ASTM C1907-21

Standard Practice for Preparation of Plutonium Materials by Pyrohydrolysis for Determination of Fluoride, Chloride, or Both

SIGNIFICANCE AND USE
5.1 This practice provides a means of collecting fluoride and chloride from plutonium test materials for analysis by ISE or IC. The results can be used to determine whether the material meets the requirements of Specifications C757 or C833, or other specification agreed by a supplier and customer, for fluoride or chloride content, or both.
SCOPE
1.1 This practice provides a procedure for the preparation of samples of plutonium (Pu) materials, using pyrohydrolysis, for subsequent measurement of fluoride, chloride, or both, by ion chromatography (IC) or ion-selective electrode (ISE).  
1.2 This practice utilizes a sample size of 0.3 ± 0.1 g and is therefore suitable when the larger sample size used in Test Methods C697 and C698 is not available.  
1.3 Test materials within the scope of this practice include plutonium dioxide powder and mixed (U, Pu) oxide powder. Pellets of plutonium dioxide and mixed (U, Pu) oxide may also be treated after pulverization and with use of an accelerant. Samples of neptunium oxide may also be prepared using this practice.  
1.4 Full recovery may not be achieved for levels above 50 μg/g fluoride or 50 μg/g chloride (1).2 At higher levels precipitation may occur in the reaction vessel or condenser, or both. The user should validate suitability of the method above these levels.  
1.5 The procedure described in this practice may be applicable to other plutonium materials, such as plutonium compounds and scrap metals. The user must determine the safety and applicability of this practice to such materials.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 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.  
1.8 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.

General Information

• Status: Published
• Publication Date: 14-Feb-2021
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C852/C852M-16 - Standard Guide for Design Criteria for Plutonium Gloveboxes
• Effective Date: 01-Nov-2016
• Refers: ASTM C697-16 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Plutonium Dioxide Powders and Pellets
• Effective Date: 01-Jun-2016
• Refers: ASTM C698-16 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Mixed Oxides ((U, Pu)O<inf>2</inf>)
• Effective Date: 01-Jun-2016
• Refers: ASTM C757-16 - Standard Specification for Nuclear-Grade Plutonium Dioxide Powder for Light Water Reactors
• Effective Date: 01-Apr-2016
• Refers: ASTM C1502-16 - Standard Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide
• Effective Date: 15-Jan-2016
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013
• Refers: ASTM C833-13 - Standard Specification for Sintered (Uranium-Plutonium) Dioxide Pellets
• Effective Date: 01-Jan-2013
• Refers: ASTM C1068-03(2011) - Standard Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
• Effective Date: 01-Jun-2011
• Refers: ASTM D4327-11 - Standard Test Method for Anions in Water by Suppressed Ion Chromatography
• Effective Date: 01-Mar-2011
• Refers: ASTM C859-10b - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Nov-2010
• Refers: ASTM C859-10a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Aug-2010

Overview

ASTM C1907-21 is the standard practice for the preparation of plutonium materials by pyrohydrolysis for the determination of fluoride, chloride, or both. Developed by ASTM International, this standard outlines a reliable method for preparing samples of plutonium (Pu) and related oxide materials to enable precise measurement of halide impurities, specifically fluoride and chloride, using ion chromatography (IC) or ion-selective electrode (ISE) analysis. This practice supports nuclear industry quality control by ensuring that materials meet strict specification requirements for fluoride and chloride content, as referenced in ASTM specifications such as C757 and C833, or other agreed-upon standards.

Key Topics

• Sample Preparation by Pyrohydrolysis
  • Utilizes a sample size of 0.3 ± 0.1 g, making it suitable when larger sample amounts (as required by ASTM C697 and C698) are unavailable.
  • Applies to materials including plutonium dioxide powder, mixed uranium-plutonium oxide powder, their pellets (after pulverization and with accelerant), and neptunium oxide.
• Measurement of Halides
  • Fluoride and chloride are volatilized by pyrohydrolysis at high temperatures (900 to 1000 °C) in a stream of moist argon or oxygen.
  • Collected analytes are then quantified by ISE or IC, enabling accurate assessment of halide concentrations in nuclear materials.
• Quality Control and Limitations
  • The procedure provides full recovery of halides up to approximately 50 µg/g; at higher concentrations, precipitation may limit recovery, and users should validate method suitability.
  • Can be adapted for other plutonium materials, such as compounds or scrap, though users must evaluate safety and applicability.
• Safety and Regulatory Compliance
  • Stresses the importance of adequate laboratory controls, use of glove boxes, off-gas filtration, and proper waste management due to the radioactive and toxic nature of plutonium materials.
  • Requires compliance with health, safety, and environmental regulations, and laboratory best practices.

Applications

• Nuclear Fuel Quality Assurance
  • Assists in verifying that plutonium dioxide powders and mixed (U,Pu) oxide pellets meet the low-halide requirements essential for reactor safety and performance.
• Analytical Laboratories in Nuclear Industry
  • Offers a standardized, reproducible method that is particularly beneficial when sample material is limited.
  • Enables laboratories to perform routine analysis or validate materials for compliance with specifications and regulatory requirements.
• Research and Development
  • Facilitates the accurate study of halide behavior in advanced fuel types, recycled nuclear materials, or developmental reactor fuels.
• Material Acceptance and Certification
  • Provides data necessary for material acceptance between suppliers and customers, supporting transparent and traceable quality control.

Related Standards

• ASTM C757 - Specification for Nuclear-Grade Plutonium Dioxide Powder for Light Water Reactors
• ASTM C833 - Specification for Sintered (Uranium-Plutonium) Dioxide Pellets for Light Water Reactors
• ASTM C697 & C698 - Test methods for analysis of nuclear-grade plutonium dioxide and mixed oxides
• ASTM C1502 - Test method for determination of total chlorine and fluorine in uranium dioxide and gadolinium oxide
• ASTM D4327 - Test method for anions in water by suppressed ion chromatography
• ASTM C852/C852M - Guide for design criteria for plutonium gloveboxes
• ASTM C1068 - Guide for qualification of measurement methods by a laboratory within the nuclear industry

ASTM C1907-21 plays a critical role in supporting rigorous quality control of nuclear materials by providing a standardized approach for determining fluoride and chloride levels, which are crucial for fuel performance, regulatory compliance, and operational safety in the nuclear sector.

Standards Content (Sample)

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.
Designation: C1907 − 21
Standard Practice for
Preparation of Plutonium Materials by Pyrohydrolysis for
Determination of Fluoride, Chloride, or Both
This standard is issued under the fixed designation C1907; 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 ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 Thispracticeprovidesaprocedureforthepreparationof
mendations issued by the World Trade Organization Technical
samples of plutonium (Pu) materials, using pyrohydrolysis, for
Barriers to Trade (TBT) Committee.
subsequent measurement of fluoride, chloride, or both, by ion
chromatography (IC) or ion-selective electrode (ISE).
2. Referenced Documents
1.2 This practice utilizes a sample size of 0.3 6 0.1 g and is
2.1 ASTM Standards:
therefore suitable when the larger sample size used in Test
C697 Test Methods for Chemical, Mass Spectrometric, and
Methods C697 and C698 is not available.
Spectrochemical Analysis of Nuclear-Grade Plutonium
1.3 Test materials within the scope of this practice include
Dioxide Powders and Pellets
plutonium dioxide powder and mixed (U, Pu) oxide powder.
C698 Test Methods for Chemical, Mass Spectrometric, and
Pellets of plutonium dioxide and mixed (U, Pu) oxide may also
Spectrochemical Analysis of Nuclear-Grade Mixed Ox-
be treated after pulverization and with use of an accelerant.
ides ((U, Pu)O )
Samples of neptunium oxide may also be prepared using this
C757 Specification for Nuclear-Grade Plutonium Dioxide
practice.
Powder for Light Water Reactors
C833 Specification for Sintered (Uranium-Plutonium) Diox-
1.4 Full recovery may not be achieved for levels above
ide Pellets for Light Water Reactors
50 µg⁄g fluoride or 50 µg/g chloride (1). At higher levels
C852/C852M Guide for Design Criteria for Plutonium
precipitation may occur in the reaction vessel or condenser, or
Gloveboxes
both. The user should validate suitability of the method above
C859 Terminology Relating to Nuclear Materials
these levels.
C1068 Guide for Qualification of Measurement Methods by
1.5 The procedure described in this practice may be appli-
a Laboratory Within the Nuclear Industry
cable to other plutonium materials, such as plutonium com-
C1502 Test Method for Determination of Total Chlorine and
pounds and scrap metals. The user must determine the safety
Fluorine in Uranium Dioxide and Gadolinium Oxide
and applicability of this practice to such materials.
D1193 Specification for Reagent Water
1.6 The values stated in SI units are to be regarded as
D4327 Test Method for Anions in Water by Suppressed Ion
standard. No other units of measurement are included in this
Chromatography
standard.
3. Terminology
1.7 This standard does not purport to address all of the
3.1 Except as otherwise defined herein, definitions of terms
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- are as given in Terminology C859.
priate safety, health, and environmental practices and deter-
3.2 Definitions:
mine the applicability of regulatory limitations prior to use.
3.2.1 accelerant, n—a chemical compound or a flux that
1.8 This international standard was developed in accor-
will decrease the reaction time or pyrohydrolysis time. C1502
dance with internationally recognized principles on standard-
3.2.2 pyrohydrolysis, n—treatment involving heating of a
sample in a stream of moist argon or oxygen at a temperature
of 900 to 1000 °C.
This practice 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 Feb. 15, 2021. Published May 2021. DOI: 10.1520/ For referenced ASTM standards, visit the ASTM website, www.astm.org, or
C1907-21. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1907 − 21
3.3 Definitions of Terms Specific to This Standard: 6.3 UraniumOxide(U O )—Halogen-freepowderusedasa
3 8
3.3.1 test material, n—material being treated by pyrohydro- blank and as the medium for pyrohydrolyzing the chloride
lysis in accordance with this practice. standard solution (6.6) and the fluoride standard solution (6.9).
3.3.1.1 Discussion—These materials include plutonium di- The U O serves as an accelerant for the reaction.
3 8
oxidepowderandpellets,andmixed(U,Pu)oxidepowderand
6.4 Tungsten Oxide (WO )—Accelerant utilized when pre-
pellets, and other materials that meet the criteria given in 1.4.
paring pellets for analysis.
4. Summary of Practice
6.5 Sodium Chloride (NaCl).
4.1 A sample of 0.3 6 0.1 g of test material is treated by
6.6 ChlorideStandardSolution(1mL=1mgCl)—Dissolve
pyrohydrolysis in a quartz reaction tube with a stream of moist
1.65 g of NaCl in water and dilute to 1 L.
argon or oxygen at a temperature of 900 to 1000 °C (2-4).
6.7 Chloride Standard Solution (1 mL= 0.4 mg Cl)—Dilute
NOTE 1—The use of argon or oxygen is recommended, rather than
40 mL of chloride standard solution (1 mL = 1 mg Cl) to
steam or moist air, to purge the pyrohydrolysis system of undesired
100 mL with water.
fluoride compounds (2).
6.8 Sodium Fluoride (NaF).
4.2 Pelletsarepulverizedandanaccelerantsuchastungsten
oxide is added. 6.9 Fluoride Standard Solution(1mL=1mgF)—Dissolve
2.21 g of NaF in water and dilute to 1L.
4.3 Oxidesareplacedinastreamofmoistargonandheated,
driving off F and Cl. These analytes are condensed as trace 6.10 Fluoride Standard Solution (1 mL= 0.4 mg F)—Dilute
levels of hydrofluoric acid (HF) and hydrochloric acid (HCl),
40mLoffluoridestandardsolution(1mL=1mgF)to100mL
respectively. The distillate is then transferred for quantitative with water.
analysis by IC or ISE (see 4.4).
6.11 Argon (if Used as Carrier Gas)—Greater than 99.99 %
4.4 Fluoride and chloride are measured in the absorption
purity.
solution using ISE as described inTest Method C1502 or using
6.12 Oxygen (if Used as Carrier Gas)—Greater than 99.5 %
IC as described in Test Method D4327.
purity.
4.5 As stated in Test Methods C697 and C698, fluoride and
chloride may also be measured by spectrophotometry, and
7. Apparatus
chloride may also be measured by microtitrimetry (4, 5), but
7.1 See Figs. 1 and 2 for examples of apparatus described
these methods typically require a larger sample size. If a
below.
method other than ISE or IC is used for the analysis, that
method should be qualified as described in Guide C1068.
7.2 Gas Flow Meter—A flowmeter and a rate controller to
adjust the flow of gas to 60 6 2 mL/min.
5. Significance and Use
7.3 Heat Source—Heating mantle or hot plate used to
5.1 Thispracticeprovidesameansofcollectingfluorideand
generate steam to moisten the argon or oxygen.
chloride from plutonium test materials for analysis by ISE or
7.4 Closure, such as a rubber or ground glass stopper or
IC. The results can be used to determine whether the material
rubber clamps, sufficient to ensure that the reaction tube is leak
meets the requirements of Specifications C757 or C833,or
tight.
other specification agreed by a supplier and customer, for
fluoride or chloride content, or both.
7.5 Furnace Temperature Gauge, capable of reading to at
least 1200 °C.
6. Reagents
NOTE 2—A calibrated thermocouple may be used in lieu of a tempera-
ture gauge. Traceability of the calibration to a national reference system
6.1 Purity of Reagents—Reagent grade chemicals shall be
such as the U.S. National Institute of Standards andTechnology (NIST) is
used.Unlessotherwiseindicated,itisintendedthatallreagents
recommended.
conform to the specifications of the Committee on Analytical
7.6 Collection Vessel—Plastic or glass container (graduated
Reagents of the American Chemical Society where such
cylinder, graduated vial, test tube, or beaker).
specifications are available. Other grades may be used, pro-
vided it is first ascertained that the reagent is of sufficiently
7.7 Condenser Tube—Glass tube with water jacket to con-
highpuritytopermititsusewithoutlesseningthequalityofthe
dense the gases containing chloride and fluoride for collection
final result.
in the collection vessel (7.6).
6.2 Purity of Water—Unless otherwise indicated, references
7.8 Tube Furnace—Atube furnace capable of maintaining a
to water shall be understood to mean reagent water as defined
temperature from 900 to 1000 °C. The bore of the furnace
by Type I of Specification D1193.
should be about 32 mm in diameter and about 300 mm in
length.
Reagent Chemicals, American Chemistry Society Specifications, American
7.9 Combustion Boat, made from quartz (fused-silica) or
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
platinum. A boat about 100 mm long is made by cutting
listed by the American Chemical Society, see Analar Standards for Laboratory
lengthwise a silica tube 20 mm in diameter and flattening one
Chemicals,BDHLtd.,
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