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
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - StructuralCivil Engineering and Geosciences Branch (ESGBECGB ) 1 Secondary - None I. AREAS OF REVIEW The following areas related to the seismic system analysis described in the applicant's safety analysis report (SAR) are reviewed. 1. Seismic Analysis Methods For all Category I structures, systems, and components (SSCs) , the applicable seismic 2 analysis methods (response spectra, single time history or multiple time histories, equivalent static load) are reviewed. The manner in which the dynamic system analysis method is performed, including the modeling of foundation torsion, rocking, and translation, is reviewed. The method chosen for selection of significant modes and an adequate number of masses or degrees of freedom is reviewed. The manner in which consideration is given in the seismic dynamic analysis to maximum relative displacements between supports is reviewed. In addition, other significant effects that are accounted for in the dynamic seismic analysis such as hydrodynamic effects and nonlinear response are reviewed. If tests or empirical methods are used in lieu of analysis for any Category I structure, the testing procedure, load levels, and acceptance basis are also reviewed. The SRP criteria generally deal with linear elastic analysis coupled with allowable stresses near elastic limits of the structures. However, for certain special cases (e.g., evaluation of as-built structures), the staff has accepted the concept of DRAFT Rev. 3 - April 1996 3.7.2-2 limited inelastic/nonlinear behavior when appropriate. The actual analysis, incorporating inelastic/nonlinear considerations, is reviewed on a case-by-case basis. 2. Natural Frequencies and Responses For the operating license review, significant natural frequencies and responses for major Category I structures are reviewed. In addition, the response spectra at major Category I equipment elevations and points of support are reviewed. 3. Procedures Used for Analytical