ELV-02753, Special Rept Re Listed Invalid Diesel Generator Failures. Causes & Corrective Actions Listed

Special Rept Re Listed Invalid Diesel Generator Failures. Causes & Corrective Actions Listed

ML20077E600
Person / Time
Site:	Vogtle
Issue date:	06/04/1991
From:	Mccoy C GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ELV-02753, ELV-2753, NUDOCS 9106110094
Download: ML20077E600 (5)

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. - n. 4 V,,,e il e1 "C r u ,, . 2ew ,..m June 4, 1991 ELV-02753 0944 Docket Nas. 50-424 50-425 U S. Nuclear Regulatory Commission AlIN: Document Control Desk Washington, D. C. 20555 Gentleren:

V0GTLE ELECTRIC GENERATING PLANT SPECIAL REPORT 11LV.AllD QlESEL GENERATOR FAILURES As a result of discussions with NRC Region 11 personnel during the inspection of August 6 through 17, 1990 and telephone conversations subsequent to the inspection, Georgia Power Company is submitting this Special Report describing several Diesel Generator (DG) trips and shutdowns. During the referenced discussions, Vogtle Electric Generating Plant (VEGP) personnel were advised that start and load attempts that were tianually aborted, evt.n though the reason for stopping the DG would not have prevented the DG from performing its safety function, should be considered to be reportable as invalid failures pursuant to Regulatory Guide 1.108. Furthermore, problems occurring during inaintenance or troubleshooting activities may also be reportable as invalid failures. In light of this new interpretatuon, VEGP has reviewed the records of DG start and load attempts for Plant Vogtle and the events described in the enclosure were reclassified as invalid failures, in the future, VEGP will abide by the above interpretation of Regulatory Guide 1.108 when making reportability determinations.

Sincerely, C. K. McCoy CKM/NJS/gmb

Enclosure:

Special Report 1-91-1 xc: Georaia Power Company Mr. W. B. Shipman Mr. P. D. Rushton Mr. S. H. Chesnut NORMS U. S. Nuclear Reaulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. D. S. Hood, Licensing Project Manager, NRR Mr. B. R. Bonser, Senior Resident inspector, Vogtle ~,

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V0GTLE ELECTRIC GENERATING PLANT - UNITS 1 & 2 TECHNICAL SPECIFICATION SPECIAL REPORT l 31-1 DIESEL GENERATOR INVAllD FAILURES A. DESCRIPTION OF DIESEL GENERATOR (DG) INVALID FAILURES Dalf QESCRIPTION ACTION TAKEN

1. 8-17-88 DG 1B was manually unloaded due to a grid The test run was fluctuation which caused an uncontrolled completed, increase in output. The DG was left running until the grid frequency returned to 60 Hz when the test run was completed.

This was not considered a failure because the DG ra, continuously even though the test itself was interrupted.

2. 3-15-89 DG 1A tripped because a barring device The lockout pin was lockout pin was improperly installed reinstalled and the by the operator and vibrated loose. test was rerun.

This was an invalid failure because it can be attributed to operator error.

3. 5-24-89 DG 18 was manually stopped after an air The gasket was leak was found at the turbocharger to replaced and the intercooler gasket. This was not test was rerun.

! considered a failure because the decision

! to stop was optional and DG operation in the emergency or normal modes was not affected.

4. 5-31-89 DG 2B was manually stopped as a The DG was restarted precautionary step after a minor lube and the test was oil leak was found on the lube oil completed. The leak heat exchanger. The leak was not was later repaired.

sufficient to cause an operability concern. This was not considered a failure because the decision to stop was optional and operation in the

' emergency or normal modes was not affected, l

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TECHNICAL SPECIflCATION SPECIAL REPORT l-91-1 (CONTINUED)

DIESEL GENERATOR INVAllD FAILURES Qal[ QfSCRIPTION ACTION TAKEN 5, 8-26-89 DG IB was manually stopped after The DG was restarted receiving spurious alarms associated and the test was with control air charging on the DG completed, start. These alarms can be expected following maintenance in which the control air system is depressurized.

Had the operator not stopped the engine prematurely, the alarms should have cleared automatically. An inspection confirmed there were no problems and the engine was restarted approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> later without alarms. This was not considered a failure because the decision to stop was optional and emergency operation would not have been affected.

6. 8-20-89 DG 1A was manually stopped when operators NSCW was restored realized that the Nuclear Service and the test was Cooling Water System (NSCW) (which rerun, supplies cooling water for the jacket water coolirg system) was out of service, This was not considered to be reportable because the DG should not have been started while NSCW was out of service.

7. 8-20-89 DG 1A was manually stopped when a The alarm was reset spurious alarm for high jacket water and the test was temperature occurred. This alarm, which completed normally.

is generated from thermocouples, should have cleared had the DG not been manually stopped. No problem was found and the DG was restarted. The decision to stop was optional sud emergency operation would not have oeen affected.

8. 7-19-90 DG IB was manually stopped twice due to The voltage re'-tive power swings at 100% load, regulator was altnough no swings were observed at replaced and the expected emergency load 1 vels. The DG test was rerun.

was )ut of service due '. 2nother fatiore and, since troubleshooting was in progress, this was not considered to be rennrt able.

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TECHNICAL SPECIFICATION SPECIAL REPORT l-91-1 (CONTINUED)

DIESEL GENERATOR INVAllD FAILURES

8. OTHER DG INVAllD FAILURES Other invalid failures of DGlB, as listed below, occurred during troubleshootirg following the 3-20-90 Site Area Emergency. Although these were listed in correspondence #ELV-02059, dated 8-30-90, they were not identified as invalid failures. These failures were not considered reportable because the tests were performed prior to the diesel being declared operable following an engine disassembly, inspection and instrument calibration procedure during the refueling outage. Since these problems are a direct result of calibration techniques performed during the outage, the initial runs were considered to be component functinnal tests only and not reportable.

QAlf DESCRIPTION 6LJ10N TAKEN

1. 3-21-90 DG 1B tripped twice due to a lack of The fuel lines fuel in the fuel lines followino an were primed and 18 month overhaul, the DG was restarted.

2. 3-21-90 DG 1B was started after priming the The governor was fuel lines for the purpose of vented and the DG adjusting the governor. This run was manually was conservatively classified as an stopped after invalid failure even though the approximately 15 process of adjusting the governor minutes.

is considered to be a normal post-maintenance evolution.

3. 3-21-90 DG 1B was manually stopped twice after The alarms cleared receiving spurious alarms upon starting. and the DG was This was attributed to operator error restarted.

in that these alarms should have cleared shortly after starting.

4. 3-22-90 DG 18 tripped on high lube oil The switch was temperature due to a switch which was recalibrated and out of calibration, rather than there the test was rerun, being an actual high temperature condition.

5. 3-23-90 DG 1B tripped on low jacket '.ater The alarm cleared pressure shortly after the t<.,, circuit's and the DG ran 60 second lockout period had c.pired. successfully.

Troubleshooting found no cause.

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1 TECHNICAL SPECiflCATION SPECIAL REPORT l-91-1 (CONTINUED)

DIESEL GENERATOR INVAllD FAILURES DATI DESCRIPTION ACTION TAKEli

6. 3-24-90 DG IB was manually stopped after The alarm was receiving a high jacket water temperature cleared and the trip alarm and the engine continued DG was rerun running. No cause for the trip signal successfully, could be found.

C.

SUMMARY

Because these tests were invalid failures, there is no effect on the surveillance testing frequency of each of the DG's involved. Additionally, because these failures occurred during maintenance and testing procedures, the availability of the DG for emergency use was not affected by the ,

failures.

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