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:
rmining whether the structure is a capable tectonic source within this definition. Notwithstanding the foregoing paragraphs, the association of a structure with geological structures that are at least pre-Quaternary, such as many of those found in the Central and Eastern regions of the United States, in the absence of conflicting evi dence will demonstrate that the structure is not a ca pable tectonic source within this definition. 1.165-10 K Seismogenic Source - A seismogenic source is a portion of the earth that we assume has uniform earthquake potential (same expected maximum earthquake and recurrence frequency), distinct from the seismicity of the surrounding regions. A seismogenic source will generate vibratory ground motion but is assumed not to cause surface dis placement. Seismogenic sources cover a wide range of possibilities from a well-defined tectonic structure to simply a large region of diffuse seis micity (seismotectonic province) thought to be characterized by the same earthquake recurrence model. A seismogenic source is also characterized by its involvement in the current tectonic regime (the Quaternary, or approximately the last 2 million years). Stable Continental Region -A stable continental re gion (SCR) is composed of continental crust, including continental shelves, slopes, and attenuated continental crust, and excludes active plate boundaries and zones of currently active tectonics directly influenced by plate margin processes. It exhibits no significant deforma tion associated with the major Mesozoic-to-Cenozoic (last 240 million years) orogenic belts. It excludes ma jor zones of Neogene (last 25 million years) rifting, vol canism, or suturing. Stationary Poisson Process - A probabilistic model of the occurrence of an event over time (space) that is characterized by (1) the occurrence of the event in small intervals is constant over time (space), (2) the occur rence of two (or more) events in a small interval is neg ligible, and (3) the