Nuke Plant Sees Red for Safety Violations

Wednesday, May 11, 2011 @ 11:05 AM gHale

After deciding a failed emergency cooling system at an Alabama nuclear plant could have been a serious safety problem, federal regulators ordered an in-depth inspection.

A red finding against the Browns Ferry nuclear power plant near Athens, Ala., came about after the U.S. Nuclear Regulatory Commission (NRC) investigated how a valve on a residual heat removal system became stuck shut. The NRC has issued only five red findings — the most severe ranking the agency gives to problems uncovered in its inspections — since its current oversight program started in 2001.

NRC said the utility, owned by the Tennessee Valley Authority (TVA), must pay for detailed inspections of the plant’s performance, its safety culture and organization. The agency said it could not immediately estimate inspection costs.

In an emergency, the failure of the valve could have meant one of the plant’s emergency cooling systems would not have worked as designed. Officials fixed the problem, identified as the plant was undergoing refueling in October 2010, before the Unit 1 reactor returned to service.

“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 II administrator. “However, significant problems involving key safety systems warrant more extensive NRC inspection and oversight.”

The valve failed sometime after March 2009 but no one discovered it until more than a year later.

TVA officials are unsure on if they will appeal the NRC decision.

“Obviously we’re disappointed with the NRC’s findings on this matter,” Chief Nuclear Officer Preston Swafford said. “The safe operation of all our units is our primary concern, and we take any regulatory report of a violation very seriously.”

Experts said a failure of the valve could have left one of the plant’s emergency cooling systems unable to function in an emergency, for example, if the reactor suddenly lost the coolant needed to keep its nuclear fuel from melting.

The worst outcome could have resulted from a series of what McCree called unlikely events involving a plant fire. In case of a fire, operators would protectively shut down some safety equipment, potentially including one of the residual heat removal loops. If the second system did not function because of the valve failure, plant operators would need to rely on other cooling equipment.

TVA officials blamed the problem on a manufacturer’s defect in equipment it doesn’t ordinarily inspect. Utility spokesman Ray Golden said the valve failure never caused an accident or threatened public safety. The utility has inspected similar valves at the plant and has not found any problems, he said. TVA officials also said testing showed the stuck valve would have eventually opened, though NRC officials dispute this claim.

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