NRC CAL – NOV (White)

On December 28, 2016, the NRC issued a Notice of Violation associated with a White Significance Determination Process finding to Pacific Gas and Electric Company (the licensee), for a violation involving the licensee's failure to develop adequate instructions for the installation of external limit switches on safety-related motor-operated valves as required by Technical Specification 5.4.1.a "Procedures," at the Diablo Canyon Power Plant. Specifically, Procedure MP E-53.10R, "Augmented Stem Lubrication for Limitorque Operated Valves," Revision 4, used to perform maintenance on safety-related equipment, failed to provide instructions to establish and check the travel of external switches installed on motor-operated valves are within vendor established criteria. Consequently, the limit switch for valve RHR-2-8700B was installed, such that, it was operated repeatedly beyond overtravel tolerances resulting in its failure on May 16, 2016. Additionally, the licensee also violated Technical Specification 3.5.2 because train B of the emergency core cooling system was determined to be inoperable for greater than the technical specification allowed outage time of 14 days.