05000296/LER-2004-001, Regarding Inoperability of Diesel Generator 3D Beyond TS Allowable Outage Time
| ML041260504 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/23/2004 |
| From: | Bhatnagar A Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 04-001-00 | |
| Download: ML041260504 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 2962004001R00 - NRC Website | |
text
April 23, 2004 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Mail Stop OWFN, P1-35 Washington, D. C. 20555-0001
Dear Sir:
TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT (BFN) -
UNIT 3 - DOCKET 50-296 - FACILITY OPERATING LICENSE DPR LICENSEE EVENT REPORT (LER) 50-296/2004-001-00 The enclosed report provides details of a failure to meet the requirements of a Technical Specifications Limiting Condition for Operation due to inoperability of Diesel Generator 3D.
In accordance with 10 CFR 50.73(a)(2)(i)(B), TVA is reporting this event as any operation or condition prohibited by the plants Technical Specifications. There are no commitments contained in this letter.
Sincerely, Original signed by Ashok S. Bhatnagar cc: See page 2
U.S. Nuclear Regulatory Commission Page 2 April 23, 2004 Enclosure cc (Enclosure):
(Via NRC Electronic Distribution)
Ms. Eva Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Stephen J. Cahill, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970
U.S. Nuclear Regulatory Commission Page 3 April 23, 2004 TEA:PSH:BAB Enclosure cc (Enclosure):
A. S. Bhatnagar, PAB 1B-BFN M. J. Burzynski, BR 4X-C M. D. Skaggs, POB 2C-BFN F. C. Mashburn, BR 4X-C D. F. Helms, LP 6A-C P. W. Wilson, PAB 1G-BFN K. W. Singer, LP 6A-C E. J. Vigluicci, ET 11A-K LEREvents@inpo.org NSRB Support, LP 5M-C EDMS-K s:\\licensing\\lic\\submit\\lers\\u3 ler 2004-01 R0a.doc
Abstract
On February 2, 2004, Diesel Generator (DG) 3D was declared inoperable and taken out of service for planned maintenance. On February 9, 2004, following successful completion of post-maintenance testing, the DG was returned to service and declared operable. On February 25, 2004, during performance of surveillance testing, the common accident portion of the DG output breaker control circuitry was found to be incapable of accomplishing its design function of tripping the breaker. Investigation determined that the problem with this circuit had been created during reinstallation of the breaker into its shutdown board compartment on February 9, 2004; therefore, the DG had been inoperable dating back to February 2, 2004.
This period of approximately 23 days exceeded the 14 days out-of service time allowed by the Technical Specifications (TS). In summary, a violation of the TS requirements commenced on February 16, 2004, when the allowable 14 day interval elapsed, and this condition was discovered on February 25, 2004.
The breaker was found misaligned in its compartment due to interference by a grounding device. The grounding devices will be inspected and those showing damage will be replaced with a more rugged design.
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
VII. ADDITIONAL INFORMATION
A.
Failed Components DG 3D output breaker 1836 ground contact device (Wyle/Siemens part 18-760-065-001)
B.
Previous LERs on Similar Events None C.
Additional Information
None D.
Safety System Functional Failure Consideration:
All aspects of DG 3D operation remained fully functional with the exception of the breaker trip/load resequencing which occurs following the initiation of an accident signal from Unit 2. The probability of an accident event on Unit 3, accompanied by a loss of offsite power necessitating DG operation, concurrent with a real or spurious accident on Unit 2 is very small; therefore, the probability of the loss of DG 3D through overloading as a result of this circuits malfunctioning is very small. In any case, the function of DG 3D and its supplied loads are also accomplished through the operation of redundant DGs 3A, 3B, and 3C and their supplied loads; therefore, no safety function was lost. This condition does not constitute a safety system functional failure as referenced in 10 CFR 50.73(a)(2)(v), and it will not be included in Performance Indicator reporting performed in accordance with NEI 99-02.
E.
Loss of Normal Heat Removal Consideration:
N/A This event did not involve a reactor scram.
VIII. COMMITMENTS
None