Document: NUREG-0800
Document ID: 94da2f11-6df6-47d0-a25e-edeb21a4d649
Document Type: srp
Title: 3.7.1-12
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1419/ML14198A460.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.0
CFR Part: 
CFR Title: 

Content:
e randomized soil profiles similar to those used in the PSHA process and reviewed under SRP Section 2.5.2 and as described in DC/COL-ISG-017. From this set of randomized columns, three individual soil columns are generated with individual layer properties (shear wave velocity and iterated hysteretic damping) selected at the best estimate (BE), lower bound (LB) at minus one standard deviation values, and upper bound (UB) at plus one standard deviation values. For SSI analyses, the LB and UB profiles may be modified to ensure that they satisfy the criteria of COV in velocity properties as described in SRP Section 3.7.2. These individual soil columns are to be used in deterministic site response and SSI analyses described in SRP Section 3.7.2. Free-field response spectra are then generated at the ground surface from the FIRS input at the foundation level for each of these three deterministic soil profiles. The envelope of these three spectra (BE, LB, and UB) should equal or exceed the corresponding PBSRS. If the envelope spectra do not equal or exceed the PBSRS, additional soil profiles can be developed for which SSI analyses are to be performed or, the input time histories may be modified in accordance with DC/COL-ISG-017, Section 5.2 – “Position on Site-Consistent Seismic Input and Soil Profiles Properties for the SSI Analysis.” v. When the site-specific FIRS and the CSDRS are calculated at the same elevation, confirm that the CSDRS envelop the FIRS as indicated in DC/COL-ISG-017 provided that the site-specific soil profile is captured within the range of profiles considered in the development of the CSDRS. For this case the standard design is acceptable for that site, assuming no other issue is identified during the review process. If the CSDRS do not envelop the site-specific FIRS, then proceed to step viii. vi. When the site-specific FIRS and the CSDRS are determined at different elevations, the CSDRS-consistent spectra should be calculated at the