No: I-14-039 October 21, 2014

CONTACT: Diane Screnci, 610-337-5330

 Neil Sheehan, 610-337-5331 

NRC Issues ‘White’ Inspection Finding for Millstone 3 Nuclear Plant;

Level of Oversight to be Increased

The Nuclear Regulatory Commission will increase its level of oversight at the Millstone Unit 3 

nuclear power plant following the finalization of a “white” (low to moderate safety significance) 

inspection finding for the Waterford, Conn., facility. The finding, which involves a violation of NRC 

requirements, is based on the plant owner’s failure to promptly identify and correct repetitive problems 

involving a pump that is part of a reactor safety system.

Specifically, NRC inspectors determined that from May 2013 through February 2014, Millstone 

Unit 3’s turbine-driven auxiliary feedwater pump was operated improperly due to the installation of an 

incorrect bearing. This manifested itself in two cases of oscillations, or unexpected fluctuations, in 

reactor coolant flow from the pump and three trips, or shutdowns, of the pump because of 

overspeeding.

The auxiliary, or back-up, feedwater system is one of several that can be used to help cool down 

the reactor following a shutdown by pumping water into the secondary side of the plant’s steam 

generators. The steam generators are essentially large heat exchangers that convert heat produced by 

the reactor into steam, which in turn is used to spin the plant’s turbine and generate electricity.

Although Dominion Nuclear Connecticut Inc., the plant’s owner and operator, has taken action to 

repair the pump and has completed a root-cause evaluation, the NRC is taking enforcement action 

because of the length of time it took for the issue to be addressed.

“Our inspectors have carefully documented multiple problems involving this pump that occurred 

over the course of many months,” Acting NRC Region I Administrator David Lew said. “What 

concerns the NRC is that despite repeated efforts to repair this important component, the problems 

persisted and called into the question the pump’s past reliability.”

Under the NRC’s Reactor Oversight Process, inspection findings are classified by color based on 

their safety significance. The colors range from “green,” for a very low safety issue, to “white,” 

“yellow” or “red,” which connotes high safety significance. Because this finding has been finalized as 

“white,” Millstone Unit 3 will move from the Licensee Response Column of the NRC’s Action Matrix 

to the Regulatory Response Column and be subject to additional inspections by the agency.
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The NRC conducted a Special Inspection at Millstone Unit 3 in February and May in response to 

the problems involving the auxiliary feedwater pump. Among the areas that were reviewed during the 

inspection were Dominion’s responses to the issues, including the adequacy and completeness of 

testing on the pump and a root-cause evaluation of the problems.

 On Sept. 15, 2014, the NRC initiated an additional Special Inspection at Millstone Unit 3 in 

response to further unrelated problems with the pump. This action occurred after the pump failed 

quarterly surveillance tests in July and September. That Special Inspection is still in progress, and the 

results will be detailed in an inspection report to be issued within 45 days of its completion.