ML20087P652

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Updated Potential Significant Deficiency Rept SD-47 Re Possibly Underdesigned Seismic Duct Welds.Initially Reported on 831109.Calculations on Required Weld Strength Being Reviewed.Next Rept by 840608
ML20087P652
Person / Time
Site: Millstone Dominion icon.png
Issue date: 03/09/1984
From: Counsil W, Sears C
NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To: Murley T
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
FO449A, SD-47, NUDOCS 8404090244
Download: ML20087P652 (2)


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General Offices

se0RTetas? UTtJTES SEnveCE Cowassy (203) 666-6911 es0Rt (ast seuCLE4A Eegacy Canarassv March 9,1984 Docket No. 50-423 F0449A Dr. Thomas E. Murley Regional Administrator Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Reference:

(1) W. G. Counsil letter to T. E. Murley, F0429A, dated December 9,1983.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Construction:

Seismic Duct Welds Potentially Underdesigned (SD-47)

In a November 9,1983 telephone conversation between your Mr. T. Elsasser and our Mr. R. W. Vogel, Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency in the construction of Millstone Unit No. 3 as required by 10CFR50.55(e). The potential significant deficiency involves duct weld joints which may be underdesigned with respect to seismic requirements.

This was the result of inconsistent interpretation of weld symbols between the duct fabricator and the architect-engineer. This resulted in partial penetration welds (rather than full penetration welds which was expected by the duct designer.)

Our architect-engineer, Stone & Webster Engineering Corporation (SWEC), has conducted a test program on weld strength and inspected a random sample of existing welds. Calculations on required weld strength are currently being reviewed by SWEC, however, conclusions have not been finalized at this time.

1 8404090244 840309 PDR ADOCK 05000423 I.

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We are not able to provide you with a final report at this time. We will provide you with an update on this matter by June 8,1984.

Very truly yours,

m. 4.buU W. G. Counsil Senior Vice President l

W By: C. F. Sears Vice President Nuclear and Environmental Engineering cc: Mr. R. C. DeYoung, Director Division of Inspection and Enforcement t U. S. Nuclear Regulatory Commission Phillips Building 7920 Norfolk Avenue Bethesda, MD 20014 4

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