The North Anna nuclear plant faces increased oversight from the U. S. Nuclear Regulatory Commission due to a violation of low to moderate safety significance linked to the maintenance of the plant’s emergency diesel generators.
North Anna, operated by Dominion, is on Lake Anna about 40 miles northwest of Richmond.
The NRC staff determined that a violation involving the failure of North Anna personnel to establish and maintain appropriate maintenance procedures for the plant’s emergency diesel generators is a “white” finding, meaning it has low to moderate safety significance.
The NRC uses a color-coded system to categorize inspection findings. They range from “green,” for an issue of very low safety significance, to “white,” “yellow” and “red,” which is assessed for the most safety significant violations.
The violation stems from the failure of one of the plant’s four emergency diesel generators following the Aug. 23 earthquake that affected the area. The failure was not caused by the earthquake and repairs were completed a short time later. Ensuing inspections determined that the plant’s maintenance procedures did not provide adequate guidance for installing specific gaskets on the generators. Dominion has since revised its maintenance procedures.
At Dominion’s request, NRC staff held a Regulatory Conference on April 20 to discuss the risk significance of the finding with the licensee. After reviewing the information developed during the inspection and the supplemental information provided by Dominion during the conference, the staff concluded that the inspection finding is appropriately characterized as “white.”
The finding puts North Anna into the Regulatory Response Column on the NRC Action Matrix, meaning the plant will be subject to additional NRC inspections beyond the baseline inspections that are conducted at all nuclear plants.