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:
h lateral extent and depth to permit the suitable design of all necessary excavations and engineered structures. The information acquired should also support development of geologic cross sections and subsurface profiles that contain field testing data (e.g., N-values, cone penetration test values, and seismic wave velocities) constructed through the foundations of safety-related structures and other important structures at the site. Subsurface investigations for less critical foundations of power plants should be carried out at a spacing and depth of penetration necessary to define the geologic conditions and geotechnical engineering properties of the subsurface materials. Subsurface investigations in areas remote from plant foundations might be needed to complete the geologic description and confirm the geologic conditions of the site. Subsurface investigations for materials to be used for backfill, improvement of subsurface conditions, or ground water control under the foundations of safety-related structures, including granular and nongranular materials, should be performed to confirm that stability and durability requirements will be met and to validate the material properties to be used for design and analysis. Boreholes are one effective way to obtain detailed information on subsurface geologic conditions and the engineering properties of subsurface materials. Core and other samples recovered from boreholes, geophysical and borehole surveys, and other in situ borehole tests can provide important subsurface information. Test pits, trenches, and exploratory shafts can be used to complement the borehole exploration results; provide additional detailed information on rock and soil conditions, faulting, and density of in situ materials; and obtain high-quality undisturbed samples. DG-1392, Page 14 4.4 Borings and Exploratory Excavations Field operations conducted at the site should be supervised by experienced personnel familiar with site operations, and