ENS 47286

v t e ENS Event
14:20 Sep 21, 2011
Title	Relay Malfunction Resulted in a Valid Undervoltage Signal
Event Description	On 9/21/11 at 10:20 a.m. during the performance of a simulated loss of offsite power testing off the E33 4KV emergency bus, an unplanned start of the E3 Emergency Diesel Generator (EDG) occurred due to a valid bus under voltage signal caused by a relay malfunction. The bus being tested was inoperable in support of the test and was not carrying any required safety system loads at the time of the event. The EDG was secured and troubleshooting initiated. The initial determination was the EDG actuation was from an invalid signal but following further review it was determined that the relay malfunction had caused an untimely bus transfer that resulted in a valid 4KV bus under voltage condition. The NRC Resident Inspector has been notified.

ENS 47286 +/-
Where
Peach Bottom Pennsylvania (NRC Region 1)
Reporting

10 CFR 50.72(b)(3)(iv)(A), System Actuation
LER:	05000277/LER-2011-003
Time - Person (Reporting Time:+8.47 h0.353 days <br />0.0504 weeks <br />0.0116 months <br />)
Opened:	Tom Dingel 22:48 Sep 21, 2011
NRC Officer:	Joe O'Hara
Last Updated:	Sep 21, 2011
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v • d • e

v t e Emergency Notification System
Peach Bottom with 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2024-07-10T11:28:00 [Table view]
[ENS list for Peach Bottom]

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