Event Notification Report for February 26, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/25/2011 - 02/26/2011
EVENT NUMBERS
46645
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 46645
Facility: DUANE ARNOLD
Region: 3 State: IA
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: JEFF MIELL
HQ OPS Officer: BILL HUFFMAN
Region: 3 State: IA
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: JEFF MIELL
HQ OPS Officer: BILL HUFFMAN
Notification Date: 02/26/2011
Notification Time: 12:16 [ET]
Event Date: 02/26/2011
Event Time: 09:48 [CST]
Last Update Date: 04/21/2011
Notification Time: 12:16 [ET]
Event Date: 02/26/2011
Event Time: 09:48 [CST]
Last Update Date: 04/21/2011
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):
DAVID HILLS (R3DO)
DAVID HILLS (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
HIGH PRESSURE COOLANT INJECTION SYSTEM INOPERABLE
"High Pressure Coolant Injection (HPCI) system declared inoperable due to Flow Indicating Controller process value indicating 542 gpm while in standby readiness condition. This condition could impact the system response time in developing flow for events it was credited in mitigating.
"HPCI declared inoperable per TS 3.5.1 Condition F which allows 14 days to restore to operable status.
"Preliminary cause is air intrusion into instrument sensing lines following pre-planned maintenance where system draining was performed. Troubleshooting is in progress.
"All remaining ECCS and RCIC are operable and available. Grid stability has been verified."
The NRC senior resident has been notified.
* * * RETRACTION AT 1216 ON 4/21/2011 FROM BOB MURRELL TO MARK ABRAMOVITZ * * *
"The purpose of this notification is to retract a previous report made on 2/26/2011 at 1216 (EDT) (EN 46645). Notification of the event to the NRC was initially made as a result of declaring High Pressure Coolant Injection (HPCI) system inoperable due to Flow Indicating Controller process value indicating 542 gpm while in standby readiness condition. This condition could have impacted the system response time in developing flow for events it was credited to mitigate.
"Subsequent to the initial report, NextEra Energy Duane Arnold (NextEra) has determined that the HPCI system was capable of performing its safety function.
"NextEra concluded that the erroneous Flow Indicator Controller indication was due to air entrainment in the instrument sensing line. A detailed engineering analysis has concluded that the HPCI system was capable of providing design required flow rates with the flow offset.
"This event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73.
"The NRC Senior Resident Inspector has been notified."
Tech spec required flow is 2700 gpm. Calculations show that a margin of 600 gpm exists between the tech spec flow rate, and the HPCI automatic flow setpoint, therefore, with an error of 542 gpm, the required flow is met.
Notified the R3DO (Phillips).
"High Pressure Coolant Injection (HPCI) system declared inoperable due to Flow Indicating Controller process value indicating 542 gpm while in standby readiness condition. This condition could impact the system response time in developing flow for events it was credited in mitigating.
"HPCI declared inoperable per TS 3.5.1 Condition F which allows 14 days to restore to operable status.
"Preliminary cause is air intrusion into instrument sensing lines following pre-planned maintenance where system draining was performed. Troubleshooting is in progress.
"All remaining ECCS and RCIC are operable and available. Grid stability has been verified."
The NRC senior resident has been notified.
* * * RETRACTION AT 1216 ON 4/21/2011 FROM BOB MURRELL TO MARK ABRAMOVITZ * * *
"The purpose of this notification is to retract a previous report made on 2/26/2011 at 1216 (EDT) (EN 46645). Notification of the event to the NRC was initially made as a result of declaring High Pressure Coolant Injection (HPCI) system inoperable due to Flow Indicating Controller process value indicating 542 gpm while in standby readiness condition. This condition could have impacted the system response time in developing flow for events it was credited to mitigate.
"Subsequent to the initial report, NextEra Energy Duane Arnold (NextEra) has determined that the HPCI system was capable of performing its safety function.
"NextEra concluded that the erroneous Flow Indicator Controller indication was due to air entrainment in the instrument sensing line. A detailed engineering analysis has concluded that the HPCI system was capable of providing design required flow rates with the flow offset.
"This event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73.
"The NRC Senior Resident Inspector has been notified."
Tech spec required flow is 2700 gpm. Calculations show that a margin of 600 gpm exists between the tech spec flow rate, and the HPCI automatic flow setpoint, therefore, with an error of 542 gpm, the required flow is met.
Notified the R3DO (Phillips).