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:
prevent piston movement. Hydraulic piston sampler (Osterberg Sampler) Thin-walled tube is pushed into soil by hydraulic pressure. Fixed piston is in contact with top of sample during push. Undisturbed samples in cohesive soils, silts, and sands above or below the water table. Not possible to determine amount of sampler penetration during push. Does not have vacuum breaker in piston. Free-piston sampler Thin-walled tube is pushed into soil. Piston rests on top of soil sample during push. Undisturbed samples in stiff, cohesive soils. Representative samples in soft to medium cohesive soils and silts. May not be suitable for sampling in cohesionless soils. Free piston provides no control of specific recovery ratio. Open drive sampler Thin-walled open tube is pushed into soil. Undisturbed samples in stiff, cohesive soils. Representative samples in soft to medium cohesive soils and silts. Small diameter of tubes may not be suitable for sampling in cohesionless soils or for undisturbed sampling in uncased boreholes. No control of specific recovery ratio. Swedish Foil Sampler Sample tube is pushed into soil, while stainless steel strips unrolling from spools envelop sample. Piston, fixed by chain from surface, maintains contact with top of sample. Continuous undisturbed samples up to 20 meters (66 feet) long in very soft to soft clays. Small sampler diameter increases sample disturbance. Not suitable for soils containing gravels, sand layers, or shells, which may rupture foils and damage samples. Difficulty may be encountered in alternating hard and soft layers, with squeezing of soft layers and reduction in thickness. Requires experienced operator. Pitcher sampler Thin-walled tube is pushed into soil by spring above sampler, while outer core bit reams hole. Cuttings are removed by circulating drilling fluid. Undisturbed samples in stiff, hard, brittle, cohesive soils and sands with cementation, and in soft rock. Effective in sampling alternating hard and soft layers.