ASTM C799-19 - 1.7.2019
 
Significance and Use

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. Scope

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:

 

Sections

Determination of Uranium

8

Specific Gravity by Pycnometry

 16 – 21

Free Acid by Oxalate Complexation

 22 – 28

Determination of Thorium

29

Determination of Chromium

30

Determination of Molybdenum

31

Halogens Separation by Steam Distillation

 32 – 36

Fluoride by Specific Ion Electrode

 37 – 43

Halogen Distillate Analysis: Chloride, Bromide, and Iodide by
  Amperometric Microtitrimetry

44

Determination of Chloride and Bromide

45

Determination of Sulfur by X-Ray Fluorescence

46

Sulfate Sulfur by (Photometric) Turbidimetry

47

Phosphorus by the Molybdenum Blue (Photometric) Method

 55 – 62

Silicon by the Molybdenum Blue (Photometric) Method

63 – 70

Carbon by Persulfate Oxidation-Acid Titrimetry

71

Conversion to U3O8

72 – 75

Boron by Emission Spectrography

A

Impurity Elements by Spark Source Mass Spectrography

77

Isotopic Composition by Thermal Ionization Mass Spectrometry

78

Uranium-232 by Alpha Spectrometry

79 – 85

Total Alpha Activity by Direct Alpha Counting

86 – 92

Fission Product Activity by Beta Counting

93 – 99

Entrained Organic Matter by Infrared Spectrophotometry

100

Fission Product Activity by Gamma Counting

101

Determination of Arsenic

102

Determination of Impurities for the EBC Calculation

103

Determination of Technetium 99

104

Determination of Plutonium and Neptunium

105

1.3 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.

 
2. Referenced Documents

C1267-17(2022)

Standard Test Method for Uranium by Iron (II) Reduction in Phosphoric Acid Followed by Chromium (VI) Titration in the Presence of Vanadium

C1287-18

Standard Test Method for Determination of Impurities in Nuclear Grade Uranium Compounds by Inductively Coupled Plasma Mass Spectrometry

C1295-24

Standard Test Method for Gamma Energy Emission from Fission and Decay Products in Uranium Hexafluoride and Uranyl Nitrate Solution

C1296-95(2001)

Standard Test Method for Determination of Sulfur in Uranium Oxides and Uranyl Nitrate Solutions by X-Ray Fluorescence (XRF)

C1380-04

Standard Test Method for Determination of Uranium Content and Isotopic Composition by Isotope Dilution Mass Spectrometry

C1413-18

Standard Test Method for Isotopic Analysis of Hydrolyzed Uranium Hexafluoride and Uranyl Nitrate Solutions by Thermal Ionization Mass Spectrometry

C1561-10(2016)

Standard Guide for Determination of Plutonium and Neptunium in Uranium Hexafluoride and U-Rich Matrix by Alpha Spectrometry

C1233-15(2021)

Standard Practice for Determining Equivalent Boron Contents of Nuclear Materials

C696-19

Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Uranium Dioxide Powders and Pellets

C1254-18

Standard Test Method for Determination of Uranium in Mineral Acids by X-Ray Fluorescence

C1219-05

Standard Test Methods for Arsenic in Uranium Hexafluoride

C788-03(2021)

Standard Specification for Nuclear-Grade Uranyl Nitrate Solution or Crystals

D1193-06(2018)

Standard Specification for Reagent Water

E12-70(1991)e01

Terminology Relating to Density and Specific Gravity of Solids, Liquids, and Gases (Withdrawn 1996)

E60-11(2022)e1

Standard Practice for Analysis of Metals, Ores, and Related Materials by Spectrophotometry (Includes all amendments and changes 6/29/2022).

Reagent

Chemicals Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.

C761-18

Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Uranium Hexafluoride

ISO 7097

Determination of Uranium in Uranium Product Solutions and Solids with Cerium IV Oxidation Titrimetric Method Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.