ENS 45006

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v t e ENS Event
08:06 Feb 23, 2009
Title	Inadvertent Actuation of Turbine Auxiliary Feedwater Pump
Event Description	On February 23, 2009 at 0406, with Unit 1 at 100% power level, McGuire Nuclear Station experienced an inadvertent actuation of the Unit 1 Turbine Driven Auxiliary/Emergency Feedwater (TDAFW) Pump. This event occurred when power was removed to the steam admittance solenoid valves for the Unit 1 TDAFW Pump prior to isolating the steam supply to the pump. Removing power to the steam admittance valves caused them to fail open, starting the pump and injecting water into all four Unit 1 Steam Generators (S/Gs). Flow to the S/Gs was isolated by manually closing the Unit 1 TDAFW discharge isolation valve to each S/G. During recovery from the event, power was restored to the steam admittance solenoid valves for the running Unit 1 TDAFW Pump. Restoration of power generated a pump auto start signal which resulted in inadvertent automatic closure of both trains of blowdown containment isolation valves and both trains of sample containment isolation valves for each Unit 1 S/G. Subsequent evaluation of the event concluded that the actuation of the Unit 1 TDAFW Pump, S/G blowdown containment isolation valves, and S/G sample containment isolation valves was not the result of a valid signal initiated in response to actual plant conditions or parameters satisfying the requirements for initiation of the safety function provided by the respective component. In addition, the actuation of these components was not the result of an intentional manual initiation. Therefore, actuation of the Unit 1 TDAFW Pump, S/G blowdown containment isolation valves, and S/G sample containment isolation valves represented invalid actuations which are not reportable per the requirements of 10 CFR 50.72(b)(3)(iv)(A). Although the actuation of these components represented invalid actuations, they were not pre-planned, the systems were not removed from service, and the safety function provided by the components had not already been completed. Therefore, McGuire is reporting actuation of the Unit 1 TDAFW Pump, S/G blowdown containment isolation valves, and S/G sample containment isolation valves in accordance with the requirements of 10 CFR 50.73(a)(2)(iv)(A). Note that closing the Unit 1 TDAFW Pump discharge isolation valve to each S/G to isolate flow rendered the Unit 1 TDAFW inoperable. However, these valves were opened and the Unit 1 TDAFW Pump was restored to an operable status within the required completion time specified in the Auxiliary Feedwater System Technical Specification. As indicated in 10 CFR 50.73(a)(1), in the case of an invalid actuation reported under 10 CFR 50.73(a)(2)(iv)(A) other than actuation of the Reactor Protection System when the reactor is critical, the licensee may, at its option, provide a telephone notification to the NRC within 60 days after discovery of the event instead of submitting a written LER. In these cases the telephone report is not considered an LER. McGuire is exercising this option by providing this telephone notification. The following additional information is being provided as part of the telephone notification of this event: The Unit 1 TDAFW Pump injected water into all four Unit 1 S/Gs for approximately 3 and 1/2, minutes before flow was isolated by manually closing the Unit 1 TDAFW discharge isolation valve to each S/G. Subsequent evaluation determined that Unit 1 reactor power did not exceed 100% during the event. The actuation of the Unit 1 TDAFW Pump was complete and successful. This event actuated both trains of blowdown containment isolation valves and both trains of sample containment isolation valves for each Unit 1 S/G. Each train's actuation was complete and successful. The licensee has notified the NRC Resident Inspector. The TDAFW pump was being removed from service, and the steam admittance solenoid valves should have been isolated prior to removing power to them.

ENS 45006 +/-
Where
Mcguire North Carolina (NRC Region 2)
Reporting

10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation
Time - Person (Reporting Time:+1375.28 h57.303 days <br />8.186 weeks <br />1.884 months <br />)
Opened:	Wayne Hoyle 14:23 Apr 21, 2009
NRC Officer:	Karl Diederich
Last Updated:	Apr 21, 2009
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v • d • e

v t e Emergency Notification System
McGuire with 10 CFR 50.73(a)(1), Submit an LER
WEEKMONTHYEAR2023-01-01T11:04:00 [Table view]
[ENS list for McGuire]

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