ENS 44227

v t e ENS Event
20:10 May 20, 2008
Title	Offsite Power Grid Disturbance
Event Description	On Tuesday, May 20, 2008, at approximately 1310 PDT, the offsite power grid connected to San Onofre experienced a momentary system disturbance. Control Room indicators alerted Operators that the grid frequency dipped to approximately 59.69 Hz. Because frequency dipped below 59.7 Hz, SCE is reporting this event in accordance with 10CFR50.72(b)(3)(v)(D). The frequency dip lasted approximately 10 seconds, reportedly due to a high voltage DC transmission line disturbance in Oregon. The grid is currently operating at nominal frequency. At the time of the event, San Onofre Unit 2 was operating in Mode 1 at approximately 99 percent power and Unit 3 was operating in Mode 1 at approximately 80 percent power. The NRC Senior Resident Inspector has been notified of this event and provided a copy of this report.

ENS 44227 +/-
Where
San Onofre California (NRC Region 4)
Reporting

10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
Time - Person (Reporting Time:+-1.43 h-0.0596 days <br />-0.00851 weeks <br />-0.00196 months <br />)
Opened:	Susan Gardner 18:44 May 20, 2008
NRC Officer:	Mark Abramovitz
Last Updated:	May 20, 2008
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v • d • e

v t e Emergency Notification System
San Onofre with 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
WEEKMONTHYEAR2010-01-13T19:25:00 [Table view]
[ENS list for San Onofre]

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