ASTM C791 – Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide
Description:
Significance and Use
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.
Scope
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:
| Sections | |
| Total Carbon by Combustion in an Inductive Furnace and Infrared Measurement | 8 – 17 |
| Total Boron by Titrimetry and ICP OES | 18 – 28 |
| Isotopic Composition by Mass Spectrometry | 29 – 33 |
| Pyrohydrolysis | 34 – 41 |
| Chloride by Constant-Current Coulometry | 42 – 50 |
| Chloride and Fluoride by Ion-Selective Electrode | 51 – 59 |
| Water by Constant-Voltage Coulometry and Weight Loss on Drying | 60 – 63 |
| Metallic Impurities by DCArc OES and wet chemical methods | 64 and 65 |
| Soluble Boron by Titrimetry and ICP OES | 66 – 80 |
| Free Carbon by a Coulometric Method | 81 – 90 |
ASTM C786