ML19332D403

Final & Interim Deficiency Rept CP-89-030 Re Auxiliary Feedwater Pump Turbine Low Lube Oil Pressure Switch Electrical Separation.Initially Reported on 891027.Rept Corrected to Require Two Fuses in Series

ML19332D403
Person / Time
Site:	Comanche Peak
Issue date:	11/27/1989
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-89-030, CP-89-30, TXX-89820, NUDOCS 8912010146
Download: ML19332D403 (2)

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. Log- # TXX-89820 File # 10110, 903.10 l

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November 27, 1989 Exewtive Vice President l

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' U -S. Nuclear Regulatory Commission Attn: Document Control Desk j Washington, D. C. 20555 i l

SUBJECT:

COMANCHE ~ PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50 446 1

.AFW PUMP TURBINE LOW LUBE OIL PRESSURE SWITCH l SDAR: CP-89-030 (FINAL REPORT FOR UNIT 1, INTERIM REPORT FOR UNIT 2)

Gentlemen:

On October 27, 1989, TV Electric informed the NRC of a deficiency involving ,

o Auxiliary Feedwater (AFW) Pump Turbine Low Lube Oil Pressure Switch electrical '

separation. After further evaluation, this condition has been determined to f be reportable under the provisions of 100FR50.55(e).

• DESCRIPTION  ;

Low lubricating oil pressure switch 1 PS-2452- upplied as a component part of'the seismically qualified Auxiliary Fet m, Pump Turbine skid. ,

During design validation the electrical power supply for this switch was found to-be from a Class IE power source with single fuse isolation. Even though the lube oil switch does not provide a safety related function and could have. .

been powered form a non-safety (Train C) source, a Class IE power supply with a single fuse is acceptable provided the switch is fully qualified. -

Therefore, design validation identified the need for reconciliation with the qualification status for this component. Final reconciliation performed by the Equipment Qualification group found that the pressure switch was qualified  ;

for-pressure boundary integrity, but supporting-documentation for the internal .

electrical integrity of the switch was not available. Without the appropriate ,

documentation to demonstrate qualification, TU Electric determined that the power supply from a Class 1E source with single fuse isolation does not meet the CPSES electrical separation design criteria. Failure to verify the qualification status of this switch prior to implementing the specified electrical.' arrangement is considered a deficiency in the original design for E this component.

This deficiency was found as part of the structured program for design validation and reconciliation as described by the Equipment Qualification Project Status Report.

P' 8912010146 891127 5 l 'o ADOCK 0500g j

{DR P. O. Box 1002 Glen Rose. Texas 76043-1002 1-

__ 'V-4 TXX 89820 November 27, 1989 Page 2 of 2< f 3:

.l SAFETY IMPLICATIONS Failure of the pressure switch could degrade the Class 1E instrument bus and-affect the operation of other safety related instruments powered from the same '

bus. The described condition represents a significant deficiency in the final ,

design as approved and released for construction,

• In the event this condition had remained uncorrected, it may have adversely affected the safe operation of the plant, and therefore, is considered-reportable pursuant to 10CFR50.55(e),

CSRRECTIVE ACTION The nonconformance report identifying this deficiency has been.dispositioned to require two fuses in series in the pressure switch power supply circuit.

This corrective action for Unit 1 is scheduled to be completed prior to Unit 1 fuel load, The Unit 2 corrective action for this condition will be assessed after resumption of the balance of engineering activities for Unit 2.

Sincerely, William J. Cahill, Jr.

By: - -

-Jot 8W. Beck Vice President, Nuclear Engineering WJH/smp c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3)