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:
solution methods for the generation of in-structure response spectra. These techniques do not involve time history analysis. The basis and justification for the use of either of the above methods are reviewed. 6. Three Components of Earthquake Motion The procedures by which the three components of earthquake motion are considered in determining the seismic response of structures, systems, and componentsSSCs are 4 reviewed. 7. Combination of Modal Responses When a response spectrum method is used for calculating the seismic response of structures, systems, or componentsSSCs , the phase relationship between various modes 5 is lost. Only the maximum response for each mode can be determined. The maximum responses for modes do not in general occur at the same time, and these responses have to be combined according to some procedure selected to approximate or bound the response of the system. When a response spectrum method is used, the description of the DRAFT Rev. 3 - April 1996 3.7.2-4 procedure for combining modal responses (shears, moments, stresses, deflections, and accelerations) is reviewed, including that for modes with closely spaced frequencies. 8. Interaction of Non-Category I Structures with Category I Structures The design criteria to account for the seismic motion of non-Category I structures or portions thereof in the seismic design of Category I structures or portions thereof are reviewed. The seismic design of structures whose continued function is not required but whose failure could adversely impact the safety function of a Category I structure, or result in incapacitating injury to control room occupants, is reviewed. The procedures 6 that are used to protect Category I structures from the structural failure of non-Category I structures, due to seismic effects, are reviewed. 9. Effects of Parameter Variations on Floor Responses The procedures that are used to consider the effects of the expected variations of structural properties, dampings values ,