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:
illing rate, settling or dropping of drill rods, abnormally low resistance to drilling or advance of samplers, core loss, and instability or heave of the side and bottom of boreholes. Influx of ground water, depths and amounts of water or drilling mud losses and depths at which circulation is recovered, and any other unique feature or occurrence should be recorded on the boring logs and geologic cross sections. Incomplete or abandoned borings should be described with the same care as successfully completed borings. Logs of the walls and floor of exploratory trenches and other excavations should be presented in a graphic format that shows important components of the soil and structural features in rock units in sufficient detail to permit independent evaluation. Photomosaic panoramas can provide additional perspective and verification of trench features. Locations of all exploration efforts should be recorded in a GIS database and shown on geologic cross sections along with elevations and all pertinent data. 5. Ground Water Investigations Knowledge of ground water conditions and the relationship of those conditions to surface water and variations associated with seasons or tides is needed for foundation analyses. Ground water levels and conditions are normally observed in boreholes at the time they are drilled. However, these observations should be supplemented by additional data from properly installed wells with piezometers that are monitored at regular intervals from time of installation at least through the construction period. Appendix G to this guide tabulates types of instruments for measuring ground water pressure and the advantages and limitations of each. ASTM D5092, “Standard Practice for Design and Installation of Groundwater Monitoring Wells” (Ref. 27) provides guidance on the design and installation of ground water monitoring wells. Types of piezometers, construction details, and sounding devices are described in EM 1110-2-1908, “Instrumentation