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:
nt of porosity. Useful in hydrology and engineering property determinations. Widely used. Borehole effects, calibration, source intensity, and bound water all affect measurement precision. Radioactive source hazard. Neutron activation Neutron capture Concentration of selected radioactive materials in strata. Detects elements such as U, Na, Mn. Used to determine oil-water contact (oil industry) and in prospecting for minerals (Al, Cu). Source intensity and presence of two or more elements having similar radiation energy affect data. Borehole magnetic Nuclear precession Deposition, sequence, and age of strata. Distinguishes ages of lithologically identical units. Earth field reversal intervals under study. Still subject of research. Mechanical caliper Diameter of borehole Measures borehole diameter. Useful in a wet or dry hole. Must be recalibrated for each run. Averages 3 diameters. Acoustic caliper Sonic ranging Measures borehole diameter. Large range. Useful with highly irregular shapes. Requires fluid-filled hole and accurate positioning. Temperature Temperature Measures temperature of fluids and borehole sidewalls. Detects zones of inflow or fluid loss. Rapid, economical, and generally accurate. None of importance. Fluid resistivity Fluid electrical resistance Water-quality determinations and auxiliary log for rock resistivity. Economical tool. Borehole fluid must be same as ground water. Tracers Direction of fluid flow Determines direction of fluid flow. Economical. Environmental considerations often preclude use of radioactive tracers. Flowmeter Fluid velocity and quantity Determines velocity of subsurface fluid flow and, in most cases, quantity of flow. Interpretation is simple. Impeller flowmeters usually cannot measure flows less than 1–1.7 centimeters per second (2–3 ft/minute). Borehole dipmeter Sidewall resistivity Provides strike and dip of bedding planes. Also used for fracture detection. Useful in determining information on location and orientation