Document: NUREG-0800
Document ID: 78905d69-1945-4638-99b9-2db68eb3da77
Document Type: srp
Title: SEISMIC SYSTEM ANALYSIS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070318.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
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CFR Title: 

Content:
atural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated in the past. This SRP section reviews methods for seismic analysis and modeling of structures and major plant systems to assure that they accurately and/or conservatively represent the behavior of SSCs during postulated seismic events. Appropriate guidance for implementation of and achieving compliance with the requirements of General Design Criterion 2 is provided in Regulatory Guides 1.92 and 1.122. Regulatory Guide 1.92 provides various procedures acceptable to the staff for combining the three dimensional modal responses for both the response spectrum analysis approach and the time history analysis approach of nuclear power plant structures. Additionally, Regulatory Guide 1.122 describes methods acceptable to the NRC staff, to be used in developing two horizontal and one vertical floor design response spectra at various floors or other equipment support locations of interest from the time history motions, resulting from the dynamic analysis of the supporting structure. Thus, Regulatory Guide 1.122 provides the appropriate guidance for mathematical treatment of floor response spectra when dealing with in-structure seismic response analysis. Meeting the requirements of General Design Criterion 2, in conjunction with the guidelines provided in Regulatory Guides 1.92 and 1.122 assures that safety-related SSCs will continue to function following a seismic event, such that the plant can be brought to, and maintained in a safe shutdown condition. 2. Appendix A to 10 CFR 100 provides definitions for the OBE and the SSE and requires that the engineering methods used to ensure that the required safety functions are maintained during and after the vibratory ground motion associated with the SSE shall involve the use of either a suitable dynamic analysis