ML20132G887

Special Rept 85-07:on 850826,diesel Generator Failed to Come Up to Rated Voltage During Surveillance Test.Caused by Electrician Incorrectly Installing Relay Wiring.Relay Leads Landed Correctly.Electrician Counseled

ML20132G887
Person / Time
Site:	Callaway
Issue date:	09/23/1985
From:	Miltenberger S UNION ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
85-07, 85-7, ULNRC-1182, NUDOCS 8510010652
Download: ML20132G887 (4)

Text

s UNION ELECTRIC COMPANY Co% Plant September 23, 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-1182

Dear Mr. Keppler:

DOCKET NUMBER 50-483

, CALLAWAY PLANT UNIT 1 FACILITY OPERATING LICENSE NPF-30

! SPECIAL REPORT 85-07 DIESEL GENERATOR FAILURE DURING AN INVALID TEST The enclosed Special Report is submitted pursuant to 1

Technical Specifications 4.8.1.1.3 and 6.9.2 concerning a diesel generator failure during an invalid test.

=1 h S. E. Miltenberger Manager, Callaway Plant

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[ Enclosure

! cc: Distribution attached pgA*iM8%,33 s

Mailing Address RO. Box 620 Fulton,MO65251 9%

SEP 2 51985 i

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g cc distribution for ULNRC-1182 Mr. Tom Alexion Office of Nuclear Reactor Regulation U.~S. Nuclear. Regulatory Commission Mail Stop P-316' 7920 Norfolk Avenue Bethesda, MD 20014 American Nuclear Insurers e/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, CA 30339 Mr. Nicholas A. Petrick Executive Director, SNUPPS 5 Choke Cherry Road Rockville, Maryland 20850 Mr. J. H. Smith Bechtel Power Corporation SNUPPS Project 15740 Shady Grove Road Gaithersburg, Maryland 20877-1454 NR'C Resident Inspector D. F. Schnell J. F. McLaughlin J. E. Davis (Z40LER)

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

J. M. Price J. D. Blosser R.-A. McAleenan S. L. Auston (470)(NSRB)

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

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SPECIAL REPORT 85-07

. DIESEL GENERATOR FAILURE DURING AN INVALID TEST On 8/26/85 at approximately 1655 CDT, with the plant in Mode 1 at 100% power and normal operating temperature and pressure, diesel generator (D/G) 'A,' NE01, failed to come up to rated. voltage during the performance of surveillance procedure OSP-NE-00002, Standby D/G Periodic Tests. The unsuccessful start can definitely be attributed to operating error and is therefore not considered a valid test or failure. Starts 4 of the D/G's have been tracked since the completion of Preoperational Testing on 5/11/84. The starting history of the D/G's as of this report date is summarized as follows: ,

I No. of Failures No. of Failures D/G No. of Valid Tests During Valid Tests During Invalid Tests l

i A 23 1* 4#

B 20 0 Il

• Reference Special Report 84-02.

] # Reference Special Reports 85-01, 85-02, Land 85-07.

i $ Reference Special Report 85-05.

i D/G-' A' was being started to verify operability of the D/G af ter a maintenance outage which began at 0426 on 8/26/85. During the outage a relay in the Static Exciter Voltage Regulator for the D/G was replaced.

The relay provides a pulse kill contact to the pulse generator for.the generator. field power amplifier. During replacement of the relay, a lead was landed at an incorrect terminal. The incorrect wiring resulted i in a loss of power to the pulse generator for the power amplifier and thus left the generator with no excitation other than residual.

magnetism. The D/G subsequently failed to attain its rated voltage

! during the start attempt at'1655. The electrician's error in installing

} the relay ~ caused the unsuccessful start, therefore this.D/G start i attempt is not considered a valid test or failure as was stated above.

1 The relay leads were landed correctly and OSP-NE-00002 completed satisfactorily. The-D/G was declared operable at 2030 on~8/26/85 and thus had been out-of-service for approximately 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> due to the outage.

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The electrician'who replaced the relay thought he was familiar with the required work since he had previously replaced the corresponding

. relay for D/G 'B' correctly. Consequently, he failed to verify correct wiring of the relay, by comparison with the schematic diagram, as required by the work authorizing document. -Additionally, the electrician did not utilize good work practices-when he tagged the leads prior to removing them from the. original relay. He simply numbered them from left to right rather than match the tag numbers to 4 the terminal numbers on the relay. When he_relanded the leads, he had

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SPECIAL REPORT 85-07 Page 2 them in the correct s'equence (i.e., 1-3; but the terminal left vacated was the wrong one (the relay has ',ix terminals, five of which are used).

To prevent recurrence, the slectrician was counseled regarding his failure to properly follow proce3nres and informed that further errors of this type could lead to additional disciplinary actions. Also, a letter was sent to Maintenance Electrical Personnel emphasizing the need to carefully follow work instructions rather than relying on memory.

The letter also provided guidance on the proper methods for tagging terminations.

Surveillance tests are currently perfersed at least once per 31 days for each D/G. This is in conformance with the schedule of Regulatory Position C.2.d of Regulatory Guide 1.108, Revision 1, August 1977, and Technical Specification Table 4.8-1 which require the test interval to be not more than 31 days if the number of failures in the last 100 valid tests is one or zero.

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