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:
ethods can be used to (1) measure shear-wave velocity profiles, (2) determine subsurface geologic conditions such as strata layers and thickness, faults, voids, and underground objects, and (3) derive important material engineering properties (e.g., elastic moduli). The surface geophysical measurements should be correlated with borehole geophysical data and geologic logs to derive maximum benefit from the measurements. 4.10.3 Borehole Geophysics Geophysical borehole logs are very useful for determining geologic, hydrologic, and engineering properties of subsurface materials, including correlation of lithologic units between boreholes. A suitable suite of geophysical logging methods (Ref. 23) should be used for borehole geophysics study. Appendix E to this guide lists some of the applicable geophysical logging methods, along with the geologic characteristics and engineering parameters the methods can help to determine. Crosshole and single borehole geophysical methods can be used to obtain detailed information about subsurface materials in both horizontal and vertical directions. These methods can be used to determine site shear wave velocity profiles and derive engineering and hydrogeologic properties, such as shear modulus, porosity, and permeability. When very detailed information is needed, tomographic methods can be used to determine the geophysical properties of materials between boreholes. Geophysical borehole logging methods include P-S suspension (Ref. 26), caliper, gamma, electrical resistivity, electromagnetic induction, fluid resistivity, temperature, flowmeter, television, acoustic televiewer, and other logs. These borehole loggings can measure in situ seismic waves; determine lithology; measure dip and strike of important structural features of the rock units; evaluate intrusion of grout into the rock mass; distinguish and analyze fractures, shear zones, soft zones, cavities, and other discontinuities; and characterize water quality and flow. Borehole