ML20029C152
| ML20029C152 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 03/21/1991 |
| From: | Woodard J ALABAMA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9103260302 | |
| Download: ML20029C152 (3) | |
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/\\l[](){][))[] }\\)n'Of vee eiesda-Ngem March i1,1991 Fen m'n*orowm ra*y Pro i 10CFR50.36 Docket Nos. 50 348 50-364 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Joseph M. Farley Nuclear Plant Annual Diesel Generator Reliability Data Report Gentlemen:
Attached is the Annual Diesel Generator Reliability Data Report'which is submitted in.accordance with Technical Specification 6.9.1.12.
This report
- provides the number of tests (valid or invalid) and the number of failures for each dir.sel generator at Farley Nuclear Plant for 1990. Also provided is the information identified in Regulatery' Position C.3.b of Regulatory Guide 1.108, Revision 1, 1977, for each failure.
i Respectfully submitted, ALABAMA POWER COMPANY D
dxD.Woodard
-JDW/DRC:maf 12.78 Attachment
- xc: Mr. S. D. Ebneter Mr. S.-T. Hoffman
-Mr. G. F. Maxwell I
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ANNUAL DIESEL GENERATOR RELIABILITY DATA REQET FOR 129Q This diesel generator (DG) reliability report for the year 1990 is submitted in accordance with Technical Specification 6.9.1.12.
The table below shows the number of tests (valid or invalid) and the number of failures for each of the five DGs at f arley Nuclear Plant.
TABLE Diesei Generator 1-2A 18 2B IC 2C Total Valid Successful 36 42 39 37 34 188 Tests invalid Tests 17 17 21 20 11 86 Valid failures 0
0 2
0 0
2 Invalid failures 0
0 0
0 0
0 The following paragraphs provide the information required by Regulatory Position C.3.b of Regulatery Guide 1.108, Revision 1, 1977 for the valid failures identified above.
2B DG Failure on 07/09/90 At 1449 on 07/09/90, during a surveillance test, the 28 DG tripped.
The trip occurred while swapping lubricating oil strainers.
During the surveillance, a high pressure differential was noted across the on-service set of lubricating oil strainers which indicated that the strainer 3 were becoming clogged.
(There are two sets of strainers in parallel.) The standby :,et of strainers was placed in service and the on-service set was cleaned, placed back in the strainer housing, and vented.
However, it appears that the venting was not done adequately because when the operator switched back to the normal on-service set of strainers, oil pressure dropped momentarily and the DG tripped on low lubricating oil pressure.
l Following an inspection of the DG and the oil strainers, the DG was tested successfully.
The 2B DG was returned to service at 0140 on 07/10/90.
The procedure for swapping the lubricating oil strainers (FNP 0 SOP-38.2) has been revised to provide additional guidance.
This was the first failure in the last 100 valid starts for this type of DG, No change in the surveillance schedule was necessary.
The surveillance schedule remained at 14 days in accordance with Technical l
Specifications.
l l
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V. S. Nuclear Regulatory Commission Page 2 2B DG Failure on 11/26/90 At 0215 on 11/26/90, during a refueling outage, the EB DG was started for normal surveillance.
The lubricating oil pressure, which normally reaches between 95 and 100 psi, reached only approximately 54 psi.
The lubricating oil strainers were swapped but the DG tripped due to low lubricating oil pressure. The low lube oil pressure was caused by swapping to a set of clogged strainers. The strainers were replaced and the DG was restarted with no problems.
Lubricating oil pressure was normal.
The DG was returned to service at 0707 on 11/26/90.
Investigation showed that both sets of strainers were clogged. A failed differential pressure gauge caused some confusion concerning when the strainers were clogged and needed to be cleaned. To improve awareness of the status of diesel generator lube oil strainers serial numbers have been placed on each strainer.
FNP 0-S0P 38.2 has been revised to require recording strainer serial numbers when they are installed or removed. This revision will assist operators in determining an expected frequency of strainer cleaning so that clogging may be prevented.
The strainer differential pressure gauges will be added to the Preventive Maintenance Program.
This was the second failure in the last 100 valid starts for this type of DG. No change in the surveillance schedule was necessary.
The surveillance schedule remained at 14 days in accordance with Technical Specifications.
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