Event Notification Report for April 15, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/14/2000 - 04/15/2000
Power Reactor
Event Number: 36892
Facility: BROWNS FERRY
Region: 2 State: AL
Unit: [] [] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: D. SMITH
HQ OPS Officer: JOHN MacKINNON
Region: 2 State: AL
Unit: [] [] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: D. SMITH
HQ OPS Officer: JOHN MacKINNON
Notification Date: 04/15/2000
Notification Time: 14:22 [ET]
Event Date: 04/15/2000
Event Time: 12:26 [CDT]
Last Update Date: 04/16/2000
Notification Time: 14:22 [ET]
Event Date: 04/15/2000
Event Time: 12:26 [CDT]
Last Update Date: 04/16/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(1)(iv) - ECCS INJECTION 50.72(b)(2)(ii) - ESF ACTUATION
10 CFR Section:
50.72(b)(1)(iv) - ECCS INJECTION 50.72(b)(2)(ii) - ESF ACTUATION
Person (Organization):
CHRIS CHRISTENSEN (R2)
CHRIS CHRISTENSEN (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 3 | A/R | Y | 70 | Power Operation | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM ON LOW REACTOR VESSEL WATER LEVEL (RVWL) DUE TO 1 OF 2 REACTOR FEED PUMPS (RFP) TRIPPING. HPCI & RCIC INJECTED INTO THE REACTOR VESSEL FOR LESS THAN ONE MINUTE.
Unit 3 was in coastdown planning to enter its scheduled refueling outage on 04/16/00. Reactor power level had been reduced from 82% to 70% to place RFP "3A" in service and remove RFP "3C" from service to investigate the pumps high EHC oil filter pressure. RFP "3C" tripped unexpectedly causing an automatic reactor scram on low RVWL. Two rods did not indicate fully inserted (digital indication for rods 22-47 & 18-47 indicated that they were not fully inserted but both rods had a green background indication on the scram pattern indicating that they were fully inserted) and the appropriated Emergency Operating Instructions EOIs ( 1& C5) were entered. An Alternate Rod Insertion (ARI) was initiated per the EOIs after which both rods indicated that they were fully inserted into the core.
Due to low RVWL both Recirculation Pumps Tripped (RPT trip) and High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) automatically actuated and discharged into the Reactor Vessel for less than one minute before they were secured. Primary Containment Isolation Systems Group 2 (Rad Waste), 3 (Reactor Water Cleanup), 6 (Containment) & 8 (Traversing in-core probe) were also received along with the auto start of the Control Room Ventilation System (CREVS) and the Standby Gas Treatment System (SBGT) as expected. All other system operated properly.
The licensee is investigating why RFP "3C" tripped and why the digital rod position for rods 22-48 & 18-47 indicated that they had not fully inserted into the core.
No work was being performed on RFP "3C" when it tripped.
The NRC Resident Inspector was notified of this event by the licensee.
* * * UPDATE ON 04/16/00 AT 1538 ET BY DON SMITH TAKEN BY MACKINNON * * *
On 04/15/00, Browns Ferry Nuclear Plant reported that two control rods (22-47 and 18-47) did not indicate being fully inserted following the low Reactor water level scram at 1226 CT. This is corrected by this update as control rods 22-47 and 22-15.
Subsequent review of process computer control rod data has confirmed that the two rods (22-47 and 22-15) did fully insert at the time if the scram as expected. R2DO (Chris Christensen) notified.
The NRC Resident Inspector was notified of this event update by the licensee.
Unit 3 was in coastdown planning to enter its scheduled refueling outage on 04/16/00. Reactor power level had been reduced from 82% to 70% to place RFP "3A" in service and remove RFP "3C" from service to investigate the pumps high EHC oil filter pressure. RFP "3C" tripped unexpectedly causing an automatic reactor scram on low RVWL. Two rods did not indicate fully inserted (digital indication for rods 22-47 & 18-47 indicated that they were not fully inserted but both rods had a green background indication on the scram pattern indicating that they were fully inserted) and the appropriated Emergency Operating Instructions EOIs ( 1& C5) were entered. An Alternate Rod Insertion (ARI) was initiated per the EOIs after which both rods indicated that they were fully inserted into the core.
Due to low RVWL both Recirculation Pumps Tripped (RPT trip) and High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) automatically actuated and discharged into the Reactor Vessel for less than one minute before they were secured. Primary Containment Isolation Systems Group 2 (Rad Waste), 3 (Reactor Water Cleanup), 6 (Containment) & 8 (Traversing in-core probe) were also received along with the auto start of the Control Room Ventilation System (CREVS) and the Standby Gas Treatment System (SBGT) as expected. All other system operated properly.
The licensee is investigating why RFP "3C" tripped and why the digital rod position for rods 22-48 & 18-47 indicated that they had not fully inserted into the core.
No work was being performed on RFP "3C" when it tripped.
The NRC Resident Inspector was notified of this event by the licensee.
* * * UPDATE ON 04/16/00 AT 1538 ET BY DON SMITH TAKEN BY MACKINNON * * *
On 04/15/00, Browns Ferry Nuclear Plant reported that two control rods (22-47 and 18-47) did not indicate being fully inserted following the low Reactor water level scram at 1226 CT. This is corrected by this update as control rods 22-47 and 22-15.
Subsequent review of process computer control rod data has confirmed that the two rods (22-47 and 22-15) did fully insert at the time if the scram as expected. R2DO (Chris Christensen) notified.
The NRC Resident Inspector was notified of this event update by the licensee.
Power Reactor
Event Number: 36893
Facility: BRAIDWOOD
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: RAHRIG
HQ OPS Officer: JOHN MacKINNON
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: RAHRIG
HQ OPS Officer: JOHN MacKINNON
Notification Date: 04/15/2000
Notification Time: 19:22 [ET]
Event Date: 04/15/2000
Event Time: 17:14 [CDT]
Last Update Date: 04/15/2000
Notification Time: 19:22 [ET]
Event Date: 04/15/2000
Event Time: 17:14 [CDT]
Last Update Date: 04/15/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
Person (Organization):
PATRICK HILAND (R3)
PATRICK HILAND (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
AUTOMATIC REACTOR TRIP ON NEGATIVE FLUX RATE TRIP - DROPPED ROD.
At 1714 CT Unit 2 tripped from a Nuclear Instrumentation (from all 4 Power Ranges) negative rate (coincidence with 2 of 4 Power Range Rate change of 5% in 2 seconds) signal. The initiating event appears to have been a dropped rod. Control Bank "B" P-10 Stationary Gripper Fuse has been found blown. Following the trip the Motor Driven and the Diesel Driven Auxiliary feedwater pumps actuated on low steam generator water level signals from all 4 steam generators. A P-14 (high 2 on 2 of 4 steam generator levels for Steam Generator "2C") was processed during the first second of the reactor trip. This is an ESF actuation but is considered an invalid signal, because Steam Generator "2C" did not have a high water level, but is reportable. All rods fully inserted into the core. The Unit is stable in Hot Standby with heat being removed via the steam dumps to the main condenser and main feedwater is being supplied to maintain proper steam generator water levels. Offsite power is available. Steam Generator atmospheric valves may have opened but there are no leaking steam generator tubes.
The NRC Resident Inspector was notified of this event by the licensee.
At 1714 CT Unit 2 tripped from a Nuclear Instrumentation (from all 4 Power Ranges) negative rate (coincidence with 2 of 4 Power Range Rate change of 5% in 2 seconds) signal. The initiating event appears to have been a dropped rod. Control Bank "B" P-10 Stationary Gripper Fuse has been found blown. Following the trip the Motor Driven and the Diesel Driven Auxiliary feedwater pumps actuated on low steam generator water level signals from all 4 steam generators. A P-14 (high 2 on 2 of 4 steam generator levels for Steam Generator "2C") was processed during the first second of the reactor trip. This is an ESF actuation but is considered an invalid signal, because Steam Generator "2C" did not have a high water level, but is reportable. All rods fully inserted into the core. The Unit is stable in Hot Standby with heat being removed via the steam dumps to the main condenser and main feedwater is being supplied to maintain proper steam generator water levels. Offsite power is available. Steam Generator atmospheric valves may have opened but there are no leaking steam generator tubes.
The NRC Resident Inspector was notified of this event by the licensee.
Power Reactor
Event Number: 36894
Facility: KEWAUNEE
Region: 3 State: WI
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: TIM SMITH
HQ OPS Officer: JOHN MacKINNON
Region: 3 State: WI
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: TIM SMITH
HQ OPS Officer: JOHN MacKINNON
Notification Date: 04/15/2000
Notification Time: 23:28 [ET]
Event Date: 04/15/2000
Event Time: 20:45 [CDT]
Last Update Date: 04/15/2000
Notification Time: 23:28 [ET]
Event Date: 04/15/2000
Event Time: 20:45 [CDT]
Last Update Date: 04/15/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
Person (Organization):
PATRICK HILAND (R3)
PATRICK HILAND (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 97 | Power Operation | 97 | Power Operation |
STEAM GENERATOR BLOWDOWN AND BLOWDOWN SAMPLE ISOALTION VALVES CLOSED DUE TO RADIATION MONITOR R-15 FAILURE.
Radiation Monitor R-15 air ejector exhaust failed indicating a detector no count failure. This failure caused steam generator blowdown isolation valves and steam generator blowdown sample isoaltion valves isolations to close. These valves have a containment isolation function for a main steam line rupture within containment. Their post Loss Of Coolant Accident function is to provide steam generator isolation. HS-17-1, Humidification steam inlet CV to office/warehouse ventilation also closed as designed. Offsite Dose Calculation Manual compensatory measures have been implemented. Instrument and control personnel have been called in to begin failure investigation. Chemistry Department personnel have been contacted concerning the steam generator blowdown isolation.
Licensee thinks that Radiation Monitor R-15 air ejector exhaust failed because its chart recorder indicates erratic downscale counts for approximately 20 minutes. Per Radiation Monitor Logic a failure of the monitor will occur if no counts are detected for 5 minutes. The licensee also stated they have been having problems with this detector in the past and it had been recently replaced.
The NRC Resident Inspector was notified of this event by the licensee.
Radiation Monitor R-15 air ejector exhaust failed indicating a detector no count failure. This failure caused steam generator blowdown isolation valves and steam generator blowdown sample isoaltion valves isolations to close. These valves have a containment isolation function for a main steam line rupture within containment. Their post Loss Of Coolant Accident function is to provide steam generator isolation. HS-17-1, Humidification steam inlet CV to office/warehouse ventilation also closed as designed. Offsite Dose Calculation Manual compensatory measures have been implemented. Instrument and control personnel have been called in to begin failure investigation. Chemistry Department personnel have been contacted concerning the steam generator blowdown isolation.
Licensee thinks that Radiation Monitor R-15 air ejector exhaust failed because its chart recorder indicates erratic downscale counts for approximately 20 minutes. Per Radiation Monitor Logic a failure of the monitor will occur if no counts are detected for 5 minutes. The licensee also stated they have been having problems with this detector in the past and it had been recently replaced.
The NRC Resident Inspector was notified of this event by the licensee.