Document: NUREG-0800
Document ID: e40387bd-a6d6-49ae-a11b-6d22124df03a
Document Type: srp
Title: Each calculated spectrum of the artificial time history is considered to envelop the
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070317.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.0
CFR Part: 
CFR Title: 

Content:
as governed by Regulatory Guide 1.60 definitions.) Similarly, power below 0.3 Hz has no influence on stiff nuclear plant facilities, so that checks below 0.3 Hz are DRAFT Rev. 3 - April 1996 3.7.1-14 unnecessary. This minimum check is set at 80 percent of the target PSD so as to be sufficiently high to prevent a deficiency of power over any broad frequency band, but sufficiently low that this requirement introduces no additional conservatism over that already embodied in the Regulatory Guide 1.60 response spectrum. A time history meeting this minimum PSD requirement will produce a response spectrum that lies below the Regulatory Guide 1.60 response spectrum at all frequencies. To produce a response spectrum that accurately fits the 2 percent damped, 1.0 g, Regulatory Guide 1.60 response spectrum at all frequencies above 0.25 Hz, the PSD defined by Equation (2) can be used with the resulting time history being clipped at ±1.0 g (Ref. 7see NUREG/CR-3509, Reference 9) . 79 To produce a response spectrum that conservatively envelops the 1.0 g Regulatory Guide 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. SRP Draft Section 3.7.1 Attachment A - Proposed Changes in Order of Occurrence 3.7.1-15 DRAFT Rev. 3 - April 1996 Item numbers in the following table correspond to superscript numbers in the redline/strikeout copy of the draft SRP section. Item Source Description 1. SRP-UDP Format Item, Update PRB Changed PRB name to reflect latest responsibility names. assignments for SRP section 3.7.1. 2. Editorial. Added document title and changed reference citation to the updated Item number in VI. References. 3. Editorial. Consistent with other SRP sections, added the acronym SSC for "structure, system and component," to be used in lieu of the full expression. 4. Editorial. Deleted "operating basis earthquake," as the acronym "OBE" had been