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:
o receiver(s) in other borehole(s), and transit time is recorded. In situ measurement of compression wave velocity and shear wave velocity in soils and rocks. Requires deviation survey of boreholes to eliminate errors due to deviation of holes from vertical. Refraction of signal through adjacent high-velocity beds must be considered. Uphole/downhole seismic test Seismic signal is transmitted between borehole and ground surface, and transit time is recorded. In situ measurement of compression wave velocity and shear wave velocity in soils and rocks. Apparent velocity obtained is time average for all strata between source and receiver. P-S-suspension log A 7-meter probe contains a source and two receivers spaced 1 meter apart, suspended by a cable. The source generates a pressure wave in the borehole fluid. The pressure wave is converted to seismic waves (P and S) at the borehole wall, and the P and S waves are then converted back to pressure waves in the fluid and received by the geophones. The transit time over the gauge length is recorded as the difference in arrival times at the receivers. Measurement of shear and compression wave velocities for soil and rock continuously along the borehole. Results represent only the material immediately adjacent to the borehole. Three-dimensional velocity log Logging tool contains transmitting and receiving transducer separated by fixed gauge length. Signal is transmitted through rock adjacent to borehole, and wave train at receiver is recorded. Measurement of compression wave and shear wave velocities in rock. Detection of void spaces, open fractures, and zones of weakness. Results represent only the material immediately adjacent to the borehole. Can be obtained only in uncased, fluid-filled borehole. Correction required for variation in hole size. Use is limited to materials with P-wave velocity greater than that of borehole fluid. DG-1392, Appendix C, Page C-7 APPENDIX C, Cont’d. METHOD PROCEDURE APPLICABILITY LIMITATIONS