ML20082T030

Final Significant Const Deficiency Rept 70 Re GE 480-volt Trip Coils Failing to Drop Out After Tripping.Capability of Excessive Current Flowing Through Coils Eliminated

ML20082T030
Person / Time
Site:	Waterford
Issue date:	12/02/1983
From:	Gerrets T LOUISIANA POWER & LIGHT CO.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, 70, W3K83-1881, NUDOCS 8312150124
Download: ML20082T030 (3)

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i I OUISIANA POW E R & LiG HT /Waterford 3 SES/P. O. Box B/Killona, LA 70066 N!i$SEsS$ December 2, 1983 W3K83-1881 Q-3-A35.07.70 Mr. John T. Collins Regionel Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012

REFERENCE:

LP&L letter W3K83-1512 dated October 7, 1983 f*lM@lMO\V/Y+

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Dear Mr. Collins:

DEC 8123

SUBJECT:

Waterford SES Unit No. 3 J d Docket No. 50-382 Signiticant Construction Deficiency No. 70 "GE 480-V Trip Coils Do Not Drop Out After Tripping" Final Report In accordance with the requirements of 10CFR50.55(e), we are hereby providing two copies of_the Final Report of Significant Construction Deficiency No. 70,

-GE 480-V Trip Coils Do Not Drop Out After Tripping".

If you have any questions, please advise.

Very truly yours, D &

T. F. Gerrets Quality Assurance Manager TFG:CNH:VBR cc: Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 (15 copies) 8312150124 831202 PDR ADOCK 05000302 S PDR l

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E., . .

Mr. John T.-Collins December 2, 1983

- W3K83- 1881 Page 2-cc:- Director Office of Management Information and Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555

'Mr. E.'L. Blake Shaw, Pittman, Potts, & Trowbridge 1800 M Street,-N.W.

Washington, D.C. 20036 Mr. W. M. Stevenson Monroe & Lemann 1424 Whitney Building New Orleans,. Louisiana 70130

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• FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY REPORT NO. 70 "GE 480 VOLT TRIP COILS DO NOT DROP OUT AFTER TRIPPING" INTRODUCTION' Thts-report is submitted pursuant to 10CFR50.55(e). It describes a deficiency that existed in the control circuits of 480 volt switchgear breakers. This problem is considered reportable under the requirements of 10CFR50.55(e).

To1the best of our knowledge, this problem has not been identified to the Nuclear Regulatory Commission pursuant to 10CFR21.

DESCRIPTION OF PROBLEM

~During preoperational testing of the pressurizer heater circuits, some of the 480 volt switchgtar breakers failed to close after tripping. It was determined that the green light circuits which monitor trip coil continuity were allowing excessive current to flow through the coils after tripping.

this prevented them from dropping out and disabled the closing mechanism.

The following switchgear utilize costrol circuits which had this problem:

3A21 3B21 3A31-S 3B31-S 3AB31-S 3A32 3B32

( 3A22 3B22 SAFETY IMPLICATIONS It has been determined that this trip coil circuit design could render inoperative safety related equipment required for safe shutdown of the plant if left uncorrected.

CORRECTIVE ACTION Nonconformance Report No W3-5737 was initiated to implement corrective action Lin accordance with revised design documents (DCN-IC-1424 R1 & 1425 R2) which eliminated the capability of excessive current flowing through the trip coils, thereby allowing proper breaker closing' action. All corrective action and testing has-been completed and NCR No. W3-5737 has been closed.

This report is submitted as the Final Report.

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