ML20140J494

Forwards Results of Steam Generator Weld Indication Evaluation.Indications Identified in Tubesheet to Channel Head Weld Region for No 22 Steam Generator

ML20140J494
Person / Time
Site:	Prairie Island
Issue date:	05/06/1997
From:	Sorensen J NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20140J498	List: ML20140J494 ML20141A979 ML20141A991
References
NUDOCS 9705140106
Download: ML20140J494 (2)

Text

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Northern States Power Company Prairio Island Nuclear Generating Plant 1717 Wakonade Dr. East Welch, Minnesota 55089 l

May 6,1997 10 CFR Part 50 l Section 50.55a I

I U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT l Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Steam Generator Weld Indication Evaluation l

During the Unit 2 refueling outage in Winter 1997, ultrasonic examinations of the steam generators were performed in accordance with ASME Boiler and Pressure Vessel Code Section XI. Examinations were done to satisfy the first period requirements of the third ten-yeai interval. The third ten-year interval plan for Prairie Island was written to conform to the 1989 edition of ASME Section XI.

During the examinations, indications were identified in the tubesheet to channel head weld region for #22 steam generator (see attached cover sheets to examination report

1. 97-0136). These indications exceed the allowable flaw size when evaluated against the standards provided in ASME Section XI, IWB-3500. Accordingly, we performed an analytical evaluation of each of these flaws per ASME Section XI, IWB-3610. These flaws were found acceptable per these analyses. Attached for your review are the results of these evaluations. The procedure used for these evaluations is contained in WCAP-14166 which we submitted for review in January 1995.

In this letter we have made no new Nuclear Regulatory Commission commitments.

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e USNRC NORTHERN STATES POWER COMPANY May 6,1997 Page 2 Please contact Jack Leveille (612-388-1121, Ext. 4662) if you have any questions i related to this letter.  !

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Joel P Sorensen i 1

Plant Manager l

Prairie Island Nuclear Generating Plant 1 J

l 4

l c: Regional Administrator- Region ill, NRC Senior Resident Inspector, NRC ,

NRR Project Manager, NRC J E Silberg 4

Attachment:

Ultrasonic Examination Reports #97-0136 and #97-0136 R1  ;

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