United States Nuclear Regulatory Commission - Protecting People and the Environment
Home > NRC Library > Document Collections > Reports Associated with Events > Event Notification Reports > 2006 > March 24

Event Notification Report for March 24, 2006

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
03/23/2006 - 03/24/2006

** EVENT NUMBERS **


42425 42429 42444 42445 42446

To top of page
Power Reactor Event Number: 42425
Facility: SAINT LUCIE
Region: 2 State: FL
Unit: [ ] [2] [ ]
RX Type: [1] CE,[2] CE
NRC Notified By: JOHN BRADY
HQ OPS Officer: JOHN KNOKE
Notification Date: 03/17/2006
Notification Time: 01:30 [ET]
Event Date: 03/16/2006
Event Time: 22:50 [EST]
Last Update Date: 03/23/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
MIKE ERNSTES (R2)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 100 Power Operation 100 Power Operation

Event Text

LOSS OF COMMUNICATION - ERDADS COMPUTER FAILED

"On 3/16/2006 at approximately 2010 [EST], the U2 ERDADS computer failed and stopped providing updated plant data to the Unit 2 and Technical Support Center operator consoles, leaving the displays essentially static. Investigation of the failure mode is ongoing and attempts to restore the ERDADS to normal are in progress.

"Loss of the ERDADS output for greater than one hour is reportable as a major loss of assessment and communication capability under 10 CFR 50.72(b)(3)(xiii)."


The licensee notified the NRC Resident Inspector.

* * * UPDATE FROM J. HESSLING TO W. GOTT AT 1603 ON 03/23/06 * * *

ERDADS system is restored.

The licensee notified the NRC Resident Inspector.

Notified R2DO (C. Evans)

To top of page
Power Reactor Event Number: 42429
Facility: SAINT LUCIE
Region: 2 State: FL
Unit: [ ] [2] [ ]
RX Type: [1] CE,[2] CE
NRC Notified By: CALVIN WARD
HQ OPS Officer: JOHN MacKINNON
Notification Date: 03/19/2006
Notification Time: 17:44 [ET]
Event Date: 03/19/2006
Event Time: 12:40 [EST]
Last Update Date: 03/23/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
MIKE ERNSTES (R2)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 100 Power Operation 100 Power Operation

Event Text

UNIT 2 ERDADS (EMERGENCY RESPONSE DATA ACQUISITION AND DISPLAY SYSTEM) COMPUTER DECLARED INOPERABLE.

"On 3/19/06 at approximately 1240, the U2 ERDADS computer failed and stopped providing updated plant data to the Unit 2 and Technical Support Center Operator Consoles, leaving the displays essentially static. Investigation of the failure mode is ongoing and attempts to restore the ERDADS to normal are in progress. A similar event occurred on 3/16/06, EN# 42425. Loss of the ERDADS output for greater than one hour is reportable as a major loss of assessment and communication capability under 10 CFR 50.72(b)(3)(xiii)."

The ERDADS computer has been restored but the licensee does not considered it fully operable. Vendor is coming in on 3/20/06 to try to correct the ERDADS computer problem.

The NRC Resident Inspector was notified of this by the licensee.

* * * UPDATE FROM J. HESSLING TO W. GOTT AT 1603 ON 03/23/06 * * *

ERDADS system is restored.

The licensee notified the NRC Resident Inspector.

Notified R2DO (C. Evans)

To top of page
Power Reactor Event Number: 42444
Facility: SEQUOYAH
Region: 2 State: TN
Unit: [ ] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: JAY WHITWORTH
HQ OPS Officer: PETE SNYDER
Notification Date: 03/22/2006
Notification Time: 19:49 [ET]
Event Date: 03/22/2006
Event Time: 16:24 [EST]
Last Update Date: 03/23/2006
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
Person (Organization):
CAROLYN EVANS (R2)

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

Event Text

TURBINE TRIP / REACTOR TRIP CAUSED BY MAIN GENERATOR TRIP

"This notification fulfills the 4-hr. non-emergency reporting requirement for Reactor Protection System actuation and the 8-hr. non-emergency reporting requirement for an ESF actuation (specifically Auxiliary Feedwater System start).

"At 1624 EST, Unit 2 reactor tripped from full power due to main generator trip caused by actuation of the main generator neutral overvoltage relay (the 100% stator ground fault relay also actuated). Safety Injection did not actuate and was not required to actuate.

"All automatic actions occurred as designed (e.g., steam dump operation, feedwater system, etc.).

"The operating crew responded to the trip using emergency procedures. The unit is being maintained in Mode 3 (Hot Standby) using General Operating Instructions.

"No primary steam or steam generator safety valves opened due to this trip.

"An investigation has been initiated to determine the cause of this unit trip. A recovery plan will be developed."

All control rods fully inserted on the reactor trip. Decay heat is being removed by auxiliary feedwater feeding the steam generators and steaming through the steam dump valves to the main condenser. Offsite power is stable and all emergency busses are being powered via offsite power. All Emergency Diesel Generators are available if required.

The licensee notified the NRC Resident Inspector.

To top of page
Power Reactor Event Number: 42445
Facility: SAINT LUCIE
Region: 2 State: FL
Unit: [1] [2] [ ]
RX Type: [1] CE,[2] CE
NRC Notified By: JOE HESSLING
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 03/23/2006
Notification Time: 10:25 [ET]
Event Date: 03/23/2006
Event Time: 10:30 [EST]
Last Update Date: 03/23/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
CAROLYN EVANS (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

Event Text

MAINTENANCE ON ENS PHONE LINE

"At approximately 1030 this morning, the ENS lines for unit 1, unit 2, and Technical Support Center will be unreliable and may be unavailable for maintenance on off-site telephone circuitry. The expected duration will be until 1600 on 3/23/06. Commercial telephones will still be available. The loss of the ENS communications is reportable under 10CFR 50.72 (b)(3)(xiii). St Lucie will perform a phone test following ENS restoration."

Commercial phone lines to the site are still available.

The licensee notified the NRC Resident Inspector.

* * * UPDATE FROM J. HESSLING TO W. GOTT AT 1603 ON 03/23/06 * * *

ENS lines for unit 1, unit 2 and the Technical Support Center have been restored and tested.

The licensee notified the NRC Resident Inspector.

Notified R2DO (C. Evans)

To top of page
Power Reactor Event Number: 42446
Facility: MCGUIRE
Region: 2 State: NC
Unit: [1] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: FRED KIRK
HQ OPS Officer: STEVE SANDIN
Notification Date: 03/23/2006
Notification Time: 18:20 [ET]
Event Date: 03/23/2006
Event Time: 12:50 [EST]
Last Update Date: 03/23/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
OTHER UNSPEC REQMNT
Person (Organization):
CAROLYN EVANS (R2)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 99 Power Operation
2 N Y 100 Power Operation 99 Power Operation

Event Text

24-HOUR CONDITION OF LICENSE REPORT DUE TO THERMAL POWER POTENTIALLY EXCEEDING LICENSED LIMIT

"McGuire Unit 1 and Unit 2 may have been operating greater than design thermal power limits of 3411 MW [Megawatt] by approximately 0.08% due to discovery of non-conservative thermal power calculations. Preliminary evaluation of Steam Generator Blow Down inputs into the thermal power calorimetric indicates a non-conservative error resulting in indicated total thermal power being approximately 0.08% lower than actual. Additional evaluations to confirm indicated power are ongoing. Power was reduced as soon as the on duty shift was made aware of the error and both Unit 1 and Unit 2 indicated thermal power is being limited to less than 99.85% to ensure actual reactor power remains less than 3411 MW.

"This notification is being made pursuant to the McGuire Facility Operating License Condition 2.C.(1) Maximum Power Level."

The licensee will inform the NRC Resident Inspector.

Page Last Reviewed/Updated Friday, March 30, 2012
Friday, March 30, 2012