TXX-6341, Final Deficiency Rept CP-86-14 Re 6.9 Kv Switchgear Breaker Jack Shaft Weld Failure.Initially Reported on 860311.All Jack Shafts in 6.9 Kv Switchgear Scheduled to Be Replaced by 871121

Final Deficiency Rept CP-86-14 Re 6.9 Kv Switchgear Breaker Jack Shaft Weld Failure.Initially Reported on 860311.All Jack Shafts in 6.9 Kv Switchgear Scheduled to Be Replaced by 871121

ML20207S865
Person / Time
Site:	Comanche Peak
Issue date:	03/16/1987
From:	Council W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-86-14, TXX-6341, NUDOCS 8703200344
Download: ML20207S865 (7)

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, Ref #10CFR50.55(e)

S lQ 1UELECTRIC y e . March 16, 1987 y j' newsin na n uma g- ,

• -F U.S. Nuclear Regulatory Commission

.. ATTN: Document Control Desk

/ Washington, D.C. 20555 d

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50-446 6.9KV SWITCHGEAR BREAKER JACK SHAFT WELD FAILURE SDAR: CP-86-14 (FINAL REPORT)

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Gentlemen:

[

l? On March 11, 1986, we verbally notified your Mr. T. F. Westerman of a

~ deficiency involving a weld failure in a component of a Class IE 6.9KV switchgear breaker. This is a final report of a potentially reportable item

", under the provisions of 10CFR50.55(e). Our last report, logged TXX-6172, was submitted on December 18, 1986. We have concluded that this deficiency is reportable under the provisions of 10CFR50.55(e) and the required information follows:

DESCRIPTION OF PROBLEM During normal maintenance, a 6.9KV switchgear breaker (IA3 cubicle 7: service air compressor) was closed and reopened automatically due to a phase imbalance. Our subsequent investigation revealed that a weld connecting the right hand jack shaft and the lever arm had failed due to inadequate weld fussion. The defective breaker was replaced with a spare.

4 During a subsequent common mode failure analysis, a visual inspection program of all critical breakers and a statistical random sample check on the non-critical breakers was completed using acceptance criteria provided by the breaker manufacturer (Brown Boveri). The initial results of this inspection concluded that the jack shaft welds did not meet the vendor's acceptance criteria in all cases.

As a result of these findings, the manufacturer initiated an evaluation of the established design criteria, including design testing to verify breaker operability.

' Adequate inspection criteria could not be developed for installed jackshafts.

The models developed for the test program were not adequate to assure -

cparability of the breakers; therefore the jackshafts will be replaced.

s/o3 200344 870316 POR ADOCK 05000445 ,

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PDR 400 North Olisc Street I..it 81 Dallas Teus 75201 dg

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TXX-6341 S. ..

• March 16, 1987 1" Page 2 ,n

. I a SAFETY IMPLICATION i The lack of adequate welding between the jack shaft and the lever arm could

, result in. failure of the breaker. The safety of plant operations could have y, been adversely affected had this condition remained uncorrected.

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5 CORRECTIVE ACTION

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M All jack shafts in, the 6.9KV switchgear at CPSES are scheduled to be replaced by November 21, 1987.

. l' .

If any subsequent reports of this issue (SDAR CP-86-14) are required concerning the status of implementation of corrective acticns under the,.

provision lof 10CFR50.55(e), they will be reported via SDAR: CP-87-03, "6.9KV Switchgear Installation".

,a Very truly yours, s W. G. Counsil JCH/ef- .)

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c c Mr. E. H. Johrison, Region IV - b <

v Mr. D. L. <Keney '- RI, Region IV ' '

Mr. H. S'."PMllips - RI, Region IV 4 1 l .)

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File N). 10002 COMMITMENT TRACKING OUTG0ING CORRESPONDENCE EVALUATION SHEET DOCUMENT IDENTIFICATION Title /

Subject:

6.9KV Switchgear Breaker Jack Shaft Weld Log No. TXX-6341 Failure SDAR CP-86-14, (Final Report) File 10110 908.3 Date 03/16/87 ITEM TRACKING Item Tracking Item No. Description Types

• Document /No.

001 All jack shafts in the 6.9KV switchgear at CPSES are ,EA' LCR-87-140

. scheduled to be replaced by November 21, 1987. Note: Any yA subsequent reports of this issue will be reported via SDAR, CP-87-03, "6.9KV Switchgear Installation." See LCR-87-139.

• Item Types: EA - External Action OB - Operational Basis DB - Design Basis IA - Internal Action D0 - Description Only AS - (See LCR form)

COMPLETED BY REVIEWED BY .

Initials 388 Date 1/4/r/

/ Initials Date3[77 l

MAP 16 '87 11:07 CPSES SITE SERVICES PAGE.05 FIGURE 7.2 REPORTABILITY EVALUATION FORM DATE IDENTIFIED: February 7, 1986 , SERIAL NO: 0140 SOURCE OF INFORMATION: Tcr-86144 (Tusco Miantenance Eng.. Problem STATEMENT OF PROBLEM: Report 86-045) - A t t a c h e~il A component weld f a ilu r e o,,f ,,a sing 1 N .'MTi switchgcar breaker.

The breakers were procured per PO CP-0423 and are c l a s ti i f i e d as IE components. Additional inspections will be r5f6~1 l red using vendor provided criteria.

EVALUATION A351GNED T0: RDC/PBs EVAEUATION DUE DATE: February 28,198*

EVALUATION: The iack shafts installed in the 6.9kv switchgent at

_CPSES contain weldments which exhibit both lack of fusion and oroper fillet wcld size nn specified by the man u lis e t d r e r of subicct itemn. -

l ~

The lack of adequate welding between LIie right haud Jat k shatt and t

___the lever arm could result in failure of the breaker. -

The safety of plant operations couJd have~been adversely --

effected had this condition remained uncorrected.

RECOMMENDATION:

PORTABLE 4 YES NO / APPLICABLE TO: _ 50.55(eJ EVALUATOR: _

,, y .-

DATE: 3, / , D -

y 0 REVIEW 0FREPORTABILITYRECOMME,JDAT10f1 f CONCLUSION: REPORTABLE _ A. YES ~ ff0 / APPLICABLE T0: 50.55(e)

CGMMENTS:

.. ._ PART 21

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& L A.Wh.ee

________a...____________________....._____________

CONCLUS!0ft: REPORTABLE YES 11 0 / APPLICABLE TO:

COMMENTS:

~~ 50.55(e)

__ ,PART 21

._ X BOTH

/ /A A _ _

RVIEWER: _ ./, h. W 4 4. d elg n ,A ,/

DATE:

N//t./f,1 i1E0 CS_1

LICENSING COMITMENT RESOLUTION (LCR) FORM LCR No. LCR-87-140 Rev. No. 0 Date: 03/16/87 T0: J. L. Barker Comitment

Description:

All jack shafts in the 6.9KV switchgear at CPSES are scheduled to be replaced by November 21, 1987. Note: Any subsequent reports of this issue will be reported via SDAR, CP-87-03, "6.9KV Switchgear Installation." See LCR-87-139.

Comitment Source: TXX-6341 Date: 03/16/87 File: 10110 Due Date: 11/21/87 This is a comitted date.

Licensing Lead: D. A. Ringle 979-8879 Above is a description of formal commitment made by Texas Utilities to a regulatory agency. This commitment requires action by your organization by the date shown. Please complete the reverse side and return this form to document the resolution of this commitment.

If resolution cannot be achieved by the commitment due date, provide a new resolution date at least seven (7) calender days prior to the date specified.

Iofeend '

This comitment requires-Exters Action and resolution should be accomplished by completion of the comitted action.

M Signature, Supervisor Docket Licensing 3A c/rr Date Copy to: LCR log, T. A. Hope, D. A. Ringle L. D. Nace, J. E. Krechting, R. E. Camp, D. M. Reynerson

y

, LCR No.

TO: Supervisor Docket Licensing This conunitment has been resolved as noted below:

C CLOSED - All required actions completed within the conunitment schedule.

O CLOSED - All required actions completed but conunitment/ schedule revised as noted below.

] WITHDRAWN - This conusitment withdrawn as noted below.

[ SUPERSEDED - This commitment has been superseded by a later commitment as noted below.

O OrseR - See description beiow.

Remarks:

(Signature, responsible NEO VP, etc.) (Date)

Copy to:

~

0

Outgring Corr:sp:ndence bec (3):

M. D. Spence

• INP0

• K. L. Scheppele A W. G. Counsil R. T. Jenkins H. C. Schmidt J. W. Beck R. A. Jones A. B. Scott R. P. Baker S. D. Karpyak B. C. Scott

• R. E. Ballard G. S. Keeley/ C. E. Scott E. Brabazon J. S. Marshall

• L. K. Sterchi J. L. Barker

• R. P. Klause P. B. Stevens

• W. R. Burchette J. E. Krechting J. F. Streeter

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• B. Tartt R. D. Calder

• D. F. Landers

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• R. L. Cloud D. M. McAfee/

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• N. S. Reynolds J. C. Hicks March 2, 1987

• - First Class Mail

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