Event Notification Report for May 24, 2005
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/23/2005 - 05/24/2005
Power Reactor
Event Number: 41726
Facility: LIMERICK
Region: 1 State: PA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: PHIL CHASE
HQ OPS Officer: BILL GOTT
Region: 1 State: PA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: PHIL CHASE
HQ OPS Officer: BILL GOTT
Notification Date: 05/24/2005
Notification Time: 15:33 [ET]
Event Date: 05/24/2005
Event Time: 09:14 [EDT]
Last Update Date: 05/24/2005
Notification Time: 15:33 [ET]
Event Date: 05/24/2005
Event Time: 09:14 [EDT]
Last Update Date: 05/24/2005
Emergency Class: NON EMERGENCY
10 CFR Section:
26.73 - FITNESS FOR DUTY
10 CFR Section:
26.73 - FITNESS FOR DUTY
Person (Organization):
CLIFFORD ANDERSON (R1)
CLIFFORD ANDERSON (R1)
| 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 |
FITNESS FOR DUTY
A non-licensed employee supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details.
The licensee notified the NRC Resident Inspector.
A non-licensed employee supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details.
The licensee notified the NRC Resident Inspector.
Power Reactor
Event Number: 41728
Facility: OCONEE
Region: 2 State: SC
Unit: [1] [2] [3]
RX Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP
NRC Notified By: RANDY TODD
HQ OPS Officer: WESLEY HELD
Region: 2 State: SC
Unit: [1] [2] [3]
RX Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP
NRC Notified By: RANDY TODD
HQ OPS Officer: WESLEY HELD
Notification Date: 05/24/2005
Notification Time: 20:00 [ET]
Event Date: 05/24/2005
Event Time: 13:50 [EDT]
Last Update Date: 05/24/2005
Notification Time: 20:00 [ET]
Event Date: 05/24/2005
Event Time: 13:50 [EDT]
Last Update Date: 05/24/2005
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):
DAVID AYRES (R2)
DAVID AYRES (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 |
| 3 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNANALYZED CONDITION INVOLVING EMERGENCY BACKUP POWER GENERATORS
"Event: On 5-19-05, Oconee discovered that an electrical contactor had failed at Keowee Hydro Station. This contactor normally can provide auxiliary power from one Keowee Hydro Unit (KHU) to cooling fans on the Keowee Main Transformer, which is part of the Overhead power path (one train of emergency power to the three Oconee units). At the time, power to the cooling fans was being provided by an alternate power source. A problem report (PIP) was written and an Operability Assessment concluded that the Overhead power path was fully operable. On 5-24-05 at 1350 hours, it was recognized that the alternate power source supplying the cooling fans was supplied from the auxiliary power bus associated with the KHU then aligned to the Underground power path (the redundant train of emergency power to the three Oconee units).
"It was recognized that this alignment presented a single failure vulnerability in that loss of the auxiliary power bus for the KHU aligned to the Underground path could also result in loss of Main Transformer cooling on the Overhead power path. As a result, Operations declared entry at 1350 hours into Technical Specification (TS) 3.8.1 condition C for the Overhead power path being inoperable (a 72 hour allowed completion time). A review of available information indicates that the electrical contactor actually failed on or before 5-2-05. Therefore the period of vulnerability to this potential single failure was approximately 22 days. This condition is being reported as an unanalyzed condition per guidance in NUREG 1022 section 3.2.4.
"Initial Safety Significance: If the postulated single failure occurred during a design basis event, it is expected that, without credit for Operator intervention, both KHUs would fail, but the failure is not expected until a minimum of one hour after the loss of auxiliary power. During this time Operations would have been able to realign the KHU with auxiliary power to the Underground path and/or to have started and aligned a combustion turbine at Lee Steam Station. Therefore, the condition being reported is not expected to result in a loss of safety function.
"Corrective Action(s): The immediate corrective action was to realign the Keowee units to the opposite power paths. This aligned the KHU capable of supplying power to the Main Transformer cooling fans to the Overhead path. The KHU associated with the failed contactor was aligned to the Underground path. The TS condition was exited at 1540 hours when this realignment was complete."
The licensee notified the NRC Resident Inspector.
"Event: On 5-19-05, Oconee discovered that an electrical contactor had failed at Keowee Hydro Station. This contactor normally can provide auxiliary power from one Keowee Hydro Unit (KHU) to cooling fans on the Keowee Main Transformer, which is part of the Overhead power path (one train of emergency power to the three Oconee units). At the time, power to the cooling fans was being provided by an alternate power source. A problem report (PIP) was written and an Operability Assessment concluded that the Overhead power path was fully operable. On 5-24-05 at 1350 hours, it was recognized that the alternate power source supplying the cooling fans was supplied from the auxiliary power bus associated with the KHU then aligned to the Underground power path (the redundant train of emergency power to the three Oconee units).
"It was recognized that this alignment presented a single failure vulnerability in that loss of the auxiliary power bus for the KHU aligned to the Underground path could also result in loss of Main Transformer cooling on the Overhead power path. As a result, Operations declared entry at 1350 hours into Technical Specification (TS) 3.8.1 condition C for the Overhead power path being inoperable (a 72 hour allowed completion time). A review of available information indicates that the electrical contactor actually failed on or before 5-2-05. Therefore the period of vulnerability to this potential single failure was approximately 22 days. This condition is being reported as an unanalyzed condition per guidance in NUREG 1022 section 3.2.4.
"Initial Safety Significance: If the postulated single failure occurred during a design basis event, it is expected that, without credit for Operator intervention, both KHUs would fail, but the failure is not expected until a minimum of one hour after the loss of auxiliary power. During this time Operations would have been able to realign the KHU with auxiliary power to the Underground path and/or to have started and aligned a combustion turbine at Lee Steam Station. Therefore, the condition being reported is not expected to result in a loss of safety function.
"Corrective Action(s): The immediate corrective action was to realign the Keowee units to the opposite power paths. This aligned the KHU capable of supplying power to the Main Transformer cooling fans to the Overhead path. The KHU associated with the failed contactor was aligned to the Underground path. The TS condition was exited at 1540 hours when this realignment was complete."
The licensee notified the NRC Resident Inspector.