Document: NUREG-0800
Document ID: e7548e72-8c59-4c82-98dd-ff425e1de29a
Document Type: srp
Title: SEISMIC DESIGN PARAMETERS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12352A305.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.1
CFR Part: 
CFR Title: 

Content:
n the design of a standard plant. The use of unsmoothed design response spectra to develop the input ground motion (design time history) will be reviewed on a case-by-case basis. A review is also made of the approach used to demonstrate that the horizontal component of the SSE ground motion in the free-field at the foundation level of seismic Category I structures is an appropriate response spectrum with a peak ground acceleration of at least 0.1 g, as required by Appendix S to 10 CFR Part 50. B. Design Time Histories. Acceleration time histories for computing the response of seismic Category I SSCs are reviewed. The extent to which these time histories are compatible with the design response spectra are reviewed. When an appropriate recorded or specified time history is not available as input ground motion for seismic system analysis, the three spatial components of artificial time histories may be generated from the design response spectra for the purpose of carrying out a time history analysis of the SSCs. In demonstrating the statistical independence of the three components of ground motion, the correlation coefficients between the time histories are reviewed. The response spectra obtained from such artificial time histories of ground motion should generally envelop the design response spectra for all damping values to be used. 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 3.7.1-4 Draft Revision 4 - December 2012 may be considered. In either case, the time histories may be real or artificial. Option 1: Single Set of Time Histories. The