1、Designation: C698 16Standard Test Methods forChemical, Mass Spectrometric, and SpectrochemicalAnalysis of Nuclear-Grade Mixed Oxides (U, Pu)O2)1This standard is issued under the fixed designation C698; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover procedures for the chemical,mass spectrometric, and spectroche
3、mical analysis of nuclear-grade mixed oxides, (U, Pu)O2, powders and pellets to deter-mine compliance with specifications.1.2 The analytical procedures appear in the following order:SectionsUranium in the Presence of Pu by Potentiometric Titration2Plutonium by Controlled-Potential Coulometry2Plutoni
4、um by Amperometric Titration with Iron (II)2Nitrogen by Distillation Spectrophotometry Using NesslerReagent8 to 15Carbon (Total) by Direct Combustion-Thermal Conductivity 16 to 26Total Chlorine and Fluorine by Pyrohydrolysis 27 to 34Sulfur by Distillation-Spectrophotometry 35 to 43Moisture by the Co
5、ulometric, Electrolytic Moisture Analyzer 44 to 51Isotopic Composition by Mass Spectrometry3Rare Earths by Copper Spark Spectroscopy 52 to 59Trace Impurities by Carrier Distillation Spectroscopy 60 to 68Impurities by Spark-Source Mass Spectrography 69 to 75Total Gas in Reactor-Grade Mixed Dioxide Pe
6、llets4Tungsten by Dithiol-Spectrophotometry 76 to 84Rare Earth Elements by Spectroscopy 85 to 88Plutonium-238 Isotopic Abundance by Alpha Spectrometry5Americium-241 in Plutonium by Gamma-Ray SpectrometryUranium and Plutonium Isotopic Analysis by MassSpectrometry89 to 97Oxygen-to-Metal Atom Ratio by
7、Gravimetry 98 to 1051.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard
8、to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. (For specific safetyprecaution statements, see Sections 6, 13.2.5, 41.7, and 93.6.1.)2. Referenced Documents2.1 ASTM Standards:6C697 Test Methods for Chemical, Mass Spectrom
9、etric, andSpectrochemical Analysis of Nuclear-Grade PlutoniumDioxide Powders and PelletsC833 Specification for Sintered (Uranium-Plutonium) Diox-ide PelletsC852 Guide for Design Criteria for Plutonium GloveboxesC859 Terminology Relating to Nuclear MaterialsC1068 Guide for Qualification of Measuremen
10、t Methods bya Laboratory Within the Nuclear IndustryC1108 Test Method for Plutonium by Controlled-PotentialCoulometryC1165 Test Method for Determining Plutonium byControlled-Potential Coulometry in H2SO4at a PlatinumWorking ElectrodeC1168 Practice for Preparation and Dissolution of PlutoniumMaterial
11、s for AnalysisC1204 Test Method for Uranium in Presence of Plutoniumby Iron(II) Reduction in Phosphoric Acid Followed byChromium(VI) TitrationC1206 Test Method for Plutonium by Iron (II)/Chromium(VI) Amperometric Titration (Withdrawn 2015)7C1233 Practice for Determining Equivalent Boron Contentsof N
12、uclear MaterialsC1268 Test Method for Quantitative Determination of241Am in Plutonium by Gamma-Ray SpectrometryC1415 Test Method for238Pu Isotopic Abundance By AlphaSpectrometryC1432 Test Method for Determination of Impurities inPlutonium: Acid Dissolution, Ion Exchange MatrixSeparation, and Inducti
13、vely Coupled Plasma-AtomicEmission Spectroscopic (ICP/AES) AnalysisC1625 Test Method for Uranium and Plutonium Concentra-tions and Isotopic Abundances by Thermal IonizationMass Spectrometry1These test methods are under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and are the direct re
14、sponsibility of Subcommittee C26.05 onMethods of Test.Current edition approved June 1, 2016. Published July 2016. Originally approvedin 1972. Last previous edition approved in 2010 as C698 10. DOI: 10.1520/C0698-16.2Discontinued as of November 15, 1992.3Discontinued as of May 30, 1980.4Discontinued
15、as of June 2016.5Discontinued as of January 1, 2004.6For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.7The last
16、 approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1C1637 Test Method for the Determination of Impurities inPlutonium Metal:Acid Digestion and Inductively CoupledP
17、lasma-Mass Spectroscopy (ICP-MS) AnalysisC1672 Test Method for Determination of Uranium or Pluto-nium Isotopic Composition or Concentration by the TotalEvaporation Method Using a Thermal Ionization MassSpectrometerC1817 Test Method for The Determination of the Oxygen toMetal (O/M) Ratio in Sintered
18、Mixed Oxide (U, Pu)O2)Pellets by GravimetryD1193 Specification for Reagent WaterD4327 Test Method for Anions in Water by Suppressed IonChromatographyE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by SpectrophotometryE115 Practice for Photographic Processing in Optical Emis-sion Spec
19、trographic Analysis (Withdrawn 2002)7E116 Practice for Photographic Photometry in Spectro-chemical Analysis (Withdrawn 2002)7E130 Practice for Designation of Shapes and Sizes ofGraphite Electrodes (Withdrawn 2013)73. Terminology3.1 Except as otherwise defined herein, definitions of termsare as given
20、 in Terminology C859.4. Significance and Use4.1 Mixed oxide, a mixture of uranium and plutoniumoxides, is used as a nuclear-reactor fuel in the form of pellets.The plutonium content may be up to 10 weight %, and thediluent uranium may be of any235U enrichment. In order to besuitable for use as a nuc
21、lear fuel, the material must meet certaincriteria for combined uranium and plutonium content, effectivefissile content, and impurity content as described in Specifica-tion C833.4.1.1 The material is assayed for uranium and plutonium todetermine whether the plutonium content is as specified by thepur
22、chaser, and whether the material contains the minimumcombined uranium and plutonium contents specified on a dryweight basis.4.1.2 Determination of the isotopic content of the plutoniumand uranium in the mixed oxide is made to establish whetherthe effective fissile content is in compliance with the p
23、urchas-ers specifications.4.1.3 Impurity content is determined to ensure that themaximum concentration limit of certain impurity elements isnot exceeded. Determination of impurities is also required forcalculation of the equivalent boron content (EBC) as describedin Practice C1233.4.2 Fitness for Pu
24、rpose of Safeguards and Nuclear SafetyApplicationsMethods intended for use in safeguards andnuclear safety applications shall meet the requirements speci-fied by Guide C1068 for use in such applications.5. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherw
25、ise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.8Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high puri
26、ty to permit its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D1193.6. Safety Precautions6.1 Since plutonium- and uranium-bearing materials areradioactive
27、and toxic, adequate laboratory facilities, gloveboxes, fume hoods, and so forth, along with safe techniquesmust be used in handling samples containing these materials.Glove boxes should be fitted with off-gas filters capable ofsustained operation with dust-laden atmospheres. A detaileddiscussion of
28、all the precautions necessary is beyond the scopeof these test methods; however, personnel who handle thesematerials should be familiar with such safe handling practicesas are given in Guide C852 and in Refs (1-3).96.2 Adequate laboratory facilities, such as fume hoods andcontrolled ventilation, alo
29、ng with safe techniques, must be usedin this procedure. Extreme care should be exercised in usinghydrofluoric acid and other hot, concentrated acids. Use ofproper gloves is recommended. Refer to the laboratoryschemical hygiene plan and other applicable guidance forhandling chemical and radioactive m
30、aterials and for the man-agement of radioactive, mixed, and hazardous waste.6.3 Hydrofluoric acid is a highly corrosive acid that canseverely burn skin, eyes and mucous membranes. Hydrofluoricacid differs from other acids because the fluoride ion readilypenetrates the skin, causing destruction of de
31、ep tissue layers.Unlike other acids that are rapidly neutralized, hydrofluoricacid reactions with tissue may continue for days if leftuntreated. Familiarization and compliance with the Safety DataSheet is essential.6.4 Perchloric acid (HClO4) forms explosive compoundswith organics and many metal sal
32、ts.Avoid exposure by contactwith the skin or eyes, or by inhalation of fumes. Familiarizationand compliance with the Safety Data Sheet is essential. Carryout sample dissolution with perchloric acid in a fume hoodwith a scrubber unit that is specially designed for use withHClO4.7. Sampling and Dissol
33、ution7.1 Criteria for sampling this material are given in Specifi-cation C833.7.2 Samples can be dissolved using the appropriate disso-lution techniques described in Practice C1168.8Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions
34、 on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.9The boldface numbers in parentheses
35、 refer to the list of references at the end ofthese test methods.C698 162URANIUM IN THE PRESENCE OF PLUTONIUM BYPOTENTIOMETRIC TITRATION(This test method was discontinued in 1992 and replaced byTest Method C1204.)PLUTONIUM BY CONTROLLED POTENTIALCOULOMETRY(This test method was discontinued in 1992 a
36、nd replaced byTest Method C1165.)PLUTONIUM BY CONTROLLED-POTENTIALCOULOMETRY(With appropriate sample preparation, controlled-potentialcoulometric measurement as described in Test MethodC1108 may be used for plutonium determination.)PLUTONIUM BY AMPEROMETRIC TITRATIONWITH IRON(II)(This test method wa
37、s discontinued in 1992 and replaced byTest Method C1206, which was withdrawn in 2015.)NITROGEN BY DISTILLATIONSPECTROPHOTOMETRY USING NESSLERREAGENT8. Scope8.1 This test method covers the determination of 5 to 100g/g of nitride nitrogen in mixtures of plutonium and uraniumoxides in either pellet or
38、powder form.9. Summary of Test Method9.1 The sample is dissolved in hydrochloric acid by thesealed tube test method or by phosphoric acid-hydrofluoricacid solution, after which the solution is made basic withsodium hydroxide and nitrogen is separated as ammonia bysteam distillation. Nessler reagent
39、is added to the distillate toform the yellow ammonium complex and the absorbance of thesolution is measured at approximately 430 nm (4, 5).10. Apparatus10.1 Distillation Apparatus (see Fig. 1 for an example).10.2 Spectrophotometer, visible-range.11. Reagents11.1 Ammonium Chloride (NH4Cl)Dry the salt
40、 for2hat110 to 120C.11.2 Boric Acid Solution (40 g/litre)Dissolve 40 g of boricacid (H3BO3) in 800 mL of hot water. Cool to approximately20C and dilute to 1 L.11.3 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).11.4 Hydrofluoric Acid (sp gr 1.15)Concentrated hydro-fluoric acid (
41、HF). See safety precaution in 6.3.11.5 Nessler ReagentTo prepare, dissolve 50 g of potas-sium iodide (KI) in a minimum of cold ammonia-free water,approximately 35 mL. Add a saturated solution of mercuricchloride (HgCl2, 22 g/350 mL) slowly until the first slightprecipitate of red mercuric iodide per
42、sists. Add 400 mL of 9 Nsodium hydroxide (NaOH) and dilute to 1 L with water. Mix,and allow the solution to stand overnight. Decant the superna-tant liquid and store in a brown bottle.11.6 Nitrogen, Standard Solution (1 mL = 0.01 mg N)Dissolve 3.819 g of NH4Cl in water and dilute to 1 L. Transfer10
43、mL of this solution to a 1-L volumetric flask and dilute tovolume with ammonia-free water.11.7 Sodium Hydroxide (9N)Dissolve 360 g of sodiumhydroxide (NaOH) in ammonia-free water and dilute to 1 L.11.8 Sodium Hydroxide Solution(50 %)Dissolve NaOHin an equal weight of ammonia-free water.11.9 Water, A
44、mmonia-FreeTo prepare, pass distilled waterthrough a mixed-bed resin demineralizer and store in a tightlystoppered chemical-resistant glass bottle.12. Precautions12.1 The use of ammonia or other volatile nitrogenouscompounds in the vicinity can lead to serious error. Thefollowing precautionary measu
45、res should be taken: (1) Cleanall glassware and rinse with ammonia-free water immediatelyprior to use, and (2) avoid contamination of the atmosphere inthe vicinity of the test by ammonia or other volatile nitrog-enous compounds.13. Procedure13.1 Dissolution of Sample:13.1.1 Transfer a weighed sample
46、, in the range from 1.0 to1.5 g, to a 50-mL beaker.13.1.2 Crush the pellet samples to a particle size of 1 mm orless in a diamond mortar.FIG. 1 Distillation ApparatusC698 16313.1.3 To the sample add 5 mL of HCl (sp gr 1.19) and 3drops of HF (sp gr 1.15). Heat to put the sample into solution.NOTE 1Co
47、ncentrated phosphoric acid or mixtures of phosphoric acidand hydrofluoric acids or of phosphoric and sulfuric acids may be used forthe dissolution of mixed oxide samples. Such acids may require apurification step in order to reduce the nitrogen blank before being used inthis procedure.13.2 Distillat
48、ion:13.2.1 Quantitatively transfer the sample solution to thedistilling flask of the apparatus. Add 20 mL of ammonia-freewater and then clamp the flask into place on the distillationapparatus (see Fig. 2 for an example).13.2.2 Turn on the steam generator but do not close with thestopper.13.2.3 Add 5
49、 mL of boric acid solution (4 %) to a 50-mLgraduated flask and position this trap so that the condenser tipis below the surface of the boric acid solution.13.2.4 Transfer 20 mL of NaOH solution (50 %) to thefunnel in the distillation head.13.2.5 When the water begins to boil in the steam generator,replace the stopper and slowly open the stopcock on thedistilling flask to allow the NaOH solution to run into thesample solution. (WarningThe NaOH solution must beadded slowly to avoid a violent reaction, which may lead to aloss of sample.)13.2.6 Steam distill unti
