ML20082T115
| ML20082T115 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/12/1991 |
| From: | Blosser J UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| ULNRC-2480, NUDOCS 9109180109 | |
| Download: ML20082T115 (4) | |
Text
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UNION Euronuc
?E CaMaway PlaM September 12, 1991 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 ULNRC-2420 Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 FACILITY OPERATINC LICENSE NPF-30 S?ECIAL REPORT 91-02 VALID DIESEL GENERATOR FAILURE DUE TO GOVERNOR ACTUATOR FAILURE This Special Report is being subm*.tted pursuant to Technical Specification (T/S) 4.8.1.1.3 and 6,9.2 concerning 1.he valid failure of Diesel Generator (D/G)
'A' due to a governor actuator failing during a one hour load run test.
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[e J. D. Blos r Manager, Callaway Plant res JDB/TPS/MKD/lrj Enclo ure cc: Distribution attached l
9109180109 910w 2 POR ADOCK 05000483 g
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Mak1g Aadress' P.O. Box 62C, Fulton, MO 65251
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cc distribution for ULNRC 2480
..Mr.iAc Bert-Davis-Mr. M. David Lynch (2 copies)
Regiona1' Administrator
-U.S. Nuclear Regulatory Commission
- Region 111L OWFN - Mail Stop113E21-U.S; Nuclear Regulatory Commission.
t Wachington, D.C, 20555' 4
-799 Roosevelt Road Glen Ellyn,LIL. 60137
. Manager,-Electric Department Mr. Harold K. Chernoff
. Missouri Public Service Commission Supervisor Licensing
.P.O. Box 360 Wolf Creek Nuclear Operating Corp.
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Jefferson City, MO 65102 P. O. Box 411 Burlington, KS 66839 L
Records Center Mr. R. L. Hague i
Institute of Nuclear Power Operations Chief, Froject Section 3C Suite 1500 U.S. Nuclear Regulatory Commission 1100 Circle.75 Parkway Region III
-i Atlanta, CA'30339 799 Roosevelt Road l
Clon Ellyn, IL 60137
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NRC Senior Resident Inspector
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e SPECIAL REPORT 91-02 VALID DIESEL GENERATOR FAILURE DUE TO GOVERNOR ACTUATOR FAILURE On 8/14/91, at 0354 CDT, Emergency Diesel Generator (D/G)
'A' failed during a one hour load run test due to a component failure. This was a valid failure which is reported per Technical Specification (T/S) 4.8.1.1.3.
At 0215 CDT, on 8/14/91, following routine maintenance including replacement of a crankcase vacuum hose, a post-maintenance run on the
'A' D/G was completed satisfactory. At 0301, the D/G was started again in accordar.e with procedure OSP-NE.00002, Standby Diesel Generator Periodic Tests, for the one hour full load run test per 1/S surveillance 4.8.1.1.2.a.5. At 0354, the
'A' D/G tripped and the generator output breaker opened.
The cause of this inability to maintain the load run for an hour is attributed to the failure of the D/G governor actuator (Woodward model
- EG.B50). The failure causid the governor to stop the surply of fuel to the engine. The engine coasted down and the output breaker tripped on reverse power.
The failed governor was sent to the D/G vendor (Colt) for evaluation.
Corrective actions to prevent recurrence are pending the results of this evaluation. The governor was replaced, tested, and the D/G was declared operable at 0550 on 8/15/91, following a successful one hour load run. A review of site operational and industry experience, contacts with other utilities using similar units and the diesel vendor indicate that this type of failure is an isolated occurrence, Regulatory Position C.2.e(3) of Regulatory Guide 1.108, Revision 1, August 1977, states: " Successful starts,...followed by successful loading (sequential or manual) to at least 50% of continuous rating and continued operation for at least one hour should be considered valid successful tests." Since D/G
'A' was cuccessfully started and loaded, this was a valid test. However, since the D/G did not complete the one hour run, this was a valid failure.
A starting history of D/G
'A' as of this report date is summariced as follows:
No. of No. of Failures No. of Failures Valid Tests During Valid Tests During Invalid Tests 131 5*@
7#
- Special Reports 84 02, 87-10 & 89 03, LER 87-002-00
@ Four failures in the last 100 valid tests. One failure in the last 20 valid tests.
- Special Reports 85 01, 85 02, 85-07, 86-01, 89 02, 89-07, 90-01 6
e Page 2 Special Report 91-02 Surveillance tests are currently performed at least once per 31 days for D/G 'A*
This is in conformance with the schedule in T/S Table 4.B-1 which requires a test interval of not more than 31 days if the number of failures in the last 20 valid tests is one or less, or the number of failures in the last 100 valid tes ; is four or less.
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