【国外标准】 Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Uranyl Nitrate Solutions

4.1 Uranyl nitrate solution is used as a feed material for conversion to the hexafluoride as well as for direct conversion to the oxide. In order to be suitable for this purpose, the material must meet certain criteria for uranium content, isotopic composition, acidity, radioactivity, and impurity content. These methods are designed to show whether a given material meets the specifications for these items described in Specification C788.4.1.1 An assay is performed to determine whether the material has the specified uranium content.4.1.2 Determination of the isotopic content of the uranium is made to establish whether the effective fissile content is in accordance with the purchaser’s specifications.4.1.3 Acidity, organic content, and alpha, beta, and gamma activity are measured to establish that they do not exceed their maximum limits.4.1.4 Impurity content is determined to ensure that the maximum concentration limit of certain impurity elements is not exceeded. Impurity concentrations are also required for calculation of the equivalent boron content (EBC), and the total equivalent boron content (TEBC).1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications.1.2 The analytical procedures appear in the following order:  SectionsDetermination of Uranium 8Specific Gravity by Pycnometry  16 – 21Free Acid by Oxalate Complexation  22 – 28Determination of Thorium 29Determination of Chromium 30Determination of Molybdenum 31Halogens Separation by Steam Distillation  32 – 36Fluoride by Specific Ion Electrode  37 – 43Halogen Distillate Analysis: Chloride, Bromide, and Iodide by  Amperometric Microtitrimetry 44Determination of Chloride and Bromide 45Determination of Sulfur by X-Ray Fluorescence 46Sulfate Sulfur by (Photometric) Turbidimetry 47Phosphorus by the Molybdenum Blue (Photometric) Method  55 – 62Silicon by the Molybdenum Blue (Photometric) Method 63 – 70Carbon by Persulfate Oxidation-Acid Titrimetry 71Conversion to U3O8 72 – 75Boron by Emission Spectrography AImpurity Elements by Spark Source Mass Spectrography 77Isotopic Composition by Thermal Ionization Mass Spectrometry 78Uranium-232 by Alpha Spectrometry 79 – 85Total Alpha Activity by Direct Alpha Counting 86 – 92Fission Product Activity by Beta Counting 93 – 99Entrained Organic Matter by Infrared Spectrophotometry 100Fission Product Activity by Gamma Counting 101Determination of Arsenic 102Determination of Impurities for the EBC Calculation 103Determination of Technetium 99 104Determination of Plutonium and Neptunium 1051.3 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 precautionary statements are given in Section 6.1.5 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.