Document: NUREG-0800
Document ID: 006d1df0-36dd-4f98-9175-0687be132d43
Document Type: srp
Title: Geologic and Tectonic Characteristics of Site and Region.   Seismic sources
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730593.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.2.2
CFR Part: 
CFR Title: 

Content:
ied. In the CEUS, the seismic sources will most likely be seismogenic sources with large regions of diffuse seismicity, each characterized by its own recurrence model. The staff interprets seismogenic sources to be regions of assumed uniform seismicity (same frequency of occurrence) distinct from the seismicity of the surrounding area. The proposed seismogenic sources may be based on seismicity studies, differences in geologic history, differences in the current tectonic regime, or other tectonic considerations. The staff considers that the most important factors for the determination of seismic sources include both (1) development and characteristics of the current tectonic regime of the region that is most likely reflected in the Quaternary period (approximately the last 1.8 million years and younger geologic history) and (2) the pattern and level of historical seismicity. Those characteristics of geologic structure, tectonic history, present and past stress regimes, and seismicity that distinguish the various seismic sources and the particular areas within those sources where historical earthquakes have occurred should be described. Alternative regional tectonic models derived from available literature should be discussed. The model that best conforms to the observed data is accepted. In addition, in those areas where there are capable tectonic sources, the results of the additional investigative requirements described in SRP Section 2.5.1 must be presented. The discussion should be augmented by a regional-scale map showing the seismic sources, earthquake epicenters, locations of geologic structures, and other features that characterize the seismic sources. 3.