Event Notification Report for October 13, 2006
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/12/2006 - 10/13/2006
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 42906
Facility: BRUNSWICK
Region: 2 State: NC
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: MICHAEL POTTER
HQ OPS Officer: STEVE SANDIN
Region: 2 State: NC
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: MICHAEL POTTER
HQ OPS Officer: STEVE SANDIN
Notification Date: 10/13/2006
Notification Time: 16:55 [ET]
Event Date: 10/13/2006
Event Time: 13:57 [EDT]
Last Update Date: 12/05/2006
Notification Time: 16:55 [ET]
Event Date: 10/13/2006
Event Time: 13:57 [EDT]
Last Update Date: 12/05/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
JAY HENSON (R2)
JAY HENSON (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 |
HIGH PRESSURE COOLANT INJECTION (HPCI) SYSTEM DECLARED INOPERABLE DUE TO POTENTIAL TURBINE EXHAUST DIAPHRAGM FAILURE
"On October 13, 2006 at 1357 (EST) Unit 2 HPCI system was declared inoperable due to indications of a leaking rupture diaphragm in the turbine steam exhaust line.
"This determination was made when water was discovered in the E41-PSH-N012A and E41-PSH-N012C instrument lines during the performance of 0MST- HPCI23Q (HPCI Turbine Exhaust Diaphragm High Pressure Instrument Channel Calibration).
"TS LCO 3.5.1. 'ECCS - Operating,' Condition D was entered for the HPCI system being declared inoperable. The Reactor Core Isolation Cooling (RCIC) system was verified operable per Required Action D.1. Required Action D.2 of TS LCO 3.5.1 requires the HPCI system to be returned to operable status within 14 days.
"The initial safety significance of this condition is considered to be minimal. The RCIC system and all other required ECCS, are operable at this time.
"HPCI has been isolated and will be placed under clearance to allow the turbine exhaust diaphragm to be inspected and replaced if necessary
" The [NRC] Resident Inspector has been notified."
* * * RETRACTION FROM M. TURKAL TO P. SNYDER ON 12/05/06 * * *
"Upon further review, it has been determined that the HPCI system was not rendered inoperable as a result of the condition identified on October 13, 2006.
"The HPCI system is equipped with two rupture diaphragms on the steam exhaust line installed in series. Between the rupture discs are four instrument lines leading to pressure switches (i.e., E41-PSH-N012A, N012B, N012C, and N012D) and a header vent line that vents to the HPCI room atmosphere. The HPCI Turbine Exhaust Diaphragm Pressure - High signals are initiated from these pressure switches; which are required to be operable per Technical Specification 3.3.6.1, 'Primary Containment Isolation Instrumentation,' to isolate the HPCI exhaust line in the event of a degraded inner rupture disc, before the redundant outer disc is significantly challenged. This isolation provides equipment protection and [is] not assumed in any transient or accident analysis.
"The suspected leaking inner rupture diaphragm was confirmed to be fully intact and, as such, not a source of the water (i.e., approximately 1.125 quarts) in the E41-PSH-N012A and E41-PSH-N012C instrument lines. The most likely source of this water is residual water remaining from a rupture disc failure that occurred in November 2003. Engineering has evaluated the potential impact of the residual water and determined that both the HPCI system and the HPCI Turbine Exhaust Diaphragm Pressure - High isolation function remained operable. There was not sufficient water in the lines to affect the function of the HPCI rupture diaphragms if required. In addition, the quantity of water discovered would not have prevented a HPCI initiation, if required, as evidenced by successful operation of the Unit 2 HPCI system on at least 10 occasions since November 2003. The Technical Specification required function of the pressure switches was not impacted by the presence of residual water. Investigation of this condition is documented in the corrective action program is Nuclear Condition Report (NCR) 209265.
"On this basis, the HPCI system was capable of performing its function to mitigate the consequences of an accident and the issue is not reportable under 10 CFR 50.72(b)(3)(v)(D).
"The NRC Resident Inspector was notified of this retraction."
Notified R2DO (Landis).
"On October 13, 2006 at 1357 (EST) Unit 2 HPCI system was declared inoperable due to indications of a leaking rupture diaphragm in the turbine steam exhaust line.
"This determination was made when water was discovered in the E41-PSH-N012A and E41-PSH-N012C instrument lines during the performance of 0MST- HPCI23Q (HPCI Turbine Exhaust Diaphragm High Pressure Instrument Channel Calibration).
"TS LCO 3.5.1. 'ECCS - Operating,' Condition D was entered for the HPCI system being declared inoperable. The Reactor Core Isolation Cooling (RCIC) system was verified operable per Required Action D.1. Required Action D.2 of TS LCO 3.5.1 requires the HPCI system to be returned to operable status within 14 days.
"The initial safety significance of this condition is considered to be minimal. The RCIC system and all other required ECCS, are operable at this time.
"HPCI has been isolated and will be placed under clearance to allow the turbine exhaust diaphragm to be inspected and replaced if necessary
" The [NRC] Resident Inspector has been notified."
* * * RETRACTION FROM M. TURKAL TO P. SNYDER ON 12/05/06 * * *
"Upon further review, it has been determined that the HPCI system was not rendered inoperable as a result of the condition identified on October 13, 2006.
"The HPCI system is equipped with two rupture diaphragms on the steam exhaust line installed in series. Between the rupture discs are four instrument lines leading to pressure switches (i.e., E41-PSH-N012A, N012B, N012C, and N012D) and a header vent line that vents to the HPCI room atmosphere. The HPCI Turbine Exhaust Diaphragm Pressure - High signals are initiated from these pressure switches; which are required to be operable per Technical Specification 3.3.6.1, 'Primary Containment Isolation Instrumentation,' to isolate the HPCI exhaust line in the event of a degraded inner rupture disc, before the redundant outer disc is significantly challenged. This isolation provides equipment protection and [is] not assumed in any transient or accident analysis.
"The suspected leaking inner rupture diaphragm was confirmed to be fully intact and, as such, not a source of the water (i.e., approximately 1.125 quarts) in the E41-PSH-N012A and E41-PSH-N012C instrument lines. The most likely source of this water is residual water remaining from a rupture disc failure that occurred in November 2003. Engineering has evaluated the potential impact of the residual water and determined that both the HPCI system and the HPCI Turbine Exhaust Diaphragm Pressure - High isolation function remained operable. There was not sufficient water in the lines to affect the function of the HPCI rupture diaphragms if required. In addition, the quantity of water discovered would not have prevented a HPCI initiation, if required, as evidenced by successful operation of the Unit 2 HPCI system on at least 10 occasions since November 2003. The Technical Specification required function of the pressure switches was not impacted by the presence of residual water. Investigation of this condition is documented in the corrective action program is Nuclear Condition Report (NCR) 209265.
"On this basis, the HPCI system was capable of performing its function to mitigate the consequences of an accident and the issue is not reportable under 10 CFR 50.72(b)(3)(v)(D).
"The NRC Resident Inspector was notified of this retraction."
Notified R2DO (Landis).
Power Reactor
Event Number: 42904
Facility: QUAD CITIES
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-3,[2] GE-3
NRC Notified By: KEVIN CRAVENS
HQ OPS Officer: JOHN MacKINNON
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-3,[2] GE-3
NRC Notified By: KEVIN CRAVENS
HQ OPS Officer: JOHN MacKINNON
Notification Date: 10/13/2006
Notification Time: 11:46 [ET]
Event Date: 10/13/2006
Event Time: 10:34 [CDT]
Last Update Date: 10/13/2006
Notification Time: 11:46 [ET]
Event Date: 10/13/2006
Event Time: 10:34 [CDT]
Last Update Date: 10/13/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
Person (Organization):
DAVE PASSEHL (R3)
DAVE PASSEHL (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 89 | Power Operation |
INITIATION OF REACTOR SHUTDOWN REQUIRED BY TECHNICAL SPECIFICATION 3.1.7, ACTION C.1
"On October 13, 2006, at 1034 hours, a Reactor Shutdown was initiated in response to Technical Specification 3.1.7, Action C.1.
"At 2236 hours on October 12, 2006, it was determined that the Standby Liquid Control tank had a pinhole leak. In accordance with ASME Code requirements for Class 2 pressure boundaries, the SLC tank was declared inoperable, rendering the SLC system inoperable. TS Action 3.1.7, Action B.1, was entered at 2236 hours on October 12, 2006 and TS Action 3.1.7, Action C.1, was entered at 0636 hours on October 13, 2006.
"The SLC tank and system remain available. The pinhole leak does not affect the structural integrity of the tank, and the level, temperature and concentration of the boron solution are being maintained per requirements."
All ECCS and EDGs are operable and available and the electrical grid is stable. The licensee informed the NRC Resident Inspector.
At 1130 CDT, the licensee received a 72 hour extension in getting to Mode 3 (Hot Shutdown). The licensee is currently holding reactor power at 82% in anticipation of bringing the reactor to 100% full power while in parallel performing the necessary repairs to the Standby Liquid Control tank.
"On October 13, 2006, at 1034 hours, a Reactor Shutdown was initiated in response to Technical Specification 3.1.7, Action C.1.
"At 2236 hours on October 12, 2006, it was determined that the Standby Liquid Control tank had a pinhole leak. In accordance with ASME Code requirements for Class 2 pressure boundaries, the SLC tank was declared inoperable, rendering the SLC system inoperable. TS Action 3.1.7, Action B.1, was entered at 2236 hours on October 12, 2006 and TS Action 3.1.7, Action C.1, was entered at 0636 hours on October 13, 2006.
"The SLC tank and system remain available. The pinhole leak does not affect the structural integrity of the tank, and the level, temperature and concentration of the boron solution are being maintained per requirements."
All ECCS and EDGs are operable and available and the electrical grid is stable. The licensee informed the NRC Resident Inspector.
At 1130 CDT, the licensee received a 72 hour extension in getting to Mode 3 (Hot Shutdown). The licensee is currently holding reactor power at 82% in anticipation of bringing the reactor to 100% full power while in parallel performing the necessary repairs to the Standby Liquid Control tank.