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:
amples of rock and soil should be obtained for identification and classification, mechanical analyses, and anticipated laboratory testing. The need for, number, and distribution of samples will depend on testing requirements and the variability of the field conditions. A sufficient number of samples should be collected to meet the needs of laboratory testing, especially when undisturbed samples are required. It is important to obtain good-quality undisturbed samples for cyclic load testing. In general, soil and rock samples should be collected from more than one principal boring within the foundation support zone of each safety-related structure. Sampling of soil and rock in boreholes should include, as a minimum, recovery of samples at regular intervals and where changes in materials occur. One or more borings for each major structure DG-1392, Page 16 should be continuously sampled. Proper sampling methods should be used to collect soil samples. Standard penetration and cone penetration tests should be used with sufficient coverage to define the soil profile and variations in soil conditions. Alternating split spoon and undisturbed samples with depth is recommended for soil samples. Color photographs of all cores should be taken soon after removal from the borehole to document the condition of subsurface materials at the time of drilling. For a deeply embedded structure, sampling intervals should be properly determined and detailed field testing should be carried out along the length of the embedded portion of the structure to obtain sufficient geologic and geotechnical information. 4.5.1 Sampling Rock The engineering characteristics of the rock mass are related primarily to composition and geologic features of the rock units, including bedding planes, joints, fractures, orientation, position, length and spacing of any other geologic discontinuities, surface infilling, and weathering. Rock outcrops may be one of the information sources necessary for rock mass