19:35 Mar 14, 2007
Two Out of Three Auxiliary Feedwater Pumps Out of Service
A pinhole leak was discovered on B train Essential Service Water (ESW) system piping while preparing the pipe surface for non-destructive examination. Control room personnel were notified of the leak at 1435. B ESW was immediately declared inoperable. At the time of control room notification, surveillance testing on the Turbine Driven Auxiliary Feedwater Pump (TDAFP) was in progress. This surveillance testing made the TDAFP inoperable and non-functional. The surveillance activities were terminated and the TDAFP was returned to operable status at 1438.
B ESW is the safety related water source for B train of auxiliary feedwater (AFW). For the three minute period between notification of the pinhole leak until the TDAFP was restored to operable status, there were two auxiliary feed pumps inoperable. This met the conditions for entry into T/S LCO Action 3.7.5.D which requires a plant shut down to Hot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. This action was exited when the TDAFP surveillance testing was terminated. Additionally, with 2 of 3 auxiliary feedwater pumps non-functional for 3 minutes, there was a condition which could have prevented fulfillment of a safety function for those 3 minutes.
The licensee notified the NRC Resident Inspector.
The licensee provided the following information as the basis for retracting this report:
On March 14, 2007, (Event Number 43240) Callaway Plant reported a condition that, at the time, was believed to be a condition which could have prevented fulfillment of a safety function. At that time the 'A' motor driven auxiliary feedwater pump (MDAPP) was operable, the turbine driven auxiliary feedwater pump was not functional because of a surveillance test in progress. The 'B' MDAFP was presumed to be non-functional because of a pinhole leak in the 'B' train essential service water (ESW) system piping. 'B' ESW is the safety related water source for the 'B' MDAFP.
Subsequent inspection, non-destructive examination, analysis and evaluation of the 'B' train ESW piping determined that the structural integrity of the pipe was retained. 'B' ESW pump was able to provide the required flow to the train. 'B' train ESW was functional with the pinhole leak. With the 'B' ESW train functional, the 'B' train of auxiliary feedwater had its emergency water source. The auxiliary feedwater system would have been able to fulfill its safety function. This event is not reportable per 10CFR50.72(b)(3)(v).The licensee will inform the NRC Resident Inspector. Notified R4DO (O'Keefe).
Missouri (NRC Region 4)
|10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor|
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
|Time - Person (Reporting Time:+2.78 h0.116 days <br />0.0165 weeks <br />0.00381 months <br />)|
22:22 Mar 14, 2007
|NRC Officer:||Jason Kozal|
|Last Updated:||May 4, 2007|
|43240 - NRC Website|
Power Operation (100 %)
Power Operation (100 %)