ML20128G226

Requests NRC Review & Approval to Use ASME Code Case N-411, Alternative Damping Values for Seismic Analysis of Piping, by 850718 for Response Spectrum Analyses of Selected Piping

ML20128G226
Person / Time
Site:	Davis Besse
Issue date:	07/02/1985
From:	Williams J TOLEDO EDISON CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
1163, TAC-59225, NUDOCS 8507090110
Download: ML20128G226 (2)

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Docket No. 50-346 TOLEDO License No. NPF-3 EDISON Serial No. 1163 July 2, 1985 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz Operating Reactor Branch No. 4 Division of Licensing United States Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Stolz:

The Toledo Edison Company requests NRC approval to use ASME Code Case N-411, Alternative Damping Values for Seismic Analysis of Piping, an alternative to Table N-1230-1, Appendix N of ASME Section III, Division 1, for response spectrum seismic analyses of selected piping at the Davis-Besse Nuclear Power Station Unit No. 1.

It is Toledo Edison's intention to utilize Code Case N-411 damping values for selected new response spectrum seismic analyses, reconciliation work, modifications, and support optimization. These code case values may be used in lieu of the critical damping value of 0.5% currently specified in subsection 3.7.1.3 and Table 3.7-1 of the USAR for both the Operating Basis Earthquake (OBE) and Safe Shutdown Earthquake (SSE). The USAR will -

be revised in subsequent amendments to reflect any use of Code Case N-411.

When Code Case N-411 damping values are used, piping displacements will be checked to ensure that displacements can be accommodated, that there will be no adverse interaction with adjacent structures, components and equip-ment, and that any mounted equipment can withstand the increased motion.

When the alternate damping criteria of Code Case N-411 are used, Toledo Edison will not mix Regulatory Guide 1.61 criteria and the alternate criteria of this Code Case in a given analysis.

' Toledo Edison requests the NRC issue its approval to use Code Case N-411 on an expeditious basis by July 18, 1985.

[ool IO f Db f U S .00 THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MAOISON AVENUE TOLEDO, OHIO 43652

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D ck2t No. 50-346

' License No. NPF-3 Serial No. 1163

. July 2, 1985 Page.2' Enclosed is a' check for $150 as L required by 10 CFR 170.12(c) for this review and approval.

Very truly.yours,-

p tv% J v.

' Joe Willisims , = J r.

Senior Vice President, Nuclear.

JW:DRW:lah cc: DB-1 NRC Resident Inspector i3 u-

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