【国外标准】 Standard Practice for Preparation and Dissolution of Uranium Materials for Analysis

4.1 The materials covered that must meet ASTM specifications are uranium metal and uranium oxide.4.2 Uranium materials are used as nuclear reactor fuel. For this use, these materials must meet certain criteria for uranium content, uranium-235 enrichment, and impurity content, as described in Specifications C753 and C776. The material is assayed for uranium to determine whether the content is as specified.4.3 Uranium alloys, refractory uranium materials, and uranium containing scrap and ash are unique uranium materials for which the user must determine the applicability of this practice. In general, these unique uranium materials are dissolved with various acid mixtures or by fusion with various fluxes.1.1 This practice covers dissolution treatments for uranium materials that are applicable to the test methods used for characterizing these materials for uranium elemental, isotopic, and impurities determinations. Dissolution treatments for the major uranium materials assayed for uranium or analyzed for other components are listed.1.2 The treatments, in order of presentation, are as follows:Procedure Title SectionDissolution of Uranium Metal and Oxide with Nitric Acid 8.1Dissolution of Uranium Oxides with Nitric Acid and Residue  Treatment 8.2Dissolution of Uranium-Aluminum Alloys in Hydrochloric Acid with Residue Treatment 8.3Dissolution of Uranium Scrap and Ash by Leaching with Nitric Acid and Treatment of Residue by Carbonate Fusion 8.4Dissolution of Refractory Uranium-Containing Material by Carbonate Fusion 8.5Dissolution of Uranium—Aluminum AlloysUranium Scrap and Ash, and RefractoryUranium-Containing Materials byMicrowave Treatment 8.61.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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 hazards statements are given in Section 7.1.5 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.