ML18096A605

Special Rept 92-3:on 920302,jacket Water Leakage Developed After Loading DG 2A.On 920305,DG 2A Tripped on Low Lube Oil Pressure.Both Events Caused by Equipment Failure.Tube Connector Compression Fitting Replaced & Diesel Retested

ML18096A605
Person / Time
Site:	Salem
Issue date:	03/26/1992
From:	Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
92-3, NUDOCS 9204010324
Download: ML18096A605 (4)

Text

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• Public Serv*1ce Electric and Gas Company P.O. Box 236 Hancocks 8(1dge, New Jersey 08038 Salem Generating Station March26, 1992 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEH' GENERATING STATIOIJ LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 SPECIAL REPORT 92~3 This Special Report addressee the circumstances surrouriding two (2) 2A Diesel Generator valid failures occurring March 2, 1992 and March 5, 1992. This report is being submitted pursuant to the requirements of Technical Specification Surveillance 4 .. 8.1.1.4.

yours, General Manager -

Salem Operations MJP:pc Distribution

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TJNIT 2 SPECIAL REPOR~2-3

• Salem Generating -Station - Unit 2 Public Service Electric & Gas Company Hanco~k's B~idge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Two (2) Valid 2A Diesel Generator Failures Event Date(s): 3/2/92 and 3/5/92 Report Date: 3/26/92 This report was initiated by Incident Report Nos.92-152 and 92-163.

They address two (2) valid failures inv6l~ing 2A Diesel Geneiator (D/G) occurring on March 2, 1992 and March 5, .1992. It is being 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:

"Re:_p_g];"_ts - All diesel generator failures, - valid or non-valid, shall be reported to the Commission pursuant to Specification 6.9.1. ' "

CONDITIONS

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PRIOR

- - - TO OCCURRENCE: ---------*-

Mode 5 (Cold Shutdown) - 5th Refueling Outage in progress DESCRIPTION ------

OF OCCURRENCE:

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Following the complet~on of 2A D/G preventive maintenance activities, a successful post maintenance test and 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> operability retest were performed. On March 2, 1992, at 0140 hours0.00162 days <br />0.0389 hours <br />2.314815e-4 weeks <br />5.327e-5 months <br />, a twenty-four (24) hour endurance run was initiated. Jacket water leakage developed approximately twenty (20) minutes after loading 2A DIG to 2860 kW in accordance with Technical Specification Surveillance requirements.

Due-to the size of the leak, the surveillance test run was terminated and 2A D/G was removed from service. The leak was permanently repaired and_ a maintenance ietest and one hour op~rability surveillance run were successfully performed.

On March 5, 1992, at 0157 hours0.00182 days <br />0.0436 hours <br />2.595899e-4 weeks <br />5.97385e-5 months <br />, following generator inspection and minor maintenance repairs (i.e., exhaust leak repair), a post maintenance surveillance test of 2A D/G was performed in accordance with Surveillance Procedure SP(O) 4.8.1.1.2., "Electrical Power Systems - Emergency Diesels". During the test, the D/G tripped on Low Lube Oil Pressure prior to accepting load.

Technical Specification 3.8.1.2 Action Statement was not entered for the above events since the Limiting Condition for Operation was met; i.e., the other two (2) D/Gs were operable.

UNIT 2 SPECIAL REPORT '-3

• The cause of the jacket water leakage is equipment failure. A Weatherhead 7/8" tube connector compr~ssion_fitting had failed~ The fitting's ferrule cracked in service. No installation*defects or nonconformances were noted during disassembly of the fitting.

l1<?:rc}:_1*_5 ..!_1_~~2_ l,i_<?_W__ µu_l;>_e ___Q;L l __ J'_r_e~-~:u;r;:_~ __Trip E\_7_ep. t The cause of the 2A D/G Low Lube Oil Pressure trip is equipment failure. Troubleshooting revealed the electrohydraulic governor actuator (Woodward Governor) failed preventing the diesel engine from attaining rated speed. It is postulated that the shutdown solenoid, inside the governor, failed in the open position bleeding the hydraulic fluid off the governor resulting in the fuel racks going to the shutdown condition.

The failed governor was recently rebuilt and installed on February 16, 1992 during preventive maintenance work activities. The governor was rebuilt by "Gerhardt's Inc.-". The failed governor is being sent out for failure analysis. *Bench testing and disassembly inspections will be conducted.

• The Marc6 2, 199~ jacket water leak and the March 5, 1992 governor failure events are valid failures as described in Regulatory Guide 1.108. These two (2) 2A D/G valid failures are the first failures in the last 20 valid tests. In accordance with Technical .Specification Table 4. 8-1, "Diesel Generator Test Schedule", the *surveillance has been dhanged to once every 7.days from once per every 31 days.

With the Unit in -Mode 5, only two (2) of the three (3) D/Gs are required to provide power to the minimum safeguards equipment required for analyzed accident ahd transient conditions. Therefore, this event did not impact the health and safety of the general

• public.

The Weatherhead 7/8 tube connector compression fitting cracked ferrule was replaced.

A review of the D/Gs eq~ip~ent history indicates that the March 2, 1992 jacket water leak was an isolated event due to a cracked ferrule.

A maintenance rete~t, one (1) hour operability run and a twenty-four (24) hour endurance run, including a hot restart test using the revised procedure, were successfully completed following replacement of the failed governor.

The failed governor is being sent out for failure analysis. Bench testing and disassembly inspections will be conducted.

£ U N I T 2 SPECIAL REPORT . , 3 *-

In accordance with Technical Specification Table 4.8-1, ~Diesel Generator Test Schedule, the surveillance h~s ~een changed to once every 7 days from orice per every 31 days.

General Manager -

Salem Operations MJP:pc SORC Mtg.92-036