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:
ential concrete cracking on structural stiffness should be addressed.58 10. Use of Equivalent Vertical Static Factors Use of constant static factors as response loads in the vertical direction for the seismic design of any Category I structure, system, or component in lieu of a detailed dynamic method is reviewed to determine that constant vertical static factors are used only if the structure is rigid in the vertical direction. 11. Methods Used to Account for Torsional Effects The methods of seismic analysis are reviewed to determine that the torsional effects of vibration are incorporated by including the torsional degrees of freedom in the dynamic model. Justification provided by the applicant for the use of any approximate method to account for torsional effects is judged to ensure that it results in a conservative design. 12. Comparison of Responses Where applicable, the responses obtained from both time history and response spectrum methods at selected points in major Category I structures are compared to judge the DRAFT Rev. 3 - April 1996 3.7.2-22 accuracy of the analyses conducted. The applicant is asked to discuss the reasons for the large differences in the results of the two methods. 13. Analysis Procedure for Damping The analysis procedure to account for damping in different elements of the model of a coupled system is reviewed to determine that it is in accordance with the acceptance criteria of subsection II.13 of this SRP section. 14. Determination of Category I Structure Overturning Moments Methods to determine Category I structure overturning moments are reviewed to determine compliance with the acceptance criteria of subsection II.14 of this SRP section. In the ABWR and System 80+ design certification FSERs the Staff accepted an exemption to the 10 CFR 100 Appendix A requirement that all safety-related SSCs be designed to remain functional and within applicable stress and deformation limits when subjected to an OBE. Acceptance of the exemption was