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:
n the modal response combination. When modes with closely spaced modal frequencies exist (two modes having frequencies within 10 percent of each other), the methods delineated in Reference 8Regulatory Guide 1.92 are acceptable. Use of other methods for considering closely spaced modes, such 45 as those outlined in References 48 and 910 will be reviewed and accepted on a case-by- 46 case basis. Acceptance criteria for the adequate consideration of high-frequency modes are provided in Appendix A to this SRP section. 8. Interaction of Non-Category I Structures with Category I Structures To be acceptable, the interfaces between Category I and non-Category I structures and plant equipment must be designed for the dynamic loads and displacements produced by both the Category I and non-Category I structures and plant equipment. In addition, a statement indicating the fact that all non-Category I structures meet any one of the following requirements should be provided. a. The collapse of any non-Category I structure will not cause the non-Category I structure to strike a seismic Category I structure or component. b. The collapse of any non-Category I structure will not impair the integrity of seismic Category I structures or components, nor result in incapacitating injury to control room occupants.47 c. The non-Category I structures will be analyzed and designed to prevent their failure under SSE conditions in a manner such that the margin of safety of these structures is equivalent to that of Category I structures. 9. Effects of Parameter Variations on Floor Response Spectra Consideration should be given in the analysis to the effects on floor response spectra (e.g., peak width and period coordinates) of expected variations of structural properties, dampings values , soil properties, and soil-structure interactions. The acceptance criteria 48 for the consideration of the effects of parameter variations are provided in subsection II.5 of this SRP section. 10. Use of