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 Functions 7.1 Surveying, Mapping, and Development of the GIS Database Surveying is an important function that should accompany all essential site investigation activities from reconnaissance through construction mapping. Many methods of surveying are available, from traditional triangulation or plane table work and leveling to electronic distance and GPS measurements. For mapping small areas, plane table methods may still be rapid enough. In most cases, however, GPS or differential GPS together with automated recording and computing procedures is the most suitable method. Procedures for GPS surveying can be found in EM-1110-1-1003, “NAVSTAR Global Positioning System Surveying,” issued 2011 (Ref. 18). The GPS measurements and other surveyed locations should be tied to National Geodetic Survey (NGS) markers to be compatible with topographic and digital maps of various types. Survey results should have adequate precision with no more than 0.3 meter (1.0 foot) onshore and 1.5 meters (5.0 feet) offshore for plan coordinates and 3 centimeters (0.1 foot) onshore and 0.3 meter (1.0 foot) offshore for elevation. For greater accuracy, it might still be necessary to perform a certain amount of conventional leveling. A suitable coordinate system for the site should be chosen. Three-dimensional coordinate systems include the World Geodetic System of 1984, the International Terrestrial Reference Frame, and the North American Datum of 1983 (NAD 83). Coordinates should be referred to NAD 83 to be legally recognized in most U.S. jurisdictions. Moreover, NGS provides software for converting the ellipsoid-based heights of NAD 83 to the sea-level-based heights that appear on topographic maps. NAD 83 coordinates are readily determined when measurements tie the site to an NGS marker. All three-dimensional information should be entered into a GIS database because data of various types, in the form of tables, can be associated with a coordinate system and recalled to form the desired