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:
4 interaction, development of floor response spectra, inclusion of torsional effects, seismic analysis of Category I concrete dams, evaluation of Category I structure overturning, and determination of composite damping. The review included design criteria and procedures for evaluation of the interaction of non-Category I structures with Category I structures and the effects of parameter variations on floor response spectra. The review also included criteria and seismic analysis procedures for Category I buried piping outside containment and above-ground Category I tanks. The system and subsystem analyses are performed by the applicant on an elastic and linear basis. Time history methods form the bases for the analyses of all major Category I structures, systems, and componentsSSCs . When the modal response spectrum 65 method is used, the methods used in combining modal responses are in conformance with the position of Regulatory Guide 1.92 and also meet high-frequency mode contribution requirements. The square root of the sum of the squares of the maximum codirectional responses is used in accounting for three components of the earthquake motion for both the time history and response spectrum methods. Floor spectra inputs to be used for design and test verifications of structures, systems, and componentsSSCs are generated 66 from the time history method and they are in conformance with the position of Regulatory Guide 1.122. A vertical seismic system dynamic analysis is employed for all DRAFT Rev. 3 - April 1996 3.7.2-24 structures, systems, and componentsSSCs where analyses show significant structural 67 amplification in the vertical direction. Torsional effects and stability against overturning are considered. A coupled structure and soil model is used to evaluate soil-structure interaction effects upon seismic responses. Appropriate nonlinear stress-strain and damping relationships for the soil are considered in the analysis. We conclude that the use of the