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:
t be run. Requires highly experienced personnel. Repeatable source required. DG-1392, Appendix E, Page E-3 APPENDIX E, Cont’d. GEOPHYSICAL METHOD BASIC MEASUREMENT APPLICATION ADVANTAGES LIMITATIONS Borehole spontaneous potential Natural earth potential Correlates deposits, locates water resources, studies rock deformation, assesses permeability, and determines ground water salinity. Widely used, economical tool. Particularly useful in the identification of highly porous strata (sand, etc.). Log must be run in a fluid-filled, uncased boring. Not all influences on potentials are known. Single-point resistivity Strata electrical resistance adjacent to a single electrode In conjunction with spontaneous potential, correlates strata and locates porous materials. Widely used, economical tool. Log obtained simultaneous with spontaneous potential. Strata resistivity difficult to obtain. Log must be run in a fluid-filled, uncased boring. Influenced by drill fluid. Long and short-normal resistivity Near-hole electrical resistance Measures resistivity within a radius of 40 to 165 centimeters (16 to 64 inches). Widely used, economical tool. Influenced by drill fluid invasion. Log must be run in a fluid-filled, uncased boring. Lateral resistivity Far-hole electrical resistance Measures resistivity within a radius of 6 m (20 ft). Less drill fluid invasion influence. Log must be run in a fluid-filled, uncased boring. Investigation radius limited in low-moisture strata. Induction resistivity Far-hole electrical resistance Measures resistivity in air- or oil-filled holes. Log can be run in a nonconductive casing. Large, heavy tool. Borehole imagery (acoustic) Sonic image of borehole wall Detects cavities, joints, fractures in borehole wall. Determines attitude (strike and dip) of structures. Useful in examining casing interior. Graphic display of images. Fluid clarity immaterial. Highly experienced operator required. Slow log to obtain. Probe awkward and delicate. Continuous sonic