Event Notification Report for February 21, 1999
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/20/1999 - 02/21/1999
EVENT NUMBERS
35391
35391
Power Reactor
Event Number: 35391
Facility: GRAND GULF
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: HANKS
HQ OPS Officer: CHAUNCEY GOULD
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: HANKS
HQ OPS Officer: CHAUNCEY GOULD
Notification Date: 02/21/1999
Notification Time: 22:25 [ET]
Event Date: 02/21/1999
Event Time: 20:50 [CST]
Last Update Date: 02/21/1999
Notification Time: 22:25 [ET]
Event Date: 02/21/1999
Event Time: 20:50 [CST]
Last Update Date: 02/21/1999
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
Person (Organization):
LAWRENCE YANDELL (R4)
LAWRENCE YANDELL (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 100 | Power Operation | 0 | Hot Shutdown |
REACTOR WAS MANUALLY SCRAMMED FROM 100% POWER DUE TO LOSS OF CONDENSER VACUUM.
THE "A" MAIN CONDENSER HAD A SEAL FAILURE ON THE EXPANSION JOINT WHICH RESULTED IN A DECREASE AND LOSS OF CONDENSER VACUUM. DUE TO THIS CONDITION, A MANUAL SCRAM WAS INITIATED FOLLOWED BY A MAIN TURBINE TRIP. THE CONTROLLED SHUTDOWN HAD NO IMMEDIATE PROBLEMS. ALL RODS FULLY INSERTED. NO ECCS ACTUATIONS OCCURRED. THE LICENSEE ANTICIPATES THAT REACTOR VESSEL PRESSURE MAY BE LATER CONTROLLED VIA THE RELIEF VALVES DEPENDING ON THE COOLDOWN RATE (REACTOR VESSEL PRESSURE IS CURRENTLY 550 LBS). THE CURRENT HEAT SINK IS THE MAIN CONDENSER, BUT THE LICENSEE IS PREPARING TO SHUT THE MSIVs AND SHIFT THE HEAT SINK TO THE SUPPRESSION POOL.
THE RESIDENT INSPECTOR WAS NOTIFIED.
THE "A" MAIN CONDENSER HAD A SEAL FAILURE ON THE EXPANSION JOINT WHICH RESULTED IN A DECREASE AND LOSS OF CONDENSER VACUUM. DUE TO THIS CONDITION, A MANUAL SCRAM WAS INITIATED FOLLOWED BY A MAIN TURBINE TRIP. THE CONTROLLED SHUTDOWN HAD NO IMMEDIATE PROBLEMS. ALL RODS FULLY INSERTED. NO ECCS ACTUATIONS OCCURRED. THE LICENSEE ANTICIPATES THAT REACTOR VESSEL PRESSURE MAY BE LATER CONTROLLED VIA THE RELIEF VALVES DEPENDING ON THE COOLDOWN RATE (REACTOR VESSEL PRESSURE IS CURRENTLY 550 LBS). THE CURRENT HEAT SINK IS THE MAIN CONDENSER, BUT THE LICENSEE IS PREPARING TO SHUT THE MSIVs AND SHIFT THE HEAT SINK TO THE SUPPRESSION POOL.
THE RESIDENT INSPECTOR WAS NOTIFIED.