ML19344D530

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Responds to IE Bulletin 79-03.Ultrasonic Examination Results Indicate No Rejectable Porosity or Lack of Fusion on Any ASME SA-312 Stainless Steel Pipe Mfg by Youngstown Welding & Engineering Co
ML19344D530
Person / Time
Site: Millstone Dominion icon.png
Issue date: 02/20/1980
From: Counsil W
NORTHEAST UTILITIES
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
IEB-79-03, IEB-79-3, NUDOCS 8003120673
Download: ML19344D530 (2)


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'l February 20, 1980 Docket No. 50-336 Mr. Boyce 11. Grier , Director Region I office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King e Z Prussia, PA 19406

References:

(1) B. il. Grier letter to W. G. Counsil cated Ilarch 12, 1979 forwarding I6E Bulletin No. 79-03.

(2) W. G. Counsil letter to B. H. Grier dated April 16, 1979.

(3) W. G. Counsil letter to B. H. Grier dated May 3, 1979.

Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Longitudinal Weld Defects in ASSIE SA-312 Stainless Steel Pipe l

In Reference (1), Northeast Nuclear Energy Company (NNECO) was requested to determine whether ASME SA-312, Type 304, or other welded (without filler metal) pipe manufactured by Youngstown Welding and Engineering Company is in use or planned for use in safety-related systems.

NNECO responded to this request in Reference (2) and, in Reference (3), provided the results of exmninations performed to date on the subject piping. Included in Reference (3) was a commitment to examine the remaining subject pipe at Millstone Unit No. 2 prior to the start of Cycle 4 operaticn.

NNECO hereby informs the NRC Staff that the ultrasonic examinations of the subject piping required by I&E Bulletin No. 79-03 have been completed with the exception of four (4) welds in Spools 199, 200, 201, and 202. The results of the examina-tions indicate that there is no rejectable porosity or lack of fusion, on any SA-312 pipe in use at Millstone Unit No. 2, as described by Reference (1). A total of 543 f eet of piping at Hillstone Unit No. 2 was identified as questionable Youngstown SA-312 pipe. The welds which were not inspected comprise 43 feet of the subject seam-welded pipe, represcnting 7.9% of the total. These welds were not examined because their location in high radiation fields rendered them inaccessibl.e.

In addition to the ultrasonic examinations, NNECO has conducted a review of the radiographs of all circumferential butt welds in the affected piping including Spools 199, 200, 201, and 202. Included in these radiographs are two to three inches of the longitudinal seam welds. These reviews did not indicate any imperfections of the t. ge described in Reference (1).

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liased on the results of the ultrasonic examinations performed to date and the reviews of the radiographs of the circumf erential butt welds of the subject piping, NMECO has determined that a high level of confidence exists assuring that the remaining unexamined piping will not contain imperf ections of the type described in Ref erence (1).

In recognition of ALARA concerns and the high level of confidence assuring the integrity of the remaining piping, NNECO does not intend to examine the remaining subj ect piping. Therefore, this issue is resolved.

We trust this information satisfactorily dispositions the Reference (1) concerns.

Very truly yours, NORTIIEAST NUCLEAR ENERGY COMPANY fl 1

} (Ak1L W. ~G. Counsil Vice President