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:
yses can typically be placed at the free ground surface or at the foundation level using the guidance in this SRP Section 3.7.1, “Seismic Design Parameters,” as supplemented by DC/COL-ISG-017. The design response spectra for the OBE and SSE are reviewed. The design response spectra, in general, are relatively smooth plots not exhibiting random peaks and valleys. The use of smooth spectra is preferred in the design and is 3.7.1-4 Revision 4 – December 2014 needed for generic site seismic hazard evaluation, as in the design of a standard plant. The use of unsmoothed design response spectra to develop the input ground motions (design time histories) are 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 PGA 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 is 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. 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