ASTM C1636-22

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Designation: C1636 − 13 C1636 − 22
Standard Guide for the
Determination of Uranium-232 in Uranium Hexafluoride
This standard is issued under the fixed designation C1636; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This methodguide covers the determination of U in uranium hexafluoride by alpha spectrometry.
1.2 The values stated in SI units are to be regarded as standard. standard, except where the non-SI unit of molar, M, is used for
the concentration of chemicals and reagents. The unit of electronvolt (eV) is outside the SI but its use with the SI is accepted by
the International Committee for Weights and Measures (CIPM, Comité International des Poids et Mesures) and the U. S. National
Institute of Science and Technology (NIST). No other units of measurement are included in this standard.
1.3 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 safety, health, and healthenvironmental practices and to determine the
applicability of regulatory limitations prior to use.
1.4 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
2.1 ASTM Standards:
C787 Specification for Uranium Hexafluoride for Enrichment
C859 Terminology Relating to Nuclear Materials
C996 Specification for Uranium Hexafluoride Enriched to Less Than 5 % U
C1163 Practice for Mounting Actinides for Alpha Spectrometry Using Neodymium Fluoride
C1284 Practice for Electrodeposition of the Actinides for Alpha Spectrometry
C1429 Test Method for Isotopic Analysis of Uranium Hexafluoride by Double-Standard Multi-Collector Gas Mass Spectrometer
C1474 Test Method for Analysis of Isotopic Composition of Uranium in Nuclear-Grade Fuel Material by Quadrupole
Inductively Coupled Plasma-Mass Spectrometry
C1477 Test Method for Isotopic Abundance Analysis of Uranium Hexafluoride and Uranyl Nitrate Solutions by Multi-Collector,
Inductively Coupled Plasma-Mass Spectrometry
C1625 Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass
Spectrometry
C1672 Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total
Evaporation Method Using a Thermal Ionization Mass Spectrometer
C1832 Test Method for Determination of Uranium Isotopic Composition by Modified Total Evaporation (MTE) Method Using
Thermal Ionization Mass Spectrometer
This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.
Current edition approved Jan. 1, 2013Feb. 1, 2022. Published January 2013March 2022. Originally approved in 2006. Last previous edition approved in 20062013 as
C1636 – 06a.C1636 – 13. DOI: 10.1520/C1636-13.10.1520/C1636-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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C1636 − 22
D1193 Specification for Reagent Water
D3084 Practice for Alpha-Particle Spectrometry of Water
D3648 Practices for the Measurement of Radioactivity
2.2 Other StandardsStandards:
DIN 25711 Determination of the U isotopic content in uranium containing nuclear fuel solutions by α spectrometry.spec-
trometry
ISO 21847–3 Nuclear Fuel Technology—Alpha Spectrometry—Partfuel technology—Alpha spectrometry—Part 3: Determina-
tion of uranium-232 in uranium and its compounds.compounds
3. Terminology
3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.
Available from Deutsches Institut für Normung e.V., Berlin, Germany (www.din.de). e.V.(DIN), Am DIN-Platz, Burggrafenstrasse 6, 10787 Berlin, Germany,
http://www.din.de.
Pall Life Sciences (formerly Gelman) Metricel filter has been found to be acceptable. If you are aware of alternative suppliers, please provide this information to ASTM
International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee,Available from American National
Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org. which you may attend.
C1636 − 22
3.2 Definitions:
3.2.1 region-of-interest (ROI)—the channels, or region, in the alpha spectra in which the counts due to a specific radioisotope
appear on a functioning calibrated alpha spectrometry system.
3.2.2 Reagent blank—DI water processed the same as the samples; used in the determination of the minimum detectable activity.
4. Summary of Guide
4.1 An aliquot of hydrolyzed uranium hexafluoride equivalent to 60 micrograms 60 μg of uranium is converted to a nitric acid
system and the uranium is extracted onto a solid phase extraction column. The daughters of uranium decay products Uranium
progeny isotopes are rinsed from the column and the uranium is then selectively eluted. The uranium is reduced and then
coprecipitated with neodymium fluoride. Test Method Practice C1163 provides further information on the use of neodymium
fluoride to prepare actinide mounts for alpha spectrometry. The sample is then counted by alpha spectrometry, and the U is
calculated based on the observed activities of the uranium isotopes in the alpha spectra.
4.2 While this guide does not present details on electrodeposition as an alternative to neodymium fluoride precipitation for the
preparation of a mount for alpha spectrometry, Practice C1284 does present details on that option.
4.3 AlternateAlternative separation chemistry approaches may be found in the literature. It is the responsibility of the user of such
alternative separation approaches to validate theretheir effectiveness, especially the removal of potentially interfering thorium
isotopes (section (6.1).
5. Significance and Use
5.1 The methodguide is applicable to the analysis of materials to demonstrate compliance with the specifications set forth in
232 238
Specifications C787 and C996. Some other specifications may be expressed in terms of mass of U per mass of only U (see
ISO 21847–3:2007).
6. Interferences
228 232 228
6.1 Incomplete removal of Th and/or the ingrowth (3 % of the U value/month) from Th after the U/Th separation could
possibly interfere with the U determination. Method DIN 25711 addresses the potential capability for this method to eliminate
this potential interference.
6.2 Since only the relative amount of U, relative to total uranium, is being determined in this methodguide, there is no impact
to chemical loss in the separation or sample mounting chemistry. Therefore, unlike most alpha spectrometry methods, no yield
tracer is necessary or useful.
235 236
6.3 The alpha emission energies of U and U are relatively close. Thus there is the potential for overlap of counts from one
isotope into the ROI of the other. Where the alpha spectrometry system (section (7.1) provides, spectral de-convolution algorithms
may be used in the analysis of the spectra. Such de-convolution may allow for minimization of any possible bias in the reported
results. However, it should be noted that these two isotopes typically account for a relatively small amount of the overall uranium
mass. So any Any bias between the two should result in a relatively small overall bias in the reported U result.
7. Apparatus
7.1 Alpha spectrometry system, Alpha spectrometry system. See practices see Practices D3084 and D3648 for a description of the
apparatus.
232 234 235 236 238
7.1.1 A ROI for each uranium isotope ( U, U, U, U, and U) will need to be defined for the alpha spectrometry system
being used. Based on these defined ROIs the fractional abundance of alpha decays within the energy range of the ROI for each
isotope (AB in section 12.1) must be determined.
i
7.2 Ion exchange columns, Ion Exchange Columns, able to hold a 10 mL resin bed and 15 mL solution washes.
7.3 Filter Paper, 0.1 μm pore size, 25-mm diameter, and compatible with HF.
C1636 − 22
7.3 Vacuum Funnel—funnel, Polysulfonepolysulfone twist-lock with stainless steel screen for filter mounting.
8. Reagents and Materials
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades of reagents may be used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the accuracy of the determination.
8.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined in
Specification D1193.
8.3 Ammonium oxalate (0.1M)—Dissolve 14.2 g (NH ) C O •H·H O in approximately 500 mL water and dilute to 1 litre.1 L.
4 2 2 4 2
8.4 Ethanol—Ethyl alcohol, absolute (200 proof), denatured.
8.5 Hydrochloric acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
8.6 Hydrochloric acid (9M)—Add 750 mL concentrated HCl to 100 mL water and dilute to 1 litre.1 L.
8.7 Hydrochloric acid (1.5M)—Add 125 mL concentrated HCl to 500 mL water and dilute to 1 litre.1 L.
8.8 Hydrochloric acid (1M)—Add 83 mL concentrated HCl to 500 mL water and dilute to 1 litre.1 L.
8.9 Hydrofluoric acid (minimum 48 % assay)—Concentrated HF, reagent grade.
Warning—Severe burns can result from exposure of skin to concentrated hydrofluoric acid.
8.10 Neodymium chloride (10 mg Nd/mL)—Heat 25 mL of concentrated hydrochloric acid and 1.17 g of neodymium oxide on a
hotplate until the neodymium oxide is in solution. Cool the solution and dilute to 100 mL with water.
8.11 Neodymium chloride (100 μg Nd/mL)—Dilute 1 mL of 10 mg Nd/mL solution to 100 mL with water.
8.12 Neodymium oxide (Nd O ).
2 3
8.13 Nitric acid (sp gr 1.42)—Concentrated nitric acid (HNO ).
8.14 Nitric acid (3M)—Add 188 mL concentrated nitric acid to 500 mL water and dilute to 1 litre.1 L.
8.15 Oxalic acid in 1M HCl (0.1M)—Dissolve 12.6 g H C O •H·H O in 500 mL 1M HCl and dilute to 1 litre 1 L with 1M HCl.
2 2 4 2
8.16 20 % Titanium Trichloride (TiCl ) aqueous solution—available as a 20 % (w/v) solution of titanium trichloride from
commercial suppliers.
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.
C1636 − 22
8.17 Extraction Chromatography Resin, containing oc
...