PNO-II-05-011, Turkey Point, Unit 4 - Loss of Offsite Power Due to Loss of Startup Transformer
| ML053060083 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 11/01/2005 |
| From: | Casto C, Binoy Desai NRC/RGN-II |
| To: | |
| References | |
| PNO-II-05-011 | |
| Download: ML053060083 (1) | |
November 1, 2005 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-05-011 This preliminary notification constitutes EARLY notice of events of possible safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region II staff (Atlanta, Georgia) on this date.
Facility Licensee Emergency Classification Florida Power & Light Co. X Notification of Unusual Event Turkey Point, Unit 4 Alert Florida City, Florida Site Area Emergency Dockets/License: 50-251 General Emergency Not Applicable
Subject:
Turkey Point Unit 4 Loss of Offsite Power due to Loss of Startup Transformer The state of Florida was informed by the licensee via their event notification system.
Region II received initial notification of this occurrence by telephone call from headquarters operations center approximately 11:00 p.m., (EDT) on October 31, 2005.
Turkey Point Unit 4 experienced a loss of offsite power due to a loss of the startup transformer at approximately 10:27 p.m. on October 31, 2005. At the time of the event, the unit was in Mode 3, with loads powered from the startup transformer. Further, decay heat was being removed by the standby feedwater pump. As a result of the event, both the Unit 4 emergency diesel generators started to provide power to Unit 4 loads as designed. Also, the three steam driven emergency feedwater pumps started as expected. With the loss of the startup transformer, the running reactor coolant pumps tripped as expected and the unit went into natural circulation. Decay heat removal was not interrupted as result of the event. The licensee declared an NOUE at 10:27 p.m., on October 31, 2005.
The exact cause of the startup transformer failure is not known.
The licensee is in a 24-hour Technical Specification 3.8, Action Statement to restore the startup transformer, or be in cold shutdown (Mode 5) in the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The licensee is currently in hot shutdown (Mode 4), with plans to align the residual heat removal system (RHR) in service. Unit 4 continues to be in the NOUE.
Unit 3 remained at 60 percent power during the event.
The information presented herein has been discussed with the licensee, and is current as of 11:00 a.m., on November 1, 2005.
CONTACT: Charles Casto 404-562-4500 Binoy Desai 404-562-4560