A self-revealing
NCV was identified for failure to properly follow procedure when calibrating Loop 3 Steam Pressure Channel 1 on Unit 1. Because of failure to follow procedure, automatic
steam generator level control rapidly reduced
feedwater flow to the point where programmed level could not be maintained and caused the operators to manually trip the reactor. The licensee entered the problem into their corrective action program and initiated actions to prevent recurrence. The finding was more than minor because it was associated with the human performance attribute of the
Initiating Events Cornerstone and resulted in an upset in plant stability by causing a
reactor trip. While the finding resulted in an actual trip, the finding was determined to be of very low safety significance, because it did not contribute to the likelihood of a loss of coolant accident, contribute to a loss of mitigation equipment functions, or increase the likelihood of a fire or flood. The cause of the finding was associated with the human error prevention techniques aspect of the human performance cross-cutting area, because the involved instrument technicians failed to follow proper placekeeping practices and failed to verify and validate the proper starting place in the procedure after taking a break. (Section 1R22)
