1、Designation: C 696 99 (Reapproved 2005)Standard Test Methods forChemical, Mass Spectrometric, and SpectrochemicalAnalysis of Nuclear-Grade Uranium Dioxide Powders andPellets1This standard is issued under the fixed designation C 696; the number immediately following the designation indicates the year
2、 oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover procedures for the chemical,ma
3、ss spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets to determinecompliance with specifications.1.2 The analytical procedures appear in the following order:SectionsUranium by Ferrous Sulfate Reduction in PhosphoricAcid and Dichromate Titration Method2C
4、1267 Test Method for Uranium By Iron (II) Reduc-tion In Phosphoric Acid Followed By Chromium(VI) Titration In The Presence of Vanadium3Uranium and Oxygen Uranium Atomic Ratio by theIgnition (Gravimetric) Impurity Correction Method7-13Carbon (Total) by Direct Combustion-Thermal Con-ductivity Method2C
5、 1408 Test Method for Carbon (Total) in UraniumOxide Powders and Pellets By Direct Combustion-Infrared Detection Method3Total Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method14-20Moisture by the Coulometric, Electrolytic MoistureAnalyzer Method21-28Nitrogen by the Kjeldahl Meth
6、od 29-36Isotopic Uranium Composition by Multiple-FilamentSurface Ionization Mass Spectrometric Method4Spectrochemical Determination of Trace Elements inHigh-Purity Uranium Dioxide37-44Silver, Spectrochemical Determination of, by GalliumOxideCarrier D-C Arc Technique45 to 46Rare Earths by Copper Spar
7、k-SpectrochemicalMethod2Impurity Elements by a Spark-Source Mass Spectro-graphic Method2C 761 Test Method for Chemical, Mass Spectromet-ric, Spectrochemical, Nuclear, and RadiochemicalAnalysis of Uranium Hexafluoride3C 1287 Test Method for Determination of ImpuritiesIn Uranium Dioxide By Inductively
8、 CoupledPlasma Mass Spectrometry3Surface Area by Nitrogen Absorption Method 47-53Total Gas in Reactor-Grade Uranium Dioxide Pellets2Thorium and Rare Earth Elements by Spectroscopy2Hydrogen by Inert Gas Fusion 54-63Uranium Isotopic Analysis by Mass Spectrometry2SectionsC 1413 Test Method for Isotopic
9、 Analysis of Hydroly-sed Uranium Hexafluoride and Uranyl Nitrate So-lutions By Thermal Ionization Mass Spectrometry32. Referenced Documents2.1 ASTM Standards:3C 753 Specification for Nuclear-Grade, Sinterable UraniumDioxide PowderC 761 Test Method for Chemical, Mass Spectrometric,Spectrochemical, Nu
10、clear, and Radiochemical Analysis ofUranium HexafluorideC 776 Specification for Sintered Uranium Dioxide PelletsC 1267 Test Method for Uranium By Iron (II) Reduction InPhosphoric Acid Followed By Chromium (VI) Titration InThe Presence of VanadiumC 1287 Test Method for Determination of Impurities InU
11、ranium Dioxide By Inductively Coupled Plasma MassSpectrometryC 1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisC 1408 Test Method for Carbon (Total) in Uranium OxidePowders and Pellets By Direct Combustion-Infrared De-tection MethodC 1413 Test Method for Isotopic Analys
12、is of HydrolysedUranium Hexafluoride and Uranyl Nitrate Solutions ByThermal Ionization Mass SpectrometryD 1193 Specification for Reagent WaterE115 Practice for Photographic Processing in OpticalEmission Spectrographic AnalysisE 130 Practice for Designation of Shapes and Sizes ofGraphite ElectrodesE
13、402 Test Method for SpectrographicAnalysis of Uranium1These test methods are under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the direct responsibility of subcommittee C26.05 onMethods of Test.Current edition approved June 1, 2005. Published December 2005. Originallyapproved
14、in 1972. Last previous edition approved in 1999 as C 696 99.2Discontinued January 1999. See C 69680.3For 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 Do
15、cument Summary page onthe ASTM website.4Discontinued as of May 30, 1980.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Oxide (U3O8) by Gallium Oxide-Carrier Technique3. Significance and Use3.1 Uranium dioxide is used as a nuclear-re
16、actor fuel. Inorder to be suitable for this purpose, the material must meetcertain criteria for uranium content, stoichiometry, isotopiccomposition, and impurity content. These test methods aredesigned to show whether or not a given material meets thespecifications for these items as described in Sp
17、ecificationsC 753 and C 776.3.1.1 An assay is performed to determine whether thematerial has the minimum uranium content specified on a dryweight basis.3.1.2 The stoichiometry of the oxide is useful for predictingits sintering behavior in the pellet production process.3.1.3 Determination of the isot
18、opic content of the uraniumin the uranium dioxide powder is made to establish whether theeffective fissile content is in compliance with the purchasersspecifications.3.1.4 Impurity content is determined to ensure that themaximum concentration limit of certain impurity elements isnot exceeded. Determ
19、ination of impurities is also required forcalculation of the equivalent boron content (EBC).4. Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analyti
20、cal Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4.2 Purity of Water Unless otherwise in
21、dicated, refer-ences to water shall be understood to mean reagent waterconforming to Specification D 1193.5. Safety Precautions5.1 Proper precautions should be taken to prevent inhala-tion, or ingestion of uranium dioxide powders or dust duringgrinding or handling operations.6. Sampling6.1 Criteria
22、for sampling this material are given in Specifi-cation C 753 and Specification C 776.6.2 Samples can be dissolved using the appropriate disso-lution techniques described in Practice C 1347, but finaldetermination of applicability must be made by the user.URANIUM BY FERROUS SULFATE REDUCTION INPHOSPH
23、ORIC ACID AND DICHROMATETITRATION METHODThis test method was withdrawn in January 1999 andreplaced by Test method C 1267.URANIUM AND OXYGEN TO URANIUM ATOMICRATIO BY THE IGNITION (GRAVIMETRIC)IMPURITY CORRECTION METHOD7. Scope7.1 This test method covers the determination of uraniumand the oxygen to
24、uranium atomic ratio in nuclear-gradeuranium dioxide powder and pellets.8. Summary of Test Method8.1 A weighed portion of UO2is dried under reducedpressure in a nitrogen atmosphere, desiccated, and weighed.The dried oxide is then converted to U3O8by ignition at 900C(8, 9).9. Interferences9.1 The wei
25、ght of U3O8is corrected for the nonvolatileimpurities present as determined by spectrographic analysis.An extended ignition time may be required if significantamounts of anions that are difficult to decompose are present.10. Apparatus10.1 Vacuum Oven, capable of maintaining and controllingtemperatur
26、es to 180C and equipped with double stopcocksand a vacuum gage (range from 0 to 102 kPa (0 to 30 in. Hg).10.2 Drying TowerPrepare a U-tube filled with a carbondioxide absorbent6and a suitable moisture absorbent, that is,anhydrous magnesium perchlorate Mg(ClO4)2.10.3 Muffle Furnace, capable of mainta
27、ining and controllingtemperatures to 1000C.11. Procedure11.1 Transfer approximately 5 to 10 g of UO2powder or upto 50 g of pellets to a tared platinum crucible and weigh towithin 0.1 mg.11.2 Place the crucible in a vacuum oven set at roomtemperature, seal the oven, and reduce the pressure to approxi
28、-mately 95 to 102 kPa (28 to 30 in. Hg).11.3 Close the vacuum valve and slowly flush the oven withdry nitrogen.11.4 Close the nitrogen inlet and reduce the pressure to 95to 102 kPa (28 to 30 in. Hg). Repeat the nitrogen flush as instep 11.3 to give a total of three flushes.11.5 Close the nitrogen in
29、let valve, reduce the pressure to 95to 102 kPa (28 to 30 in. Hg), set the temperature at 45C forpowder samples or 160C for pellets, and maintain theseconditions for 4 h. After 4 h of heating turn off the heat andallow the oven to cool to room temperature while underreduced pressure.5Reagent Chemical
30、s, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions 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 Fo
31、rmulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.6Ascarite has been found satisfactory for this purpose.C 696 99 (2005)211.6 Turn off the vacuum valve and slowly introduce drynitrogen until the oven door can be opened.11.7 Transfer the crucible to a desiccator and cool. Removethe c
32、rucible and weigh immediately (8).11.8 Place the crucible containing the dried oxide in amuffle furnace set at 900C. Ignite powder samples for 3 h.Pellets should be preheated at 500C for 3 h, then ignited 3 hat 900C.11.9 Remove the crucible from the furnace, allow to cool inthe air 2 to 3 min then p
33、lace the crucible in a desiccator andcool to room temperature. Weigh the crucible and repeat steps11.8 and 11.9 until a constant weight is obtained.11.10 Submit the ignited sample for spectrographic analy-sis.12. Calculation12.1 Loss on Vacuum DryingCalculate as follows basedon original sample:Loss,
34、 wt % 5 S 2 W1!/S 3 100 (1)where:S = initial sample mass, andW1= sample mass after vacuum drying, g.12.2 Uranium ContentCalculate as follows:U, wt % 5 0.8480 W22 W2I!/S! 3 100 2 0.01 % Note1! (2)where:0.8480 = U3O8to uranium conversion factor for naturaluranium. Corrections must be made in this fact
35、oras the uranium isotopic abundance deviates fromnatural uranium,W2= grams of U3O8after ignition,S = initial sample mass, andI = total grams of all impurity-element oxides pergram of ignited U3O8(Note 2).NOTE 1All nonvolatile impurity values reported as less than thethreshold of detection are consid
36、ered to contribute a total correction of0.01 % to the uranium percent.NOTE 2See Table 1 to obtain conversion factors for many commonimpurity elements encountered.12.3 Oxygen-to-Uranium RatioCalculate as follows fromthe original sample, U wt %:O/U 5 100 2 U wt % 2 Z 2n!A!#/15.999U! wt %# (3)where:A =
37、 atomic mass of uranium based on isotopic abundance,O = atom % of oxygen,U = atom % of uranium,n = moisture content, %, andZ = total impurities correction, %.13. Precision and Accuracy13.1 For atomic ratios of O/U in the range from 2.00 to 2.10the standard deviation was found to be 0.007 absolute at
38、 95 %confidence level.CARBON (TOTAL) BY DIRECT COMBUSTION-THERMAL CONDUCTIVITY METHODThis test method was withdrawn in January 1999 andreplaced by Test Method C 1408TOTAL CHLORINE AND FLUORINE BYPYROHYDROLYSIS ION-SELECTIVE ELECTRODEMETHOD14. Scope14.1 This test method covers the determination of ch
39、lorineand fluorine in nuclear-grade uranium dioxide. Witha1to10-gsample, concentrations of 5 to 200 g/g of chlorine and 1 to200 g/g of fluorine are determined without interference.15. Summary of Test Method15.1 The halogens are separated from powdered uraniumdioxide by pyrohydrolysis in a quartz tub
40、e with a stream of wetoxygen at a temperature of 900 to 1000C (10, 11, 12, 13).Chloride and fluoride are volatilized as acids, absorbed in abuffer solution, and measured with ion-selective electrodes (13,14, 15).16. Apparatus16.1 Pyrohydrolysis EquipmentA suitable assembly ofapparatus is shown in Fi
41、g. 1.16.1.1 Gas Flow Regulator and Flowmeter.16.1.2 Hot Plate, used to warm the water saturating thesparge gas to 50 to 80C.TABLE 1 Conversion Factors for Impurity CorrectionImpurity Assumed Oxide Form Gravimetric FactorAl Al2O31.89Ba BaO 1.12Be BeO 2.78Bi Bi2O31.11Ca CaO 1.40Cd CdO 1.14Co Co2O31.41
42、Cr Cr2O31.46Cu CuO 1.25Fe Fe2O31.43Li Li2O 2.15Mg MgO 1.66Mn MnO21.58Mo MoO31.50Na Na2O 1.35Ni NiO 1.27PP2O52.29Pb PbO21.15Sb Sb2O41.26Si SiO22.14Sn SnO21.27Ti TiO21.67VV2O51.79Zn ZnO 1.24Zr ZrO21.35Ta Ta2O51.22WW31.26C 696 99 (2005)316.1.3 Combustion Tube Furnace, having a bore of about 32mm (114 i
43、n.), a length of about 305 mm (12 in.), and thecapability of maintaining a temperature of 1000C.16.1.4 Quartz Reaction Tube (Fig. 2)The exit end shouldnot extend over 51 mm (2 in.) beyond the furnace with aground joint connecting to the delivery tube. The delivery tubeextends into a polyethylene abs
44、orption vessel with a tip capableof giving a stream of fine bubbles.16.1.5 Combustion Boat A platinum or quartz boat with a10-ml capacity (89 to 102 mm (312 to 4 in.) long, 12.7 mm (12in.) wide, and 9.53 mm (38 in.) high).16.1.6 Absorption VesselA 50-mL polyethylene graduateor tube is satisfactory.1
45、6.2 Ion-Specific ElectrodesA fluoride-specific activityelectrode7; chloride-specific electrode.816.3 pH Meter and Double-Junction Reference Electrode,such as a mercuric sulfate, sleeve junction type. The metershould have an expandable scale with a sensitivity of 1 mV.16.4 Magnetic Stirrer.16.5 Beake
46、rs, 50-mL polyethylene.17. Reagents17.1 Accelerator, U3O8halogen-free, can be used but a fluxof sodium tungstate (Na2WO4) with tungsten trioxide (WO3)may be used to advantage (10, 11). Special preparation of themixture is necessary.NOTE 3Dehydrate 165 g of Na2WO4in a large platinum dish.Transfer the
47、 dried material to a mortar, add 116 g of WO3, and grind themixture to ensure good mixing. Transfer the mixture into a platinum dishand heat with a burner for 2 h. Cool the melt, transfer the flux to a mortarand grind to a coarse powder. Store the flux in an airtight bottle. Mix about8 g of flux wit
48、h each portion of sample to be pyrohydrolyzed.17.2 Buffer SolutionDissolve 0.1 g potassium acetate(KC2H3O2) in water, add 0.050 mL of acetic acid (CH3CO2H,sp gr 1.05), and dilute to 1 litre.17.3 Chloride, Standard Solution (1 mL = 100 g Cl)Dissolve 165 mg of dry sodium chloride (NaCl) in water anddi
49、lute to 1 litre.17.4 Distilled WaterThe water must be free of all chlo-rides and fluorides.17.5 Fluoride, Standard Solution (1mL=50gF)Dissolve 111 mg of sodium fluoride (NaF) in water and diluteto 1 litre. Store the solution in a polyethylene bottle.17.6 Compressed Oxygen or Air.18. Procedure18.1 Adjust the pyrohydrolysis system to operating condi-tion as follows:7The sole source of supply of the apparatus known to the committee at this timeis the Orion Model 9409, sold by Orion Research, Cambridge, Mass. If you areaware of alter
