ENS 44092

v t e ENS Event
15:40 Mar 25, 2008
Title	Plant Shutdown Initiated Due To Degraded Battery Voltage
Event Description	On March 25, 2008 at approximately 0640 PDT, SCE discovered a battery with voltage slightly below Technical Specification limits. At approximately 0840 PDT, plant operators began cooling Moisture Separator Reheaters (MSR) in preparation for a Shutdown as required by TS 3.8.4. Initiating MSR cooldown reduced reactor power by 0.1%. Although plant operators had not initiated boration or control rod insertion, SCE is, nevertheless, reporting this occurrence in accordance with 10CFR50.72(b)(2)(i). At approximately 0850 PDT, the battery was restored to Operable status and MSR cooldown was suspended. At approximately 1112 PDT, the Unit was returned to full power. SCE is continuing to assess if additional actions are required. At the time the shutdown was initiated, Unit 2 was operating at about 100% power. Unit 3 continues to operate at about 100% power. The NRC Resident Inspectors have been briefed on the shutdown plans and will be provided with a copy of this report. Preliminary information indicates that the degraded voltage was due to loose terminal bolts.

ENS 44092 +/-
Where
San Onofre California (NRC Region 4)
Reporting

10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown
Time - Person (Reporting Time:+-0.23 h-0.00958 days <br />-0.00137 weeks <br />-3.15054e-4 months <br />)
Opened:	Susan Gardner 15:26 Mar 25, 2008
NRC Officer:	Bill Huffman
Last Updated:	Mar 25, 2008
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v • d • e

v t e Emergency Notification System
San Onofre with 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown
WEEKMONTHYEAR2009-12-12T09:26:00 [Table view]
[ENS list for San Onofre]

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