ML20215N871

Special Rept 86-10:on 861007,diesel Generator 2A Valid Test Failed to Achieve Rated Speed in 10 S.Caused by Malfunctioning Switching Tachometer.Tachometer Replaced & Diesel Retested Successfully

ML20215N871
Person / Time
Site:	Salem
Issue date:	10/31/1986
From:	Zupko J Public Service Enterprise Group
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
86-10, NUDOCS 8611100011
Download: ML20215N871 (3)

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aPSEG Public Service Electnc and Gas Company P.O. Box E Hancocks Bndge. New Jersey 08038 Salem Generating Station October 31, 1986 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 REPORT 86-10 SPECIAL REPORT This Special Report describcs a valid test failure of No. 2A Diesel Generator on October 7, 1986. This report is being submitted pursuant to the requirements of Technical Specification Surveillance 4.8.1.1.4.

Sincerely yours, t V

( J .' H . Zupko, Jr.

General Manager-Salem Operations MJP:pc Distribution 8611100011 861031 PDR ADOCK 05000311 S PDR The Energy People ff3%

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~& p, SPECIAL REPORT NUMBER 86-10 PLANT IDENTIFICATION:

Salem-Generating Station - Unit 2 Public. Service Electric & Gas Company H2ncock's Bridge, New. Jersey 08038 IDENTIFICATION OF OCCURRENCE:

2A Diesel Generator Valid Test Failure - Failure To Achieve Rated-Speed In Less:Than Or Equal To 10 Seconds Event Date: 10/07/86 Report Date -10/31/86 This report was initiated by Incident, Report No. 86-326-CONDITIONS PRIOR TO OCCURRENCE:

Mode 5 . Reactor Power On - Unit '.oad 0 MWe DESCRIPTION OF OCCURRENCE:

This special report describes a valid test failure involving 2A Diesel Generator occurring on October 07, 1986. This report is

-submitted for informational purposes in accordance with Technical Specification Surveillance Requirement 4.8.1.1.4 and contains the information required by Regulatory Guide 1.108, Revision 1, August 1977, Regulatory Position C.3.b.

' Surveillance Requirement 4.8.1.1.4 states:

" Reports - All diesel' generator-failures, valid or non-valid, j shall be reported to the Commission pursuant to Specification 6.9.1. ... "

On October 07, 1986, an operational test of 2A Diesel Generator was in progress (in accordance with Surveillance Procedure SP(0) i 4.8.1.1.2., " Electrical Power Systems - Emergency Diesels"). During the test, No. 2A Diesel Generator failed to achieve rated speed in

i. less than or equal to 10 seconds. This was the third valid test failure within the last 100 diesel starts. No. 2A Diesel Generator was unavailable from the time of failure on October 07, 1986 at 0406

..~

hours until October 22,-1986 at 1632 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20976e-4 months <br />, when repairs and testing were completed. The extended time period for the return to service of the diesel is due.ro. required maintenance in support of the t current Unit 2 outage. With this failure, the current surveillance '

test interval is every seven (7) days (in compliance with Regulatory

[ LPosition C.2.d of Regulatory Guide 1.108).

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r-u po UNIT 2'SPECIAL REPORT 86-10 APPARENT CAUSE OF OCCURRENCE:

' Investigation revealed the Turbo Boost Air System solenoid valves, which provide air to the turbo charger to bring the diesel up to 900 rpm in less than or equal to 10 seconds, did not open at 200 rpm (diesel speed) as required. The switching tachometer which senses engine speed and controls the solenoid valves malfunctioned causing.

the solenoid valves to delay their opening.

ANALYSIS OF OCCURRENCE:

The failure of a diesel gene;ator to start and accelerate to 900 rpm.

within 10 seconds is a reportable' event in accordance with Regulatory Guide 1.108 as a valid test failure.. With the Unit in Mode 5, only two (2) diesel generators are required to be operable to provide emergency power.for equipment required to maintain the Unit in a

. shutdown condition and to assure sufficient instrumentation is available to monitor plant status. Had No. 2A Diesel Generator failed with the Unit at power, the remaining diesels are capable of providing power to the minimum safeguards equipment required for accident and transient conditions.

CORRECTIVE ACTION:

The switching tachometer was replaced and the diesel was retested successfully.

g Gentral Manager -

Salem Operations MJP:pc SORC Mtg.~86-090-t i

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