Event Notification Report for August 18, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/17/2011 - 08/18/2011
Power Reactor
Event Number: 47167
Facility: GINNA
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: DANIEL DEAN
HQ OPS Officer: HOWIE CROUCH
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: DANIEL DEAN
HQ OPS Officer: HOWIE CROUCH
Notification Date: 08/18/2011
Notification Time: 16:11 [ET]
Event Date: 08/18/2011
Event Time: 10:00 [EDT]
Last Update Date: 08/18/2011
Notification Time: 16:11 [ET]
Event Date: 08/18/2011
Event Time: 10:00 [EDT]
Last Update Date: 08/18/2011
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Person (Organization):
JAMES TRAPP (R1DO)
JAMES TRAPP (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNANALYZED CONDITION THAT COULD POTENTIALLY IMPACT BOTH TRAINS OF 480V SAFEGUARDS BUSES
"During NFPA-805 Fire PRA [Probabilistic Risk Assessment] model development, Ginna Station identified a non-compliance with the Appendix R requirement to maintain one train of systems that are necessary to achieve and maintain hot shutdown and remain free from fire damage. A fire in the Turbine Building could cause a loss of 4160V power to the 480V safeguards buses while disabling control power to the 480V bus normal supply breakers and preventing both diesel generator output breakers from closing. Since the non-safety related 4160V buses are located in the same area of the turbine building, this could potentially impact both trains of AC power. This was determined to be an unanalyzed condition reportable in accordance with 10CFR50.72(b)(3)(ii)(B). Compensatory measures have been established to provide interim guidance to identify the condition and locally trip the bus supply breaker prior to closing the diesel generator output breaker."
The licensee has notified the NRC Resident Inspector.
"During NFPA-805 Fire PRA [Probabilistic Risk Assessment] model development, Ginna Station identified a non-compliance with the Appendix R requirement to maintain one train of systems that are necessary to achieve and maintain hot shutdown and remain free from fire damage. A fire in the Turbine Building could cause a loss of 4160V power to the 480V safeguards buses while disabling control power to the 480V bus normal supply breakers and preventing both diesel generator output breakers from closing. Since the non-safety related 4160V buses are located in the same area of the turbine building, this could potentially impact both trains of AC power. This was determined to be an unanalyzed condition reportable in accordance with 10CFR50.72(b)(3)(ii)(B). Compensatory measures have been established to provide interim guidance to identify the condition and locally trip the bus supply breaker prior to closing the diesel generator output breaker."
The licensee has notified the NRC Resident Inspector.
Power Reactor
Event Number: 47169
Facility: SEQUOYAH
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MARLIN QUARBERG
HQ OPS Officer: VINCE KLCO
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MARLIN QUARBERG
HQ OPS Officer: VINCE KLCO
Notification Date: 08/19/2011
Notification Time: 01:10 [ET]
Event Date: 08/18/2011
Event Time: 22:50 [EDT]
Last Update Date: 08/19/2011
Notification Time: 01:10 [ET]
Event Date: 08/18/2011
Event Time: 22:50 [EDT]
Last Update Date: 08/19/2011
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
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
SCOTT SHAEFFER (R2DO)
SCOTT SHAEFFER (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
AUTOMATIC REACTOR TRIP DUE TO REACTOR COOLANT PUMP BUS UNDERVOLTAGE
"At 2250 EDT on 8/18/2011, Unit 1 Reactor/Turbine automatically tripped on RCP [Reactor Coolant Pump] Busses UV [Under-Voltage] trip.
"Following the reactor trip, all safety-related equipment operated as designed. Auxiliary Feedwater automatically actuated as expected from the Feedwater Isolation Signal. No primary PORVs and/or Safety Valves opened during or after this trip.
"Unit 1 is currently being maintained in Mode 3 at NOT/NOP, approximately 548 F [degrees] and 2233 psig, with Auxiliary Feedwater supplying the Steam Generators.
"At the time of the trip, a 50G (instantaneous overcurrent ground) relay flag was found dropped on the '1A' 6.9 KV unit board. Subsequently, the '1A' 6.9 KV start bus was found to have transferred to its alternate supply, 'B' CSST [Common Station Service Transformer]. 1A condenser circulating water pump motor trip out was also received in the MCR [Main Control Room].
"The method of decay heat removal is via steam dumps to the condenser with MSIVs open. The current temperature and pressure is stable. There is no indications of any primary/secondary leakage. All control rods inserted. The electrical alignment is normal with the exception of the above mentioned items, supplied from off-site power. There is no impact to Unit 2. Unit 2 is operating at 100% power/ Mode 1."
The licensee notified the NRC Resident Inspector.
"At 2250 EDT on 8/18/2011, Unit 1 Reactor/Turbine automatically tripped on RCP [Reactor Coolant Pump] Busses UV [Under-Voltage] trip.
"Following the reactor trip, all safety-related equipment operated as designed. Auxiliary Feedwater automatically actuated as expected from the Feedwater Isolation Signal. No primary PORVs and/or Safety Valves opened during or after this trip.
"Unit 1 is currently being maintained in Mode 3 at NOT/NOP, approximately 548 F [degrees] and 2233 psig, with Auxiliary Feedwater supplying the Steam Generators.
"At the time of the trip, a 50G (instantaneous overcurrent ground) relay flag was found dropped on the '1A' 6.9 KV unit board. Subsequently, the '1A' 6.9 KV start bus was found to have transferred to its alternate supply, 'B' CSST [Common Station Service Transformer]. 1A condenser circulating water pump motor trip out was also received in the MCR [Main Control Room].
"The method of decay heat removal is via steam dumps to the condenser with MSIVs open. The current temperature and pressure is stable. There is no indications of any primary/secondary leakage. All control rods inserted. The electrical alignment is normal with the exception of the above mentioned items, supplied from off-site power. There is no impact to Unit 2. Unit 2 is operating at 100% power/ Mode 1."
The licensee notified the NRC Resident Inspector.