ML17037C118

Letter Reporting Cracks That Were Discovered in the Reactor Steam Dryer Assembly at Nine Mile Point

ML17037C118
Person / Time
Site:	Nine Mile Point
Issue date:	05/07/1973
From:	Burt P Niagara Mohawk Power Corp
To:	Skovholt D US Atomic Energy Commission (AEC)
References
Download: ML17037C118 (4)

Text

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AEC El U IO'f FOR ART TEMPORARY FORi>A COAATROL iNO'100 FI FROMM Niagara Mohawk Power Corporation Lycoming, -New York 13093 Allister Burt 5-7-73 5-11-73'ATE OF DOC:

DATE REC'D LTR MEi~IO RPZ OTmR TO 2 Donald J; Skovholt CLASS'P Xi'RIG CC IitFuT

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50-220 DESCRIPTION:

Ltr,reporting of cracks that were discovered.

in the Keactor Steam Dryer assembly at Nine Mile Point...,..

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MOHAWK Nine Mile Point Nuclear Station Post Office Box 32

Lycoming, New York 13093 May 7, 1973 Mr. Donald J. Skovholt Assistant Director for Reactor Operations Division of Reactor Licensing United States Atomic Enexgy Commission 1<ashington, D. C.

20545

Dear Mr. Skovholt:

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Provisional Operating License:

DPR-17 Docket No.:

50-220 The purpose of this letter is to infor'm you of cracks that were discovered in the Reactor Steam Dryer assembly at Nine Mile Point Nuclear Station, Unit ¹l.

The steam dryer assembly is mounted in the reactor vessel above the steam separator assembly.

It forms the top and sides of the wet steam plenum and provides a seal between the wet steam plenum and the dry steam flowing out the top and down the steam nozzles.

Moisture is removed by impinging on the dryer vanes, flowing down through collecting troughs and drain tubes to the reactor water in the downcomer annulus below the steam separators.

The cracking that has occuxred is limited to the upper portion of the dryer assembly in existing welds except for a 3" extension of one crack into the parent metal.

At this time an investigation and repair procedure formulation is being performed by Nine Mile Point Staff and General Electric Company, the Nuclear Steam supply manufacturer.

A complete report will be submitted in the next semi-annual report.

PAB:cm Very truly yours, P. Allister Burt, General Superintendent Nuclear Generation gLOO