Document: NRC Regulatory Guide
Document ID: cfc61809-5745-460f-8a26-13c168659924
Document Type: regulatory_guide
Title: Identification and Characterization of Seismic Sources and Determination of Safe Shutdown Earthquake Ground Motion
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740084.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.165
CFR Part: 
CFR Title: 

Content:
what rela tionships exist between observed tectonic structures in a seismic source within the CEUS and the current earthquake activity that may be associated with that source. Generally, the observed tectonic structure re sulted from ancient tectonic forces that are no longer present. The historical seismicity record, the results of regional and site studies, and judgment play key roles. If, on the other hand, strong correlations and data exist suggesting a relationship between seismic ity and seismic sources, approaches used for more ac tive tectonic regions can be applied. The primary objective of geological, seismologi cal, and geophysical investigations is to develop an up to-date, site-specific earth science data base that sup plements existing information (Ref. D.1). In the CEUS the results of these investigations will also be used to assess whether new data and their interpretation are consistent with the information used as the basis for ac cepted probabilistic seismic hazard studies. If the new data are consistent with the existing earth science data base, modification of the hazard analysis is not required. For sites in the CEUS where there is signifi cant new information (see Appendix E) provided by the site investigation, and for sites in the Western United States, site-specific seismic sources are to be de termined. It is anticipated that for most sites in the CEUS, new information will have been adequately bounded by existing seismic source interpretations. The following is a general list of characteristics to be evaluated for a seismic source for site-specific source interpretations: "* Source zone geometry (location and extent, both surface and subsurface), "• Historical and instrumental seismicity associated with each source, "* Paleoseismicity, * Relationship of the potential seismic source to other potential seismic sources in the region, "* Seismic potential of the seismic source, based on the source's known characteristics, including