ML20111C800

Special Rept 85-01:on 850129,two Invalid Failures of Diesel Generator a Occurred.Caused by Operator Error During Installation of Transfer Switch.Appropriate Personnel Counseled

ML20111C800
Person / Time
Site:	Callaway
Issue date:	02/28/1985
From:	Miltenberger S UNION ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
85-01, 85-1, ULNRC-1048, NUDOCS 8503150542
Download: ML20111C800 (4)

Text

_ , h/W UNION Ei_ecTmc COMPANY CALLAWAY PLANT M A# LING ADDRESS:

P. O. SOM 8 20 FULTO N. MO. 6 5 2 51 February 28, 1985 Mr. James G. Keppler Regional Administrator Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 ULNRC-1048

Dear Mr. Keppler:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 85-01 DIESEL GENERATOR INVALID FAILURES The enclosed Special Report is submitted pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2 concerning two invalid failures of a diesel geserator.

' L S. E. Miltenberger Manager, Callaway Plant WRC/WRR/JWK/drs Enclosure ec: Distribution attached l

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i cc distribution for ULNRC-1048 i American Nuclear Insurers c/o Dottie Sherman, Library The Exchange Suite 245

270 Farmington Avenue Farmington, CT 06032 Records Center

. Institute of Nuclear Power Operations Suite 1500 1100 circle 75 Parkway

• Atlanta, GA 30339 NRC Resident' Inspector Missouri Public Service Commission D. F. Schnell J. F. McLaughlin J. E. Davis (Z40SR)

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D. W. Capone /R P. Wendling F. D. Field R. L. Powers A. C. Passwater/D. E. Shafer/D. J. Walker G. A. Hughes W. R. Robinson (QA Record)

W. R. Campbell G. L. Randolph J. M. Price R. A. McAleenan L. K.'Robertson (470)(NSRB)

Merlin Williams, Wolf Creek l SEM Chrono 3456-0021.6 3456-0260 Z40ULNRC G56.37 N. Date

'l 1

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y SPECIAL REPORT 85-01 DIESEL GENERATOR? INVALID FAILURES on 1/29/85 two invalid failures of diesel generator (D/G) "A,"

NE01, occurred while performing' operations surveillance procedure OSP-SA-0017A~ Train A Safety Injection Signal / Containment Spray

.Actuatien Signal (SIS /CSAS). Slave Relay Test. Both unsuccessful. start and~1oad attempts can definitely be attributed to operating error.and are therefore not considered valid tests or failures. Starts of the' diesel generators have-been tracked since the completion of Preoperational Testing on 5/11/84.. Between.5/11/84 and 1/30/85 there were thirteen valid tests of D/G "A" with-one valid failure. The failures on 1/29/85 are the first two invalid failures of D/G "A."

A planned outage of D/G "A" began at 0510 CST on 1/28/85 so that

'various work requests and preventive maintenance tasks associated with the Standby Generation System could be performed. A voltage regulator.

transfer switch was replaced in the generator control. panel at 2330 on 1/28/85 as part of the outage.

At 1643 on 1/29/85, in conjunction with the D/G operability testing, the performance of OSP-SA-0017A was authorized. Tested by'this procedure is the Train A SI Slave Relay which, when actuated, starts D/G "A." Procedure OSP-NE-A0001, Diesel Generator Operability Test, was also to be satisfied by the start per OSP-SA-0017A~to verify operability of the D/G after the outage. At approximately 1936 D/G "A" started on a valid start signal from the SI Slave Relay but subsequently tripped out on cverspeed. In preparation for'an eventual restart of the engine..the operator pressed the engine reset button. With the start signal still present from the SI Slave Relay, the engine'again started and tripped out on overspeed. The normal operating engine speed is 514 r.p.m. It was noted by the operator that engine speed was in excess of 550.r.p.m.

Therefore the overspeed trip was valid and not the result of a spurious electronic signal.

Troubleshooting to determine the cause of the. trip was initiated under a generic work request. The investigation found that the: transfer switch which had been installed during the outage had=not been wired correctly. " Shorting bars" had not been installed which made the Static Exciter Voltage Regulator (SEVR) inoperable. The failure of the SEVR in-turn rendered the electric governor inoperable thus allowing an excess'ive engine speed'and causing the overspeed trip. These failures-are therefore' attributed to operator error during.the installation of the transfer. switch and are not considered valid tests or failures.

The " shorting bars" were installed and OSP-NE-A0001'was completed

, satisfactorily.at 0334 on 1/30/85. D/G "A" was declared operable and returned to service at 0340 The D/G was unavailable for-approximatelyl 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br /> due to the outage. Approximately 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> elapsed-from the time the' switch was incorrectly installed until'the D/G was declared operable. The applicable Technical Specification requirements which verify the, operability of the~ remaining AC electrical' power sou'rces were satisfied during L the course of_the outage.

3lP A

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SPECIAL REPORT.85-01 Page 2 The omission of the " shorting bars" during the installation of the

-transfer switch was pointed out to engineers, planners,_and maintenance personnel with an emphasis on ensuring that work packages fully identify the parts and assembly steps necessary to complete an installation.

This error is considered an isolated case for which no further corrective action is deemed necessary.

Sucveillance tests are currently performed at-least one per'31 days. This is in conformance with the schedule of Regulatory _ Position C.2.d which requires the test interval to be not more than.31 days if the number of failure in the last 100 valid tests is one or zero.