| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
12/30/2008 - 12/31/2008 ** EVENT NUMBERS ** |
 | !!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!! | | Power Reactor | Event Number: 44645 | Facility: PALISADES
Region: 3 State: MI
Unit: [1] [ ] [ ]
RX Type: [1] CE
NRC Notified By: BRUCE BAUER
HQ OPS Officer: JOHN KNOKE | Notification Date: 11/07/2008
Notification Time: 22:00 [ET]
Event Date: 11/07/2008
Event Time: 14:41 [EST]
Last Update Date: 12/30/2008 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
KENNETH RIEMER (R3)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text LOAD CALULATIONS FOR EDG WERE INCORRECT
"During a review it was determined that the Diesel Generator load calculation (EA-ELEC-LDTAB-005) did not account for worst case load from the Containment Air Cooler Fan Motors (V-1A, V-2A, V-3A). Initial review indicates that with the worst case fan motor loading, Diesel Generator 1-2 could be loaded beyond its 2 hour rating following a Loss of Coolant Accident (LOCA) during the time period prior to Recirculation Actuation (RAS).
"The horsepower loading for the motors used in the Diesel Generator load calculation was based on the original specification for the motors. In 1993 calculation EA-DPAL93-110 was done to determine the impact of partial flooding of the air coolers coils on the cooling fan performance. The 1993 calculation calculated a fan motor load that was higher than what is used in the diesel generator load calculation. However, the diesel generator load calculation was not updated as a result of the 1993 calculation.
"The higher motor power requirement is 17 kW per fan. There are 3 Containment Air Cooler fans loaded on Diesel Generator 1-2. The extra loading, when combined with the possible additional load from operating the diesel generator at increased frequency, raises the calculated load to 2782 kW, which is above the 2 hour rating of 2750 kW. The overload only applies during a time segment of the diesel generator load profile prior to RAS. This could result in the loss of the diesel generator.
"There is only 1 Containment Air Cooler Fan Motor (V4A) loaded on Diesel Generator 1-1 and has 121 kW margin available. Therefore, there is no concern about overloading Diesel Generator 1-1.
"Placed hand switches (42-299CS & 42-277CS) for Turbine Generator Emergency Air Side Seal Oil Backup Pump (P-23) and Turbine Turning Gear Oil Pump (P-26) in Pull-To-Lock position, which prevents the pumps from automatically starting. This reduces the potential load on 1-2 D/G by 71 kW. This restores the load on the diesel to within the margin."
Licensee has notified the NRC Resident Inspector
* * * RETRACTION AT 1416 EST ON 12/30/08 FROM DAVIS TO HUFFMAN * * *
"Entergy Nuclear Operations Inc. (ENO) is retracting Event Notification EN #44645 which reported a loss of a safety function due to the 1-2 emergency diesel generator (EDG) load calculation not accounting for the worst-case load from the containment air cooler fan motors. The initial review indicated that, with the worst-case fan motor loading, the 1-2 EDG could have been loaded beyond the 2750 kW two-hour peak loading limits following a loss-of-coolant accident during the time period prior to a recirculation actuation signal. This condition may have caused 1-2 EDG to become inoperable, and could have prevented fulfillment of a safety function.
"In a subsequent evaluation of loading capability, completed on December 18, 2008, ENO determined the 1-2 EDG was operable. The EDGs are rated for 2750 kW two-hour peak operation. It was determined that the postulated peak load for the 1-2 EDG would have been 2819 kW for a period of approximately thirty-eight minutes. However, based on engineering information obtained from the vendor of the 1-2 EDG, Fairbanks-Morris Engine, and reviewed by ENO, the 1-2 EDG could have been operated up to 2830 kW for fifty minutes before any susceptibility to damage might occur. In addition, under the peak loading condition of 2819 kW, the speed of the 1-2 EDG would have remained above the Technical Specification limit of 59.5 Hz. The subsequent review confirmed that the safety function would have been fulfilled. Therefore, ENO is retracting this event notification."
The licensee has notified the NRC Resident Inspector. R3DO (Cameron) notified. |
| Power Reactor | Event Number: 44746 | Facility: KEWAUNEE
Region: 3 State: WI
Unit: [1] [ ] [ ]
RX Type: [1] W-2-LP
NRC Notified By: TIM BUNKELMAN
HQ OPS Officer: BILL HUFFMAN | Notification Date: 12/30/2008
Notification Time: 16:36 [ET]
Event Date: 12/30/2008
Event Time: 11:13 [CST]
Last Update Date: 12/30/2008 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
50.72(b)(3)(v)(A) - POT UNABLE TO SAFE SD
50.72(b)(3)(v)(B) - POT RHR INOP
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
JAMNES CAMERON (R3)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text NON-FUNCTIONAL STEAM EXCLUSION / CONTROL ROOM EXCLUSION ZONE (CREZ) BARRIER
"On 12/30/08 at 1113 an Operator transiting though a steam exclusion / CREZ door found the door sweep separated from the door. This prevented the door from performing its Steam Exclusion and CREZ boundary functions as the opening, due to the missing sweep, exceeded the allowable opening size for the respective functions.
"Repairs were completed on the door at 1157 on 12/30/08. While the door sweep was not intact, the barrier was non-functional. In accordance with TRM 3.0.9 Section A.1 all equipment supported by that steam exclusion barrier was immediately declared inoperable. This zone includes both trains of Control Room Post Accident Recirculation and the Control Room itself. TS 3.0.c was entered when the sweep was identified degraded and exited following repairs.
"Therefore, this is reportable under 10CFR50.72(b)(3)(v), 'Any event or condition that at the time of discovery could have prevented the fulfillment of a safety function', and under 10CFR50.72(b)(3)(ii)(B), 'any event or condition that results in the nuclear plant being in an unanalyzed condition that significantly degrades plant safety'.
"The licensee notified the NRC Resident Inspector." | |