Document: NUREG-0800
Document ID: 1121c8ce-ab70-416c-9784-421014a1b25b
Document Type: srp
Title: SEISMIC DESIGN PARAMETERS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1419/ML14198A460.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.1
CFR Part: 
CFR Title: 

Content:
gn response spectra. The procedures used to generate response spectra from the artificial time histories and the comparisons of these response spectra with the design response spectra are reviewed. In addition to the comparison of the response spectra derived from the ground motion time histories with the design response spectra, the frequency intervals at which the spectral values are calculated are also reviewed. When time history analyses are performed, either of the following options may be considered. In either case, the time histories may be real or artificial. Option 1: Single Set of Time Histories. The justification for the use of the single set of time histories is reviewed. The approach used to demonstrate that the response spectra generated from the time histories envelop the design response spectra are reviewed. Depending on the approach used, the application of the requirements to match a target power spectral density (PSD) function compatible with the design response spectra may also be reviewed. Option 2: Multiple Sets of Time Histories. In lieu of the use of a single time history, multiple artificial or real ground motion time histories may be used for the seismic analyses and design of the SSCs. The parameters describing the time histories and the number of time histories are reviewed. The approach used to demonstrate the adequacy of the set of multiple time histories, in terms of the enveloping criteria and having sufficient power over the frequency range of interest, is reviewed. In some instances, a nonlinear analysis of the SSCs may be appropriate (e.g., stability analysis and evaluation of existing structures). Multiple time 3.7.1-5 Revision 4 – December 2014 history analyses using artificial or real earthquake time histories may be used when such analyses are proposed. The adequacy of time histories used for the nonlinear analyses is reviewed. 2. Percentage of Critical Damping Values. The percentage of critical damping values used for the