Document: NUREG-0800
Document ID: acd9ebb4-ee58-4db4-b1b3-47182cad2c4f
Document Type: srp
Title: Safe Shutdown Earthquake
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0423/ML042390209.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.2.6
CFR Part: 
CFR Title: 

Content:
- - 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 C~ 43 4hc following steps suummarize the staft review of the SLE. 1. Both horizontal and vertical component site-specific response spectra should be developed statistically from response spectra of recorded strong motion records that are selected to have similar source, propagation path, and recording site properties as the controlling earthquakes. It must be ensured that the recorded motions represent free-field conditions and are free of or corrected for any soil- structure interaction effects that may be present because of locations .affor housing of recording instruments. Important source properties include magnitude and, if possible, fault type7 and tectonic environment. Propagation path properties include distance, depth, and attenuation. Relevant site properties include shear velocity profile and other factors that affect the amplitude of waves at different frequencies. A sufficiently large number of site-specific time- histories or response spectra or both should be used to obtain an adequately broadband spectrum to encompass the uncertainties in these parameters. An 84th percentile response spectrum for the records should be presented for each damping value of interest. and eempared to the SSE 2.5.2-12 I free field and design response spectrum (e.g., Refs. 30, 31, 32, and 33 2 ). The staff considers direct estimates of spectral 3 ordinates preferable to scaling of spectra to peak accelerations. 4A 4 the Eastrn United States, relatively little infermation is availabce on 5 magnitudes for the larger historic earthquakes; hence, it may be 6 appropriatc to rely on intensity observations (descriptions of 7 earthquake offsets) to estimate magnitudes of historic events (c.g.7 8 Refs. 34 and 35). If the data for site-specific response spectra were 9 not obtained under geologic conditions similar to those at the site, 10 corrections for site effects should be included in the development of 11 the site-specific