Document: NUREG-0800
Document ID: 48a7b79e-0dde-49df-9914-7c7b714c22f8
Document Type: srp
Title: Geologic and Tectonic Characteristics of Site and Region.  For sites in the
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1331/ML13316C066.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.2.2
CFR Part: 
CFR Title: 

Content:
CEUS, the seismic source characterization model described in NUREG-2115, “Central and Eastern United States Seismic Source Characterization for Nuclear Facilities” (CEUS-SSC) provides an acceptable starting model for nuclear power plant PSHA studies. The CEUS-SSC model is primarily a regional-scale model and therefore local seismic sources need to be analyzed for potential inclusion in the PSHA. Hence, COL, CP, and ESP applicants will need to conduct local geologic investigations to determine if local seismic sources should be included as part of the site characterization. The larger regional seismic sources characterized by the model will also need to be evaluated as future studies and data might indicate that updates are appropriate. Before deciding whether new models and/or updates to existing models are needed, rather than 2.5.2-7 Revision 5 – July 2014 using a pre-established percentage increase in the seismic hazard, applicants should consider factors such as the views of the scientific community, uncertainty in estimations, and the final impact on the seismic hazard calculations. Updates to any seismic sources or ground motion prediction equations (GMPEs) should be conducted consistent with the methods described in NUREG/CR-6372, “Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts” and NUREG-2117, “Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies.” Therefore to meet the requirements of 10 CFR 100.23, this subsection is acceptable when adequate information is provided to demonstrate: (1) that a thorough investigation has been conducted to identify seismic sources that could be significant in estimating the seismic hazards of the region if they exist; and (2) that existing sources (in the PSHA) are consistent with the results of site and regional investigations or the sources have been updated in accordance with Regulatory Position 3 and Appendix C of RG 1.208. For sites