A self-revealing non-cited violation (
NCV) of
Technical Specification 5.4, Procedures was identified. Specifically, a human performance error associated with inadvertently isolating instrument air to the turbine building, auxiliary building, and control building, resulted in an
automatic trip of the B main feed pump and a subsequent manual
reactor trip. The licensee immediately restored instrument air and stabilized the plant in Mode 3. The licensee has entered the issue into their corrective action program and is in the process of implementing enhanced human error reduction techniques and improving procedural rigor and compliance throughout the site organization. This issue is more than minor because it is associated with a cornerstone attribute, and it adversely affected the objective of the
Initiating Events cornerstone. Specifically, the performance deficiency is a human performance error which led to a
reactor trip and adversely impacted plant stability. The finding was determined to be of very low safety significance (Green) because the event did not contribute to both the likelihood of a
reactor trip and the likelihood that mitigation equipment or functions would not be available. The inspectors determined that the cause of this finding was related to the Work Practices component of the Human Performance cross-cutting area.
H.4(c) Specifically, due to less-than-adequate supervisory and management oversight of the work activity i.e., no in-field supervisory oversight for first-time performers and inadequate pre-job brief
