ML17303B003

Special Rept 1-SR-88-003:on 880304,output Breaker on Diesel Generator B Did Not Close Properly During Surveillance Testing.Cause Undetermined.Evaluation Initiated to Determine Cause of Improper Breaker Operation

ML17303B003
Person / Time
Site:	Palo Verde
Issue date:	04/04/1988
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
1-SR-88-003, 1-SR-88-3, 192-00358-JGH-T, 192-358-JGH-T, NUDOCS 8804120437
Download: ML17303B003 (7)

Text

REGUL i INFORMATION DISTRIBUTI STEM (RIDS)

C ACCESSION NBR: 8804120437 DOC. DATE: 88/04/04 NOTARIZED: NQ DOCH,E (

FACIL: STN-50-.528 Palo Verde Nuclear Stations Unit 1i Arizona Publi 05000528 AUTH. NAME *UTHOR AFFILIATION HAYNES'. G. Arizona Nuclear Power Prospect (formerly Arizona Public Ser~

RECIP. NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Spec ial Repti-SR-88-003: on 880304. output breaker on Unit "B" diesel generator 1

did not close properly during surveillance testing. Cause initiated. Approved work document to troubleshoot cause oW breaker malfunction initiated.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER) ~ Incident Rpti etc.

NOTES: Standardi zed p lani. 050005". (;,

RECIPIENT COPIES RECIPIENT COPIES ID CODE/M*ME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 PD5 PD 1 1 LICITRAr E 1 1 DAVIS' 1 1 INTERNAL: *CRS MICHELSQN 1 1 ACRS MOELLER 2 2 AEOD/DOA 4 J AEOD/DSP/NAS 1 1 AEOD/DSP/RQAB 2 2 AEOD/DSP/TP*B 1 1 ARM/DCTS/D*B 1 DEDRO 1 NRR/DEST/ADS 7E .1 0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ I CSB 7 1 NRR/DEST/MEB 9H 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEBT/RSB 8E 1 NRR/DEBT/SGB 8D 1 1 NRR/DLPG/HFB 10 1 1 NRR /DLP G/GAB 10 1 1 NRR/DOEA/EAB 11 1 NRR/DREP /RAB 10 1 1 NRR/DREP/RPB 10 2 2 D I B 9A 1 1 NRR/PMAS/ ILRB12 1 1 REG FIL - 02 2 1 RES TELFORD> J 1 E/EIB 1 RES/DRPS DIR 1 1 RGN5 FILE 01 I 1 EXTERNAL: EG,'G GROH, M 4 FORD BLDG HOYLE A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC H*RRISi J 1 1 NSI C MAYS) G 1 1 NOTES:

TOTAL NUMBER OF COPIES REQUIRED: LTTR 47 ENCL 46

Arizona Nuclear Power Project P.O. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00358-JGH/TDS/DAJ April 4, 1988 U. S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528 (License No. NPF-41)

Special Report 1-SR-88-003 File: 88-020-404 Attached please find Special Report 1-SR-88-003 prepared and submitted pursuant to Technical Specification 4.8. 1. 1.3 and Technical Specification 6.9.2. This report discusses a valid emergency diesel generator fai lure.

If you have any questions, please contact T. D. Shriver, Compliance Manager at (602) 393-2521.

Very truly yours, J. G. Haynes Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment cc: 0. H. DeNichele (all w/a)

E. E. Van Brunt, Jr.

J. B. ltartin T. J. Polich E. A. Licitra A. C. Gehr INPO Records Center 8804i20437 88040405000528 PDR ADOCK 8

r

PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Valid Diesel Generator Failure on Harch 4, 1988 Docket No. 50-528 License No. NPF-41 Special Report 1-SR-88-003 This Special Report describes an event involving a valid failure of an Emergency Diesel Generator. The report is provided pursuant to Technical Specifications 4.8. 1. 1.3 and 6.9.2 and contains the information recommended in Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977.

At approximately 0120 HST on Harch 4, 1988 Palo Verde Unit 1 was in Hode 3 (HOT STANDBY) when an output breaker on the Unit 1 "B" Diesel Generator did not close properly during surveillance testing. Subsequent attempts were unsuccessful in closing the breaker and the diesel generator was declared inoperable at approximately 0135 HST. As a result of the "B" Diesel Generator inoperability, the appropriate activities were initiated to comply with Technical Specification ACTION requirement 3.8.1. 1(b).

On Harch 4, 1988, surveillance testing was being conducted in accordance with approved procedures pursuant to Technical Specification 4.8. 1. 1.2 for demonstrating "B" Diesel Generator oper ability. The diesel generator was being tested on a monthly (i.e. once per 31 days) basis. At approximately 0120 HST, the "B" Emergency Diesel Generator was started in accordance with approved surveillance testing procedures. No problems were noted during the diesel generator start. While initially attempting to parallel the generator with the normal, off-site power supply, the output breaker would not close.

Subsequent attempts were unsuccessful in closing the breaker.

As immediate corrective action, an approved work document to troubleshoot the cause of the breaker malfunction was initiated. During the troubleshooting, the breaker was placed in the "Test" mode. On the first attempt to close the breaker while in the "Test" mode, the breaker operated properly. The breaker was then placed in the "normal" position and the breaker operated properly.

After the breaker was observed to operate properly, the emergency diesel was loaded and the remaining portions of the surveillance test completed successfully. Emergency Diesel Generator "B" was then declared operable at approximately 0622 HST. The diesel generator was unavailable for approximately five (5) hours.

After the diesel generator was returned to operability, an approved work document was initiated to perform a routine maintenance activity on the breaker. During the performance of the breaker maintenance, no discrepancies were identified and only minor (i.e. no affect on breaker operability) adjustments were necessary. A functional test of the breaker was then performed and no deficiencies were noted.

I Special Report 1-SR-88-003 Page 2 A root cause of failure engineering evaluation has been initiated to determine the cause of the improper breaker operation and the corrective actions to prevent recurrence. Additional corrective measures will be taken, as necessary, based upon the results of the root cause determination.

The emergency diesel failure described herein is the second (2) failure in the last 100 tests and the first (1) failure in the last twenty (20) tests on the "B" Diesel generator. Additionally, the number of failures in the last 100 diesel generator tests for Unit 1 is less than seven. Pursuant to Technical Specification 4.8. 1. 1.2, the current surveillance test interval (once per 31 days) will be continued.

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