ML20140D274

Special Rept 85-015:on 851215,diesel Generator B Output Breaker Tripped on Reserve Power.Caused by Operator Error. Operator Reclosed Output Breaker & Successfully Paralleled & Loaded Unit

ML20140D274
Person / Time
Site:	Wolf Creek
Issue date:	01/14/1986
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
85-015, 85-15, KMLNRC-86-004, KMLNRC-86-4, NUDOCS 8601290243
Download: ML20140D274 (2)

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KANSAS GAS AND ELECTRIC COMPANY THE ELECTAsC COMPANY GLENN L MOESTEP.

VCE Passersv7 meVCLEAR January 14, 1986 R @ M Qu i' JAN I 7 S3G Mr. R. D. Martin, Regional Administrator j

'J.S. Nuclear Regulatory Commission Region IV --- J i

611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 KMLNRC 86-004 Re: Docket No. STN 50-482 Subj : Special Report 85-015

Dear Mr. Martin:

l The enclosed Special Report is submitted pursuant to Technical l Specifications 4.8.1.1.3 and 6.9.2. l l

Yours very truly, l Glenn L. Koester Vice President - Nuclear GLK:see Attachment xc: P0'Connor (2), w/a JCummins, w/a

-7 h[YO' 8601290243 860114 I g'k PDR ADOCK 05000482 /

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201 N. Market - Wichita, Kansas - Mail Address: PO. Box 208 i Wichita, Kansas 67201 - Telephene: Area Code (316) 261-6451

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e SPECIAL REPORT 85-015 DIESEL GENERATOR "B" INVALID FAILURE On December 15, 1985, an invalid failure of Diesel Generator (D/G) "B" occurred. This Special Report is being submitted pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2.

At approximately 0252 CST on December 15, 1985, D/G "B" was started in accordance with surveillance procedure STS KJ-005B, " Manual / Auto Start, Synchronization, and Loading of Emergency Diesel Generator NE02." The engine start met the acceptance criteria for a successful start, and personnel proceeded to parallel and load the unit onto the bus. However, the output breaker tripped on reserve power shortly after the unit was paralleled. The reverse power trip was the result of insufficient loading rate upon breaker closure, i.e. paralleling. The operator reclosed the output breaker, and successfully paralleled and loaded the unit at approximately 0312 CST.

Maintenance personnel subsequently confirmed that the output breaker trip was not due to an electrical or mechanical problem in the system. The engine was run loaded until 0412 CST, and secured at 0416 CST, with no further problems encountered.

The successful start followed by an unsuccessful loading attempt can definitely be attributed to operating error (insufficient loading rate) and therefore is considered a nonvalid failure per Regulatory Position C.2.e.(2) of Regulatory Guide 1.108, Revision 1.

At no time during this testing sequence was D/G "B" considered to be unavailable for service.

Including the events described in this report, there 'iave been sixteen (16) valid successful tests performed on D/G "B" since th completion of preoperational testing on D/G "B". D/G "B" has experienced six (6) invalid failures and zero valid failures. During this same time frame, there have been sixteen (16) valid successful tests on D/G "A". D/G "A" has experienced one valid failure and nine (9) invalid failures.

The invalid f ailure discussed in this report had no ef fect on the diesel generator testing frequency of once per thirty-one days. This is in conformance with the schedule presented in Regulatory Position C.2.d.(1) of Regulatory Guide 1.108 and with Technical Specification Table 4.8-1, which require the testing interval to be not more than thirty-one days if the number of valid failures in the last 100 valid tests is one or zero.