ML20009F005

Supplemental Final Rept for Significant Const Deficiency 8 Re Containment Electrical Penetration Bolting Failure. Tompkins-Beckwith,Inc Performed Weld Repairs & Rewelded Pemnuts.Acceptability Confirmed by Ebasco

ML20009F005
Person / Time
Site:	Waterford
Issue date:	07/14/1981
From:	Aswell D, Milhiser R, Wills J LOUISIANA POWER & LIGHT CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CCFR-50.55E, 10CFR-050.55E, 10CFR-50.55E, W3K81-0253, W3K81-253, NUDOCS 8107280599
Download: ML20009F005 (4)

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I LOUISIANA P O W E R & L I G H T! e o.DELARONDE STREET 142 box soos. NEW ORLEANS. LOUISIANA 70174 * (504) 366-2345 Eu$sysY$

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July 14, 1981 v'c= %*at*a-ar e W3K81-0253 Q-3-A35.07.08 Mr. K. V. Seyfrit, Director, Region IV U. S. Nuclear Regulatory Commission Of fice of Inspection and Enforcement

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SUBJECT:

Waterford SES Unit No. 3 Docket No. 50-382

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3 Supplemental Final Report for M

Q Significant Construction Deficiency No. 8 O

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" Containment Electrical Penetration Bolting Fail' f

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Reference:

LP&L Letter to USNRC LPL 10342 dated December 29, Mk

Dear Mr. Seyfrit:

Attached herewith is a Supplemental Final Report on Significant Construction Deficiency No. 8 which provides a description of problems encountered in implementing the corrective action described in the Final Report of Signific a t Construction Deficiency No. 8 dated December 27, 1978, and the final corrective action taken to close this problem.

If you have any questions, please advise.

Very truly yours, D. L. Aswell DLA/LLB/grf cc: 1) Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 (with 15 copies of report) h})

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Director Office of Management Information and Program Control

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U. S. Nuclear Regulatory Commission Washington, D. C. 20555 (with 1 copy of report) 8107280599 810713 PDR ADOCK 05000382 S

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LOUISIANA POWER & LIGHT COMPAhT WATERFORD SES UNIT NO. 3 SUPPLEMENTAL FINAL REPORT FOR SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 8

" CONTAINMENT ELECTRICAL PENETRATION BOLTING FAILURE" f[

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Reviewed by j

R. J. Milhtte~i7-Site Manager

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J/L.VWills - Project Superintendent

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Date Review by

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7 gg 7 !N J;. Hart'- Project Licen ing Engineer Date L

Reviewed by

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R. A. Har'tnett VQ. A. Site Supervisor Date July 6, 1981 l

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SUPPLEMENTAL FINAL REPORT FOR SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 8

" CONTAINMENT ELECTRICAL PENETRATION BOLTING FAILURE" INTRODUCTION This report is submitted pursuant to 10CFR50.55(e) (3).

It describes deficiencies in containment electrical penetrations at Waterford Unit No. 3.

BACKGkOUND A.

Synopsis of Incident During the installation of Conax Corporation containment electrical penetrations at the Waterford Unit No. 3 Project, it was noted that the bolted connections that connect the horizontal channel sections of the termination subassembly to the header mounting brackets were loose or disengaged.

Conax Corporation has confirmed that this method of attachment was employed in 32 low voltage control and instrumentation penetrations.

B.

Resolution Conax Corporation has modified their design for Waterford 3 such that the pemnuts are welded in place, in lieu of the pressed connections in question.

DISCUSSION The "pemnuts" were installed by Conax Corporation (manufacturer's drawing's 7320-10001, Ebasco No. 1564-2332 R3).

The problem identified at Waterford 3 cast doubt on the seismic capabilities of the "pemnuts" although further investigations would be necessary to make a conclusive statement.

A man-agement decision was made to modify the design rather th?n undertake an extensive evaluation program to justify the acceptability of the design.

We have b"en informed by Conax Corporation that the " press fit" peanut de-sign has been utilized in electrical penetration terminc1 block mounting brackets delivered to Millstone Nuclear Power Station Ur;it 3, North Anna Units 3 and 4, St. Lucie Plant Unit 2 and LaSalle Count) Station Unit 1.

SUPPLEMENTAL PROBLEM DESCRIPTION Subsequent to receipt of the modified connections (welded pemnuts in lieu of pressed connections) at the Waterford Site and during attempts to install the brackets, it was detected that the workmanship of the weldments was not of desired quality and in some cases very poor. Deficiencies detected included pinholes, undercut and lack of fusion.

These observations cast doubt and concern with regard to the capability of the pemnuts to remain in place and perform as required.

Investigation into the cause revealed that the probable cause of this poor workmanship was attributed in part to the welding technique used, that being the lack of proper base metal preparation.

r J SUPPLEMENTAL CORRECTIVE ACTION Due to construction schedule constraints, a site contractor, Tompkins-Beckwith, Inc., was permitted to perform weld repairs and reweld the pemnuts in accordance with Field Change Request FCR-E-911.

The vendor, Conax, was apprised of the deficiencies detected and required to provide certification for subsequent shipments certifying that the pemnuts successfully passed a torque test of 100 inch-pounds in compliance with Conax procedure IPS-374 and IPS-151 R/1.

The Ebasco Site Quality Assurance organization confirmed the acceptability of the modification through visual inspection of the weldments and by subjecting the pemnuts to a torque test thereby establishing the capability of the modification.

Fischbach & Moore, Inc., completed the installation of the 98 electrical penetration mounting flanges on April 14, 1981.

The mounting flange bolts were torqued to 75 + 25 inch-pounds at time of installation in accordance with Conax procedure IPS-151 R/1.

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