Document: NRC Regulatory Guide
Document ID: 1859c547-c10c-4ce4-ad2e-e54f7b66d4ef
Document Type: regulatory_guide
Title: Laboratory Investigations of Soils and Rocks for Engineering Analysis and Design of Nuclear Power Plants + HISTORY – HISTORY 07/2014 – DG-1256 , Proposed Revision 3 08/2001 – DG-1109 , Proposed Revision 2 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1318/ML13186A032.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.138
CFR Part: 
CFR Title: 

Content:
cal and clinical changes. Therefore, the samples should not be retained for long periods, particularly if in contact with unprotected steel tubes. Storage for long periods may discredit any subsequent determination of their engineering properties. The duration of storage before testing should be recorded for each sample test. Samples that have been stored for long periods should not be considered to have the characteristics of undisturbed samples and, therefore, should not be tested as such. Delays between sampling and testing and the control kept over specimen volumes during storage affect the strength and compressibility of clay specimens measured in the laboratory. 2.2. Rocks a. Rock samples should be treated as fragile material and protected from excessive changes in humidity and temperature. Like soil samples, rock samples should be examined and tested as soon as possible. For a large testing program, the rock specimens may be stored, but every effort should be made to protect the stored samples against damage. DG-1256, Page 6 3. Initial Identification and Examination of Samples a. The initial description of a sample should include, but should not be limited to, what investigators can see, feel, and smell. For additional information, ASTM D2488, “Standard Practice for Description and Identification of Soils (Visual-Manual Procedure)” (Ref. 20), describes procedures necessary to describe and identify a soil sample based on visual identification and manual testing. ASTM D4452, “Standard Methods for X-Ray Radiography of Soil Samples” (Ref. 21), describes procedures before x-ray testing of soil samples for the detection of inherent abnormalities and disturbances. This guidance is especially useful for undisturbed samples. ASTM D2487, “Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System)” (Ref. 22), describes the various soil groups in detail and discusses the method of identification so that those who use the