Event Notification Report for February 08, 2002
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/07/2002 - 02/08/2002
EVENT NUMBERS
38686
Power Reactor
Event Number: 38686
Facility: HATCH
Region: 2 State: GA
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: ED BURKETT
HQ OPS Officer: FANGIE JONES
Region: 2 State: GA
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: ED BURKETT
HQ OPS Officer: FANGIE JONES
Notification Date: 02/09/2002
Notification Time: 00:30 [ET]
Event Date: 02/08/2002
Event Time: 22:52 [EST]
Last Update Date: 02/09/2002
Notification Time: 00:30 [ET]
Event Date: 02/08/2002
Event Time: 22:52 [EST]
Last Update Date: 02/09/2002
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
Person (Organization):
PAUL FREDRICKSON (R2)
PAUL FREDRICKSON (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 27 | Power Operation | 0 | Hot Shutdown |
MANUAL REACTOR SCRAM - DEGRADED VACUUM DUE TO ACTIONS FOR HIGH OFFGAS HYDROGEN
"Plant Hatch Unit 1 was SCRAMMED at 2252 EST on 02-08-2002. The Reactor was SCRAMMED from approximately 27% RTP and the Main Turbine subsequently tripped. Degraded function of the Main Condenser Offgas Recombiner system had resulted in high Hydrogen in the Offgas. The 'Failure of Recombiner' Abnormal Operating procedure (AOP) had been entered at approximately 2100 and a power reduction begun from 100% RTP at about 2105. Per the AOP, the inservice Steam jet Air Ejector was removed from service at 2220 (due to the Offgas Hydrogen concentration reaching approximately 4%). Hatch Unit 1 was subsequently scrammed due to degrading Condenser Vacuum. The mechanical vacuum pump was placed in service after the SCRAM to maintain Condenser Vacuum as the heat sink. The lowest Reactor Water Level noted during the SCRAM (approximately 7" above Instrument zero) was above any ESF actuation settings, so no ESFs were required or received. No Reactor Pressure increase was noted during the SCRAM. At this time plans are to proceed to Cold Shutdown for repairs to the Offgas Recombiner system and other maintenance. Air purge had been placed inservice to purge the Hydrogen from the Offgas system at around 2230, and remains inservice to reduce Hydrogen concentrations."
The licensee notified the NRC Resident Inspector.
"Plant Hatch Unit 1 was SCRAMMED at 2252 EST on 02-08-2002. The Reactor was SCRAMMED from approximately 27% RTP and the Main Turbine subsequently tripped. Degraded function of the Main Condenser Offgas Recombiner system had resulted in high Hydrogen in the Offgas. The 'Failure of Recombiner' Abnormal Operating procedure (AOP) had been entered at approximately 2100 and a power reduction begun from 100% RTP at about 2105. Per the AOP, the inservice Steam jet Air Ejector was removed from service at 2220 (due to the Offgas Hydrogen concentration reaching approximately 4%). Hatch Unit 1 was subsequently scrammed due to degrading Condenser Vacuum. The mechanical vacuum pump was placed in service after the SCRAM to maintain Condenser Vacuum as the heat sink. The lowest Reactor Water Level noted during the SCRAM (approximately 7" above Instrument zero) was above any ESF actuation settings, so no ESFs were required or received. No Reactor Pressure increase was noted during the SCRAM. At this time plans are to proceed to Cold Shutdown for repairs to the Offgas Recombiner system and other maintenance. Air purge had been placed inservice to purge the Hydrogen from the Offgas system at around 2230, and remains inservice to reduce Hydrogen concentrations."
The licensee notified the NRC Resident Inspector.