Значение и использование

The test methods in this method are designed to show whether a given material is in accordance with Specification C922.

Область применения

1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications.

1.2 The analytical procedures appear in the following order:

Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ionization Mass Spectrometric Method C1413 Test Method for Isotopic Analysis of Hydrolysed Uranium Hexafluoride And Uranyl Nitrate Solutions By Thermal Ionization Mass Spectrometry C1347 Practice for Preparation and Dissolution of Uranium Materials for Analysis Nitrogen by DistillationNessler Reagent (Photometric) Method6 to 16 Oxygen-to-Metal Ratio of Sintered Gadolinium Oxide-Uranium Dioxide Pellets C1430 Test Method for Determination of Uranium, Oxygen to Uranium, and Oxygen to Metal (O/M) in Sintered Uranium Dioxide and Gadolinia-Uranium Dioxide Pellets by Atmospheric Equilibration Spectrochemical Determination of Trace Impurity Elements C1517 Test Method for Determination of Metallic Impurities in Uranium Metal or Compounds by DC-Arc Emission Spectroscopy Total Gas by Hot Vacuum Extraction Ceramographic Determination of Free Gd₂O₃ and Free UO₂ to Estimate the Homogeneity of (U,Gd)O₂ Pellets17 to 24

1.3 The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use.

6.1 This test method describes the determination of nitrogen in gadolinium oxide-uranium dioxide pellets (Gd₂O₃/UO₂). With a 2 to 5-g sample, concentrations from 5 to 100 μg of nitrogen are determined without interference.

17.1 The homogeneity of Gd₂O₃ in UO₂ has been cited in Specification C922 as an important requirement for this fuel form. The uniform distribution of gadolinia in urania will result in up to three components in the pellet: free Gd₂O₃, free UO₂, and a Gd₂O₃-UO₂ solid solution. There are a number of ways for assessing uniformity of which the ceramographic method described here may not be the most definitive. This technique has been used over the gadolinia concentration range from 1 to 10 weight %.