ML20083M620
| ML20083M620 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/08/1983 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML20083M623 | List:
|
| References | |
| NUDOCS 8302010394 | |
| Download: ML20083M620 (3) | |
Text
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S A N C LEMENT E. C A LIFOR NI A 92672 b[(p.
TELEPHONE H. B. R AY January 8,1983
-a " m *> m o sv Ar.o~ u A~ AoE a U.S. Nuclear Regulatory Comission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. R. H. Engelken, Regional Administrator
Dear Sir:
Subject:
Docket No. 50-361 30-Day Reports Licensee Event Report Nos.82-164 and 82-166 San Onofre Nuclear Generating Station, Unit 2
Reference:
Letter, H. B. Ray (SCE) to R. H. Engelken (NRC),
dated June 10,1982, " Licensee Event Report No.82-015" Pursuant to Section 6.9.1.13.b of Appendix A Technical Specifications to Facility Operating License NPF-10 for San Onofre Unit 2, this submittal provides the required 30-day written reports and copies of Licensee Event Reports (LER's) for two (2) occurrences involving Limiting Condition for Operation (LCO) 3.8.1.1 associated with A.C. Electrical Power Sources.
While in Mode 1, at 1940 on December 9,1982, the monthly surveillance testing for Diesel Generator 2G002 was in progress in accordance with procedure S023-3-3.23. As a result of failure of the generator to regulate at 60Hz, it was declared inoperable and LC0 3.8.1.1 Action Statements 'a' and 'c' were invoked. Action Statement 'a' requires
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verification of the operability of the remaining A.C. power sources within one hour and at least once per eight hours thereafter.
Action Statement 'c' requires verification of the operability of safety systems powered by the remaining operable diesel generator and, in addition, verification of the operability of the steam driven auxiliary feed pump within two hours.
Testing required by Action Statements 'a' and 'c' was accomplished as required, however, on the third test of Diesel Generator 2G003 per Action Statement 'a', the diesel generator operated for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 17 minutes and then tripped. The diesel generator was declared inoperable.
at 1200 on December 10,1982, and LC0 3.8.1.1 Action Statement 'e' was invoked. This Action Statement requires verification of the operability of two off-site A.C. power sources and restoration of at least one diesel generator within two hours.
8302010394 830108 PDR ADOCK 05000361 N-n g
PDR 3 5 -1 5
Mr. R. H. Engelken January 8,1983 Action Statement 'e' was satisfied at 1225 when 2G002 was restored to operable status in accordance with S023-3-3.23. Action Statements.'a' and 'c' became governing once again and 'all requirements were satisfac-torily met.
Diesel Generator 2G003 was declared operable in accordance with S023-3-3.23 at 1915 on December 11, 1982.
Investigation revealed that in both events the problem was attributable to the electrical governor.
Corrective action included replacement of the governor on 2G003 and the governor power supplies on both diesel generators. Additional corrective action to prevent recurrence will include installation of power supplies of a different design not suscep-tible to this type of failure on all four diesel generators of Units 2 and 3.
LER's82-164 and 82-166 address these events, respectively.
Technical Specification 4.8.1.1.3 requires that additional information be provided for the failure of Diesel Generator 2G002 as determined by Regulatory Position C.2.e of Regulatory Guide 1.108.
This information is provided below.
The tripping of Diesel Generator 2G003 is not con-sidered a failure as defined in Regulatory Position C.2.e.(3) since the diesel generator ran for "at least one hour."
The following information is provided in accordance with the requirements of Regulatory Position C.3.b of Regulatory Guide 1.108:
1.
The diesel generator involved was 2G002.
2.
This was the second failure of a diesel generator of the same design and size in the last 45 tests at this plant.
(See the referenced letter for information regarding the first failure.)
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3.
The cause of the failure is discussed above.
1 4.
The corrective measures taken are discussed above.
2 I
5.
The length of time 2G002 was not available for service was 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />
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and 25 minutes (1940 on December 9,1982, to 1225 on December 10, 1982).
6.
The current test interval is 14 days, per Table 4.8-1 of the Technical Specifications.
7.
This test interval is in conformance with the schedule of Position C.2.d. of Regulatory Guide 1.108.
Since the diesel generators in both cases could have operated on the mechanical governor had there been a loss of off-site power, there was no impact on plant operation or the health and safety of plant persranel l
or the public.
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If there are any questions regarding the above, please contact me.
l Sincerely, l
HS h / % vs
Enclosures:
LER's82-164 and 82-166
Mr. R. H. Engelken January 8, 1983 cc:
A. Chaffee (USNRC Resident Inspector, San Onofre, Units 2 and 3)
R. Pate (USNRC Resident Inspector, San Onofre, Units 2 and 3)
U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Office of Management Information and Program Control Institute of Nuclear Power Operations (INFO) l 1
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