ML20076E274

Rev 0 to Hope Creek Generating Station Bailey 862 Sys Logic Module Failure Data Rept,Second Quarter 1991

ML20076E274
Person / Time
Site:	Hope Creek
Issue date:	07/01/1991
From:	Public Service Enterprise Group
To:
Shared Package
ML20076E272	List: ML20076E270 ML20076E274
References
HC.SE-PR.RL-001, HC.SE-PR.RL-001(Q)R1, HC.SE-PR.RL-1, HC.SE-PR.RL-1(Q)R1, NUDOCS 9108190194
Download: ML20076E274 (4)

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HC.SE-PR.RL-0001(Q)

Revision 1 HOPE CREEK GENERATING STATION BAILEY 862 SYSTEM LOGIC MODULE FAILURE DATA REPORT PERIOD: SECOND QUARTER 1991 l PREPARED BY:

SYSTEM ENGINEER 7!l!91 DATE APPROVED BY: dL[ d. )P.I g: .

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i _ TECHNICAL ENGINEER ' DATE l

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Distribution:

SORC Technical Manager Station Licensing Engineer Maintenance Controls Engineer Functional Supervisor, E&PB I&C

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BAILEY SSLM REPORT A.

SUMMARY

OF FAILURES BY MONTH DURING REPORT PERIOD AEEIL 1991 NO FAILURES MAX 1991 NO FAILURES JUNE 1991

1) 06/10/91 1BC653 SLOT 1-3-11 0-1008 N-1518 OUTPUT BUFFER #5 FAILED OPEN CONFIRMED FAILURE OUTPUT BUFFER #6 SHORTED WO 910610082 PROBLEM: 1AX502 TAP CHANGER CONTROLLER ALTERNATING BETWEEN AUTO AND MANUAL.

2) 06/17/91 1BC653 SLOT 5-4-3 0-2281 N-1422 ,

LOGIC OUTPUT #3 SHORTED CONFIRMED FAILURE LOGIC OUTPUT #4 OPENED BUFFER OUTPUT #4 SHORTED

((')T WO 910613092 PROBLEM: 'B' SECONDARY CONDENSATE PUMP TRIPPED WITH NO FIELD FAULTS.

s TOTAL MONTHLY FAILURES = 2 TOTAL QUARTERLY FAILURES =2 BBLM'S B. FAILURE RATE DATA 1). 26 CONFIRMED FAILURES FROM 07/01/90 THRU 06/30/91. .

2) 2278 SSLM POPULATION

3) ANNUAL FAILURE RATE PERCENTAGE:

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a. 26 + 2278 = 0.01141 x 100 = 1.41 %

4) MEAN TIME BETWEEN FAILURES DETERMINATION:

MTBF FROM 07/01/90 THRU 06/30/91,

a. 12 MONTH SERVICE HOURS = 8760 HOURS

b. TOTAL MODULE SERVICE HOURS

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8760 x 2278 = 19.95 x 10 6 19.95 x 106 + 26 FAILURES = 767,511 HOURS

c. 26 + 19.95 x 106 = 1.30 FAILURES PER MILLION HOURS FAILURE RATE.

C. COMPARISON STANDARD

1) THE IEEE 122 HIANDARD EXPECTED FAILURE RATE OF SOLID ,

. STATE COMPUTATION DEVICES IS EQUAL TO 1.19 FAILURER RER MILLION RQJ!RE- FAILURE RATE.

2) THE HCGS-BAILEY 112 SSLM FAILURE RATE FROM sEL T 193_Q THRU-2MH 1991 IS EQUAL TO 1.30 FAILURES EER HILLION HOURS ZAILURE EAIL.

D. ANALYSIS

1) HCGS BAILEY 862 SSLM FAILURE RATE APPEARS TO-HAVE A SLIGHT DECREASE DURING THE LATEST 12 MONTH PERIOD. ,

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> THIS DECREASE IS ATTRIBUTIBLE TO ONLY ONE FORCED OUTAGE IN NOVEMBER AND THE THIRD REFUEL OUTAGE FROM 12/90 TO 3/91. HOPE CREEK HAS-SHOWN CONSISTENTLY GOOD FAILURE RATES DURING ITS NONOUTAGE PERIODS.

2) ONE CONFIRMED FAILURE HAD SIGNIFICANCE WITH REGARD .

TO SAFE AND RELIABLE OPERATION OF THE PLANT.

TRIPPING OF THE 'B'. SECONDARY CONDENSATE PUMP '

RESULTED IH A RUNBACK AND A CHALLENGE TO-THE PLANT-AND THE OPERATORS.'ALL SYSTEMS WORKED AS PER DESIGN I TO MITIGATE =THE CONSEQUENCES OF-THE CONDENSATE' PUMP l

. TRIP. THE IDENTIFIED FAILURE-WHICH CAUSED THE TRIP, '

A FAILED LOGIC OUTPUT SIGNAL IS RELATIVELY RARE AS COMPARED TO OTHER KNOWN-FAILURE MECHANISMS-SUCH AS INPUT OR' OUTPUT BUFFER FAILURES.

E. . RECOMMENDATIONS <

t 1) NO SPECIFIC RECOMMENDATIONS ARE BEING MADE AS A.  !

L RESULT OF THE TWO MODULE FAILURES THIS QUARTER. ,

i 2). SYSTEM ENGINEERING HAS INSTITUTED A MONITORING OF I i LOGIC MODULE STATUS FOR THE 4.16KV INFEED BREAKERS t l BECAUSE.0F SIGNIFICANT FAILURES IN THE PREVIOUS- i QUARTER. NO MODULE FAILURES HAVE BEEN IDENTIFIED

, DURING THIS MONITORING TO DATE. THIS PROCESS-WILL-  !

l CONTINUE TO ASSIST OUR DETERMINATION OF ROOT CAUSES ,

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3) SYSTEM ENGINEERING HAS PURSUED INVESTIGATION OF BREAKER PM'S FOR ANY PROBLEMS AND HAS NOT BEEN ABLE TO IDENTIFY ANY SPECIFIC FAULTS WITH OUR PROCEDURES.

WE WILL CONTINUE To PURSUE THIS LINE SO THAT WE CAN l ELIMINATE ALL POSSIBLE FIELD INDUCED LOGIC MODULE i FAILURES. t l .Gh 9

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