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Event: At 08:00 hours Oconee Unit 1 initia … Event: At 08:00 hours Oconee Unit 1 initiated a unit shutdown per Technical Specification (TS) 3.0.3. Unit 2 initiated shutdown at 0900 (ET). It is expected that Unit 3 will initiate shutdown at 1000 hours. Target for entry into Mode 3 is 1300 hours on all units. At 0129 hours all three Oconee units received a number of alarms related to power to the 230 KV switchyard (SWYD) battery chargers. At 0200 hours Operations determined that both AC power sources to the SWYD battery chargers required by TS 3.8.3 had tripped and declared entry into TS 3.0.3 because no specific condition of TS 3.8.3 applied. Evaluation for potential applicability of other reporting criteria is still in progress.</br>Initial Safety Significance: The SWYD batteries currently have normal voltage (being monitored hourly) but are NOT considered operable per TS 3.8.5 at this time, which would also require TS 3.0.3 entry. However, if voltage drops too low the ability to remotely operate SWYD power circuit breakers would be affected, which would impact SWYD isolation capability. Local manual operation would still be possible, and operations personnel are stationed in the SWYD as a contingency.</br>Corrective Action: 1. Maintenance has identified a fault in a power transfer switch. Actions have been completed to isolate the fault and restore power to the battery chargers. 2. Measurements of battery voltages are being taken hourly. A surveillance will be performed to verify TS 3.8.5 compliance after the charger power supply is restored. 3. Shutdown of Oconee units will follow schedule above unless power and battery voltages are restored sooner (as expected).</br>The electrical grid is stable and standby emergency power remains operable. The NRC Resident Inspector has been informed. The licensee does not intend to make any State, local or other Federal notifications or issue any press release at this time.</br>* * * UPDATE AT 1400 EDT ON 7/28/04 FROM PHIL NORTH TO S. SANDIN * * * </br>At 0945 EDT both SWYD battery chargers were energized to restore battery parameters. At 1205 EDT the affected batteries were declared operable and all three (3) Units exited their respective LCOs. Units 1, 2, and 3 are currently holding at 80%, 84% and 89% power, respectively, and will commence power escalation after review and closeout of their paperwork. Notified R2DO (Decker). their paperwork. Notified R2DO (Decker).
12:00:00, 28 July 2004 +
09:52:00, 28 July 2004 +
12:00:00, 28 July 2004 +
Event: At 08:00 hours Oconee Unit 1 initia … Event: At 08:00 hours Oconee Unit 1 initiated a unit shutdown per Technical Specification (TS) 3.0.3. Unit 2 initiated shutdown at 0900 (ET). It is expected that Unit 3 will initiate shutdown at 1000 hours. Target for entry into Mode 3 is 1300 hours on all units. At 0129 hours all three Oconee units received a number of alarms related to power to the 230 KV switchyard (SWYD) battery chargers. At 0200 hours Operations determined that both AC power sources to the SWYD battery chargers required by TS 3.8.3 had tripped and declared entry into TS 3.0.3 because no specific condition of TS 3.8.3 applied. Evaluation for potential applicability of other reporting criteria is still in progress.</br>Initial Safety Significance: The SWYD batteries currently have normal voltage (being monitored hourly) but are NOT considered operable per TS 3.8.5 at this time, which would also require TS 3.0.3 entry. However, if voltage drops too low the ability to remotely operate SWYD power circuit breakers would be affected, which would impact SWYD isolation capability. Local manual operation would still be possible, and operations personnel are stationed in the SWYD as a contingency.</br>Corrective Action: 1. Maintenance has identified a fault in a power transfer switch. Actions have been completed to isolate the fault and restore power to the battery chargers. 2. Measurements of battery voltages are being taken hourly. A surveillance will be performed to verify TS 3.8.5 compliance after the charger power supply is restored. 3. Shutdown of Oconee units will follow schedule above unless power and battery voltages are restored sooner (as expected).</br>The electrical grid is stable and standby emergency power remains operable. The NRC Resident Inspector has been informed. The licensee does not intend to make any State, local or other Federal notifications or issue any press release at this time.</br>* * * UPDATE AT 1400 EDT ON 7/28/04 FROM PHIL NORTH TO S. SANDIN * * * </br>At 0945 EDT both SWYD battery chargers were energized to restore battery parameters. At 1205 EDT the affected batteries were declared operable and all three (3) Units exited their respective LCOs. Units 1, 2, and 3 are currently holding at 80%, 84% and 89% power, respectively, and will commence power escalation after review and closeout of their paperwork. Notified R2DO (Decker). their paperwork. Notified R2DO (Decker).
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