【国外标准】 Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide

4.1 Boron carbide is used as a control material in nuclear reactors. In order to be suitable for this purpose, the material must meet certain criteria for assay, isotopic composition, and impurity content. These methods are designed to show whether or not a given material meets the specifications for these items as described in Specifications C750 and C751.4.1.1 An assay is performed to determine whether the material has the specified boron and carbon content.4.1.2 Determination of the isotopic content of the boron and the free carbon content is made to establish whether the content is in compliance with the purchaser’s specifications.4.1.3 Impurity content is determined to ensure that the maximum concentration limit of certain impurities (chloride, fluoride, water, metallic impurities, soluble boron) is not exceeded.1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 The analytical procedures appear in the following order:  SectionsTotal Carbon by Combustion in an Inductive Furnace and    Infrared Measurement 8 – 17Total Boron by Titrimetry and ICP OES 18 – 28Isotopic Composition by Mass Spectrometry 29 – 33Pyrohydrolysis 34 – 41Chloride by Constant-Current Coulometry 42 – 50Chloride and Fluoride by Ion-Selective Electrode 51 – 59Water by Constant-Voltage Coulometry and Weight Loss on    Drying 60 – 63Metallic Impurities by DCArc OES and wet chemical methods 64 and 65Soluble Boron by Titrimetry and ICP OES 66 – 80Free Carbon by a Coulometric Method 81 – 901.4 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.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.