The Nuclear Regulatory Commission (NRC) staff has scheduled a regulatory conference with Dominion officials on Friday, April 20, to discuss an apparent violation of plant technical specifications associated with the failure of a gasket on an emergency diesel generator at the North Anna nuclear power plant in Louisa County.
The violation was identified when the failure prevented one of the diesel generators from performing properly after an earthquake on Aug. 23. The NRC said in a statement that the failure was not caused by nor related to the earthquake. The gasket was replaced the same day, and the problem was not found on the plant’s other diesel generators. However, NRC inspectors found that the plant staff did not have adequate procedures for installing the gasket.
Their preliminary finding, spelled out in an inspection report, involves the plant’s failure to adequately “establish and maintain an emergency diesel generator maintenance procedure.” Specifically, the procedure in place did not provide adequate guidance for the installation of a jacket water cooling inlet jumper gasket. As a result, the emergency diesel generator failed to perform its safety function on the day of the quake.
The conference, requested by Dominion, is open to the public. It will be held at 1 p.m. in the NRC’s Region II office, located at 245 Peachtree Center Ave., NE., Suite 1200, in Atlanta. “The discussion gives them an opportunity to explain what happened and the corrective actions taken,” said Joey Ledford, a spokesman for the NRC.
Jim Norvelle, a spokesman for Dominion Virginia Power in Richmond, said “Dominion Virginia Power looks forward to the opportunity to present additional details about each event to the NRC. Neither one affected the public’s health and safety, each condition was resolved safely and each unit was restarted safely.“
Within two to three weeks of the hearing, Ledford said the NRC expects to announce its final determination of the significance of the finding. The NRC evaluates regulatory performance at commercial nuclear power plants with a color-coded system which classifies findings as green, white, yellow or red, in increasing order of safety significance.
The NRC’s preliminary evaluation is “greater than green,” which means the actual significance has not been finalized, but it is greater than low safety significance. “If the determination is white, or yellow, that could lead to increased overnight and inspection at the plant,” Ledford said.