Significance and Use

This test method was developed and the instrument calibrated using ground soils from the site of a nuclear materials plant. This test method can be used to measure the extent of contamination from uranium and thorium in ground soils. Since the detection limit of this technique (nominally 20 ? g per gram) approaches typical background levels for these contaminants, the method can be used as a quick characterization of an on-site area to indicate points of contamination. Then after cleanup, EDXRF may be used to verify the elimination of contamination or other analysis methods (such as colorimetry, fluoremetry, phosphorescence, etc.) can be used if it is necessary to test for cleanup down to a required background level. This test method can also be used for the segregation of soil lots by established contamination levels during on-site construction and excavation.

1. Scope

1.1 This test method covers the energy dispersive X-ray fluorescence (EDXRF) spectrochemical analysis of trace levels of uranium and thorium in soils. Any sample matrix that differs from the general ground soil composition used for calibration (that is, fertilizer or a sample of mostly rock) would have to be calibrated separately to determine the effect of the different matrix composition.

1.2 The analysis is performed after an initial drying and grinding of the sample, and the results are reported on a dry basis. The sample preparation technique used incorporates into the sample any rocks and organic material present in the soil. This test method of sample preparation differs from other techniques that involve tumbling and sieving the sample.

1.3 Linear calibration is performed over a concentration range from 20 to 1000 ? g per gram for uranium and thorium.

1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C859 Terminology Relating to Nuclear Materials

C998 Practice for Sampling Surface Soil for Radionuclides

D420 Guide to Site Characterization for Engineering Design and Construction Purposes

D1452 Practice for Soil Exploration and Sampling by Auger Borings

D1586 Test Method for Penetration Test (SPT) and Split-Barrel Sampling of Soils

D1587 Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes

D2113 Practice for Rock Core Drilling and Sampling of Rock for Site Investigation

D3550 Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of Soils

D4697 Guide for Maintaining Test Methods in the Users Laboratory

E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials

E305 Practice for Establishing and Controlling Atomic Emission Spectrochemical Analytical Curves

E456 Terminology Relating to Quality and Statistics

E876 Practice for Use of Statistics in the Evaluation of Spectrometric Data

E882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory

Other Document

Keywords

energy dispersive X-ray fluorescence (EDXRF); soil; thorium; uranium; Energy-dispersive x-ray fluorescence (EDXRF); Soil (radioactive analysis); Thorium content; Uranium content; Wavelength dispersive X-ray fluorescence (WDXRF); XRF (X-ray fluorescence)--nuclear materials;

ICS Code

ICS Number Code 27.120.30 (Fissile materials and nuclear fuel technology)

DOI: 10.1520/C1255-11

ASTM International is a member of CrossRef.

ASTM C1255