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:
levels of investigations and the bases for them is presented in Appendix D to this regulatory guide. The levels of investigation are char acterized as follows. 1. Regional geological and seismological inves tigations are not expected to be extensive nor in great detail, but should include literature re views, the study of maps and remote sensing data, and, if necessary, ground truth reconnais sances conducted within a radius of 320 km (200 miles) of the site to identify seismic. sources (seismogenic and capable tectonic sources). 2. Geological, seismological, and geophysical in vestigations should be carried out within a ra dius of 40 km (25 miles) in greater detail than the regional investigations to identify and char- acterize the seismic and surface deformation potential of any capable tectonic sources and the seismic potential of seismogenic sources, or to demonstrate that such structures are not pres ent. Sites with capable tectonic or seismogenic sources within a radius of 40 km (25 miles) may require more extensive geological and seismo logical investigations and analyses (similar in detail to investigations and analysis usually preferred within an 8-km (5-mile) radius). 3. Detailed geological, seismological, geophysical, and geotechnical investigations should be con ducted within a radius of 8 km (5 miles) of the site, as appropriate, to evaluate the potential for tectonic deformation at or near the ground surface and to assess the ground motion transmission characteristics of soils and rocks in the site vicin ity. Investigations should include monitoring by a network of seismic stations. 4. Very detailed geological, geophysical, and geo technical engineering investigations should be conducted within the site [radius of approximate ly 1 km (0.5 miles)] to assess specific soil and rock characteristics as described in Regulatory Guide 1.132 (Ref. 8). 1.2 The areas of investigations may be expanded beyond those specified above in regions that include ca pable