05000443/LER-2005-002, Regarding Momentary Loss of Power to Emergency Bus While Transferring Power Supplies
| ML051160282 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 04/19/2005 |
| From: | Warner M Florida Power & Light Energy Seabrook |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SBK-L-05079 LER 05-002-00 | |
| Download: ML051160282 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4432005002R00 - NRC Website | |
text
I.
FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 APR 19 2005 Docket No. 50-443 SBK-L-05079 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Seabrook Station Licensee Event Report (LER) 2005-002-00 for Momentary Loss of Power to Emergency Bus While Transferring Power Supplies Enclosed is Licensee Event Report (LER) 2005-002-00. This LER reports an event that occurred at Seabrook Station on February 22, 2005.
This event is being reported pursuant to the requirements of 10 CFR 50.73(a)(2)(iv)(A).
Should you require further information regarding this matter, please contact Mr. James M.
Peschel, Regulatory Programs Manager (603) 773-7194.
Very truly yours, FPL ENERGY SEABROOK, LLC Mark E. Warner Site Vice President cc:
S. J. Collins, NRC Region I Administrator V. Nerses, NRC Project Manager, Project Directorate 1-2 G. T. Dentel, NRC Senior Resident Inspector an FPL Group company
ENCLOSURE TO SBK-L-05079
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the
- 3. PAGE Seabrook Station 05000 443 1 OF 3
- 4. TITLE Momentary Loss of Power to Emergency Bus While Transferring Power Supplies
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED S
FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER A REV MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 02 22 2005 2005 002 -
00 04 19 2005 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) 0 20.2201(b) 0l 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C) al 50.73(a)(2)(vii) 0E 20.2201(d)
El 20.2203(a)(3)(ii)
[
50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 0 20.2203(a)(2)(i)
El 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x) 0 20.2203(a)(2)(iii)
El 50.36(c)(2)
Dl 50.73(a)(2)(v)(A)
E 73.71(a)(4) 0 20.2203(a)(2)(iv) 0 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
Dl 50.73(a)(2)(v)(C)
E OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additionalcopies of NRC Form 366A) (17)
This event, which resulted in a valid actuation of the EDG and the EFW system, met the reporting criteria of 10 CFR 50.72(b)(3)(iv)(A) and 50.73(a)(2)(iv)(A). An eight-hour report (event #41428) was made at 0620 on February 22, 2005. This event is of regulatory significance because it resulted in the actuation of standby systems provided to mitigate the consequences of an accident.
This event had no adverse impact on the plant or on the health and safety of the public. The plant systems responded to the loss of power condition as designed, and no consequences resulted from this event. No inoperable structures, systems, or components contributed to the event. Following the event, however, TS 3.8.1.1, AC Sources, action a, with a 72-hour allowed outage time, was in effect for a loss of one of the two required AC sources until 1239 on February 22, 2005, when offsite power was restored to the emergency bus. Also, the shutdown of the turbine-driven EFW pump at 0337 rendered the pump inoperable due to the inability to align the pump for standby operation in the presence of a loss of power signal. This is an expected condition since the loss of power signal, which initiates EFW, remains active until offsite power is restored to the emergency bus.
Nonetheless, the pump remained functional and available for use until it was restored to operable status at 1235 on February 22, 2005.
IV. Corrective Action
Following the event, station personnel inspected the breakers that were racked to the connect position and open on the six 4,160 volt and 13,800 volt buses. The inspection concluded that the mechanical interlock mechanisms were properly engaged and would not prevent any additional breakers from closing.
The planned corrective actions for this condition include (1) revising the maintenance procedures for the 4,160 volt and 13,800 volt circuit breakers to specifically clean and lubricate the locking lever portion of the racking mechanism, (2) revising the operating procedures that direct breaker racking operations to confirm proper engagement of the mechanical interlock, (3) evaluating the scope and frequency of training on breaker racking operations, and (4) cleaning and inspecting the mechanical interlock mechanism on other breakers susceptible to the same malfunction to address the extent of condition.
Similar Events
This event was the first occurrence of a breaker failing to close on demand due to a malfunction of the breaker racking mechanism.