Event Notification Report for November 15, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/14/2000 - 11/15/2000
Power Reactor
Event Number: 37524
Facility: MCGUIRE
Region: 2 State: NC
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: VERITA BELLAMY
HQ OPS Officer: FANGIE JONES
Region: 2 State: NC
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: VERITA BELLAMY
HQ OPS Officer: FANGIE JONES
Notification Date: 11/15/2000
Notification Time: 15:49 [ET]
Event Date: 11/15/2000
Event Time: 14:22 [EST]
Last Update Date: 11/16/2000
Notification Time: 15:49 [ET]
Event Date: 11/15/2000
Event Time: 14:22 [EST]
Last Update Date: 11/16/2000
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):
MIKE ERNSTES (R2)
MIKE ERNSTES (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | M/R | Y | 100 | Power Operation | 0 | Hot Standby |
MANUAL REACTOR TRIP DUE TO FAILURE OF TURBINE RUNBACK ACTUATION CIRCUITS
Unit 2 experienced a turbine runback at 1410 EST. The control room operators noticed all status lights for overpower and overtemperature delta T runback were illuminated. The operators decided to manually trip the reactor from about 23 % rated thermal power. The reactor trip resulted in a turbine trip as expected. Auxiliary feedwater pumps started due to low-low steam generator levels. The unit is stable in Mode 3.
The runback bistables are locked in without having the logic bistables tripped that feed the trip circuit. The licensee is troubleshooting the problem and the cause is unknown at this time. The plant will remain in Mode 3 until the problem is corrected.
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1345EST FROM TIM HEADNON TO BOB STRANSKY * * *
The licensee is updating their report to include the following information:
"On November 15, 2000, McGuire Unit 2 experienced a turbine runback which ultimately resulted in plant operators manually tripping the reactor (RPS Actuation). Following the trip, the Unit 2 Auxiliary Feedwater Pumps started due to low-low steam generator levels (ESF Actuation)
"Further investigation has determined that the turbine runback was caused by actuation of all four channels of over power delta temperature (OPDT) and over temperature delta temperature (OTDT) runback logic following a trip of an electrical breaker which supplies power to the logic circuitry. The turbine runback was a result of the breaker trip and was not initiated by a valid OPDT or OTDT condition. Subsequent to the turbine runback, a decision was made to manually trip the reactor. Plant equipment necessary to safely shutdown the unit operated correctly and the Unit is stable and in Mode 3. The Unit 2 Auxiliary Feedwater Pumps have been secured. Actions needed to restart Unit 2 are in progress."
The licensee informed the NRC resident inspector. Notified R2DO(Ernstes).
Unit 2 experienced a turbine runback at 1410 EST. The control room operators noticed all status lights for overpower and overtemperature delta T runback were illuminated. The operators decided to manually trip the reactor from about 23 % rated thermal power. The reactor trip resulted in a turbine trip as expected. Auxiliary feedwater pumps started due to low-low steam generator levels. The unit is stable in Mode 3.
The runback bistables are locked in without having the logic bistables tripped that feed the trip circuit. The licensee is troubleshooting the problem and the cause is unknown at this time. The plant will remain in Mode 3 until the problem is corrected.
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1345EST FROM TIM HEADNON TO BOB STRANSKY * * *
The licensee is updating their report to include the following information:
"On November 15, 2000, McGuire Unit 2 experienced a turbine runback which ultimately resulted in plant operators manually tripping the reactor (RPS Actuation). Following the trip, the Unit 2 Auxiliary Feedwater Pumps started due to low-low steam generator levels (ESF Actuation)
"Further investigation has determined that the turbine runback was caused by actuation of all four channels of over power delta temperature (OPDT) and over temperature delta temperature (OTDT) runback logic following a trip of an electrical breaker which supplies power to the logic circuitry. The turbine runback was a result of the breaker trip and was not initiated by a valid OPDT or OTDT condition. Subsequent to the turbine runback, a decision was made to manually trip the reactor. Plant equipment necessary to safely shutdown the unit operated correctly and the Unit is stable and in Mode 3. The Unit 2 Auxiliary Feedwater Pumps have been secured. Actions needed to restart Unit 2 are in progress."
The licensee informed the NRC resident inspector. Notified R2DO(Ernstes).
Power Reactor
Event Number: 37525
Facility: OYSTER CREEK
Region: 1 State: NJ
Unit: [1] [] []
RX Type: [1] GE-2
NRC Notified By: JERE FREEMAN
HQ OPS Officer: FANGIE JONES
Region: 1 State: NJ
Unit: [1] [] []
RX Type: [1] GE-2
NRC Notified By: JERE FREEMAN
HQ OPS Officer: FANGIE JONES
Notification Date: 11/15/2000
Notification Time: 19:04 [ET]
Event Date: 11/15/2000
Event Time: 17:50 [EST]
Last Update Date: 11/16/2000
Notification Time: 19:04 [ET]
Event Date: 11/15/2000
Event Time: 17:50 [EST]
Last Update Date: 11/16/2000
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):
RICHARD BARKLEY (R1)
RICHARD BARKLEY (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 1 | Startup | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM DUE TO LOW REACTOR WATER LEVEL
The plant received a low water level reactor scram during turbine manipulation after 2 turbine bypass valves opened. All systems functioned as designed. The actual cause is not fully understood and is under investigation.
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1513EST ON 11/16/00 FROM STEVE FULLER TO S. SANDIN * * *
The following information was received as an update:
"On 11/15/00 at 1748 EST, Oyster Creek Nuclear Generating Station automatically scrammed on reactor low water level (as described on Event Number 37525). The station was in the process of restarting from the plant from the recent 1 SR refueling outage. The operators were in the process of securing High Pressure Turbine warm-up and preparing to perform Steam Chest warm-up. As they transitioned between these activities, the turbine bypass valves opened. As a result of the bypass valves opening, reactor water level increased. The operators responded to the reactor water level transient but failed to recognize the pressure reduction. The loss of inventory resulted in a low water level reactor scram.
"The station has conducted a transient assessment of this incident. The preliminary root cause was identified as a procedural deficiency. The Turbine System Operating Procedure did not provide the appropriate guidance for preventing the bypass valves from opening. Additionally, the operators demonstrated a lack of integrated system knowledge and response regarding the turbine controls system.
"Subsequent reviews of the plant data revealed that the cool down rate exceeded the plant's Technical Specification limit of 100 degrees per hour. This occurred because of the low initial power level coupled with the bypass valves not being closed in a timely manner. Engineering has assessed this condition and determined that the plant response was within our design bases. Additionally, the Post Transient Review Group (PTRG) identified a potential concern regarding the operation of the reactor low water level transmitters. One of the four reactor low water level scram switches did not actuate. Even though the PTRG suspected this switch didn't actuate because the decrease in reactor water level wasn't sufficient due to the low initial power level, this switch was subsequently tested and operated appropriately.
"Following completion of the required restart activities, the plant commenced startup activities at 2:57 EST on 11/16/00. In accordance with 10CFR50.73 a Licensee Event Report will be submitted to describe this incident, the root cause, and associated corrective actions."
The licensee will inform the NRC resident inspector. Notified R1DO(Barkley).
The plant received a low water level reactor scram during turbine manipulation after 2 turbine bypass valves opened. All systems functioned as designed. The actual cause is not fully understood and is under investigation.
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1513EST ON 11/16/00 FROM STEVE FULLER TO S. SANDIN * * *
The following information was received as an update:
"On 11/15/00 at 1748 EST, Oyster Creek Nuclear Generating Station automatically scrammed on reactor low water level (as described on Event Number 37525). The station was in the process of restarting from the plant from the recent 1 SR refueling outage. The operators were in the process of securing High Pressure Turbine warm-up and preparing to perform Steam Chest warm-up. As they transitioned between these activities, the turbine bypass valves opened. As a result of the bypass valves opening, reactor water level increased. The operators responded to the reactor water level transient but failed to recognize the pressure reduction. The loss of inventory resulted in a low water level reactor scram.
"The station has conducted a transient assessment of this incident. The preliminary root cause was identified as a procedural deficiency. The Turbine System Operating Procedure did not provide the appropriate guidance for preventing the bypass valves from opening. Additionally, the operators demonstrated a lack of integrated system knowledge and response regarding the turbine controls system.
"Subsequent reviews of the plant data revealed that the cool down rate exceeded the plant's Technical Specification limit of 100 degrees per hour. This occurred because of the low initial power level coupled with the bypass valves not being closed in a timely manner. Engineering has assessed this condition and determined that the plant response was within our design bases. Additionally, the Post Transient Review Group (PTRG) identified a potential concern regarding the operation of the reactor low water level transmitters. One of the four reactor low water level scram switches did not actuate. Even though the PTRG suspected this switch didn't actuate because the decrease in reactor water level wasn't sufficient due to the low initial power level, this switch was subsequently tested and operated appropriately.
"Following completion of the required restart activities, the plant commenced startup activities at 2:57 EST on 11/16/00. In accordance with 10CFR50.73 a Licensee Event Report will be submitted to describe this incident, the root cause, and associated corrective actions."
The licensee will inform the NRC resident inspector. Notified R1DO(Barkley).
Power Reactor
Event Number: 37526
Facility: HATCH
Region: 2 State: GA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: HARRY RUSSELL
HQ OPS Officer: FANGIE JONES
Region: 2 State: GA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: HARRY RUSSELL
HQ OPS Officer: FANGIE JONES
Notification Date: 11/15/2000
Notification Time: 20:30 [ET]
Event Date: 11/15/2000
Event Time: 19:30 [EST]
Last Update Date: 11/15/2000
Notification Time: 20:30 [ET]
Event Date: 11/15/2000
Event Time: 19:30 [EST]
Last Update Date: 11/15/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(1)(v) - OTHER ASMT/COMM INOP
10 CFR Section:
50.72(b)(1)(v) - OTHER ASMT/COMM INOP
Person (Organization):
MIKE ERNSTES (R2)
MIKE ERNSTES (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
LOSS OF PRIMARY METEOROLOGICAL TOWER INDICATIONS
The licensee suffered a loss of all indications from the primary meteorological tower and loss of backup meteorological tower delta temperature in the control room and safety parameter display system. The backup meteorological tower indications available are wind speed and direction. This reduces the ability to perform prompt offsite dose assessment. The cause is unknown and is being investigated. There were no operations or work ongoing at the time.
The licensee intends to notify the NRC Resident Inspector.
The licensee suffered a loss of all indications from the primary meteorological tower and loss of backup meteorological tower delta temperature in the control room and safety parameter display system. The backup meteorological tower indications available are wind speed and direction. This reduces the ability to perform prompt offsite dose assessment. The cause is unknown and is being investigated. There were no operations or work ongoing at the time.
The licensee intends to notify the NRC Resident Inspector.