Event Notification Report for April 29, 2001
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/28/2001 - 04/29/2001
Power Reactor
Event Number: 37951
Facility: PERRY
Region: 3 State: OH
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: ROBERT KIDDER
HQ OPS Officer: FANGIE JONES
Region: 3 State: OH
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: ROBERT KIDDER
HQ OPS Officer: FANGIE JONES
Notification Date: 04/29/2001
Notification Time: 03:18 [ET]
Event Date: 04/29/2001
Event Time: 00:50 [EDT]
Last Update Date: 04/29/2001
Notification Time: 03:18 [ET]
Event Date: 04/29/2001
Event Time: 00:50 [EDT]
Last Update Date: 04/29/2001
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 KOZAK (R3)
THOMAS KOZAK (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 16 | Power Operation | 0 | Hot Standby |
MANUAL SCRAM DUE TO DEGRADING VACUUM CONDITIONS
The licensee had reduced power to 16% and removed the main generator from service due to a stator water leak on the generator exciter causing a ground. After the main generator was off line vacuum started deteriorating and the reactor was manually scrammed. All rods fully inserted and all systems functioned normally. The plant is presently using the reactor core isolation cooling (RCIC) system for makeup and the safety relief valves to the suppression pool for decay heat removal.
The cause of the deteriorating vacuum condition is under investigation.
The licensee notified the NRC Resident Inspector.
* * * UPDATE AT 0526 EDT ON 4/29/01 BY TOM VEITCH TO FANGIE JONES * * *
The plant is using RCIC for pressure control and the motor driven feedpump for makeup to the reactor coolant system. Also, at 0116 EDT there was an automatic main steam valve isolation due to the deteriorating vacuum condition, an expected action. This is reportable under 10 CFR 50.72(b)(3)(iv)(B) as an 8 hour report.
The licensee notified the NRC Resident Inspector. The R3DO (Thomas Kozak) was notified.
* * * UPDATE AT 1641 ON 4/29/01 BY TODD HENDERSON TO DOUG WEAVER * * *
At approximately 0215 on 04/29/2001, the Main Steam Isolation Valves closed automatically as a result of the continued loss of vacuum. In a 0530 update to the original notification, this isolation was reported as a specified system actuation in accordance with 10 CFR 50.72 (b)(3)(iv)(A). In that update, the time of the actuation was originally reported as 0116 on 04/29/2001. At approximately the same time, Reactor Core Isolation Cooling (RCIC) was started to assist with pressure control. At 0227, main condenser vacuum was broken. At 0247, a Safety Relief Valve (SRV) was opened and closed to control pressure, with the motor driven feed pump supplying feedwater.
Approximately 2 minutes after the first SRV was cycled, a High Pressure Core Spray (HPCS) RPV Level 2 (130" above the top of active fuel) initiation signal was received which started the HPCS pump and Division 3 emergency diesel generator. No injection to the RPV occurred (or should have occurred) because reactor level was above the level where injection was required (Level 8 219" above the top of active fuel). A Division 2 Balance of Plant isolation signal and Redundant Reactivity Control System Level 2 also occurred at this time (with expected plant response including the tripping of both Recirculation pumps). The source of this signal has not yet been determined.
At approximately 0430, a Reactor Pressure High/Drain Temperature Low alarm was received, indicating thermal stratification in the reactor pressure vessel due to the loss of reactor recirculation. This originally delayed placing shutdown cooling in operation, but the condition has been cleared allowing progress toward initiating shutdown cooling.
The plant is currently in mode 3, with reactor level and pressure being maintained with periodic cycling of Safety Relief Valves and operation of RCIC. Residual heat removal (RHR) train 'B' is being used for suppression pool cooling. Actions are in progress to place RHR train 'A' in shutdown cooling, and bring the plant to Mode 4.
The Senior Resident Inspector has been informed of the event. The operations center notified the R3DO (Kozak).
The licensee had reduced power to 16% and removed the main generator from service due to a stator water leak on the generator exciter causing a ground. After the main generator was off line vacuum started deteriorating and the reactor was manually scrammed. All rods fully inserted and all systems functioned normally. The plant is presently using the reactor core isolation cooling (RCIC) system for makeup and the safety relief valves to the suppression pool for decay heat removal.
The cause of the deteriorating vacuum condition is under investigation.
The licensee notified the NRC Resident Inspector.
* * * UPDATE AT 0526 EDT ON 4/29/01 BY TOM VEITCH TO FANGIE JONES * * *
The plant is using RCIC for pressure control and the motor driven feedpump for makeup to the reactor coolant system. Also, at 0116 EDT there was an automatic main steam valve isolation due to the deteriorating vacuum condition, an expected action. This is reportable under 10 CFR 50.72(b)(3)(iv)(B) as an 8 hour report.
The licensee notified the NRC Resident Inspector. The R3DO (Thomas Kozak) was notified.
* * * UPDATE AT 1641 ON 4/29/01 BY TODD HENDERSON TO DOUG WEAVER * * *
At approximately 0215 on 04/29/2001, the Main Steam Isolation Valves closed automatically as a result of the continued loss of vacuum. In a 0530 update to the original notification, this isolation was reported as a specified system actuation in accordance with 10 CFR 50.72 (b)(3)(iv)(A). In that update, the time of the actuation was originally reported as 0116 on 04/29/2001. At approximately the same time, Reactor Core Isolation Cooling (RCIC) was started to assist with pressure control. At 0227, main condenser vacuum was broken. At 0247, a Safety Relief Valve (SRV) was opened and closed to control pressure, with the motor driven feed pump supplying feedwater.
Approximately 2 minutes after the first SRV was cycled, a High Pressure Core Spray (HPCS) RPV Level 2 (130" above the top of active fuel) initiation signal was received which started the HPCS pump and Division 3 emergency diesel generator. No injection to the RPV occurred (or should have occurred) because reactor level was above the level where injection was required (Level 8 219" above the top of active fuel). A Division 2 Balance of Plant isolation signal and Redundant Reactivity Control System Level 2 also occurred at this time (with expected plant response including the tripping of both Recirculation pumps). The source of this signal has not yet been determined.
At approximately 0430, a Reactor Pressure High/Drain Temperature Low alarm was received, indicating thermal stratification in the reactor pressure vessel due to the loss of reactor recirculation. This originally delayed placing shutdown cooling in operation, but the condition has been cleared allowing progress toward initiating shutdown cooling.
The plant is currently in mode 3, with reactor level and pressure being maintained with periodic cycling of Safety Relief Valves and operation of RCIC. Residual heat removal (RHR) train 'B' is being used for suppression pool cooling. Actions are in progress to place RHR train 'A' in shutdown cooling, and bring the plant to Mode 4.
The Senior Resident Inspector has been informed of the event. The operations center notified the R3DO (Kozak).
Power Reactor
Event Number: 37952
Facility: MILLSTONE
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: JOSEPH FRANKS
HQ OPS Officer: DOUG WEAVER
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: JOSEPH FRANKS
HQ OPS Officer: DOUG WEAVER
Notification Date: 04/29/2001
Notification Time: 12:19 [ET]
Event Date: 04/29/2001
Event Time: 11:28 [EDT]
Last Update Date: 04/29/2001
Notification Time: 12:19 [ET]
Event Date: 04/29/2001
Event Time: 11:28 [EDT]
Last Update Date: 04/29/2001
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):
DAVID SILK (R1)
DAVID SILK (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 97 | Power Operation | 0 | Hot Standby |
TURBINE TRIP - REACTOR TRIP
The loss of a circulating water pumped led to a turbine trip and reactor trip. All rods inserted after the trip and the plant is stable in mode 3. Reactor coolant pumps are running and the steam generators are being fed with the mainfeed system. The main condenser is available for decay heat removal. One steam generator safety valve may have lifted during the transient, but is closed now.
The cause of the circulating water pump trip is unknown.
The licensee informed the NRC resident inspector as well as State and local governments.
* * * UPDATE AT 1715 ON 4/29/01 BY FRANKS RECEIVED BY WEAVER * * *
This update corrects the time of the event from 1151 to 1128. There was also a specified system actuation after the trip. Two auxiliary feedwater pumps started after the trip on low steam generator level. Once level was restored the pumps were secured. The licensee notified the NRC resident inspector. The operations center notified R1DO (Silk).
The loss of a circulating water pumped led to a turbine trip and reactor trip. All rods inserted after the trip and the plant is stable in mode 3. Reactor coolant pumps are running and the steam generators are being fed with the mainfeed system. The main condenser is available for decay heat removal. One steam generator safety valve may have lifted during the transient, but is closed now.
The cause of the circulating water pump trip is unknown.
The licensee informed the NRC resident inspector as well as State and local governments.
* * * UPDATE AT 1715 ON 4/29/01 BY FRANKS RECEIVED BY WEAVER * * *
This update corrects the time of the event from 1151 to 1128. There was also a specified system actuation after the trip. Two auxiliary feedwater pumps started after the trip on low steam generator level. Once level was restored the pumps were secured. The licensee notified the NRC resident inspector. The operations center notified R1DO (Silk).
Power Reactor
Event Number: 37953
Facility: GRAND GULF
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DAVE HANKS
HQ OPS Officer: FANGIE JONES
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: DAVE HANKS
HQ OPS Officer: FANGIE JONES
Notification Date: 04/30/2001
Notification Time: 02:24 [ET]
Event Date: 04/29/2001
Event Time: 22:50 [CDT]
Last Update Date: 04/30/2001
Notification Time: 02:24 [ET]
Event Date: 04/29/2001
Event Time: 22:50 [CDT]
Last Update Date: 04/30/2001
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
BILL JONES (R4)
BILL JONES (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
EXPECTED LOSS OF SPDS FOR GREATER THAN 8 HOURS
Planned maintenance removed safety parameters display system (SPDS) from service for greater than 8 hours. This requires a notification per 10 CFR 50.72(b)(3)(xiii) for loss of assessment capabilities.
The licensee notified the NRC Resident Inspector.
Planned maintenance removed safety parameters display system (SPDS) from service for greater than 8 hours. This requires a notification per 10 CFR 50.72(b)(3)(xiii) for loss of assessment capabilities.
The licensee notified the NRC Resident Inspector.