ENS Event | |
|---|---|
04:33 Nov 19, 2015 | |
| Title | After-The-Fact Notification of Unusual Event |
| Event Description | Unit 3 experienced Loss of Offsite Power due to lockout on Unit 3 Startup transformer. The 3B EDG auto started and loaded on the 3B 4KV Bus. The 3A Sequencer was out of service and prevented the 3A EDG from auto starting and supplying 3A 4KV busses. With only 3B 4KV bus powered from an EDG and no offsite power to Unit 3, Unit 3 entered an Unusual Event.
Core cooling was restored with 3B RHR pump at 2343 EST. At 2350 EST, 3A 4KV Bus was manually loaded onto 3A EDG and conditions for Unusual Event were terminated. Additionally this is a non-emergency eight hour notification in accordance with 10CFR50.72(b)(3)(iv)(A), for a valid automatic actuation of the 3B Emergency Diesel Generator. While core cooling was lost, the core experienced a 3 degree heat up. Spent fuel pit cooling has also been restored. The cause of the transformer lockout is under investigation. Unit 4 was unaffected and continues to operate at 100% power. The licensee has notified state and local authorities about this event. The licensee has also notified the NRC Resident Inspector. |
| Where | |
|---|---|
Turkey Point  Florida (NRC Region 2) | |
| Reporting | |
| Other Unspec Reqmnt | |
| LER: | 05000250/LER-2015-001 Regarding Diesel Generator Start Resulting from Switchyard Protective Relay Actuation |
| Time - Person (Reporting Time:+-3.62 h-0.151 days <br />-0.0215 weeks <br />-0.00496 months <br />) | |
| Opened: | Dirk Drinkard 00:56 Nov 19, 2015 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Nov 19, 2015 |
| 51551 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 527912017-06-06T21:51:0006 June 2017 21:51:00
[Table view]Other Unspec Reqmnt Both Standby Steam Generator Feed Pumps Out of Service for Pre-Planned Maintenance ENS 515512015-11-19T04:33:00019 November 2015 04:33:00 Other Unspec Reqmnt After-The-Fact Notification of Unusual Event ENS 424002006-03-09T10:55:0009 March 2006 10:55:00 Other Unspec Reqmnt Technical Specification 3.8.1.1 Entry Due to Loss of Unit 3 Startup Transformer ENS 420742005-10-25T03:00:00025 October 2005 03:00:00 Other Unspec Reqmnt Inoperable Start-Up Transformers; High Switchyard Voltage Due to Hurricane Wilma 2017-06-06T21:51:00 | |