, which prompted in-depth inspections by the NRC.  

According to reports, there have been previous problems with the valve. Originally, the valve failed sometime after March 2009, but wasn't identified until October 2010 when the plant was being refueled. The valve was fixed at that time, and was labeled as a manufacturer's defect. Despite the plant's effort to fix the valve and inspect all others like it, the NRC criticized the plant for not finding the valve issue sooner through routine inspections.

"The valve was repaired prior to returning the unit to service and Browns Ferry continued to operate safely," said Victor McCree, the NRC's Region ll administrator. "However, significant problems involving key safety systems warrant more extensive NRC inspection and oversight." 

Had there been an emergency, the NRC worries that the faulty valve could have prevented the emergency cooling systems from working correctly. For this reason, the NRC will continue to review the safety culture, organization and performance of the plant. 

"The results of this inspection will aid the NRC in deciding whether additional regulatory actions are necessary to assure public health and safety," said McCree.  

For the time being, the NRC has issued a red finding against the Brown Ferry nuclear plant, which is the most severe ranking given to a plant for inspection. Only five red findings have been issued in the U.S. in the past decade. It is unknown whether the Tennessee Valley Authority will appeal the finding from the NRC at this time.



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Clearing up some confusion
By Donovan on 5/12/2011 7:20:39 PM , Rating: 5
There seems to be some confusion about the nature of the valve, the testing performed, and the dates involved. I am not an expert in the field, but here are the facts from the NRC's official findings as best I can summarize them.

The valve is for Low Pressure Coolant Injection (LPCI) on one of the Residual Heat Removal (RSR) loops, part of the Emergency Core Cooling System (ECCS). It is not a vent valve...it is used for emergency coolant injection at low pressures (other systems work to keep the reactor cool until the pressure can be lowered enough to use this). The failure was a separation of the disc that actually blocks flow from the stem that operates the valve.

The valve was last reassembled in June of 2006, and the NRC states this as the earliest that the failure could have occurred. The plant operator has concluded that the valve had failed as of October of 2008 based on going back and reviewing old test data. The NRC accepts this as the failure date for the record but notes that the test analysis is inconclusive. The valve was under relevant operation from March 13, 2009 until the failure was recognized on October 23, 2010, so this is the period for which a violation occurred.

The valve can and is required to be tested regularly while in-place, but the test procedure used by the plant operator was inadequate. Specifically, they tested that the indicator lights worked and the valve stem moved, but did not actually check the flow to determine if the valve really opened. The NRC determined that the testing performed did not meet regulations, and also noted that similar valve failures have occurred at the same plant (meaning they were on notice that this needed to be tested for).

Official findings on NRC's website: http://adamswebsearch.nrc.gov/idmws/ViewDocByAcces...




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