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:
oulos, "Application of Reduction Methods to Nuclear Power Plant Structures," NUREG/CR-3074, April 1983.79 410. NUREG/CP-0054, "Proceedings of the Workshop on Soil-Structure Interaction," Bethesda, MD, NUREG/CP-0054, June 16-18, 1986.80 511. ASCE Standard 4-86, "Seismic Analysis of Safety-Related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety-Related Nuclear Structures," American Society of Civil Engineers, September 1986. 12. ASME Boiler and Pressure Vessel Code, Section III, "Rules for Construction of Nuclear Power Plant Components," Division 1, Appendix N, "Dynamic Analysis Methods," American Society of Mechanical Engineers.81 613. A. S. Veletsos, "Dynamics of Structure-Foundation Systems," Structural and Geotechnical Mechanics, W. J. Hall, editor, Prentice-Hall, Inc., Englewood Cliffs, NJ, pp. 333-361, 1977. DRAFT Rev. 3 - April 1996 3.7.2-26 1014. C. A. Miller, C. J. Costantino, and A. J. Philippacopoulos, "High Soil-Structure Damping Combined with Low Structural Damping," 7th Structural Mechanics in Reactor Technology (SMiRT) Paper K 10/10, Chicago, IL, 1985. di N n 1 cn× n,i 3.7.2-27 DRAFT Rev. 3 - April 1996 APPENDIX A TO SRP SECTION 3.7.2 ACCEPTABLE METHODOLOGIES TO ACCOUNT FOR HIGH-FREQUENCY MODES Section 3.7.2 of the SRP requires that sufficient modes be included in a dynamic response analysis to ensure that an inclusion of additional modes does not result in more than a 10 percent increase in responses. The implementation of this requirement may require the inclusion of modes with natural frequencies at which the spectral acceleration roughly returns to the zero- period acceleration. The square-root-of-sum-of-squares (SRSS) combination of such modes is highly inaccurate and may be significantly unconservative. The SRSS combination of modal responses is based on the premise that peak modal responses are randomly phased in time. This assumption has been shown to be adequate throughout the majority of the frequency range for