ML20083A038

Significant Deficiency Rept SD-47 Re Underdesigned Seismic Duct Weld Joints.Initially Reported on 831109.Majority of Welds Found Acceptable.Remaining Duct Sections Will Be Reworked.Next Rept by 840309

ML20083A038
Person / Time
Site:	Millstone
Issue date:	12/09/1983
From:	Counsil W, Sears C NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, F0429A, F429A, F429A50.55E, SD-47, SD-47A, NUDOCS 8312200143
Download: ML20083A038 (2)

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December 9,1983 Docket No. 50-423 F0429A Dr. Thomas E. Murley Regional Administrator Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

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, that resulted in partial penetration welds rather than full penetration welds which was expected by the duct design.

Our architect-engineer, Stone & Webster Engineering Corporation, is in the process of reevaluating the seismic loading requirements on the ducts to determine the acceptability of partial penetration weld joints. Initial inspection of the duct sections with partial penetration welds that have been installed and inspected reveals that the majority of them are acceptable. Most of the remaining duct sections which have not yet been installed will be reworked prior to their installation.

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l l As such, we are not able to provide you with a final report at this time.

However, we will provide you with an update on this matter on or before March 9,1984. .

h- Very truly yours, w.07.C d W. G. Counsi' Senior Vice President L

By: C. F. Sears .

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

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