Document: NUREG-0800
Document ID: 45f5d841-54ef-4876-be3e-86eafc6ca90a
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/ML1235/ML12352A305.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.0
CFR Part: 
CFR Title: 

Content:
with the resulting time history being clipped at ±1.0 g (see NUREG/CR-3509). To produce a response spectrum that conservatively envelops the 1.0 g, RG 1.60 response spectrum at 2 percent damping and greater, a PSD set at 130 percent of the PSD defined by Equation (2) can be used with the resulting time history being clipped at ±1.0 g. REFERENCES 1. NUREG/CR-3509, "Power Spectral Density Functions Compatible with NRC Regulatory Guide 1.60 Response Spectra," June 1988. 2. NUREG/CR-5347, "Recommendations for Resolution of Public Comments on USI A-40, Seismic Design Criteria," June 1989. 3. RG 1.60, "Design Response Spectra for Seismic Design of Nuclear Power Plants." 3.7.1-26 Draft Revision 4 - December 2012 APPENDIX B TO SRP SECTION 3.7.1 SPECIFICATION FOR MINIMUM POWER SPECTRAL DENSITY 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 Power Spectral Density (PSD) requirement should be satisfied. When the response spectrum is derived from an envelope of spectra from multiple Magnitude and Distance bins, the envelope 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 ( ) F f of the time history by the equation .............................................................................(1) where TD is the strong motion duration over which ( ) F f is evaluated. This duration TD represents the duration of near maximum and nearly stationary power of an