Event Notification Report for July 25, 2006
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
07/24/2006 - 07/25/2006
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 42725
Facility: MILLSTONE
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: JEFF YOUNG
HQ OPS Officer: ARLON COSTA
Region: 1 State: CT
Unit: [] [2] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: JEFF YOUNG
HQ OPS Officer: ARLON COSTA
Notification Date: 07/25/2006
Notification Time: 11:41 [ET]
Event Date: 07/25/2006
Event Time: 09:45 [EDT]
Last Update Date: 08/14/2006
Notification Time: 11:41 [ET]
Event Date: 07/25/2006
Event Time: 09:45 [EDT]
Last Update Date: 08/14/2006
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):
HAROLD GRAY (R1)
HAROLD GRAY (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
REACTOR TRIP BREAKERS OPENED DURING MAINTENANCE ON STEAM GENERATOR WIDE LEVEL CHANNELS
The licensee was performing maintenance on "D" Steam Generator Low Level bistables when 4 (four) out of 8 (eight) trip control breakers opened possibly due to a 24 V DC power supply transient to 2 (two) of 4 (four) logic matrix relays. The reactor trip logic was verified to be functional and capable of processing valid reactor trip signals. The actuation was invalid as no plant transient occurred and no process variable was exceeded which would otherwise have required a reactor trip.
The licensee notified the State and the NRC Resident Inspector.
* * * RETRACTION ON 08/14/06 AT 0947 ET BY M. EWER TO MACKINNON * * *
"Upon further review, the initial notification of this event is determined to have been conservative. A review of NUREG 1022, Rev. 2, 'Event Reporting Guidelines, 10 CFR 50.72 and 50.73,' as well as the supporting comments in the notice of final rulemaking for changes to 10 CFR Parts 50 and 72 contained in the Federal Register on October 25, 2000, indicates that these documents stress the need for reporting of system actuations. As stated in NUREG 1022, 'actuation of multichannel actuation systems is defined as actuation of enough channels to complete the minimum actuation logic. Therefore, single channel actuation logic,' Per the final rulemaking, 'the principal reason for reporting an actuation of one of these systems is that it is indicative of an unplanned plant transient that the NRC needs to evaluate to determine if action is necessary to address a safety problem.'
"In the event described in CR-06-06880, a portion of the RPS actuation sufficiently to cause four of the eight TCBs to open (i.e, a half trip), but not enough channels actuated to complete the minimum actuation logic for RPS (i.e, insufficient channels to fulfill the safety function of the RPS to deenergized the control rod drive mechanisms to shutdown the reactor). There was no unplanned plant transient as a result of the half trip.
"Determination
"Based on the above assessment, this condition in NOT reportable per 10 CFR 50.73(a)(2)(iv)(A) as an actuation of any of the systems listed in paragraph 10 CFR 50.73(a)(2)(iv)(B).
"Accordingly, the report of a 4 hour non-emergency event under 10 CFR 50.72(b)(2)(iv)(b) for a half RPS trip actuation should be withdrawn."
R1DO (Lorson) notified.
The NRC Resident Inspector will be notified by the licensee of this retraction.
The licensee was performing maintenance on "D" Steam Generator Low Level bistables when 4 (four) out of 8 (eight) trip control breakers opened possibly due to a 24 V DC power supply transient to 2 (two) of 4 (four) logic matrix relays. The reactor trip logic was verified to be functional and capable of processing valid reactor trip signals. The actuation was invalid as no plant transient occurred and no process variable was exceeded which would otherwise have required a reactor trip.
The licensee notified the State and the NRC Resident Inspector.
* * * RETRACTION ON 08/14/06 AT 0947 ET BY M. EWER TO MACKINNON * * *
"Upon further review, the initial notification of this event is determined to have been conservative. A review of NUREG 1022, Rev. 2, 'Event Reporting Guidelines, 10 CFR 50.72 and 50.73,' as well as the supporting comments in the notice of final rulemaking for changes to 10 CFR Parts 50 and 72 contained in the Federal Register on October 25, 2000, indicates that these documents stress the need for reporting of system actuations. As stated in NUREG 1022, 'actuation of multichannel actuation systems is defined as actuation of enough channels to complete the minimum actuation logic. Therefore, single channel actuation logic,' Per the final rulemaking, 'the principal reason for reporting an actuation of one of these systems is that it is indicative of an unplanned plant transient that the NRC needs to evaluate to determine if action is necessary to address a safety problem.'
"In the event described in CR-06-06880, a portion of the RPS actuation sufficiently to cause four of the eight TCBs to open (i.e, a half trip), but not enough channels actuated to complete the minimum actuation logic for RPS (i.e, insufficient channels to fulfill the safety function of the RPS to deenergized the control rod drive mechanisms to shutdown the reactor). There was no unplanned plant transient as a result of the half trip.
"Determination
"Based on the above assessment, this condition in NOT reportable per 10 CFR 50.73(a)(2)(iv)(A) as an actuation of any of the systems listed in paragraph 10 CFR 50.73(a)(2)(iv)(B).
"Accordingly, the report of a 4 hour non-emergency event under 10 CFR 50.72(b)(2)(iv)(b) for a half RPS trip actuation should be withdrawn."
R1DO (Lorson) notified.
The NRC Resident Inspector will be notified by the licensee of this retraction.
Power Reactor
Event Number: 42728
Facility: COOPER
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: SKIP LEE
HQ OPS Officer: JOE O'HARA
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: SKIP LEE
HQ OPS Officer: JOE O'HARA
Notification Date: 07/25/2006
Notification Time: 16:56 [ET]
Event Date: 07/25/2006
Event Time: 15:41 [CDT]
Last Update Date: 07/25/2006
Notification Time: 16:56 [ET]
Event Date: 07/25/2006
Event Time: 15:41 [CDT]
Last Update Date: 07/25/2006
Emergency Class: UNUSUAL EVENT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
Person (Organization):
THOMAS FARNHOLTZ (R4)
MICHAEL TSCHILTZ (NRR)
MELVYN LEACH (IRD)
JIM DYER (NRR)
LON BIASCO (DHS)
THOMAS FARNHOLTZ (R4)
MICHAEL TSCHILTZ (NRR)
MELVYN LEACH (IRD)
JIM DYER (NRR)
LON BIASCO (DHS)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNUSUAL EVENT DECLARED DUE TO FIRE ALARM
Cooper Nuclear Station control room received a fire alarm at 1529 CST indicating a fire in the service water pump room. The licensee responded by dispatching a fire brigade to the service water pump room to investigate. At 1541 CST, the licensee declared an unusual event in accordance with their emergency procedures due to their inability to confirm the validity of the fire alarm within a 10 minute period. The licensee exited the unusual event at 1559 CST after determining that the alarm was a false alarm caused by welding inside the service water pump room. The licensee issued a press release.
The licensee notified the NRC Resident Inspector, the Nebraska State Patrol, the Richardson County Sheriff's Office, Nemaha County Sheriff's Office, Missouri Highway Patrol, and the Atchison County 911 Center.
Cooper Nuclear Station control room received a fire alarm at 1529 CST indicating a fire in the service water pump room. The licensee responded by dispatching a fire brigade to the service water pump room to investigate. At 1541 CST, the licensee declared an unusual event in accordance with their emergency procedures due to their inability to confirm the validity of the fire alarm within a 10 minute period. The licensee exited the unusual event at 1559 CST after determining that the alarm was a false alarm caused by welding inside the service water pump room. The licensee issued a press release.
The licensee notified the NRC Resident Inspector, the Nebraska State Patrol, the Richardson County Sheriff's Office, Nemaha County Sheriff's Office, Missouri Highway Patrol, and the Atchison County 911 Center.