Document: NUREG-0800
Document ID: 585516eb-af20-45dc-a470-9638ec9381f3
Document Type: srp
Title: Each calculated spectrum of the artificial time history is considered to envelop
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070640306.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.0
CFR Part: 
CFR Title: 

Content:
ectra," June 1988. 3. NUREG/CR-5347, "Recommendations for Resolution of Public Comments on USI A-40, Seismic Design Criteria," June 1989. 3.7.1-24 Revision 3 - March 2007 ( ) ( ) S f F f T o D = 2 2 2 π APPENDIX B TO SRP SECTION 3.7.1 SPECIFICATION FOR MINIMUM POWER SPECTRAL DENSITY (PSD) REQUIREMENT FOR HORIZONTAL SPECTRUM BASED ON NUREG/CR-6728 For a horizontal response spectrum anchored to 1.0g that is based on spectrum consistent with the Magnitude and Distance bin shapes in NUREG/CR-6728, the following minimum PSD requirement should be satisfied. When the response spectrum is derived from an envelope of spectra from multiple Magnitude and Distance bins, the envelop of the PSD should be used. For other peak accelerations, this PSD requirement should be scaled by the square of the peak acceleration. The power spectral density for an acceleration time history can be computed as either a two- sided function of positive and negative frequencies or a one-sided function of only positive frequencies. Since only positive frequencies are realizable, the one-sided PSD is used to define the target criterion. The one sided PSD is related to the Fourier amplitude of the ( ) F f time history by the equation .............................................................................(1) where is the strong motion duration over which is evaluated. This duration TD ( ) F f TD represents the duration of near maximum and nearly stationary power of an acceleration time history record. Additional guidance on estimation of for artificial time history or actual TD earthquake time history is provided in Appendix B of NUREG/CR-5347. The average one-sided PSD defined by Equation (1) should exceed 80 percent of the appropriate Magnitude and Distance bin target PSD as shown in Tables 1 through 4. At any frequency the average PSD is computed over a frequency band width of ±20 f , percent, centered on the frequency (e.g., 4 Hz to 6 Hz band width for = 5 Hz). f f The power above 25 Hz for