ML20133M757

Suggests Mod to Facility Overview in Order to Avoid Use of Specific Probabilistic Numerical Values Based on Preliminary Info Unless Absolutely Necessary.Original Response Spectrum Adequate

ML20133M757
Person / Time
Site:	Beaver Valley, 05000000
Issue date:	06/12/1979
From:	Jackson B NRC
To:	Russell W NRC
Shared Package
ML20133M133	List: IA-85-301, Forwards Draft Temporary Instruction Providing Guidance for Inspecting & Evaluating Licensee & CP Holder Responses to IE Bulletin 79-14, Seismic Analysis for As-Built.... Comments Requested by 790723.Supporting Documentation Encl ML20133M130 ML20133M162 ML20133M174 ML20133M190 ML20133M211 ML20133M223 ML20133M232 ML20133M247 ML20133M261 ML20133M293 ML20133M428 ML20133M451 ML20133M483 ML20133M505 ML20133M523 ML20133M555 ML20133M575 ML20133M607 ML20133M621 ML20133M635 ML20133M646 ML20133M662 ML20133M685 ML20133M699 ML20133M722 ML20133M737 ML20133M757 ML20133M771 ML20133M786 ML20133M842 ML20133M853 ML20133M891 ML20133M908 ML20133M919 ML20133M959 ML20133M996 ML20133N121 ML20133N130 ML20133N148 ML20133N166 ML20133N203 ML20133N381 ML20133N390 ML20133N407 ML20133N418 ML20133N421 ML20133N434 ML20133N440
References
FOIA-85-301 NUDOCS 8508130249
Download: ML20133M757 (4)

Text

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June 12, 1979 l i

I Note to: William Russell l l

On May 30, 1979, Mr. Denise provided to you an overview of the Beaver Valley site. We would like to suggest that the following modification b2 made to the overview in order that we avoid the use of specific probabilistic numerical values. based on preliminary information unless absolutely necessary.

Our overview of the Beaver Valley site indicates the following: ht!Erw ntOlQ

1. The SSE free field around motion (Housner-based spectra anchored gug" y_

at. 125g) aporoximates what the apolication of current Standard Review Plan orocedures (Trifunac and Bradv correlation and R. G.

1.60) would provide for soil or rock sites in.this region where soil amplification is not considered sionificant. For.an added persoective, the Beaver Valley spectrum is more conservative than that used for design of Maine Yankee, and is roughly equivalent to a Reculatory Guide 1.60 spectra anchored at about 0.lg for -

frequencies of 2 to 10 hertz.

2. Examination of suites of re onse soectra recorded at sites with.

different foundation conditions indicates that when representative rock motion and current methods for evaluating soil amolification are considered then the resultant derived. response spectra could exceedthepresentdesignspectraforBeaverValley.  ;

3. Althouah it is difficult to make specific predictions of such spectra without detailed analysis, the differences between the oriainal assumed ground motion and a more recent estimate would be more like, for example, -

the smaller departures noted in the Sequoyah NPP review rather than the laroer deoartures noted during our Maine Yankee review.

4. There is an almost total lack of historical seismicity in the vicinity (50 kilometer radius) of the Beaver Valley site.

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. 2-Summary Based upon limited consideration of current Standard Review Plan procedures, strong around motion records at sites with different foundation conditions and the absence of historical seismicity, we conclude that the oriainal Beaver Valley response spectrum is an adequate representation of free field ground motion for use in the nine-stress analysis which is beina evaluated under the current show cause order.

ob ckson cc: R. Denise J. Kniant ,

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UNITED STATES NUCLEAR REGULATORY COMMISSION

y WASHINGTON, D. C. 20555

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l June 12, 1979 l l

Note to: William Russell On May 30, 1979, Mr. Denise provided to .you an overview of the Beaver Valley site. We.would like to suggest that the following modification be made to the overview in order that we avoid the use of specific probabilistic numerical values based on preliminary information unless absolutely necessary.

OuroverviewoftheBeaverValleysiteindicatesthefollowinq7

1. The SSE free field around motion (H6usner-based spectra anchored 7

at. 125g) aporoximates what the apolication of current Standard Review Plan orocedures (Trifunac and Bradv correlation and R. G.

1.60) would provide for soil or rock sites in.this region where soil amplification is not considered sianificant. For.an added persoective, the Beaver Vallev soectrum is more conservative than that used for design of Maine Yankee, and is roughly equivalent to a Reculatory Guide.l.60 spectra anchored at about 0.lg for frequencies of 2 to 10 hertz.

2. Examination of suites of sesponse soectra recorded at sites with, different foundation conditions indicates that when representative rock motion and current methods for evaluating soil amolification are considered then the resultant derived. response spectra could exceedtheoresentdesignspectraforBeaverValley.

3. Althouah it is difficult to make specific predictions of such spectra without detailed analysis, the differences between the oriainal assumed ground motion and a more recent estimate would be more like, for example, the smaller departures noted in the Sequoyah NPP review rather than the laraer departures noted during our Maine Yankee review.

4. There is an almost total lack of historical seismicit.y in the vicinity (50 kilometer radius) of the Beaver Valley site.

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i Sumary Based upon limited consideration of current Standard Review Plan procedures, strong around motion records at sites with different foundation conditions and the absence of historical seismicity, we conclude that the oriainal Beaver Valley response spectrum is an adequate representation of free field ground motion for use in the oice-stress analysis which is beina evaluated under the current show cause order.

ob ckson cc: R. Denise J. Kniaht 6

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