ASTM C697-16

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

SIGNIFICANCE AND USE
4.1 Plutonium dioxide is used in mixtures with uranium dioxide as a nuclear-reactor fuel. In order to be suitable for this purpose, the material must meet certain criteria for plutonium content, isotopic composition, and impurity content. These test methods are designed to show whether or not a given material meets the specifications for these items as described in Specification C757.  
4.1.1 An assay is performed to determine whether the material has the minimum plutonium content specified on a dry weight basis.  
4.1.2 Determination of the isotopic content of the plutonium in the plutonium dioxide powder is made to establish whether the effective fissile 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 impurity elements is not exceeded. Determination of impurities is also required for calculation of the equivalent boron content (EBC) as described in Practice C1233.  
4.2 Fitness for Purpose of Safeguards and Nuclear Safety Applications—Methods intended for use in safeguards and nuclear safety applications shall meet the requirements specified by Guide C1068 for use in such applications.
SCOPE
1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets to determine compliance with specifications.  
1.2 The analytical procedures appear in the following order:    
Sections  
Plutonium Sample Handling  
8 to 10  
Plutonium by Controlled-Potential Coulometry  
2  
Plutonium by Ceric Sulfate Titration  
3  
Plutonium by Amperometric Titration with Iron(II)  
2  
Plutonium by Diode Array Spectrophotometry  
3  
Nitrogen by Distillation Spectrophotometry Using Nessler
Reagent  
11 to 18  
Carbon (Total) by Direct Combustion–Thermal Conductivity  
19 to 29  
Total Chlorine and Fluorine by Pyrohydrolysis  
30 to 37  
Sulfur by Distillation Spectrophotometry  
38 to 46  
Plutonium Isotopic Analysis by Mass Spectrometry  
4  
Rare Earth Elements by Spectroscopy  
47 to 54  
Trace Elements by Carrier–Distillation Spectroscopy  
55 to 62  
(Alternative: Impurities by ICP-AES or ICP-MS)  
Impurity Elements by Spark-Source Mass Spectrography  
63 to 69  
Moisture by the Coulometric Electrolytic Moisture Analyzer  
70 to 77  
Total Gas in Reactor-Grade Plutonium Dioxide Pellets  
5  
Plutonium-238 Isotopic Abundance by Alpha Spectrometry  
3  
Americium-241 in Plutonium by Gamma-Ray Spectrometry  
2  
Rare Earths By Copper Spark-Spectroscopy  
78 to 87  
Plutonium Isotopic Analysis by Mass Spectrometry  
88 to 96  
Oxygen-To-Metal Atom Ratio by Gravimetry  
97 to 104  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.  
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. For specific precautionary statements, see Sections 6, 16.2.5, 44.7, 51.9 and 92.5.1.

General Information

• Status: Published
• Publication Date: 31-May-2016
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Replaces: ASTM C697-10 - 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 C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C1672-23 - Standard Test Method for Determination of the Uranium, Plutonium or Americium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• Effective Date: 01-Dec-2023
• Refers: ASTM C1432-23 - Standard Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
• Effective Date: 01-Dec-2023
• Refers: ASTM C1168-23 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Oct-2023
• Refers: ASTM C1268-23 - Standard Test Method for Quantitative Determination of ²⁴¹Am in Plutonium by Gamma-Ray Spectrometry
• Effective Date: 01-Oct-2023
• Refers: ASTM C1625-19 - Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass Spectrometry
• Effective Date: 15-Sep-2019
• Refers: ASTM C1672-17 - Standard Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• Effective Date: 01-Jan-2017
• Refers: ASTM C757-16 - Standard Specification for Nuclear-Grade Plutonium Dioxide Powder for Light Water Reactors
• Effective Date: 01-Apr-2016
• Refers: ASTM C1168-15 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Sep-2015
• Refers: ASTM C1268-15 - Standard Test Method for Quantitative Determination of ²⁴¹Am in Plutonium by Gamma-Ray Spectrometry
• Effective Date: 01-Jun-2015
• Refers: ASTM C1432-15 - Standard Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
• Effective Date: 01-Jun-2015
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C1307-14 - Standard Test Method for Plutonium Assay by Plutonium (III) Diode Array Spectrophotometry
• Effective Date: 01-Jun-2014
• Refers: ASTM C1415-14 - Standard Test Method for ²³⁸Pu Isotopic Abundance By Alpha Spectrometry
• Effective Date: 01-Jun-2014

Overview

ASTM C697-16: Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Plutonium Dioxide Powders and Pellets provides a comprehensive framework for evaluating the suitability of plutonium dioxide materials used in the production of nuclear-reactor fuel. As nuclear-grade plutonium dioxide is commonly utilized in combination with uranium dioxide as fuel in light water reactors, its quality and composition are critical for fuel performance, safety, and regulatory compliance.

This ASTM standard specifies procedures for determining plutonium content, isotopic distribution, and a range of impurities in both powder and pellet forms. The test methods included in ASTM C697-16 enable laboratories to confirm materials meet the rigorous criteria established in Specification ASTM C757 and support nuclear safeguards and safety objectives.

Key Topics

ASTM C697-16 encompasses multiple essential analytical methodologies to evaluate the chemical composition of plutonium dioxide:

• Chemical Analysis: Methods for determining plutonium content to ensure products meet minimum assay requirements.
• Mass Spectrometric Analysis: Determination of isotopic composition of plutonium to verify the effective fissile content and compliance with purchasing specifications.
• Spectrochemical Analysis: Identification and quantification of impurity elements, including rare earths, trace metals, and halides to ensure they are within acceptable limits.
• Moisture Content: Procedures to measure and control moisture in samples, preserving the integrity of the plutonium dioxide.
• Analysis of Specific Elements: Protocols for nitrogen, carbon, chlorine, fluorine, sulfur, and total gas content.
• Measurement of Americium-241 and Plutonium-238: Spectrometric methods for important radionuclide inclusions.
• Quality Assurance and Control: Guides for sampling, sample handling, preparation, and preservation to prevent contamination and ensure accurate results.
• Safety Precautions: Emphasis on appropriate laboratory facilities, use of gloveboxes or fume hoods, and careful handling of hazardous chemicals.

Applications

The application of ASTM C697-16 is crucial in contexts where nuclear-grade plutonium dioxide is used, especially for:

• Production of Nuclear Reactor Fuel: Ensuring fuel material has correct plutonium content and isotopic mixture for safe and efficient reactor operation.
• Nuclear Safety: Confirming that impurity levels, including those affecting neutron economy, are controlled to minimize risks of reactor operation.
• Nuclear Safeguards: Providing reliable measurement methods to support regulatory requirements for tracking and accountability of nuclear materials.
• Quality Control in Analytical Laboratories: Establishing standardized procedures for laboratories within the nuclear industry to maintain assurance in measurement data.
• Material Compliance and Procurement: Verifying that supplied plutonium dioxide meets all contractual and regulatory specifications before use in fuel fabrication.

Related Standards

ASTM C697-16 references and complements several other important ASTM standards, streamlining the quality management and analysis of nuclear materials:

• ASTM C757 - Specification for Nuclear-Grade Plutonium Dioxide Powder for Light Water Reactors
• ASTM C1068 - Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
• ASTM C1165 - Test Method for Determining Plutonium by Controlled-Potential Coulometry
• ASTM C1307 - Test Method for Plutonium Assay by Plutonium(III) Diode Array Spectrophotometry
• ASTM C1233 - Practice for Determining Equivalent Boron Contents of Nuclear Materials
• ASTM C1432 - Test Method for Determination of Impurities in Plutonium by ICP-AES
• ASTM C1637 - Determination of Impurities in Plutonium Metal by ICP-MS

Conclusion

ASTM C697-16 serves as a critical resource for laboratories and organizations responsible for the analysis and quality assurance of nuclear-grade plutonium dioxide powders and pellets. By adhering to these standard test methods, the nuclear industry can ensure that fuel materials meet stringent safety, performance, and regulatory standards, supporting both reactor operation and nuclear safeguards.

For organizations involved in nuclear fuel production, regulatory compliance, or analytical services, ASTM C697-16 provides the essential procedures to maintain the highest quality and safety in handling plutonium dioxide materials.

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: C697 − 16
Standard Test Methods for
Chemical, Mass Spectrometric, and Spectrochemical
Analysis of Nuclear-Grade Plutonium Dioxide Powders and
Pellets
This standard is issued under the fixed designation C697; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope bility of regulatory limitations prior to use. For specific
precautionarystatements,seeSections6,16.2.5,44.7,51.9and
1.1 These test methods cover procedures for the chemical,
92.5.1.
mass spectrometric, and spectrochemical analysis of nuclear-
grade plutonium dioxide powders and pellets to determine
2. Referenced Documents
compliance with specifications.
2.1 ASTM Standards:
1.2 Theanalyticalproceduresappearinthefollowingorder:
C757Specification for Nuclear-Grade Plutonium Dioxide
Sections
Powder for Light Water Reactors
Plutonium Sample Handling 8 to 10
2 C852Guide for Design Criteria for Plutonium Gloveboxes
Plutonium by Controlled-Potential Coulometry
Plutonium by Ceric Sulfate Titration C859Terminology Relating to Nuclear Materials
Plutonium by Amperometric Titration with Iron(II)
C1068Guide for Qualification of Measurement Methods by
Plutonium by Diode Array Spectrophotometry
a Laboratory Within the Nuclear Industry
Nitrogen by Distillation Spectrophotometry Using Nessler 11 to 18
Reagent C1108Test Method for Plutonium by Controlled-Potential
Carbon (Total) by Direct Combustion–Thermal Conductivity 19 to 29
Coulometry
Total Chlorine and Fluorine by Pyrohydrolysis 30 to 37
C1165 Test Method for Determining Plutonium by
Sulfur by Distillation Spectrophotometry 38 to 46
Plutonium Isotopic Analysis by Mass Spectrometry Controlled-Potential Coulometry in H SO at a Platinum
2 4
Rare Earth Elements by Spectroscopy 47 to 54
Working Electrode
Trace Elements by Carrier–Distillation Spectroscopy 55 to 62
C1168PracticeforPreparationandDissolutionofPlutonium
(Alternative: Impurities by ICP-AES or ICP-MS)
Impurity Elements by Spark-Source Mass Spectrography 63 to 69
Materials for Analysis
Moisture by the Coulometric Electrolytic Moisture Analyzer 70 to 77
C1206Test Method for Plutonium by Iron (II)/Chromium
Total Gas in Reactor-Grade Plutonium Dioxide Pellets
(VI) Amperometric Titration (Withdrawn 2015)
Plutonium-238 Isotopic Abundance by Alpha Spectrometry
Americium-241 in Plutonium by Gamma-Ray Spectrometry
C1233Practice for Determining Equivalent Boron Contents
Rare Earths By Copper Spark-Spectroscopy 78 to 87
of Nuclear Materials
Plutonium Isotopic Analysis by Mass Spectrometry 88 to 96
C1235 Test Method for Plutonium by Titanium(III)/
Oxygen-To-Metal Atom Ratio by Gravimetry 97 to 104
Cerium(IV) Titration (Withdrawn 2005)
1.3 The values stated in SI units are to be regarded as
C1268 Test Method for Quantitative Determination of
standard. The values given in parentheses are for information
Am in Plutonium by Gamma-Ray Spectrometry
only.
C1307Test Method for PlutoniumAssay by Plutonium (III)
1.4 This standard does not purport to address all of the
Diode Array Spectrophotometry
safety concerns, if any, associated with its use. It is the 238
C1415Test Method for Pu Isotopic Abundance By Alpha
responsibility of the user of this standard to establish appro-
Spectrometry
priate safety and health practices and determine the applica-
C1432Test Method for Determination of Impurities in
Plutonium: Acid Dissolution, Ion Exchange Matrix
Separation, and Inductively Coupled Plasma-Atomic
These test methods are under the jurisdiction of ASTM Committee C26 on
Emission Spectroscopic (ICP/AES) Analysis
Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 on
Methods of Test.
CurrenteditionapprovedJune1,2016.PublishedJuly2016.Originallyapproved
in 1972. Last previous edition approved in 2010 as C697–10. DOI: 10.1520/ For referenced ASTM standards, visit the ASTM website, www.astm.org, or
C0697-16. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Discontinued as of November 15, 1992. Standards volume information, refer to the standard’s Document Summary page on
Discontinued as of January 1, 2004. the ASTM website.
4 7
Discontinued as of May 30, 1980. The last approved version of this historical standard is referenced on
Discontinued as of June 2016. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C697 − 16
C1625Test Method for Uranium and Plutonium Concentra- where such specifications are available. Other grades may be
tions and Isotopic Abundances by Thermal Ionization used, provided it is first ascertained that the reagent is of
Mass Spectrometry sufficiently high purity to permit its use without lessening the
C1637Test Method for the Determination of Impurities in accuracy of the determination.
PlutoniumMetal:AcidDigestionandInductivelyCoupled
5.2 Purity of Water—Unless otherwise indicated, references
Plasma-Mass Spectroscopy (ICP-MS) Analysis
towatershallbeunderstoodtomeanreagentwaterconforming
C1672Test Method for Determination of Uranium or Pluto-
to Specification D1193.
nium Isotopic Composition or Concentration by the Total
Evaporation Method Using a Thermal Ionization Mass
6. Safety Precautions
Spectrometer
6.1 Since plutonium bearing materials are radioactive and
D1193Specification for Reagent Water
toxic, adequate laboratory facilities, glove boxes, fume hoods,
D4327Test Method for Anions in Water by Suppressed Ion
and so forth, along with safe techniques, must be used in
Chromatography
handling samples containing these materials. Glove boxes
E60Practice for Analysis of Metals, Ores, and Related
should be fitted with off-gas filters capable of sustained
Materials by Spectrophotometry
operation with dust-laden atmospheres. A detailed discussion
E115Practice for Photographic Processing in Optical Emis-
of all the precautions necessary is beyond the scope of these
sion Spectrographic Analysis (Withdrawn 2002)
test methods; however, personnel who handle these materials
E116Practice for Photographic Photometry in Spectro-
should be familiar with such safe handling practices as are
chemical Analysis (Withdrawn 2002)
given in Guide C852 and in Refs (1-3).
E130Practice for Designation of Shapes and Sizes of
6.2 Adequate laboratory facilities, such as fume hoods and
Graphite Electrodes (Withdrawn 2013)
controlledventilation,alongwithsafetechniques,mustbeused
in all procedures in this test method. Extreme care should be
3. Terminology
exercised in using hydrofluoric acid and other hot, concen-
3.1 Except as otherwise defined herein, definitions of terms
tratedacids.Useofproperglovesisrecommended.Refertothe
are as given in Terminology C859.
laboratory’s chemical hygiene plan and other applicable guid-
ance for handling chemical and radioactive materials and for
4. Significance and Use
the management of radioactive, mixed, and hazardous waste.
4.1 Plutonium dioxide is used in mixtures with uranium
6.3 Hydrofluoric acid is a highly corrosive acid that can
dioxideasanuclear-reactorfuel.Inordertobesuitableforthis
severely burn skin, eyes, and mucous membranes. Hydroflu-
purpose, the material must meet certain criteria for plutonium
oric acid differs from other acids because the fluoride ion
content, isotopic composition, and impurity content.These test
readily penetrates the skin, causing destruction of deep tissue
methods are designed to show whether or not a given material
layers. Unlike other acids that are rapidly neutralized, hydro-
meets the specifications for these items as described in Speci-
fluoric acid reactions with tissue may continue for days if left
fication C757.
untreated.FamiliarizationandcompliancewiththeSafetyData
Sheet is essential.
4.1.1 An assay is performed to determine whether the
materialhastheminimumplutoniumcontentspecifiedonadry
6.4 Perchloric acid (HClO ) forms explosive compounds
weight basis.
withorganicsandmanymetalsalts.Avoidexposurebycontact
4.1.2 Determinationoftheisotopiccontentoftheplutonium
withtheskinoreyes,orbyinhalationoffumes.Familiarization
in the plutonium dioxide powder is made to establish whether
and compliance with the Safety Data Sheet is essential. Carry
the effective fissile content is in compliance with the purchas-
out sample dissolution with perchloric acid in a fume hood
er’s specifications. with a scrubber unit that is specially designed for use with
HClO .
4.1.3 Impurity content is determined to ensure that the
maximum concentration limit of certain impurity elements is
7. Sampling and Dissolution
not exceeded. Determination of impurities is also required for
calculationoftheequivalentboroncontent(EBC)asdescribed
7.1 Criteria for sampling this material are given in Specifi-
in Practice C1233.
cation C757.
4.2 Fitness for Purpose of Safeguards and Nuclear Safety 7.2 Samples can be dissolved using the appropriate disso-
Applications—Methods intended for use in safeguards and lution technique described in Practice C1168.
nuclear safety applications shall meet the requirements speci-
fied by Guide C1068 for use in such applications.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
5. Reagents
listed by the American Chemical Society, see Analar Standards for Laboraotry
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
5.1 Purity of Reagents—Reagent grade chemicals shall be
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
used in all tests. Unless otherwise indicated, it is intended that
MD.
all reagents shall conform to the specifications of the Commit-
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
tee onAnalytical Reagents of theAmerican Chemical Society, these test methods.
C697 − 16
PLUTONIUM SAMPLE HANDLING PLUTONIUM ASSAY BY PLUTONIUM(III) DIODE
ARRAY SPECTROPHOTOMETRY
8. Scope (With appropriate sample preparation, the measurement
described in Test Method C1307 may be used for plutonium
8.1 This test method covers the conditions necessary to
determination.)
preserve the integrity of plutonium dioxide samples. Condi-
tions listed here are directed toward the analytical chemist.
NITROGEN BY DISTILLATION
However, they are just as applicable to any group handling the
SPECTROPHOTOMETRY
material.
USING NESSLER REAGENT
9. Summary of Test Method
11. Scope
9.1 Plutoniumdioxideisveryhygroscopic.Inashorttimeit
11.1 This test method covers the determination of 5 to 100
can sorb sufficient water from an uncontrolled atmosphere to
µg/g of nitride nitrogen in 1-g samples of nuclear-grade
destroy the validity of the most accurate analytical methods.
plutonium dioxide.
An atmosphere with a dew point of−23°C has been found
adequate to prevent sorption of water, but care must be
12. Summary of Test Method
exercisedtouseequipmentandsamplecontainersknowntobe
12.1 The sample is dissolved in hydrochloric acid by the
dry.
sealed tube method or by phosphoric acid hydrofluoric acid
solution, after which the solution is made basic with sodium
10. Sample Handling Conditions
hydroxide and nitrogen is separated as ammonia by steam
10.1 All sampling and critical weighings are to be per-
distillation.Nesslerreagentisaddedtothedistillatetoformthe
formed with consideration of the hygroscopic nature of pluto-
yellowammoniumcomplexandtheabsorbanceofthesolution
nium and the applicable data quality objectives (DQOs). In
is measured at approximately 430 nm (4, 5).
some instances an atmosphere with a dew point no greater
than−23°C may be needed to meet DQOs.
13. Apparatus
10.2 All sampling equipment, including bottles, is to be
13.1 Distillation Apparatus, see Fig. 1.
dried before use. Plastic bottles are not to be used since they
13.2 Spectrophotometer, visible range.
cannot be adequately dried. Glass bottles and aluminum foil
aretobedriedat110°Cforatleast1handkeptinadesiccator
14. Reagents
until used.
14.1 Ammonium Chloride (NH Cl)—Dry salt for 2 h at 110
NOTE1—Ithasbeenshownthatplutoniumdioxidewillsorbwaterfrom
to 120°C.
apparently dry aluminum foil. The foil should be dried at 110°C before
use.
14.2 Boric Acid Solution (40 g/L)—Dissolve 40 g of boric
10.3 Quantitative methods to correct for moisture acid (H BO ) in 800 mL of hot water. Cool to approximately
3 3
20°C and dilute to 1 L.
absorption, such as drying, must be avoided. The sample will
not be representative under these conditions. It is virtually
14.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
impossible to get equal amounts of moisture in the sample and
chloric acid (HCl).
bulk of the material at the same time.
14.4 Hydrofluoric Acid (48 %)—Concentrated hydrofluoric
PLUTONIUM BY CONTROLLED- acid (HF).
POTENTIAL COULOMETRY
14.5 Nessler Reagent—To prepare, dissolve 50 g of potas-
(This test method was discontinued in 1992 and replaced by
sium iodide (KI) in a minimum of cold ammonia-free water,
Test Method C1165.)
approximately 35 mL. Add a saturated solution of mercuric
chloride (HgCl , 22 g/350 mL) slowly until the first slight
PLUTONIUM BY CONTROLLED-POTENTIAL
precipitate of red mercuric iodide persists.Add 400 mLof 9 N
COULOMETRY
sodium hydroxide solution and dilute to 1 L with water, mix,
(With appropriate sample preparation, controlled-potential
and allow the solution to stand overnight. Decant supernatant
coulometric measurement as described in Test Method C1108
liquid and store in a brown bottle.
may be used for plutonium determination.)
14.6 Nitrogen Standard Solution (1 mL=0.01 mg N)—
PLUTONIUM BY CERIC SULFATE TITRATION
Dissolve 3.819 g of NH Cl in water and dilute to 1 L.Transfer
(This test method was discontinued in 2003 and replaced by
10 mL of this solution to a 1-L volumetric flask and dilute to
Test Method C1235, which was withdrawn in 2005.)
volume with ammonia-free water.
14.7 Sodium Hydroxide (9 N)—Dissolve 360 g of sodium
PLUTONIUM BY AMPEROMETRIC TITRATION
hydroxide (NaOH) in ammonia-free water and dilute to 1 L.
WITH IRON (II)
(This test method was discontinued in 1992 and replaced by 14.8 Sodium Hydroxide (50 %)—Dissolve sodium hydrox-
Test Method C1206, which was withdrawn in 2015.) ide (NaOH) in an equal weight of water.
C697 − 16
FIG. 1 Distillation Apparatus
14.9 Water (Ammonia-free)—To prepare, pass distilled wa- 16.2.3 Add 5 mL of 4% H BO solution to a 50-mL
3 3
ter through a mixed-bed resin demineralizer and store in a graduated flask and position this trap so that the condenser tip
tightly stoppered chemical-resistant glass bottle. is below the surface of the H BO solution.
3 3
16.2.4 Transfer20mLof50%NaOHsolutiontothefunnel
15. Precautions
in the distillation head.
15.1 The use of ammonia or other volatile nitrogenous
16.2.5 Whenthewaterbeginstoboilinthesteamgenerator,
compounds in the vicinity can lead to serious error. The
replace the stopper and slowly open the stopcock on the
following precautionary measures should be taken: (1) Clean
distilling flask to allow the NaOH solution to run into the
all glassware and rinse with ammonia-free water immediately
sample solution. (Warning—The NaOH solution must be
prior to use, and (2) avoid contamination of the atmosphere in
added slowly to avoid a violent reaction, which may lead to a
the vicinity of the test by ammonia or other volatile nitrog-
loss of sample.)
enous compounds.
16.2.6 Steamdistilluntil25mLofdistillatehascollectedin
the trap.
16. Procedure
16.2.7 Remove the trap containing the distillate from the
16.1 Dissolution of Sample:
distillation apparatus and remove the stopper from the steam
16.1.1 Transfer a weighed sample in the range from 1.0 to
generator.
1.5 g to a 50-mL beaker.
16.2.8 Transfer the cooled distillate to a 50-mL volumetric
16.1.2 Crushthepelletsamplestoaparticlesizeof1mmor
flask.
less in a diamond mortar.
16.2.9 Prepare a reagent blank solution by following 16.1
16.1.3 To the crushed sample add 5 mLof HCl and 3 drops
through 16.2.8.
of HF. Heat to put sample into solution.
16.3 Measurement of Nitrogen:
NOTE 2—Concentrated phosphoric acid or mixtures of phosphoric acid
16.3.1 Add 1.0 mL of Nessler reagent to each of the
andhydrofluoricacidsorofphosphoricandsulfuricacidsmaybeusedfor
the dissolution of plutonium dioxide. Such acids may require a purifica-
distillates collected in 16.2.8 and 16.2.9 and dilute to volume
tion step in order to reduce the nitrogen blank before being used in this
with ammonia-free water, mix, and let stand 10 min.
procedure.
16.3.2 Measuretheabsorbanceofthesolutionsat430nmin
16.2 Distillation:
a 1-cm cell. Use water as the reference.
16.2.1 Quantitatively transfer the sample solution to the
16.4 Calibration Curve:
distilling flask of the apparatus. Add 20 mL of ammonia-free
water; then clamp the flask into place on the distillation 16.4.1 Add 0, 5, 10, 25, 50, 100, and 150 µg of N from the
apparatus (see Fig. 1). nitrogen standard solution to separate distilling flasks. Then
16.2.2 Turn on the steam generator, but do not close with add 5 mL of HCl and 3 drops of HF plus 20 mL of
the stopper. ammonia-free water to each flask.
C697 − 16
16.4.2 Process each solution by the procedure in 16.2 22.1.2 Combustion Tubes—Quartz combustion tubes with
through 16.3 (omit 16.2.9). integral baffle shall be used.
16.4.3 Correct for the reagent blank reading and plot the
22.1.3 Crucibles—Expendablealuminaorsimilarrefractory
absorbance of each standard against the micrograms of nitro- crucibles shall be used. The use of crucible covers is optional.
gen per 50 mL of solution.
Satisfactory operation with covers must be established by
analysis of standards. Crucibles and covers (if used) must be
17. Calculation
ignited at a temperature of 1000°C or higher for a time
17.1 From the calibration chart, read the micrograms of sufficient to produce constant blank values.
nitrogen corresponding to the absorbance of the sample solu-
22.1.4 Accelerators—Granular tin and tin foil accelerators
tion.
shall be used as required to obtain satisfactory results. The
17.1.1 Calculate the nitrogen content, N, micrograms per criterion for satisfactory results is the absence of significant
gram, of the sample as follows:
additional carbon release upon re-combustion of the specimen.
22.1.5 Catalytic Furnace and Tube—This unit, which is
N 5 A 2 B /W (1)
~ !
used to ensure complete oxidation of CO to CO , consists of a
where:
tube containing copper oxide and maintained at a temperature
A = micrograms of nitrogen from sample plus reagents,
of 300°C by a small furnace.
B = micrograms of nitrogen in blank, and
22.1.6 Carbon Dioxide Purifiers—The purifiers that follow
W = sample mass, g.
the combustion tube must remove finely divided solid metallic
oxides and oxides of sulfur and selenium, dry the gases before
18. Precision
they enter the CO trap, and protect the absorber from outside
18.1 The estimated relative standard deviation for a single
effects.Finelydividedsolidmetaloxidesareremovedfromthe
test measurement by this test method is 20% for 3 µg of
gases during their passage through the quartz wool. The SO
nitrogen and 3% for 50 to 90 µg of nitrogen.
given off by materials containing sulfur is removed by MnO
and any water vapor is absorbed in a tube containing Mg-
CARBON (TOTAL) BY DIRECT COMBUSTION-
(ClO ) .Hotcopperoxideconvertscarbonmonoxidetocarbon
4 2
THERMAL CONDUCTIVITY
dioxide.Additionalcomponentsinthepurificationtrainmaybe
required when materials containing very high amounts of
19. Scope
sulfur or of halides are being analyzed. The materials used in
19.1 This test method covers the determination of 10 to 200
the purification train must be checked frequently to ensure that
µg of residual carbon in nuclear-grade plutonium dioxide.
their absorbing capacity has not been exhausted.
20. Summary of Test Method
22.2 Vibratory Sample Pulverizer Apparatus, capable of
reducing ceramic materials such that 90% or more of the
20.1 Powdered samples are covered and mixed with an
particles are less than 149 µm (equivalent to a−100-mesh
accelerator in carbon-free crucibles and burned with oxygen in
powder).Astainlesssteelcapsuleandmixingballmustbeused
an induction heating furnace. Traces of sulfur compounds and
inordertoreducethecontaminationofthesamplewithcarbon.
water vapor are removed from the combustion products by a
purification train, and the resultant carbon monoxide is con-
verted to carbon dioxide. The purified carbon dioxide is 23. Reagents and Materials
trappedonamolecularsieve,elutedtherefromwithastreamof
23.1 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid
heliumuponapplicationofheattothetrap,andpassedthrough
(H SO ) to be used in the oxygen purification train.
2 4
a thermal conductivity cell. The amount of carbon present,
23.2 Quartz Wool, to use as a dust trap at top of combustion
being a function of the integrated change in the current of the
tube.
detectorcell,isreaddirectlyfromacalibrateddigitalvoltmeter
or strip-chart recorder.
23.3 Standard Materials—Certified reference material stan-
dardsfromanationalstandardsbodysuchastheU.S.National
21. Interferences
Institute for Standards and Technology (NIST) or equivalent.
21.1 Therearenoknowninterferencesnoteliminatedbythe
Certifiedmaterialsinsteelmatrices(steelpins,steelrings,steel
purification system.
granules,andsteelpowder)rangingfrom5µgcarbon/gsample
to 1500 µg carbon/g sample are available and have been found
22. Apparatus
satisfactory.
22.1 Commercial Combustion Apparatus, suitable for the
carbon determination, is often modified to facilitate mainte-
24. Sampling
nanceandoperationwithinthegloveboxwhichisrequiredfor
24.1 Sample Size—The normal sample size for plutonium
all work with plutonium materials.
dioxide fuel materials shall be 1 g. If necessary, this amount
22.1.1 Combustion Apparatus—This apparatus shall consist
shall be altered as required to contain less than 200 µg of
of an induction furnace suitable for operation at 1600°C, with
carbon.
a purification train, a catalytic furnace, carbon dioxide trap,
thermal conductivity cell with appropriate readout equipment, 24.2 Sample Preparation—Pellet or particulate samples
and a regulated supply of oxygen and helium. shall be reduced such that approximately 90% of the particles
C697 − 16
are less than 149 µm (equivalent to approximately a−100- 27.5 Load the sample crucible into the furnace and combust
mesh powder) prior to the weighing of the specimens. Expo- the specimen for 2 min.
sure of the powdered sample to atmospheric carbon dioxide
27.6 Remove the sample crucible and examine for evidence
should be minimized by storage of the powder in a closed vial.
of incomplete combustion. The crucible contents should be a
Refer to Sections 8 and 10 for guidance in handling plutonium
uniform fused mass.
dioxide.
28. Calculation
25. Preparation of Apparatus
28.1 Calculate the concentration of carbon in the sample by
25.1 Analysis System Purge—After having properly set the
dividing the net micrograms of carbon found by the sample
operating controls of the instrument system, condition the
mass, expressed in grams, as follows:
apparatus by combustion of several blanks prepared with the
C, µg/g 5 C 2 C /W (2)
~ !
s b
sample crucible and accelerator in the amount to be used with
the test specimen analyses. Successive blank values should where:
approach a constant value, allowing for normal statistical
C = micrograms of carbon in the sample and reagents,
s
fluctuations. The instrument should be adjusted for a 2-min
C = micrograms of carbon in reagent blank, and,
b
combustion period.
W = grams of oxide sample.
26. Calibration 29. Precision
26.1 Preparation of Standards for Combustion—Mix a
29.1 The relative standard deviation of this test method is
weighed portion of an accelerator and an accurately weighed approximately10%foraconcentrationof30µgofcarbon/gof
portion of approximately1gof reference material with a
sample.
certifiedcarbonvalueofabout0.005%ineachofthreesample
TOTAL CHLORINE AND FLUORINE BY
crucibles. Repeat with a reference material with a certified
PYROHYDROLYSIS
carbon value of about 0.5%, using an accurately weighed
portion of approximately 30 to 40 mg.
30. Scope
NOTE 3—These portions represent about 50 µg and 200 µg of carbon,
30.1 This test method covers the determination of 5 to 100
respectively.
µg/gofchlorineand1to100µg/goffluorinein1-gsamplesof
26.1.1 Weighthesteelintoataredcontainer,suchasasmall nuclear-grade plutonium dioxide.
nickel-sample boat, obtaining the mass to the nearest 0.01 mg.
31. Summary of Test Method
Transfer the chips to a 30-mm square of aluminum foil
31.1 A1 to 2-g sample of plutonium dioxide is pyrohydro-
(previously acetone washed), and fold the foil into a wrapper
lyzed at 950°C with a stream of moist air or oxygen. The
with the aid of stainless steel tongs and spatulas. The foil
halogensarevolatilizedasacidsduringthepyrohydrolysisand
should not be touched by the hands. Place the wrapped
are trapped as chloride and fluoride in a buffered solution.
standard in a numbered glass vial and transfer to the analyzer
Several procedures are outlined for the measurement of chlo-
glove box.
ride and fluoride in the resultant condensate. Chloride is
26.2 Combustion of Standards—Loadandcombustthestan-
measured by spectrophotometry, microtitrimetry, or with ion-
dards and record the results. Adjust the calibration controls in
selective electrodes and fluoride with ion-selective electrodes
suchawayastoproducethecorrectreadoutvalueonthedirect
or spectrophotometry (6, 7).
readout meter. Combust additional standards as required to
produce the correct direct readout. As an alternative, consider
32. Interferences
the readout digits as arbitrary numbers and prepare a calibra-
32.1 Bromide, iodide, cyanide, sulfide, and thiocyanate, if
tion curve of known micrograms of carbon versus the readout
presentinthecondensate,wouldinterferewiththespectropho-
value.Astripchartrecorderconnectedtopresenttheintegrated
tometric and microtitrimetric measurement of chloride.
value of the carbon dioxide response signal is helpful in
Bromide, iodide, sulfide, and cyanide interfere in the measure-
detecting and correcting for analyzer drift and noise.
ment of chloride with ion-selective electrodes, but have very
little effect upon the measurement of fluoride with selective
27. Procedure
electrodes.
27.1 Pulverize the pellet samples for 15 s in the stainless
steel capsule of the sample pulverizer. 33. Apparatus (see Fig. 2 and Fig. 3 for examples)
27.2 Weigh a sample crucible containing the required 33.1 Gas Flow Regulator—Aflowmeter and a rate control-
amount of accelerator to the nearest 0.01 g. ler to adjust the flow of sparge gas between 1 to 3 L/min.
27.3 Transfer the sample powder, not to exceed1gorof 33.2 Hot Plate—A heater used to keep the water bubbler
such size as to give not more than 200 µg of carbon, to the temperature between 50 and 90°C.
crucible. Weigh the crucible and contents to the nearest 0.01 g
33.3 Furnace—A tube furnace that is capable of maintain-
and find the specimen mass by difference.
ingatemperaturefrom900to1000°C.Theboreofthefurnace
27.4 Mix the specimen powder and the accelerator with a shouldbeabout32mm(1 ⁄4in.)indiameterandabout305mm
stainless steel spatula. (12 in.) in length.
C697 − 16
FIG. 2 Pyrohydrolysis Apparatus
FIG. 3 Quartz Reaction Tube
33.4 Reactor Tube,madefromfused-silicaorplatinum.The 34. Reagents
deliverytubeshouldbeapartoftheexitendofthereactortube
34.1 Accelerator—Halogen-free uranium oxide (U O )
3 8
and be within 51 mm (2 in.) of the furnace (see Fig. 2 for
powder used as a flux to enhance the release of chloride and
proper tube positioning).
fluoride.
33.5 Combustion Boats, made from fused-silica or plati-
34.2 Air or Oxygen, compressed.
num. A boat about 102 mm (4 in.) long is made by cutting
lengthwise a silica tube 20 mm in diameter and flattening one
34.3 Buffer Solution(0.001 N)—Preparebyadding50µLof
end to provide a handle. A fused-silica inner sleeve for the
concentratedglacialaceticacid(CH CO H,spgr1.05)and0.1
3 2
reactor tube can facilitate the movement of the boat into the
g of potassium acetate (KC H O ) to 1 L of water.
2 3 2
tube, prevent spillage, and thus prolong the life of the com-
34.4 Chloride Standard Solution (1 mL = 1 mg Cl)—
bustion tube.
Dissolve 1.65 g of sodium chloride (NaCl) in water and dilute
33.6 Collection Vessel—A plastic graduate or beaker de-
to1L.
signed to maintain most of the scrubber solution above the tip
34.5 Chloride, Standard Solution (1 mL = 5 µg Cl)—
of the delivery tube.
Preparebydiluting5mLofchloridesolution(1mL=1mgCl)
33.7 Automatic Chloride Titrator.
to 1 L with water.
33.8 Ion-Selective Electrodes, chloride and fluoride.
34.6 Ferric Ammonium Sulfate Solution (0.25 M in 9 M
nitric acid)—Dissolve 12 g of ferric ammonium sulfate
33.9 Reference Electrode—Use a double-junction type elec-
(Fe(NH )(SO ) ·12 H O) in 58 mL of concentrated nitric acid
trode such as mercuric sulfate, sleeve-junction type electrode.
4 4 2 2
(HNO , sp gr 1.42) and dilute to 100 mL with water.
Do not use a calomel electrode.
34.7 Fluoride, Standard Solution (1 mL = 1 mg F)—
33.10 Spectrophotometer, ultraviolet to visible range and
absorption cells. For a discussion on spectrophotometers and Dissolve2.21gofsodiumfluoride(NaF)inwateranddiluteto
1L.
their use see Practice E60.
33.11 pH Meter,withanexpandedscalehavingasensitivity 34.8 Fluoride, Standard Solution (1 mL = 10 µg F)—Dilute
of1mV. 10 mLof fluoride solution (1 mL=1 mg F) to 1 Lwith water.
C697 − 16
34.9 Gelatin Solution—Add6.2gofdrygelatinmixture(60 35.7 Runapyrohydrolysisblankwithhalogen-freeU O by
3 8
parts of dry gelatin+1 part of thymol blue+1 part of thymol) following the procedures, given in 35.3 – 35.6.
to 1 Lof hot water and heat with stirring until solution is clear.
36. Measurement of Chloride and Fluoride
34.10 Lanthanum-Alizarin Complexone—Dissolve 0.048 g
of alizarin complexone (3-aminomethylalizarin-N, N-diacetic 36.1 Determination of Chloride by Spectrophotometry:
acid) in 100 µL of concentrated ammonium hydroxide 36.1.1 Prepare a calibration curve by adding 0, 1, 2, 5, and
(NH OH), 1 mL of an ammonium acetate solution 10 mL of the chloride solution (1 mL=5 µg Cl) to separate
(NH C H O , 20 mass%), and 5 mL of water. Filter the 25-mL flasks. Dilute each to 20 mL with buffer solution, and
4 2 3 2
solution through a high-grade, rapid-filtering, qualitative filter add 2 mLof the ferric ammonium sulfate solution and 2 mLof
paper. Wash the paper with a small volume of water, and add the mercuric thiocyanate solution. Mix the solution and dilute
8.2 g of anhydrous sodium acetate (NaC H O)and6mLof to 25 mL with water. Mix the solutions again and allow them
2 3 2
concentrated glacial acetic acid (CH CO H, sp gr 1.05) to the tostand10min.Transfersomeofthesolutionfromtheflaskto
3 2
filtrate.Add 100 mLof acetone while swirling the filtrate.Add a1-cmabsorptioncellandreadtheabsorbanceat460nmusing
0.040 g of lanthanum oxide (La O ) dissolved in 2.5 mL of water as the reference liquid. Plot the micrograms of Cl per 25
2 3
warm 2 N HCl. Mix the two solutions and dilute to 200 mL.
mL versus the absorbance reading.
After 30 min readjust the solution volume. 36.1.2 To determine Cl in the pyrohydrolysis condensate
transfer 15 mL of the buffer solution to a 25-mL volumetric
NOTE 4—A 0.1-g/L solution is prepared by dissolving 100 mg of the
flask.Add 2 mLof the ferric ammonium sulfate solution and 2
reagent in water and diluting with isopropyl alcohol to obtain a 60%
mL of the mercuric thiocyanate solution. Mix the solutions,
alcoholic medium.
dilute to volume with water, and mix again.Allow the solution
34.11 Mercuric Thiocyanate Solution—Prepare a saturated
tostand10min.Transfersomeofthesolutionfromtheflaskto
solution by adding 0.3 g of mercuric thiocyanate (Hg(SCN) )
a 1-cm absorption cell and read the absorbance at 460 nm
to 100 mL of 95% ethanol. Shake the mixture thoroughly for
versus water as the reference. Read the micrograms of Cl
maximum dissolution of the solid. Filter the solution.
present from the calibration curve.
34.12 Nitric Acid-Acetic Acid Solution (1 N NitricAcid and
NOTE 5—A calibration curve can be prepared by drying measured
4 N Acetic Acid)—Prepare by adding 64 mL of nitric acid
aliquotsofachloridesolutiononsomehalogen-freeU O andproceeding
3 8
(HNO , sp gr 1.42) to a 1-L volumetric flask which contains
through pyrohydrolysis steps.
500 mL of water. Swirl the solution in the flask and add 230
36.1.3 Calculate the chlorine, Cl, µg/g, as follows:
mL of acetic acid (CH CO H, sp gr 1.05). Dilute the solution
3 2
Cl, µg/g 5 A 2 B V (3)
~ !
with water to 1 L.
1/WV
where:
35. Pyrohydrolysis Procedure
A = micrograms of chlorine in aliquot measured,
35.1 Prepare the pyrohydrolysis apparatus for use as fol-
B = micrograms of chlorine in blank,
lows:
W = grams of PuO pyrohydrolyzed,
35.1.1 Regulate the gas flow between 1 and 3 L/min. V = millilitres of scrub solution, and
V = aliquot of scrub solution analyzed, mL.
35.1.2 Adjust the temperature of the hot plate to heat the
water to approximately 90°C.
36.2 Determination of Chloride by Amperometric Microtit-
35.1.3 Adjustthetemperatureofthefurnaceto950 650°C.
rimetry:
35.1.4 Add 15 mLof buffer solution to the collection vessel
36.2.1 Calibrate the titrimeter by adding 5 mLof the buffer
and place around the delivery tube.
solution, 1 mL of the nitric acid-acetic acid solution, and 2
drops of the gelatin solution to a titration cell. Pipet 50 µL of
35.2 Weigh accurately, 1 to2gofthe powdered plutonium
the chloride solution (1 mL=1 mL Cl) into the titration cell.
dioxide and transfer to a combustion boat. If an accelerator,
Place the cell on the chloride titrator and follow the manufac-
U O , is used mix 4 g with the sample before loading into the
3 8
turer’s suggested sequence of operations for chloride (Note 6).
boat.
Record the time required to titrate 50 µg. Run a reagent blank
35.3 Place the boat containing the sample into the reactor
titration.
tube and quickly close the tube. The boat should be in the
NOTE 6—The Cl-analyzer generates silver ions which react to precipi-
middle of the furnace.
tate the chloride ion. The instrument uses an amperometric end point to
35.4 Allow the pyrohydrolysis to proceed for at least 30 obtain an automatic shut-off of the generating current at a pre-set
increment of indicator current. Since the rate of generating silver ion is
min.
constant, the amount of chloride precipitated is proportional to the time
35.5 Remove the collection vessel and wash down the
required for the titration.
delivery tube with some buffer solution. Dilute the solution to
36.2.2 DetermineClinthepyrohydrolysis-scrubsolutionby
25 mL with the acetate buffer. Determine the chloride and
adding5mLtoatitrationcellwhichcontains1mLofthenitric
fluoride by one or more of the measurement procedures
acid-acetic acid solution and 2 drops of the gelatin solution.
covered in Section 36.
36.2.3 Place the cell in position on the titrator. Start the
titrator and record the time required to titrate the Cl present.
35.6 Remove the boat from the reactor tube and dispose of
the sample residue. 36.2.4 Calculate the chlorine as follows:
C697 − 16
Cl, µg/g 5 V F T 2 T /V W (4)
~ !
1 s B 2 F = fluorine in aliquot of scrub solution+the blank, µg,
s
F = micrograms of fluorine in pyrohydrolysis blank,
b
where:
V = total volume of the scrub solution, mL,
V = volume of scrub solutions=25,
V = aliquot of scrub solution analyzed, mL, and
V = aliquot of scrub solution analyzed, mL,
W = grams of PuO sample.
F =
36.5 Determination of Chloride and Fluoride by Ion
µC1 standardtitrated
Chromatography—Determine the Cl and F in the scrub solu-
titrationtimeofstandard 2 titrationtimeofblank
tion from the pyrohydrolysis in accordance with Test Method
D4327. Record the micrograms of Cl or F from the calibration
or
curve and calculate the halide using Eq 6.
F 5 50/~T 2 T !, (5)
C1 B
37. Precision
T = titration time to titrate sample and blank,
s 37.1 The relative standard deviations for the measurements
T = titration time to titrate 50 µg of Cl and blank,
C1
of fluorine are approximately 7% for the range from 5 to 50
T = titration time to titrate reagent blank, and
B
µg/g and 10% for the range from 1 to 5 µg/g. The relative
W = grams of PuO pyrohydrolyzed.
standarddeviationsforthemeasurementsofchlorinevaryfrom
36.3 Determination of Chloride and Fluoride with Ion- 5% at the 5 to 50-µg/g level up to 10% below the 5-µg/g
range.
Selective Electrodes:
36.3.1 Preparation of the calibration curves requires the
SULFUR BY DISTILLATION
assembly of the meter and the ion-selective electrode with a
SPECTROPHOTOMETRY
suitable reference electrode. From these standards take the
millivolt readings for each ion-selective electrode and deter-
38. Scope
mine the halogen content per 25 mL versus millivolts, using
38.1 This test method coves the determination of sulfur in
computersoftwareoraplotonsemi-logpaper.Prepareaseries
the concentration range from 10 to 600 µg/g for samples of
of standards in acetate buffer solution by pipeting aliquots of
nuclear-grade plutonium dioxide powders or pellets.
the halogen standards into separate 25-mL flasks ranging in
concentrations as follows:
39. Summary of Test Method
Cl from 10 to 100 µg/25 mL
F from 5 to 100 µg/25 mL
39.1 Sulfur is measured spectrophotometrically as Lauth’s
36.3.2 DeterminetheClandFinthescrubsolutionfromthe
Violet following its separation by distillation as hydrogen
pyrohydrolysis by using the appropriate ion-selective elec-
sulfide (8). Higher oxidation states of sulfur are reduced to
trode. Record the micrograms of Cl or F from the calibration
sulfide by a hypophosphorous-hydriodic acid mixture, the
curve and calculate the halide as follows:
hydrogen sulfide is distilled into zinc acetate, and
p-phenylenediamine and ferric chloride are added to form
Clor F, µg/g 5 H 2 H /W (6)
~ !
s b
Lauth’s Violet. The quantity of sulfur is calculated from the
where:
measured absorbance at 595 nm and the absorbance per
H = halide in aliquot of scrub solution+blank, µg,
microgram of sulfur obtained for calibration materials having
s
H = halide in pyrohydrolysis blank, µg, and
known sulfur contents. The relative standard deviation ranges
b
W = sample mass, g.
from 12 to 3% for the concentration range from 10 to 600 µg
of sulfur per gram of sample.
36.4 Determination of Fluoride by Spectrophotometry:
36.4.1 Prepare a calibration curve by adding to separate
40. Interference
10-mLflasks 0, 50, 100, 200, 500, and 1000 µLof the fluoride
solution (1 mL=10 µg F). Add 2.0 mL of the lanthanum- 40.1 None of the impurity elements interfere when present
alizarin complexone solution and dilute to volume with water. in amounts up to twice their specification limits for plutonium
Mix and let stand 1 h. Read the absorbance at 622 nm versus dioxide.
the reagent blank. Plot the micrograms of F per 10 mL versus
41. Apparatus
absorbance reading.
36.4.2 Measure F in the pyrohydrolysis scrub solution by
41.1 Boiling Flask, adapted with a gas inlet line and fitted
pipeting 5 mL into a 10-mL volumetric flask. Add 2.0 mL of
with a water-cooled condenser and delivery tube.
the lanthanum-alizarin complexone and dilute to volume. Mix
41.2 Spectrophotometer, with matched 1-cm cells.
and let stand 1 h. Read the absorbance at 622 nm versus a
41.3 Sulfur, distillation apparatus (see Fig. 4 for example).
reagent blank and obtain the fluoride content from the calibra-
tion curve.
42. Reagents
36.4.3 Calculate the fluorine concentration, F, in the PuO
sample as follows:
42.1 Argon Gas, cylinder.
F, µg/g 5 F 2 F /W 3 V /V (7)
@~ ! #
s b 1 2 42.2 Ferric Chloride Solution, 2% FeCl in 6 M HCl.
where: 42.3 Formic Acid (HCOOH), redistilled.
C697 − 16
FIG. 4 Sulfur Distillation Apparatus
42.4 Hydriodic-Hypophosphorous Acid Reducing Mixture— of oxides and sulfur (20 to 600 µg S/g) should be analyzed to
Mix 400 mL of 7.6 M hydriodic acid (HI) with 200 mL of simulate actual sample conditions.
hypophosphorousacid(H PO ,31%)andboilunderrefluxfor
3 2
43.2 Prepareacalibrationcurveofabsorbance versussulfur
30 min with a continuous argon sparge. Test for sulfur content
(using aliquots of the sulfur standard solution) covering a
byanalyzinga15-mLaliquotasdescribedinprocedure.Reboil
concentration range from 5 to 50 µg/50 mL.
if necessary to reduce the sulfur content to below 1 µg/mL.
44. Procedure
42.5 Hydrochloric Acid (0.6 M)—Dilute 10 mL of 12 M
hydrochloric acid (HCl) to 200 mL with water.
44.1 Pulverize plutonium dioxide pellets in a mixer-mill
with a tungsten carbide container and a tungsten carbide ball.
42.6 Hydrochloric Acid (3 M)—Dilute 50 mL of 12 M HCl
to 200 mL with water.
44.2 Transfer a sample, weighed to 60.2 mg, to a 20-mL
beakerora30-mLplatinumdish.Usea0.5-gsamplewhenthe
42.7 Hydrochloric Acid (6 M)—Dilute100mLof12 MHCl
expected level of sulfur is 100 µg/g or less.
to 200 mL with water.
44.3 Add 5 mL of 15.6 M HNO and 3 to 4 drops of 28 M
42.8 Hydrochloric Acid (12 M)—Analyze an aliquot of HCl 3
HFandheatthesolutionbelowitsboilingpoint.Watchglasses
(sp gr 1.19) for sulfur content. Use only a reagent in which the
or platinum lids are recommended to avoid spattering.
sulfur content is less than 1 µg/10 mL and prepare the diluted
acids with this reagent.
44.4 Add additional amounts of HNO and HF acids until
the sample dissolves.
42.9 Hydrofluoric Acid (HF), 48%.
NOTE7—Thesealed-tubetechnique (4)isanalternatemethodthatmay
42.10 Hydroxylamine Hydrochloride (NH OH·HCl), 20%
be used to advantage for the dissolution of some samples.
aqueous solution.
44.5 Evaporate the solution just to dryness, but do not fume
42.11 Nitric Acid (15.6 M), 70% HNO .
intensely to dryness.
42.12 p-phenylenediamine (1 %)—Dissolve1gof
44.6 Add dropwise 0.5 mL of formic acid, and heat the
p-phenylenediamine in 100 mL of 0.6 M HCl.
solutionatamoderateheatuntilthevigorousreactionsubsides
42.13 Silver Nitrate (AgNO ), 1% aqueous solution.
and gases are no longer evolved.
42.14 Sulfur Calibration Solution (1 mL = 5 µg S)—
NOTE 8—The reduction of HNO by formic acid is vigorous. Keep the
Dissolve2.717gofdrypotassiumsulfate(K SO )inwaterand
2 4 dish or beaker covered with a watch glass between additions of formic
dilute to 1 L. Dilute 2.00 mL to 200 mL with water. acid.
42.15 Zinc Acetate Solution (4%)—Dissolve 20 g of zinc 44.7 Rinsethecoverglasswithwater.Add0.5mLofformic
acid and slowly evaporate the rinse and sample solution to
acetate (Zn(C H O ) ) in 500 mL of water and filter.
2 3 2 2
dryness. (Warning—Nitrate must be completely removed
43. Calibration because it reacts explosively with the reducing acid.)
43.1 Use aliquots of standard sulfur solution (1 mL=5 µg 44.8 Dissolvetheresidueinaminimumvolumeof3 MHCl
S) to test the method and check the apparatus. Ideally, blends and dilute to approximately 5 mL with water. Heat to just
C697 − 16
below the boiling point and add 20 drops of hydroxylamine 47. Scope
solution (Pu (III) blue is formed).
47.1 This test method covers the determination of
44.9 Add 30 mL of water to the trap of the distillation dysprosium, europium, gadolinium, and samarium in pluto-
apparatus (Fig. 4) and insert the trap tube. nium dioxide (PuO ) in concentrations of 0.1 to 10 µg/g of
PuO .
44.10 Pipet 10.0 mL of zinc acetate solution into a 50-mL
glass-stopperedgraduatedcylinder,diluteto35mLwithwater,
48. Summary of Test Method
and position the cylinder so the end of the delivery tube is
48.1 PuO is dissolved in a nitric-hydrofluoric acid (HNO -
2 3
immersed in the solution.
HF) mixture and evaporated to dryness. The residue is redis-
44.11 Transfer the sample solution (71.8), with a minimum
solved in dilute HNO , and the plutonium is extracted into
of water rinses, to the distillation flask and insert the reducing-
30% tributyl phosphate in n-hexane. The aqueous phase is
acid delivery tube.
treated with yttrium c
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C697 − 10 C697 − 16
Standard Test Methods for
Chemical, Mass Spectrometric, and Spectrochemical
Analysis of Nuclear-Grade Plutonium Dioxide Powders and
Pellets
This standard is issued under the fixed designation C697; 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 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade
plutonium dioxide powders and pellets to determine compliance with specifications.
1.2 The analytical procedures appear in the following order:
Sections
Plutonium Sample Handling 8 to 10
Plutonium by Controlled-Potential Coulometry
Plutonium by Ceric Sulfate Titration
Plutonium by Amperometric Titration with Iron(II)
Plutonium by Diode Array Spectrophotometry
Nitrogen by Distillation Spectrophotometry Using Nessler 11 to 18
Reagent
Carbon (Total) by Direct Combustion–Thermal Conductivity 19 to 30
Carbon (Total) by Direct Combustion–Thermal Conductivity 19 to 29
Total Chlorine and Fluorine by Pyrohydrolysis 31 to 38
Total Chlorine and Fluorine by Pyrohydrolysis 30 to 37
Sulfur by Distillation Spectrophotometry 39 to 47
Sulfur by Distillation Spectrophotometry 38 to 46
Plutonium Isotopic Analysis by Mass Spectrometry
Rare Earth Elements by Spectroscopy 48 to 55
Rare Earth Elements by Spectroscopy 47 to 54
Trace Elements by Carrier–Distillation Spectroscopy 56 to 63
Trace Elements by Carrier–Distillation Spectroscopy 55 to 62
(Alternative: Impurities by ICP-AES or ICP-MS)
Impurity Elements by Spark-Source Mass Spectrography 64 to 70
Impurity Elements by Spark-Source Mass Spectrography 63 to 69
Moisture by the Coulometric Electrolytic Moisture Analyzer 71 to 78
Moisture by the Coulometric Electrolytic Moisture Analyzer 70 to 77
Total Gas in Reactor-Grade Plutonium Dioxide Pellets 79to 86
Total Gas in Reactor-Grade Plutonium Dioxide Pellets
Plutonium-238 Isotopic Abundance by Alpha Spectrometry
Americium-241 in Plutonium by Gamma-Ray Spectrometry
Rare Earths By Copper Spark-Spectroscopy 87 to 96
Rare Earths By Copper Spark-Spectroscopy 78 to 87
Plutonium Isotopic Analysis by Mass Spectrometry 97 to 105
Plutonium Isotopic Analysis by Mass Spectrometry 88 to 96
Oxygen-To-Metal Atom Ratio by Gravimetry 106 to 114
Oxygen-To-Metal Atom Ratio by Gravimetry 97 to 104
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
These test methods are under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 on Methods
of Test.
Current edition approved June 1, 2010June 1, 2016. Published July 2010July 2016. Originally approved in 1972. Last previous edition approved in 20042010 as
C697 – 04.C697 – 10. DOI: 10.1520/C0697-10.10.1520/C0697-16.
Discontinued as of November 15, 1992.
Discontinued as of January 1, 2004.
Discontinued as of May 30, 1980.
Discontinued as of June 2016.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C697 − 16
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. For specific precautionary statements, see Sections 6, 1516.2.5, 2444.7, 111, and 52.951.9 and
101.5.192.5.1.
2. Referenced Documents
2.1 ASTM Standards:
C757 Specification for Nuclear-Grade Plutonium Dioxide Powder for Light Water Reactors
C852 Guide for Design Criteria for Plutonium Gloveboxes
C1009C859 Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the
Nuclear IndustryTerminology Relating to Nuclear Materials
C1068 Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
C1108 Test Method for Plutonium by Controlled-Potential Coulometry
C1128 Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials
C1156 Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
C1165 Test Method for Determining Plutonium by Controlled-Potential Coulometry in H SO at a Platinum Working Electrode
2 4
C1168 Practice for Preparation and Dissolution of Plutonium Materials for Analysis
C1206 Test Method for Plutonium by Iron (II)/Chromium (VI) Amperometric Titration (Withdrawn 2015)
C1210C1233 Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories
Within the Nuclear IndustryPractice for Determining Equivalent Boron Contents of Nuclear Materials
C1235 Test Method for Plutonium by Titanium(III)/Cerium(IV) Titration (Withdrawn 2005)
C1268 Test Method for Quantitative Determination of Am in Plutonium by Gamma-Ray Spectrometry
C1297 Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
C1307 Test Method for Plutonium Assay by Plutonium (III) Diode Array Spectrophotometry
C1415 Test Method for Pu Isotopic Abundance By Alpha Spectrometry
C1432 Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and
Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
C1625 Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass
Spectrometry
C1637 Test Method for the Determination of Impurities in Plutonium Metal: Acid Digestion and Inductively Coupled
Plasma-Mass Spectroscopy (ICP-MS) Analysis
C1672 Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total
Evaporation Method Using a Thermal Ionization Mass Spectrometer
D1193 Specification for Reagent Water
D4327 Test Method for Anions in Water by Suppressed Ion Chromatography
E60 Practice for Analysis of Metals, Ores, and Related Materials by Spectrophotometry
E115 Practice for Photographic Processing in Optical Emission Spectrographic Analysis (Withdrawn 2002)
E116 Practice for Photographic Photometry in Spectrochemical Analysis (Withdrawn 2002)
E130 Practice for Designation of Shapes and Sizes of Graphite Electrodes (Withdrawn 2013)
3. Terminology
3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.
4. Significance and Use
4.1 Plutonium dioxide is used in mixtures with uranium dioxide as a nuclear-reactor fuel. In order to be suitable for this purpose,
the material must meet certain criteria for plutonium content, isotopic composition, and impurity content. These test methods are
designed to show whether or not a given material meets the specifications for these items as described in Specification C757.
4.1.1 An assay is performed to determine whether the material has the minimum plutonium content specified on a dry weight
basis.
4.1.2 Determination of the isotopic content of the plutonium in the plutonium dioxide powder is made to establish whether the
effective fissile 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 impurity elements is not
exceeded. Determination of impurities is also required for calculation of the equivalent boron content (EBC).(EBC) as described
in Practice C1233.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
C697 − 16
4.2 Fitness for Purpose of Safeguards and Nuclear Safety Applications—Methods intended for use in safeguards and nuclear
safety applications shall meet the requirements specified by Guide C1068 for use in such applications.
4. Committee C26 Safeguards Statement
4.1 The materials (plutonium dioxide powders and pellets) to which these test methods apply are subject to nuclear safeguards
regulations governing their possession and use. The following analytical procedures in these test methods have been designated
as technically acceptable for generating safeguards accountability measurement data: Plutonium by Controlled-Potential
Coulometry; Plutonium by Ceric Sulfate Titration; Plutonium by Amperometric Titration with Iron (II); Plutonium by Diode Array
Spectrometry Plutonium-238 Isotopic Abundance by Alpha Spectrometry; and Plutonium Isotopic Analysis by Mass Spectrometry.
4.2 When used in conjunction with appropriate Certified Reference Materials (CRMs), these procedures can demonstrate
traceability to the national measurement base. However, adherence to these procedures does not automatically guarantee regulatory
acceptance of the resulting safeguards measurements. It remains the sole responsibility of the user of these test methods to assure
that its application to safeguards has the approval of the proper regulatory authorities.
5. Reagents
5.1 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 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.
5.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Specification D1193.
6. Safety Precautions
6.1 Since plutonium bearing materials are radioactive and toxic, adequate laboratory facilities, glovedglove boxes, fume hoods,
etc., and so forth, along with safe techniques, must be used in handling samples containing these materials. Glove boxes should
be fitted with off-gas filters capable of sustained operation with dust-laden atmospheres. A detailed discussion of all the precautions
necessary is beyond the scope of these test methods; however, personnel who handle these materials should be familiar with such
safe handling practices as are given in Guide C852 and in Refs (11-3) through (2).
6.2 Adequate laboratory facilities, such as fume hoods and controlled ventilation, along with safe techniques, must be used in
this procedure. all procedures in this test method. Extreme care should be exercised in using hydrofluoric acid and other hot,
concentrated acids. Use of proper gloves is recommended. Refer to the laboratory’s chemical hygiene plan and other applicable
guidance for handling chemical and radioactive materials and for the management of radioactive, mixed, and hazardous waste.
6.3 Hydrofluoric acid is a highly corrosive acid that can severely burn skin, eyes, and mucous membranes. Hydrofluoric acid
is similar to other acids in that the initial extent of a burn depends on the concentration, the temperature, and the duration of contact
with the acid. Hydrofluoric acid differs from other acids because the fluoride ion readily penetrates the skin, causing destruction
of deep tissue layers. Unlike other acids that are rapidly neutralized, hydrofluoric acid reactions with tissue may continue for days
if left untreated. Due to serious consequences of hydrofluoric acid burns, prevention of exposure or injury of personnel is the
primary goal. Utilization of appropriate laboratory controls (hoods) and wearing adequate personal protective equipment to protect
from skin and eye contact Familiarization and compliance with the Safety Data Sheet is essential.
6.4 Perchloric acid (HClO ) forms explosive compounds with organics and many metal salts. Avoid exposure by contact with
the skin or eyes, or by inhalation of fumes. Familiarization and compliance with the Safety Data Sheet is essential. Carry out
sample dissolution with perchloric acid in a fume hood with a scrubber unit that is specially designed for use with HClO .
7. Sampling and Dissolution
7.1 Criteria for sampling this material are given in Specification C757.
7.2 Samples can be dissolved using the appropriate dissolution technique described in Practice C1168.
PLUTONIUM SAMPLE HANDLING
8. Scope
8.1 This test method covers the conditions necessary to preserve the integrity of plutonium dioxide samples. Conditions listed
here are directed toward the analytical chemist. However, they are just as applicable to any group handling the material.
Based upon Committee C26 Safeguards Matrix (C1009, C1068, C1128, C1156, C1210, C1297).
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 LaboratoryLaboraotry Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and
National Formulary, U.S. Pharmacopeial Convention, Inc.,Inc. (USPC), Rockville, MD.
The boldface numbers in parentheses refer to the list of references at the end of these test methods.
C697 − 16
9. Summary of Test Method
9.1 Plutonium dioxide is very hygroscopic. In a short time it can sorb sufficient water from an uncontrolled atmosphere to
destroy the validity of the most accurate analytical methods. An atmosphere with a dew point of −23°C has been found adequate
to prevent sorption of water, but care must be exercised to use equipment and sample containers known to be dry.
10. Sample Handling Conditions
10.1 All sampling and critical weighings are to be performed in with consideration of the hygroscopic nature of plutonium and
the applicable data quality objectives (DQOs). In some instances an atmosphere with a dew point no greater than −23°C.
than −23°C may be needed to meet DQOs.
10.2 All sampling equipment, including bottles, is to be dried before use. Plastic bottles are not to be used since they cannot
be adequately dried. Glass bottles and aluminum foil are to be dried at 110°C for at least 1 h and kept in a desiccator until used.
NOTE 1—It has been shown that plutonium dioxide will sorb water from apparently dry aluminum foil. The foil should be dried at 110°C before use.
10.3 Quantitative methods to correct for moisture absorption, such as drying, must be avoided. The sample will not be
representative under these conditions. It is virtually impossible to get equal amounts of moisture in the sample and bulk of the
material at the same time.
PLUTONIUM BY CONTROLLED-
POTENTIAL COULOMETRY
(This test method was discontinued in 1992 and replaced by Test Method C1165.)
PLUTONIUM BY CONTROLLED-POTENTIAL COULOMETRY
(With appropriate sample preparation, controlled-potential coulometric measurement as described in Test Method C1108 may
be used for plutonium determination.)
PLUTONIUM BY CERIC SULFATE TITRATION
(This test method was discontinued in 2003 and replaced by Test Method C1235.), which was withdrawn in 2005.)
PLUTONIUM BY AMPEROMETRIC TITRATION
WITH IRON (II)
(This test method was discontinued in 1992 and replaced by Test Method C1206.) , which was withdrawn in 2015.)
STANDARD TEST METHOD FOR PLUTONIUM ASSAY BY PLUTONIUM(III) DIODE ARRAY
SPECTROPHOTOMETRY
(With appropriate sample preparation, the measurement described in Test Method C1307 may be used for plutonium
determination.)
NITROGEN BY DISTILLATION SPECTROPHOTOMETRY
USING NESSLER REAGENT
11. Scope
11.1 This test method covers the determination of 5 to 100 μg/g of nitride nitrogen in 1-g samples of nuclear-grade plutonium
dioxide.
12. Summary of Test Method
12.1 The sample is dissolved in hydrochloric acid by the sealed tube method or by phosphoric acid hydrofluoric acid solution,
after which the solution is made basic with sodium hydroxide and nitrogen is separated as ammonia by steam distillation. Nessler
reagent is added to the distillate to form the yellow ammonium complex and the absorbance of the solution is measured at
approximately 430 nm (34, 45).
13. Apparatus
13.1 Distillation Apparatus, see Fig. 1.
13.2 Spectrophotometer, visible range.
14. Reagents
14.1 Ammonium Chloride (NH Cl)—Dry salt for 2 h at 110 to 120°C.
14.2 Boric Acid Solution (40 g/L)—Dissolve 40 g of boric acid (H BO ) in 800 mL of hot water. Cool to approximately 20°C
3 3
and dilute to 1 L.
C697 − 16
FIG. 1 Distillation Apparatus
14.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
14.4 Hydrofluoric Acid (48 %)—Concentrated hydrofluoric acid (HF).
14.5 Nessler Reagent—To prepare, dissolve 50 g of potassium iodide (KI) in a minimum of cold ammonia-free water,
approximately 35 mL. Add a saturated solution of mercuric chloride (HgCl , 22 g/350 mL) slowly until the first slight precipitate
of red mercuric iodide persists. Add 400 mL of 9 N sodium hydroxide solution and dilute to 1 L with water, mix, and allow the
solution to stand overnight. Decant supernatant liquid and store in a brown bottle.
14.6 Nitrogen Standard Solution (1 mL = 0.01 mg N)—Dissolve 3.819 g of NH Cl in water and dilute to 1 L. Transfer 10 mL
of this solution to a 1-L volumetric flask and dilute to volume with ammonia-free water.
14.7 Sodium Hydroxide (9 N)—Dissolve 360 g of sodium hydroxide (NaOH) in ammonia-free water and dilute to 1 L.
14.8 Sodium Hydroxide (50 %)—Dissolve sodium hydroxide (NaOH) in an equal weight of water.
14.9 Water (Ammonia-free)—To prepare, pass distilled water through a mixed-bed resin demineralizer and store in a tightly
stoppered chemical-resistant glass bottle.
15. Precautions
15.1 The use of ammonia or other volatile nitrogenous compounds in the vicinity can lead to serious error. The following
precautionary measures should be taken: (1) Clean all glassware and rinse with ammonia-free water immediately prior to use, and
(2) avoid contamination of the atmosphere in the vicinity of the test by ammonia or other volatile nitrogenous compounds.
16. Procedure
16.1 Dissolution of Sample:
16.1.1 Transfer a weighed sample in the range from 1.0 to 1.5 g to a 50-mL beaker.
16.1.2 Transfer a weighed sample in the range from 1.0 to 1.5 g to a 50-mL beaker.Crush the pellet samples to a particle size
of 1 mm or less in a diamond mortar.
NOTE 2—Crush the pellet samples to a particle size of 1 mm or less in a diamond mortar.
16.1.3 To the crushed sample add 5 mL of HCl and 3 drops of HF. Heat to put sample into solution.
NOTE 2—Concentrated phosphoric acid or mixtures of phosphoric acid and hydrofluoric acids or of phosphoric and sulfuric acids may be used for the
dissolution of plutonium dioxide. Such acids may require a purification step in order to reduce the nitrogen blank before being used in this procedure.
16.2 Distillation:
16.2.1 Quantitatively transfer the sample solution to the distilling flask of the apparatus. Add 20 mL of ammonia-free water;
then clamp the flask into place on the distillation apparatus (see Fig. 1).
C697 − 16
16.2.2 Turn on the steam generator, but do not close with the stopper.
16.2.3 Add 5 mL of 4 % H BO solution to a 50-mL graduated flask and position this trap so that the condenser tip is below
3 3
the surface of the H BO solution.
3 3
16.2.4 Transfer 20 mL of 50 % NaOH solution to the funnel in the distillation head.
16.2.5 When the water begins to boil in the steam generator, replace the stopper and slowly open the stopcock on the distilling
flask to allow the NaOH solution to run into the sample solution. (Warning—The NaOH solution must be added slowly to avoid
a violent reaction, which may lead to a loss of sample.)
NOTE 4—The NaOH solution must be added slowly to avoid a violent reaction which may lead to a loss of sample.
16.2.6 Steam distill until 25 mL of distillate has collected in the trap.
16.2.7 Remove the trap containing the distillate from the distillation apparatus and remove the stopper from the steam generator.
16.2.8 Transfer the cooled distillate to a 50-mL volumetric flask.
16.2.9 Prepare a reagent blank solution by following 16.1 through 16.2.8.
16.3 Measurement of Nitrogen:
16.3.1 Add 1.0 mL of Nessler reagent to each of the distillates collected in 16.2.8 and 16.2.9 and dilute to volume with
ammonia-free water, mix, and let stand 10 min.
16.3.2 Measure the absorbance of the solutions at 430 nm in a 1-cm cell. Use water as the reference.
16.4 Calibration Curve:
16.4.1 Add 0, 5, 10, 25, 50, 100, and 150 μg of N from the nitrogen standard solution to separate distilling flasks. Then add
5 mL of HCl and 3 drops of HF plus 20 mL of ammonia-free water to each flask.
16.4.2 Process each solution by the procedure in 16.2 through 16.3 (omit 16.2.9).
16.4.3 Correct for the reagent blank reading and plot the absorbance of each standard against the micrograms of nitrogen per
50 mL of solution.
17. Calculation
17.1 From the calibration chart, read the micrograms of nitrogen corresponding to the absorbance of the sample solution.
17.1.1 Calculate the nitrogen content, N, micrograms per gram, of the sample as follows:
N 5 A 2 B /W (1)
~ !
where:
A = micrograms of nitrogen from sample plus reagents,
B = micrograms of nitrogen in blank, and
W = sample mass, g.
18. Precision
18.1 The estimated relative standard deviation for a single test measurement by this test method is 20 % for 3 μg of nitrogen
and 3 % for 50 to 90 μg of nitrogen.
CARBON (TOTAL) BY DIRECT COMBUSTION-THERMAL CONDUCTIVITY
19. Scope
19.1 This test method covers the determination of 10 to 200 μg of residual carbon in nuclear-grade plutonium dioxide.
20. Summary of Test Method
20.1 Powdered samples are covered and mixed with an accelerator in carbon-free crucibles and burned with oxygen in an
induction heating furnace. Traces of sulfur compounds and water vapor are removed from the combustion products by a
purification train, and the resultant carbon monoxide is converted to carbon dioxide. The purified carbon dioxide is trapped on a
molecular sieve, eluted therefrom with a stream of helium upon application of heat to the trap, and passed through a thermal
conductivity cell. The amount of carbon present, being a function of the integrated change in the current of the detector cell, is
read directly from a calibrated digital voltmeter or strip-chart recorder.
21. Interferences
21.1 There are no known interferences not eliminated by the purification system.
22. Apparatus
22.1 Commercial Combustion Apparatus, suitable for the carbon determination, is often modified to facilitate maintenance and
operation within the glove box which is required for all work with plutonium materials.
C697 − 16
22.1.1 Combustion Apparatus—This apparatus shall consist of an induction furnace suitable for operation at 1600°C, with a
purification train, a catalytic furnace, carbon dioxide trap, thermal conductivity cell with appropriate readout equipment, and a
regulated supply of oxygen and helium.
22.1.2 Combustion Tubes—Quartz combustion tubes with integral baffle shall be used.
22.1.3 Crucibles—Expendable alumina or similar refractory crucibles shall be used. The use of crucible covers is optional.
Satisfactory operation with covers must be established by analysis of standards. Crucibles and covers (if used) must be ignited at
a temperature of 1000°C or higher for a time sufficient to produce constant blank values.
22.1.4 Accelerators—Granular tin and tin foil accelerators shall be used as required to obtain satisfactory results. The criterion
for satisfactory results is the absence of significant additional carbon release upon re-combustion of the specimen.
22.1.5 Catalytic Furnace and Tube—This unit, which is used to ensure complete oxidation of CO to CO , consists of a tube
containing copper oxide and maintained at a temperature of 300°C by a small furnace.
22.1.6 Carbon Dioxide Purifiers—The purifiers that follow the combustion tube must remove finely divided solid metallic
oxides and oxides of sulfur and selenium, dry the gases before they enter the CO trap, and protect the absorber from outside
effects. Finely divided solid metal oxides are removed from the gases during their passage through the quartz wool. The SO given
off by materials containing sulfur is removed by MnO and any water vapor is absorbed in a tube containing Mg(ClO ) . Hot
2 4 2
copper oxide converts carbon monoxide to carbon dioxide. Additional components in the purification train may be required when
materials containing very high amounts of sulfur or of halides are being analyzed. The materials used in the purification train must
be checked frequently to ensure that their absorbing capacity has not been exhausted.
22.2 Vibratory Sample Pulverizer Apparatus, capable of reducing ceramic materials to a −100-mesh powder.such that 90 % or
more of the particles are less than 149 μm (equivalent to a −100-mesh powder). A stainless steel capsule and mixing ball must be
used in order to reduce the contamination of the sample with carbon.
23. Reagents and Materials
23.1 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid (H SO ) to be used in the oxygen purification train.
2 4
23.2 Quartz Wool, to use as a dust trap at top of combustion tube.
23.3 Standard Materials—Certified reference material standards from a national standards body such as the U.S. National
Institute for Standards and Technology (NIST) SRM 131b Low-Carbon Steel (0.0018 % carbon) and SRM 336 Steel (0.567 %
carbon) or their replacements.or equivalent. Certified materials in steel matrices (steel pins, steel rings, steel granules, and steel
powder) ranging from 5 μg carbon/g sample to 1500 μg carbon/g sample are available and have been found satisfactory.
24. Safety Precautions
24.1 Samples Containing Plutonium—Due to the extreme toxicity of plutonium and the certainty that some plutonium will
become airborne during the analytical operations, it is mandatory to perform all operations within an approved glove box fitted
with off-gas filters capable of sustained operation with dust-laden atmospheres.
24. Sampling
24.1 Sample Size—The normal sample size for plutonium dioxide fuel materials shall be 1 g. If necessary, this amount shall be
altered as required to contain less than 200 μg of carbon.
24.2 Sample Preparation—Pellet or particulate samples shall be reduced such that approximately 90 % of the particles are less
than 149 μm (equivalent to approximately a −100-mesh powderpowder) prior to the weighing of the specimens. Exposure of the
powdered sample to atmospheric carbon dioxide should be minimized by storage of the powder in a closed vial. Refer to Sections
8 and 10 for guidance in handling plutonium dioxide.
25. Preparation of Apparatus
25.1 Analysis System Purge—After having properly set the operating controls of the instrument system, condition the apparatus
by combustion of several blanks prepared with the sample crucible and accelerator in the amount to be used with the test specimen
analyses. Successive blank values should approach a constant value, allowing for normal statistical fluctuations. The instrument
should be adjusted for a 2-min combustion period.
26. Calibration
26.1 Preparation of Standards for Combustion—Mix a weighed portion of an accelerator and a an accurately weighed portion
of approximately 1 g of NIST 131b reference material with a certified carbon value of about 0.005 % in each of three sample
crucibles. Repeat with NIST 336, using a reference material with a certified carbon value of about 0.5 %, using an accurately
weighed portion of approximately 30 to 40 mg.
NOTE 3—These portions represent about 50 μg and 200 μg of carbon, respectively.
26.1.1 The NIST 336 steel is assigned a carbon content 0.567 % (5670 μg/g). Therefore, amounts ranging up to approximately
40 mg are used for standardization. Weigh the steel into a tared container (a container, such as a small nickel-sample boat if
C697 − 16
convenient), boat, obtaining the mass to the nearest 0.01 mg. Transfer the chips to a 30-mm square of aluminum foil (previously
acetone washed), and fold the foil into a wrapper with the aid of stainless steel tongs and spatulas. The foil should not be touched
by the hands. Place the wrapped standard in a numbered glass vial and transfer to the analyzer glove box.
26.2 Combustion of Standards—Load and combust the standards and record the results. Adjust the calibration controls in such
a way as to produce the correct readout value on the direct readout meter. Combust additional standards as required to produce
the correct direct readout. As an alternative, consider the readout digits as arbitrary numbers and prepare a calibration curve of
known micrograms of carbon versus the readout value. A strip chart recorder connected to present the intergratedintegrated value
of the carbon dioxide response signal is helpful in detecting and correcting for analyzer drift and noise.
27. Procedure
27.1 Pulverize the pellet samples for 15 s in the stainless steel capsule of the sample pulverizer.
27.2 Weigh a sample crucible containing the required amount of accelerator to the nearest 0.01 g.
27.3 Transfer the sample powder, not to exceed 1 g or of such size as to give not more than 200 μg of carbon, to the crucible.
Weigh the crucible and contents to the nearest 0.01 g and find the specimen mass by difference.
27.4 Mix the specimen powder and the accelerator with a stainless steel spatula.
27.5 Load the sample crucible into the furnace and combust the specimen for 2 min.
27.6 Remove the sample crucible and examine for evidence of incomplete combustion. The crucible contents should be a
uniform fused mass.
28. Calculation
28.1 Calculate the concentration of carbon in the sample by dividing the net micrograms of carbon found by the sample mass,
expressed in grams, as follows:
C, µg/g5 C 2 C /W (2)
~ !
s b
where:
C = micrograms of carbon in the sample and reagents,
s
C = micrograms of carbon in reagent blank, and,
b
W = grams of oxide sample.
29. Precision
29.1 The relative standard deviation of this test method is approximately 10 % for a concentration of 30 μg of carbon/g of
sample.
TOTAL CHLORINE AND FLUORINE BY PYROHYDROLYSIS
30. Scope
30.1 This test method covers the determination of 5 to 100 μg/g of chlorine and 1 to 100 μg/g of fluorine in 1-g samples of
nuclear-grade plutonium dioxide.
31. Summary of Test Method
31.1 A1 to 2-g sample of plutonium dioxide is pyrohydrolyzed at 950°C with a stream of moist air or oxygen. The halogens
are volatilized as acids during the pyrohydrolysis and are trapped as chloride and fluoride in a buffered solution. Several procedures
are outlined for the measurement of chloride and fluoride in the resultant condensate. Chloride is measured by spectrophotometry,
microtitrimetry, or with ion-selective electrodes and fluoride with ion-selective electrodes or spectrophotometry (56, 67).
32. Interferences
32.1 Bromide, iodide, cyanide, sulfide, and thiocyanate, if present in the condensate, would interfere with the spectrophoto-
metric and microtitrimetric measurement of chloride. Bromide, iodide, sulfide, and cyanide interfere in the measurement of
chloride with ion-selective electrodes, but have very little effect upon the measurement of fluoride with selective electrodes.
33. Apparatus (see Fig. 2 and Fig. 3) for examples)
33.1 Gas Flow Regulator—A flowmeter and a rate controller to adjust the flow of sparge gas between 1 to 3 L/min.
33.2 Hot Plate—A heater used to keep the water bubbler temperature between 50 and 90°C.
33.3 Furnace—A tube furnace that is capable of maintaining a temperature from 900 to 1000°C. The bore of the furnace should
be about 32 mm (1 ⁄4 in.) in diameter and about 305 mm (12 in.) in length.
C697 − 16
FIG. 2 Pyrohydrolysis Apparatus
FIG. 3 Quartz Reaction Tube
33.4 Reactor Tube, made from fused-silica or platinum. The delivery tube should be a part of the exit end of the reactor tube
and be within 51 mm (2 in.) of the furnace (see Fig. 2 for proper tube positioning).
33.5 Combustion Boats, made from fused-silica or platinum. A boat about 102 mm (4 in.) long is made by cutting lengthwise
a silica tube 20 mm in diameter and flattening one end to provide a handle. A fused-silica inner sleeve for the reactor tube can
facilitate the movement of the boat into the tube, prevent spillage, and thus prolong the life of the combustion tube.
33.6 Collection Vessel—A plastic graduate or beaker designed to maintain most of the scrubber solution above the tip of the
delivery tube.
33.7 Automatic Chloride Titrator.
33.8 Ion-Selective Electrodes, chloride and fluoride.
33.9 Reference Electrode—Use a double-junction type electrode such as mercuric sulfate, sleeve-junction type electrode. Do not
use a calomel electrode.
33.10 Spectrophotometer, ultraviolet to visible range and absorption cells. For a discussion on spectrophotometers and their use
see Practice E60.
33.11 pH Meter, with an expanded scale having a sensitivity of 1 mV.
34. Reagents
34.1 Accelerator—Halogen-free uranium oxide (U O ) powder used as a flux to enhance the release of chloride and fluoride.
3 8
34.2 Air or Oxygen, compressed.
34.3 Buffer Solution (0.001 N)—Prepare by adding 50 μL of concentrated glacial acetic acid (CH CO H, sp gr 1.05) and 0.1
3 2
g of potassium acetate (KC H O ) to 1 L of water.
2 3 2
34.4 Chloride Standard Solution (1 mL = 1 mg Cl)—Dissolve 1.65 g of sodium chloride (NaCl) in water and dilute to 1 L.
34.5 Chloride, Standard Solution (1 mL = 5 μg Cl)—Prepare by diluting 5 mL of chloride solution (1 mL = 1 mg Cl) to 1 L with
water.
34.6 Ferric Ammonium Sulfate Solution (0.25 M in 9 M nitric acid)—Dissolve 12 g of ferric ammonium sulfate
(Fe(NH )(SO ) ·12 H O) in 58 mL of concentrated nitric acid (HNO , sp gr 1.42) and dilute to 100 mL with water.
4 4 2 2 3
C697 − 16
34.7 Fluoride, Standard Solution (1 mL = 1 mg F)—Dissolve 2.21 g of sodium fluoride (NaF) in water and dilute to 1 L.
34.8 Fluoride, Standard Solution (1 mL = 10 μg F)—Dilute 10 mL of fluoride solution (1 mL = 1 mg F) to 1 L with water.
34.9 Gelatin Solution—Add 6.2 g of dry gelatin mixture (60 parts of dry gelatin + 1 part of thymol blue + 1 part of thymol) to
1 L of hot water and heat with stirring until solution is clear.
34.10 Lanthanum-Alizarin Complexone—Dissolve 0.048 g of alizarin complexone (3-aminomethylalizarin-N,N-diacetic acid)
in 100 μL of concentrated ammonium hydroxide (NH OH), 1 mL of an ammonium acetate solution (NH C H O , 20 mass %),
4 4 2 3 2
and 5 mL of water. Filter the solution through a high-grade, rapid-filtering, qualitative filter paper. Wash the paper with a small
volume of water, and add 8.2 g of anhydrous sodium acetate (NaC H O ) and 6 mL of concentrated glacial acetic acid (CH CO H,
2 3 2 3 2
sp gr 1.05) to the filtrate. Add 100 mL of acetone while swirling the filtrate. Add 0.040 g of lanthanum oxide (La O ) dissolved
2 3
in 2.5 mL of warm 2 N HCl. Mix the two solutions and dilute to 200 mL. After 30 min readjust the solution volume.
NOTE 4—A 0.1-g/L solution is prepared by dissolving 100 mg of the reagent in water and diluting with isopropyl alcohol to obtain a 60 % alcoholic
medium.
34.11 Mercuric Thiocyanate Solution—Prepare a saturated solution by adding 0.3 g of mercuric thiocyanate (Hg(SCN) ) to 100
mL of 95 % ethanol. Shake the mixture thoroughly for maximum dissolution of the solid. Filter the solution.
34.12 Nitric Acid-Acetic Acid Solution (1 N Nitric Acid and 4 N Acetic Acid)—Prepare by adding 64 mL of nitric acid (HNO ,
sp gr 1.42) to a 1-L volumetric flask which contains 500 mL of water. Swirl the solution in the flask and add 230 mL of acetic
acid (CH CO H, sp gr 1.05). Dilute the solution with water to 1 L.
3 2
35. Pyrohydrolysis Procedure
35.1 Prepare the pyrohydrolysis apparatus for use as follows:
35.1.1 Regulate the gas flow between 1 and 3 L/min.
35.1.2 Adjust the temperature of the hot plate to heat the water to approximately 90°C.
35.1.3 Adjust the temperature of the furnace to 950 6 50°C.
35.1.4 Add 15 mL of buffer solution to the collection vessel and place around the delivery tube.
35.2 Weigh accurately, 1 to 2 g of the powdered plutonium dioxide and transfer to a combustion boat. If an accelerator, U O ,
3 8
is used mix 4 g with the sample before loading into the boat.
35.3 Place the boat containing the sample into the reactor tube and quickly close the tube. The boat should be in the middle of
the furnace.
35.4 Allow the pyrohydrolysis to proceed for at least 30 min.
35.5 Remove the collection vessel and wash down the delivery tube with some buffer solution. Dilute the solution to 25 mL
with the acetate buffer. Determine the chloride and fluoride by one or more of the measurement procedures covered in Section
3736.
35.6 Remove the boat from the reactor tube and dispose of the sample residue.
35.7 Run a pyrohydrolysis blank with halogen-free U O by following the procedures, given in 36.335.3 – 36.635.6.
3 8
36. Measurement of Chloride and Fluoride
36.1 Determination of Chloride by Spectrophotometry:
36.1.1 Prepare a calibration curve by adding 0, 1, 2, 5, and 10 mL of the chloride solution (1 mL = 5 μg Cl) to separate 25-mL
flasks. Dilute each to 20 mL with buffer solution, and add 2 mL of the ferric ammonium sulfate solution and 2 mL of the mercuric
thiocyanate solution. Mix the solution and dilute to 25 mL with water. Mix the solutions again and allow them to stand 10 min.
Transfer some of the solution from the flask to a 1-cm absorption cell and read the absorbance at 460 nm using water as the
reference liquid. Plot the micrograms of Cl per 25 mL versus the absorbance reading.
36.1.2 To determine Cl in the pyrohydrolysis condensate transfer 15 mL of the buffer solution to a 25-mL volumetric flask. Add
2 mL of the ferric ammonium sulfate solution and 2 mL of the mercuric thiocyanate solution. Mix the solutions, dilute to volume
with water, and mix again. Allow the solution to stand 10 min. Transfer some of the solution from the flask to a 1-cm absorption
cell and read the absorbance at 460 nm versus water as the reference. Read the micrograms of Cl present from the calibration curve.
NOTE 5—A calibration curve can be prepared by drying measured aliquots of a chloride solution on some halogen-free U O and proceeding through
3 8
pyrohydrolysis steps.
36.1.3 Calculate the chlorine, Cl, μg/g, as follows:
Cl, µg/g5 A 2 B V (3)
~ !
1/WV
where:
A = micrograms of chlorine in aliquot measured,
B = micrograms of chlorine in blank,
C697 − 16
W = grams of PuO pyrohydrolyzed,
V = millilitres of scrub solution, and
V = aliquot of scrub solution analyzed, mL.
36.2 Determination of Chloride by Amperometric Microtitrimetry:
36.2.1 Calibrate the titrimeter by adding 5 mL of the buffer solution, 1 mL of the nitric acid-acetic acid solution, and 2 drops
of the gelatin solution to a titration cell. Pipet 50 μL of the chloride solution (1 mL = 1 mL Cl) into the titration cell. Place the cell
on the chloride titrator and follow the manufacturer’s suggested sequence of operations for chloride (Note 76). Record the time
required to titrate 50 μg. Run a reagent blank titration.
NOTE 6—The Cl-analyzer generates silver ions which react to precipitate the chloride ion. The instrument uses an amperometric end point to obtain
an automatic shut-off of the generating current at a pre-set increment of indicator current. Since the rate of generating silver ion is constant, the amount
of chloride precipitated is proportional to the time required for the titration.
36.2.2 Determine Cl in the pyrohydrolysis-scrub solution by adding 5 mL to a titration cell which contains 1 mL of the nitric
acid-acetic acid solution and 2 drops of the gelatin solution.
36.2.3 Place the cell in position on the titrator. Start the titrator and record the time required to titrate the Cl present.
36.2.4 Calculate the chlorine as follows:
Cl, µg/g5 V F T 2 T /V W (4)
~ !
1 s B 2
where:
V = volume of scrub solutions = 25,
V = aliquot of scrub solution analyzed, mL,
F =
µC1 standard titrated
titration time of standard 2 titration time of blank
or
F 5 50/ T 2 T , (5)
~ !
C1 B
T = titration time to titrate sample and blank,
s
T = titration time to titrate 50 μg of Cl and blank,
C1
T = titration time to titrate reagent blank, and
B
W = grams of PuO pyrohydrolyzed.
36.3 Determination of Chloride and Fluoride with Ion-Selective Electrodes:
36.3.1 Preparation of the calibration curves requires the assembly of the meter and the ion-selective electrode with a suitable
reference electrode. From these standards take the millivolt readings for each ion-selective electrode and plot on semi-log paper
determine the halogen content per 25 mL versus millivolts. millivolts, using computer software or a plot on semi-log paper. Prepare
a series of standards in acetate buffer solution by pipeting aliquots of the halogen standards into separate 25-mL flasks ranging in
concentrations as follows:
Cl from 10 to 100 μg/25 mL
F from 5 to 100 μg/25 mL
36.3.2 Determine the Cl and F in the scrub solution from the pyrohydrolysis by using the appropriate ion-selective electrode.
Record the micrograms of Cl or F from the calibration curve and calculate the halide as follows:
Cl or F, µg/g5 ~H 2 H !/W (6)
s b
where:
H = halide in aliquot of scrub solution + blank, μg,
s
H = halide in pyrohydrolysis blank, μg, and
b
W = sample mass, g.
36.4 Determination of Fluoride by Spectrophotometry:
36.4.1 Prepare a calibration curve by adding to separate 10-mL flasks 0, 50, 100, 200, 500, and 1000 μL of the fluoride solution
(1 mL = 10 μg F). Add 2.0 mL of the lanthanum-alizarin complexone solution and dilute to volume with water. Mix and let stand
1 h. Read the absorbance at 622 nm versus the reagent blank. Plot the micrograms of F per 10 mL versus absorbance reading.
36.4.2 Measure F in the pyrohydrolysis scrub solution by pipeting 5 mL into a 10-mL volumetric flask. Add 2.0 mL of the
lanthanum-alizarin complexone and dilute to volume. Mix and let stand 1 h. Read the absorbance at 622 nm versus a reagent blank
and obtain the fluoride content from the calibration curve.
36.4.3 Calculate the fluorine concentration, F, in the PuO sample as follows:
F, µg/g5 F 2 F /W 3V /V (7)
@~ ! #
s b 1 2
C697 − 16
where:
F = fluorine in aliquot of scrub solution + the blank, μg,
s
F = micrograms of fluorine in pyrohydrolysis blank,
b
V = total volume of the scrub solution, mL,
V = aliquot of scrub solution analyzed, mL, and
W = grams of PuO sample.
36.5 Determination of Chloride and Fluoride by Ion Chromatography—Determine the Cl and F in the scrub solution from the
pyrohydrolysis in accordance with Test Method D4327. Record the micrograms of Cl or F from the calibration curve and calculate
the halide using Eq 6.
37. Precision
37.1 The relative standard deviations for the measurements of fluorine are approximately 7 % for the range from 5 to 50 μg/g
and 10 % for the range from 1 to 5 μg/g. The relative standard deviations for the measurements of chlorine vary from 5 % at the
5 to 50-μg/g level up to 10 % below the 5-μg/g range.
SULFUR BY DISTILLATION SPECTROPHOTOMETRY
38. Scope
38.1 This test method coves the determination of sulfur in the concentration range from 10 to 600 μg/g for samples of
nuclear-grade plutonium dioxide powders or pellets.
39. Summary of Test Method
39.1 Sulfur is measured spectrophotometrically as Lauth’s Violet following its separation by distillation as hydrogen sulfide
(78). Higher oxidation states of sulfur are reduced to sulfide by a hypophosphorous-hydriodic acid mixture, the hydrogen sulfide
is distilled into zinc acetate, and p-phenylenediamine and ferric chloride are added to form Lauth’s Violet. The qua
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