【国外标准】 Standard Test Method for Radiochemical Determination of Uranium Isotopes in Soil by Alpha Spectrometry

5.1 This test method is used to analyze soil for alpha-emitting uranium isotopes. It can be used to establish baseline uranium levels and to monitor depositions from nuclear facilities.1.1 This test method covers the determination of alpha-emitting uranium isotopes in soil. This test method describes one acceptable approach to the determination of uranium isotopes in soil.21.2 The test method is designed to analyze 10 g of soil. This test method may not be able to completely dissolve all forms of uranium in the soil matrix. Studies have indicated that the use of hydrofluoric acid to dissolve soil has resulted in lower values than results using total dissolution by fusion.1.3 The lower limit of detection is dependent on count time, sample size, detector, background, and tracer yield. The chemical yield averaged 78 % in a single laboratory evaluation, and 66 % in an interlaboratory collaborative study.1.4 The values stated in SI units are to be regarded as standard. The values given 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 11.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.