PNO-II-17-002, Watts Bar Unit 2 Shutdown Due to Condenser Failure
| ML17082A621 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 03/23/2017 |
| From: | Alan Blamey Reactor Projects Region 2 Branch 6 |
| To: | |
| Alan Blamey, RII/DRP 404-997-4415 | |
| References | |
| PNO-II-17-002 | |
| Download: ML17082A621 (1) | |
March 23, 2017 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-17-002 This preliminary notification constitutes EARLY notice of events of possible safety or public interest significance. Some of the information may not yet be fully verified or evaluated by the Region II staff (Atlanta, GA).
Facility Licensee Emergency Classification Plant: Watts Bar Unit 2 Notification of Unusual Event Unit Location: Spring City, TN Alert Docket No: 50-391 Site Area Emergency General Emergency X Not Applicable
SUBJECT:
SHUTDOWN DUE TO CONDENSER FAILURE On March 23, 2017, at 12:14 a.m., Watts Bar Unit 2 was operating at 16 percent power when the B waterbox of the main condenser experienced a structural failure causing the loss of the running main feedwater pump and an automatic turbine trip. All Auxiliary Feedwater Pumps (AFW) started as expected and operators manually inserted control rods to lower reactor power to about 3 percent as directed by plant procedures. Subsequently, the operators shut all Main Steam Isolation Valves (MSIVs) due to steam in the turbine building from the damaged B condenser waterbox. Upon closure of the MSIVs, heat removal was maintained through the steam generator power operated relief valves. The reactor was later shut down as part of a planned evolution. Watts Bar Unit 2 is currently stable in Mode 3.
This preliminary notification is issued for information only and no specific reactive inspection by the staff is anticipated. Region II received initial notification of this occurrence by telephone from the senior resident inspector at 1:07 a.m. on March 23. Subsequently, at 2:48 a.m., the Tennessee Valley Authority (TVA) issued an 8-hour Event Notification52630 due to the automatic start of the AFW pumps in response to the main feedwater pump trip. The information presented herein has been discussed with TVA and the State of Tennessee, and is current as of 1:00 p.m., March 23.
ADAMS Accession Number: ML_________
CONTACT: Alan Blamey 404.997.4415 Alan.Blamey@nrc.gov