ML20059L427

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Requests Approval for Use of Steam Generator Tube Plugs for Both Mechanical & Welded Applications
ML20059L427
Person / Time
Site: Beaver Valley
Issue date: 09/07/1990
From: Sieber J
DUQUESNE LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-89-001, IEB-89-1, NUDOCS 9009260310
Download: ML20059L427 (2)


Text

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% e company gcr~s- l sm,9mt PA 1507MO34 I

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September 7, 1990 )

l U. S. Nuclear Regulatory Commission j Attnt Document Control Desk l Washington, DC 20555 '

References Beaver Valley Power Station, Unit No. 1 and No. 2 l BV-1 Docket No. 50-334, License No. DPR-66  :

BV-2 Docket No. 50-412, License No. T -73  !

Code Case N-474-1; Alloy 690 Tube P' ,

Gentlement The purpose of this submittal is to request approval, pursuant to  !

10 CFR 50.55 a (a)(3), for the use of steam generator tube plugs ,

fabricated of nickel-chromium-iron UNS N-06690 material (Alloy 690) i to plug steam generator tubes at Beaver Valley, Unit Nos. 1 and 2 for both mechanical and welded applications.

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, code case N-474-1 of the ASME Boiler and Pressure Vessel Code (approved Noverher 30, 1989) addresses Alloy 690 material and I authorizes its use in other forms for the construction of Section '

III, Division 1, Class 3 components. The material is specified in f ASME Code,Section II, material specifications SB-163, SB-167, and '

SB-168 and added in an errata to SB-166. Also, Alloy 690, in tubing  :

form (SB-163), was previously authorized for construction of Class 1  !

components.

  • The use of Alloy 690 for tube plugs as a proposed alternative to i the use of Alloy 600, in accordance with the requirements of the ASME
  • I Boiler and Pressure Vessel Code, will provide an acceptable level of quality and safety. The use of Alloy 690 material for the ,

fabrication of mechanical plugs for steam generator tubes was endorsed by the NRC' in NRC Bulletin No. 89-01, " Failure of .

Westinghouse- Steam Generator Tube Mechanical Plugs," dated May 15, 1989. Alloy 690 has superior anti-corrosion properties and similar i mechanical properties to the Alloy 600 material previously used for '

tube- plugs. The Design Stress Intensity Stipulated by the Code case i and used in the design and qualification of the tube plugs is the

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same for Alloy 690 material as for Alloy 600 material of the same form. Therefore, this material is being used,in the fabrication of tube plugs which may be utilized in the steam generators at Beaver Valley, Units l'and 2.

Authorization- of the use of the Alloy 690 material will confirm the acceptability of the use of Alloy 690 material for mechanical or i

welded plugs for removing stea..m generator tubes from service.

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Cod 3 C3co N-474-1; Alloy 690 Tub 3 Plug 3 Page 2 Beaver Valley Unit No. 2 is currently in its refueling outage.

It is our intent to use the Alloy 690 material plugs to replace certain in-place tube plugs and remove any other required tubes from service. We request that the NRC review this request and provide approval on a schedule which supports our restart from this refueling outage. This is currently scheduled for October 25, 1990. This request is similar to ones previously reviewed and approved by the NRC for other utilities.

If you have any questions, please call me or members of my staff.

Sincerely, J . Si

/VicePresident Nuclear Group cc: Mr. J. Beall, Sr. Resident Inspector Mr. T. T. Martin, NRC Region I Administrator Mr. A. W. DeAgazio, Project Manager I