Event Notification Report for January 26, 2016
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
01/25/2016 - 01/26/2016
EVENT NUMBERS
51687
Power Reactor
Event Number: 51687
Facility: SOUTH TEXAS
Region: 4 State: TX
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: SILVESTRE ROMERO JR
HQ OPS Officer: STEVEN VITTO
Region: 4 State: TX
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: SILVESTRE ROMERO JR
HQ OPS Officer: STEVEN VITTO
Notification Date: 01/27/2016
Notification Time: 01:44 [ET]
Event Date: 01/26/2016
Event Time: 23:25 [CST]
Last Update Date: 01/27/2016
Notification Time: 01:44 [ET]
Event Date: 01/26/2016
Event Time: 23:25 [CST]
Last Update Date: 01/27/2016
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
THOMAS FARNHOLTZ (R4DO)
THOMAS FARNHOLTZ (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 100 | Power Operation | 0 | Hot Standby |
MANUAL REACTOR TRIP DUE TO LOSS OF FEEDWATER TO A SINGLE STEAM GENERATOR
"At 2325 [CST] on 01/26/2016, Unit 1 was manually tripped due to loss of Feedwater on 'C' S/G [Steam Generator]. The loss of Feedwater was a result of a failure on 'C' S/G Main Feedwater Regulating Valve that caused the valve to travel closed with no Operator action. Auxiliary Feedwater and Feedwater Isolation actuated as designed. All Control and Shutdown Rods fully inserted. Intermediate Range Nl 36 [Nuclear Instrument] failed above P10 and, as a result, Source Range Nuclear Instruments were manually energized. No primary or secondary relief valves opened. There were no electrical problems. Normal operating temperature and pressure (NOT/NOP) is 567 degrees F and 2235 psig. There were no significant TS LCOs entered.
"This event was not significant to the health and safety of the public based on all safety systems performed as designed.
"Unit 2 was not affected."
Decay heat removal is being controlled via Steam Dumps. Offsite power is in the normal electrical lineup.
The NRC Resident Inspector has been notified.
"At 2325 [CST] on 01/26/2016, Unit 1 was manually tripped due to loss of Feedwater on 'C' S/G [Steam Generator]. The loss of Feedwater was a result of a failure on 'C' S/G Main Feedwater Regulating Valve that caused the valve to travel closed with no Operator action. Auxiliary Feedwater and Feedwater Isolation actuated as designed. All Control and Shutdown Rods fully inserted. Intermediate Range Nl 36 [Nuclear Instrument] failed above P10 and, as a result, Source Range Nuclear Instruments were manually energized. No primary or secondary relief valves opened. There were no electrical problems. Normal operating temperature and pressure (NOT/NOP) is 567 degrees F and 2235 psig. There were no significant TS LCOs entered.
"This event was not significant to the health and safety of the public based on all safety systems performed as designed.
"Unit 2 was not affected."
Decay heat removal is being controlled via Steam Dumps. Offsite power is in the normal electrical lineup.
The NRC Resident Inspector has been notified.