C1475-00 Standard Guide for Determination of Neptunium-237 in Soil

Copyright 2002 ASTM International,
West Conshohocken, PA. All rights reserved.

1. Scope

1.1 This guide covers the detemination of neptunium-237 in soil by means of radiochemical separations and alpha spectrometry. This guide provides options in the selection of sample preparation, separation, and measurement. Although neptunium-237 is not a component of global fallout, it is a product of production reactors and spent fuel processing. This guide is designed for analysis of ten grams of soil previously collected and treated in accordance with Practices C998 and C999. Larger-size samples of environmental soil may also be analyzed, as long as the concentrations of interferences such as uranium and thorium are at or near environmental concentrations. Depending on the choice of a sample dissolution method, all chemical forms of neptunium may not be completely solubilized. This guide should allow the determination of neptunium-237 concentrations from sub becquerel per gram levels to applicable standards depending on count time, sample size, detector efficiency, background, and tracer yield.

1.2 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 limitations prior to use. Specific precautionary statements are given in Section 8.

2. Referenced Documents

C998 Practice for Sampling Surface Soil for Radionuclides
C999 Practice for Soil Sample Preparation for the Determination of Radionuclides
C1000 Test Method for Radiochemical Determination of Uranium Isotopes in Soil by Alpha Spectrometry
C1001 Test Method for Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy
C1163 Test Method for Mounting Actinides for Alpha Spectrometry Using Neodymium Fluoride
C1284 Practice for Electrodeposition of the Actinides for Alpha Spectrometry
C1387 Guide for Determination of Technetium-99 in Soil
D1193 Specification for Reagent Water
D1890 Test Method for Beta Particle Radioactivity of Water
D3084 Practice for Alpha-Particle Spectrometry of Water
D4962 Practice for NaI(TI) Gamma-Ray Spectrometry of Water
C1317 Practice for Dissolution of Silicate or Acid-Resistant Matrix Samples
C1342 Practice for Flux Fusion Sample Dissolution
C1412 Practice for Microwave Oven Dissolution of Glass Containing Radioactive and Mixed Wastes IEEE/ASTM SI-10 Standard for the Use of the International System of Units (SI): The Modern Metric System

Index Terms 

alpha spectroscopy; americium 243; beta conuting; extraction chromatography; gamma-ray spectroscopy; neptunium-239; neptunium-237 determination; soil analysis