Document: NUREG-0800
Document ID: cb77498f-f3f6-40aa-9009-12bc5c3a0a2a
Document Type: srp
Title: -
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12353A354.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
CFR Part: 
CFR Title: 

Content:
Draft Revision 4 - December 2012 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 SSCs. When the modal response spectrum method is used, the methods used in combining modal responses are in conformance with the regulatory positions in RG 1.92, if used, alternate methods have been evaluated and found to be acceptable. Floor spectra inputs to be used for design and test verifications of SSCs are generated from the time history method, and they are in conformance with the position of RG 1.122, as augmented in this SRP section. A vertical seismic system dynamic analysis is employed for all SSCs where analyses show significant structural amplification in the vertical direction. Torsional effects and stability against overturning are considered. A coupled structure and soil model is used to evaluate SSI 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 seismic structural analysis procedures and criteria delineated above by the applicant provides an acceptable basis for the seismic design which is in conformance with the requirements of item 3 listed above. For DC and COL reviews, the findings will also summarize the staff's evaluation of requirements and restrictions (e.g., interface requirements and site parameters) and COL action items relevant to this SRP section. In addition, to the extent that the review is not discussed in other Safety Evaluation Report (SER) sections, the findings will summarize the staff's evaluation of the ITAAC, including design acceptance criteria, as applicable. V. IMPLEMENTATION The following is intended to provide guidance to applicants and licensees regarding the NRC staff's plans for using this SRP section. The staff will use this SRP section in performing safety evaluations of DC applications and