Document: NUREG-0800
Document ID: 7786a9e8-1ed1-44ea-a727-bfa570c49351
Document Type: srp
Title: -
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1235/ML12353A354.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
CFR Part: 
CFR Title: 

Content:
responses need to be considered. The NRC issued Interim Staff Guidance (DC/COL-ISG-01) on May 19, 2008, describing methods acceptable to the staff for evaluating high frequency ground motion input. It includes guidance for conducting analyses that incorporate incoherent ground motion. Because of the complexity of such analyses, and the lack of both an experience data base and test data, the implementation of the analytical methods described in DC/COL-ISG-01, for considering incoherent ground motion, is subject to staff review on a case-by-case basis. Applicants are expected to present comparisons between calculated coherent and incoherent seismic demands. Based on the staff’s current experience, the following maximum reductions in the amplitude of spectral accelerations are acceptable for the ISRS: 0 to 10 Hz – 0% reduction 30 Hz and above – 30% reduction 10 to 30 Hz – reduction based on linear variation between 0% at 10 Hz and 30% at 30 Hz