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:
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 spectra. 12 2. Where a large enough ensemble of strong-motion records is not available, 13 response spectra may be approximated by scaling that ensemble of strong- 14 motion data that represent the best estimate of source, propagation 15 path, and site properties (e.g., Ref. 36 ) Sensitivity studies 16 should show the effects of scaling. 17 3. If strong-motion records are not available, site-specific peak ground 18 acceleration, velocity, and displacement (if necessary) should be deter- 19 mined for appropriate magnitude, distance, and foundation conditions. 20 Then response spectra may be determined by scaling the acceleration, 21 velocity, and displacement values by appropriate amplification factors 22 (e.g., Ref. 3 E). Where only estimates of peak ground acecclration 23 arc available, it is aeeeptablc to selcet a peak aeceecration and use 24 this peak aeeeleratien as tc hih rquency asymptete to standardized 25 response spectra such as described in Regulatory Guide 1.60 (Ref'. 6) fer 26 both the horizontal and vertical component; of motion with the 27 appropriate amplification factors. For each controlling earthquake, the 28 peak ground motions should be determined using current relations between 29 acceleration, velocity, and, if necessary, displacement, earthquake size 30 (magnitude or intensity), and source distance. Peak ground motion 31 should be determined from state-of-the-art relationships. Relationships 32 between magnitude and ground motion are found, for example,,in 33 References 12 Due-ue to the limited data for high 34 intensities greater than Modified Mercalli Intensity (MMI) VIII, the 35 available empirical relationships between intensity and peak ground 2.5.2-13 1 2 3 4 5 6 7 8 9 10 motion may not be suitable for determining the appropriate reference