ENS Event | |
|---|---|
17:35 Sep 1, 2008 | |
| Title | Shutdown Due to Emergency Diesel Generator Shorting Ring Cracks |
| Event Description | On September 1, 2008, at about 1035 PDT, Southern California Edison (SCE) began a planned shutdown of San Onofre Unit 3. This shutdown is in anticipation of exceeding the Allowed Outage Time (AOT) of 14 days of Technical Specification 3.8.1 Action B.4 for an inoperable Diesel Generator (Train B). The AOT is due to expire on September 2, 2008 at about 0200. If the system cannot be restored within the allowed outage time, a plant shutdown is required. The initiation of this shutdown is being reported in accordance with 10CFR50.72(b)(2)(i).
An inspection of the DG generator revealed cracks in the shorting ring, requiring replacement of the generator. Post maintenance testing performed after replacement revealed anomalous readings. SCE determined that problem identification, repair and post test could not be performed before expiration of the AOT. Consequently, shutdown has been initiated. At the initiation of the shutdown, SONGS Unit 3 was operating at full power. SONGS Unit 2 is operating at approximately 99 percent power. The NRC Resident Inspectors have been briefed on the shutdown plans and will be provided with a copy of this report. |
| Where | |
|---|---|
San Onofre  California (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
| Time - Person (Reporting Time:+-0.53 h-0.0221 days <br />-0.00315 weeks <br />-7.25994e-4 months <br />) | |
| Opened: | Susan Gardner 17:03 Sep 1, 2008 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Sep 1, 2008 |
| 44456 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (46 %) |
WEEKMONTHYEARENS 455642009-12-12T09:26:00012 December 2009 09:26:00
[Table view]10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unusual Event Declared Due to Both Emergency Diesel Generators Being Inoperable ENS 444562008-09-01T17:35:0001 September 2008 17:35:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Shutdown Due to Emergency Diesel Generator Shorting Ring Cracks ENS 440922008-03-25T15:40:00025 March 2008 15:40:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Plant Shutdown Initiated Due to Degraded Battery Voltage ENS 424512006-03-29T08:01:00029 March 2006 08:01:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unit 3 Shutdown Due to Potential Safety Injection Tank Gasket Issue ENS 414102005-02-15T05:55:00015 February 2005 05:55:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Tech Spec Required Shutdown ENS 403962003-12-17T11:15:00017 December 2003 11:15:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Loss of Both Trains of Safety Injection 2009-12-12T09:26:00 | |