ML20206G223

SER Accepting Licensee Request to Use Damping Values from ASME Code Case N-411 Per Conditions Outlined in Util

ML20206G223
Person / Time
Site:	Beaver Valley
Issue date:	03/12/1987
From:	NRC
To:
Shared Package
ML20206G193	List: ML20206G190 ML20206G223
References
NUDOCS 8704140478
Download: ML20206G223 (2)

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SAFETY EVALUATION REPORT USF OF ASME CODE CASE N 411 BEAVER VALLEY POWER STATION, UNIT 1 Docket No.: 50-334

, l Use of ASME Code Case N-411 l In a letter dated January 28, 1987, the licensee submitted a proposed draft of Section B.2.1.1? of the Beaver Valley Power Station, Unit 1 Updated FSAR.

In this draft, the licensee provided a comitment to 14 conditions which will i be met if ASME Code Case N-411. " Alternate Damping Values for Seismic Analysis of Classes 1,2, and 3 Piping Sections,Section III, Division 1" is used for piping modifications and future piping stress analyses at Beaver Valley, Unit

1. This comitment includes all of the staff recomended conditions which have i to be fulfilled in order to use Code Case N-411 and which are listed in Regulatory Guide 1.84 " Design and Fabrication Code Case Acceptability, ASME Section III, Division 1," Revision 24, dated June 1986. One of these conditions is that the damping values in the Code Case may be used only in those analyses in which current seismic spectra have been employed. The Design Basis Earthquake Response Spectra for 2% damping in Figure 2.5-1 of the Beaver Valley, Unit 1 Updated FSAR is almost identical to the Safe Shutdown i . Earthquake Response Spectra for 2% damping in Fioure 3.7B-5 of the Beaver Valley, Unit 2 FSAR. In Section 2.5.2.6.4 of the Beaver Valley, Unit 2 SER dated October 1985, the staff approved this spectra. Therefore, the staff considers the Beaver Valley, Unit I seismic spectra to be " current."

In addition to comitments to the conditions of Regulatory Guide 1.84, the licensee's proposed draft of the Updated FSAR contains comitments to assess the impact of using these new damping values on the design of various safety-related components and equipment. A listing of all applications of Code Case N-411 will be maintained by the licensee and the individual files of pipe stress packages which have been reanalyzed using this Code Case will be available in its respective Design Change Package records. ,

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On the basis of the above discussion, the staff has concluded that the licensee's request to use the damping values from ASME Code Case N-411 under

the conditions outlined in the January 28, 1987 letter is acceptable.

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Principal contributor H. Brammer Dated fiarch 12, 1987 e

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