ML20065R840

Forwards Rept Re One Valid Test Failure Experienced on Diesel Generator,Per NUREG-1276

ML20065R840
Person / Time
Site:	Braidwood
Issue date:	12/13/1990
From:	Checca A COMMONWEALTH EDISON CO.
To:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
RTR-NUREG-1276 NUDOCS 9012190193
Download: ML20065R840 (2)

Text

. . . . . , . - - . - -. . . ~ ~ .~ - _ - . - - - - . . - . . . -

.c

$y4 pC D g Cammenwealth Edisen PaloRIty ReutIts 4.;y1400 Opus Place Downers Grove, Illinois 60515 g %d .

i ;.g.

5 O nlGr e ; z Ib- k "~

$$~IEi ~

December 13, 1990 Z .

13 (1LL %

Mr. A, Bert Davis Regional-Administrator

U.S. Nuclear Regulatory Co mission Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Braidwood Station Unit 2 k Diesel Generator 2DG01KA Failures HRC_Dochel lo J D-457

Reference:

(a) NUREG-1276, Technical Specification (b) June 8, 1990, S.C. Hunsader letter to A.B. Davis p

Dear Mr. Davis:

Section 4.8.1.i.3 of reference'(a) requires that all diesel generator failures, valid or nor.-valid, be reported to the NRC pursuant to Specification 6.9.2, The enclosurt provides the report that addresses one valid' test failure experienced on diesel generator 2DG01KA. The criteria used to determine' valid tests and failures is taken from section C.2.e of Regulatory

.Guid 1.108.

Reference-(b)~is the'most recent. report addressing diesel generator

. failures, submitted per Section 4.8.1.1.3.

Please direct any questions concerning this submittal to this office.

. Very Trul yours, e

. A.R. Checca Nuclear Licensing. Administrator cc: R. Pulsifer-NRR 4 H. Shafer-RIII-

. Resident Inspector-Braidwood 1- NRC Document Control-Desk i i ZNLD:672:rg E 14 9012190193 901213 1

[ 7" [^f y

• opR' i _

}Ee]( ' j

9 a

2A DG FAILURE REPORT At 0814 on November 14, 1990, the 2A Diesel Generator (DG) was started to ~ perform its monthly operability surveillance, 2Bw05 8.1.1.2.a-1.

During the timing of_the start, it was noted that the voltage indication on the local control panel and the frequency indication on the main control room panel appeared to be erroneous. The DG was shut down seventeen seconds into the run.

Subsequently all the fuses in the indication and control circuitry were checked. All the fuses appeared to be good. At 1035 a maintenance /

troubleshooting run was performed. At this time, all indications appeared normal. A nuclear work request was generated to determine the cause of the failure. Later, while troubleshooting, one of the fuses on the secondary side of the potential transformer was found to be open. It was discovered that the fuse had failed in an intermittent manner. Tne bad fuse was replaced.

At 0227 on November 15, 1990, a maintenance run was performed.

Voltage and frequency indications appeared normal, The 2A DG was loaded to 1500 kw to verify proper control. All controls operated properly. The DG was unloaded and shutdown normally.

The 2A DG was started for its operability surveillance. The one hour run at 25500 kw was completed at 1122 on November 15, 1990. The 2A DG was shutdown at 1134 and declared operable at 1230 on November 15, 1990.

The failure of the 2A DG has been determined to be-valid in accordance with Regulatory Guide 1.108. This failure is the second valid failure in the last fourteen valid tests. The 2A DG has been placed on an increased surveillance frequency per Technical Specification table 4.8-1, Pursuant to Regulatory Guide 1.108, position C.3.6.7, as of November 15, 1990, the 2A DG has had four' valid failures and the 2B DG has had one valid failure in the last 100 Unit 2 valid DG starts.

l' l

f.-

~

ZNLD:672:rg

_ _ , . _ _ ,. . _ - _ . _ __ _ _. .