Document: NRC Regulatory Guide
Document ID: a094549d-8685-4dad-b90f-c28c7d279a53
Document Type: regulatory_guide
Title: Geologic and Geotechnical Site Characterization Investigations for Nuclear Power Plants + HISTORY – HISTORY 08/2021 – DG-1392 , Proposed Revision 3 07/2014 – Periodic Review of Revision 2 – Reviewed with no issues identified 02/2001 – DG-1101 , Proposed Revision 2 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2119/ML21194A176.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.132
CFR Part: 
CFR Title: 

Content:
nd thus is not indicative of soil properties. Rayleigh wave (surface wave) dispersion Travel time and period of surface Rayleigh waves Inference of shear wave velocity in near-surface materials. Rapid technique that uses conventional refraction seismographs. Coupling of energy to the ground may be inefficient, restricting extent of survey coverage. Data resolution and penetration capability are frequency dependent; sediment layer thickness and/or depth interpretations must be considered approximate. The data interpretation model needs to be verified and validated. Vibratory (seismic) Travel time or wavelength of surface Rayleigh waves Inference of shear wave velocity in near-surface materials. Controlled vibratory source allows selection of frequency, hence wavelength and depth of penetration [up to 60 meters (m) (200 feet (ft)]. Detects low-velocity zones underlying strata of higher velocity. Accepted method. Coupling of energy to the ground may be inefficient, restricting extent of survey coverage. Data resolution and penetration capability are frequency dependent; sediment layer thickness and/or depth interpretations must be considered approximate. Reflection profiling (seismic-acoustic) Travel times of compressional waves through water and subsurface materials and amplitude of reflected signal Mapping of various lithologic horizons; detection of faults, buried stream channels, and salt domes, location of buried man- made objects; and depth determination of bedrock or other reflecting horizons. Surveys of large areas at minimal time and cost; continuity of recorded data allows direct correlation of lithologic and geologic changes; correlative drilling and coring can be kept to a minimum. Data resolution and penetration capability is frequency dependent; sediment layer thickness and/or depth to reflection horizons must be considered approximate unless true velocities are known; some bottom conditions (e.g., organic sediments) prevent penetration; water depth