1、Designation: C 1347 02Standard Practice forPreparation and Dissolution of Uranium Materials forAnalysis1This standard is issued under the fixed designation C 1347; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 This practice covers dissolution treatments for uraniummaterials that are applicable to the test methods used forcharacteriz
3、ing these materials for uranium elemental, isotopic,and impurities determinations. Dissolution treatments for themajor uranium materials assayed for uranium or analyzed forother components are listed.1.2 The treatments, in order of presentation, are as follows:Procedure Title SectionDissolution of U
4、ranium Metal and Oxide with Nitric Acid 8.1Dissolution of Uranium Oxides with Nitric Acid and ResidueTreatment8.2Dissolution of Uranium-Aluminum Alloys in Hydrochloric Acidwith Residue Treatment8.3Dissolution of Uranium Scrap and Ash by Leaching with NitricAcid and Treatment of Residue by Carbonate
5、Fusion8.4Dissolution of Refractory Uranium-Containing Material byCarbonate Fusion8.5Dissolution of UraniumAluminum AlloysUranium Scrap and Ash, and RefractoryUranium-Containing Materials byMicrowave Treatment8.61.3 The values stated in SI units are to be regarded as thestandard. The values given in
6、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 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limi
7、tations prior to use. Specific hazardsstatements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:C 753 Specification for Nuclear-Grade, Sinterable UraniumDioxide Powder2C 776 Specification for Sintered Uranium Dioxide Pellets2C 1168 Practice for Preparation and Dissolution of Pluto-
8、nium Materials for Analysis2D 1193 Specification for Reagent Water33. Summary of Practice3.1 Many uranium-containing materials such as high-puritymetals and oxides dissolve readily in various mineral acids.The dissolution of uranium-plutonium mixed oxides is coveredin Practice C 1168. Highly refract
9、ory materials require priorgrinding of samples and fusions to affect even partial dissolu-tion. Combinations of the mineral acid and fusion techniquesare used for difficult to dissolve materials.4,5,6Alternatively, thecombination of acids and a high pressure microwave have beenfound to be effective
10、with more difficult to dissolve materialsand can also be used for materials which dissolve in mineralacid in place of heating with a steam bath or hot plate.3.2 The dissolved materials are quantitatively transferred totared polyethylene bottles for subsequent sample solution massdetermination and fa
11、ctor calculation. Aliquants are obtained bymass for high-precision analysis or by volume for less preciseanalysis methods. Quantitative transfers of samples and sub-sequent solutions are required. The sample is rejected when-ever a loss is incurred, or even suspected.3.3 Solutions of dissolved sampl
12、es are inspected for undis-solved particles. Further treatment is necessary to attain com-plete solubility if particles are present. When analyzing thedissolved sample for trace impurities, caution should beexercised so the dissolution process does not cause the impu-rity to be lost or does not incr
13、ease the level of impurity beingdetermined significantly.3.4 These dissolution procedures are written for the com-plete or nearly complete dissolution of samples to obtaindestructive assay results on as near to 100 % of the sample aspossible. When sample inhomogeneity is determined to be amajor cont
14、ributor to assay error, nondestructive assay (NDA)determinations on residues from the dissolution may be re-quested at an earlier stage than suggested in these procedures;1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommit
15、tee C26.05 on Methods ofTest.Current edition approved August 10, 2002. Published November 2002. Origi-nally published as C 1347 96. Last previous edition C 1347 96a.2Annual Book of ASTM Standards, Vol 12.01.3Annual Book of ASTM Standards, Vol 11.01.4Selected Measurement Methods for Plutonium and Ura
16、nium in the NuclearFuel Cycle, Second Edition, C. J. Rodden, ed., U.S. Atomic Energy Commission,1972.5Analysis of Essential Nuclear Reactor Materials, C. J. Rodden, ed., U.S.Atomic Energy Commission, 1964.6Larsen, R. P., “Dissolution of Uranium Metal and Its Alloys,” AnalyticalChemistry, Vol 31, No.
17、 4, 1959, pp. 545549.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the contribution of the error to the total assay may bepropagated using the NDA assay value and errors for theresidue, and it may be determined that the error contr
18、ibuted tothe sample assay by the NDA determination on the residue isacceptable.3.5 The accuracy of the analytical method should be con-sidered when determining if complete dissolution of the sampleis required for difficult to dissolve matrices.4. Significance and Use4.1 The materials covered that mu
19、st meet ASTM specifica-tions are uranium metal and uranium oxide.4.2 Uranium materials are used as nuclear reactor fuel. Forthis use, these materials must meet certain criteria for uraniumcontent, uranium-235 enrichment, and impurity content, asdescribed in Specifications C 753 and C 776. The materi
20、al isassayed for uranium to determine whether the content is asspecified.4.3 Uranium alloys, refractory uranium materials, and ura-nium containing scrap and ash are unique uranium materialsfor which the user must determine the applicability of thispractice. In general, these unique uranium materials
21、 are dis-solved with various acid mixtures or by fusion with variousfluxes.5. Apparatus5.1 Balances, for determining the mass of samples andsolutions.5.2 Sample Mixing EquipmentSample tumbler or mixer,as appropriate; riffle splitter, stainless steel.5.3 FurnaceMuffle furnace, with fused silica tray
22、to holdcrucibles, capable of operation to 1200C.5.4 Heating EquipmentA steam bath in a hood; hot plates;infrared lamps; Bunsen and blast burner, with provision forboth gas and compressed air supply; microwave oven7andhigh-pressure, heavy duty dissolution vessels.5.5 HardwareMetal weighing scoop; fun
23、nel racks; tongs;rubber policemen; tripods; silica triangles; board, heat dissi-pating, at least 6.35-mm (0.25-in.) thick.5.6 Beakers, Volumetric Flasks, and BottlesBorosilicateglass is generally recommended. However, the analyst shouldbe sure that safety and sample contamination are consideredwhen
24、choosing appropriate containers.5.7 GlasswareBorosilicate glass is generally recom-mended except as specified. Watch glasses or petri dishes, tocover beakers; funnels; stirring rods; crucibles, Vycor, withlids.5.8 PlasticwareWash bottle, polyethylene, 125-mL, foraliquanting; petri dishes; narrow mou
25、th polyethylene bottles;plastic bottles, 60 mL; funnels, polypropylene; pipets, transfer.5.9 Volumetric Flask Polypropylene, 25 mL, 50 mL, and100 mL.5.10 Pipettes 10 L5 mL (or equivalent). Accuracy of 63% is adequate.5.11 Filter PaperWhatman Nos. 40 and 42, or equivalent.5.12 Filter Paper Pulp.5.13
26、Platinum WareCrucibles, with lids; platinum-tippedtongs; dishes, with lids.5.14 TFE Fluorocarbon WareStirring rods.5.15 Dry Atmosphere Box.5.16 Drying Oven.6. Reagents6.1 Purity of ReagentsReagent grade or better chemicalsshall be used in all tests; impurities analyses, for example, mayrequire that
27、all reagents and standards be prepared usingPlasma grade, trace metal grade (TMG), or better. Unlessotherwise indicated, it is intended that all reagents conform tothe specifications of the Committee on Analytical Reagents ofthe American Chemical Society where such specifications areavailable.8Other
28、 grades may be used, provided it is firstascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of measurementsmade on the prepared materials.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean laboratory-
29、accepteddemineralized or deionized water. For impurities analyses,Type 1 Reagent Grade9water may be required dependent uponthe accuracy and precision of the analysis method used.6.3 Nitric Acid (HNO3), concentrated (sp gr 1.4), 16 M .6.4 HNO3,8MAdd 500 mL of concentrated HNO3(sp gr1.4) to approximat
30、ely 400 mL of water and dilute to 1 L.6.5 HNO3,10% Add 100 mL of concentrated HNO3(sp gr1.4) to 800 mL. Type 1 Reagent Grade water and dilute to 1 L.6.6 HNO3,2% Add 20 mL of concentrated HNO3to 900mL. Type 1 Reagent Grade water and dilute to 1 L.6.7 Hydrochloric Acid (HCI), concentrated 12 M (sp gr1
31、.2).6.8 Hydrofluoric Acid (HF), concentrated 29 M (sp gr 1.2).6.9 HF 7.2 M Add 250 mL of concentrated HF, ElectronicGrade (29M ), to 700 mL Type 1 Reagent Grade water anddilute to 1 L.6.10 Sulfuric Acid (H2SO4), concentrated 18 M (sp gr 1.8).6.11 Sulfuric Acid,9MAdd 500 mL of concentrated (spgr 1.8)
32、 H2SO4to approximately 400 mL of water, cool anddilute to 1 L. Store in a glass bottle.6.12 Sodium Carbonate (Na2CO3).6.13 Sodium Bisulfate (NaHSO4).7. Hazards7.1 Since enriched uranium-bearing materials are radioac-tive and toxic, adequate laboratory facilities, including fumehoods, along with safe
33、 handling techniques, must be used in7The sole source of supply of the apparatus known to the committee at this timeis CEM Corporation, 3100 Smith Farm Road, Mathews, NC 28105. If you are awareof alternative suppliers, please provide the information to ASTM InternationalHeadquarters. Your comments w
34、ill receive careful consideration at a meeting of theresponsible technical committee which you may attend.8Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see
35、 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.9See Specification D 1193.C1347022working with samples containing these materials. A detaileddiscussion of all
36、necessary safety precautions is beyond thescope of this practice. However, personnel who handle radio-active materials should be familiar with the safe handlingpractices required in individual laboratory guidelines.7.2 Review the material safety data sheets and safetyprocedures in the laboratorys sa
37、fety manual before performingthis procedure.7.3 Elemental uranium is very reactive; assure initial reac-tions have subsided before sealing closed vessels. As turningsand powder, uranium is extremely pyrophoric, often igniting asa result of mechanical friction, a small addition of acid orwater, or ev
38、en spontaneously. The reaction of uranium alloyswith acides may create an explosive mixture.48. Procedures8.1 Dissolution of Uranium Metal and Oxide with NitricAcid:8.1.1 Clean the surface oxide from metallic uranium byplacing the metal in a small beaker and adding enough 8 MHNO3to cover it. Place t
39、he beaker on a steam bath for 10 to 20min to remove the surface oxide. When the black oxide hasbeen removed completely, decant the supernatant liquid intothe appropriate container, and rinse the metal twice withdistilled water into the container.8.1.1.1 Dry the metal by rinsing twice with acetone or
40、ethanol. Place the metal on filter paper, and allow it to dry for30 to 60 s, rolling the metal several times to expose all faces tothe atmosphere.8.1.1.2 Tare a weighing scoop on an analytical balance.Place the dry uranium metal from 8.1.1.1 in the scoop andweigh. Record the mass of the uranium meta
41、l (12 g of metalwill provide approximately 2 L of 6 g/L solution; the ratios ofmetal mass and solution mass may be adjusted, as needed, toprovide the desired concentration).NOTE 1Measure and record the room temperature, barometric pres-sure, and percent relative humidity if performing buoyancy corre
42、ctions.8.1.2 Tare a 2-L flask or polyethylene bottle on a top loaderbalance, or record the mass of the flask or bottle.8.1.3 Transfer the metal quantitatively to the tared (orweighed) flask or bottle.8.1.4 Add 250 mL of 8 M HNO3(adjust the nitric acidvolume in ratio to the metal to be dissolved sinc
43、e insufficientHNO3will cause the metal surface to become passive) to theflask or bottle. Warm the flask or bottle on a steam bath (theflask or bottle must be left unstoppered due to gas generation,but it may be covered by an inverted beaker).NOTE 2If desired, up to 20 mL of concentrated H2SO4may be
44、addedto the mixture. This will speed dissolution and ease later dissolution of thealiquants.8.1.5 When the dissolution is complete, remove the flask orbottle from the steam bath, and allow it to cool to ambienttemperature for ease of handling.8.1.6 Dilute the solution to approximately 1900 mL byaddi
45、ng distilled water in 200 to 300-mL portions and swirlingafter each addition. Allow the solution to cool to roomtemperate, dilute to 2 L, and add a stopper or top.NOTE 3Caution: Do not invert the flask or bottle prior to obtainingthe mass of the solution.8.1.7 Weigh the full flask or bottle using th
46、e top-loaderbalance, and record the solution weight.8.1.8 Invert the flask or bottle several times to mix thecontents thoroughly prior to preparing aliquants.8.2 Dissolution of Uranium Oxides with Nitric Acid andResidue TreatmentCommon laboratory techniques are de-scribed in Annex A1. The techniques
47、 are referenced to theappropriate section in parentheses at the first place in theprocedure where they may be applicable.8.2.1 Sample PreparationObtain the mass of the sampleusing a four-place balance (usually 0.5-g to 0.1-mg sensitivity).Transfer the sample quantitatively to a beaker (A1.1.1). If t
48、hesample is a powder, cover it gently with distilled water. Coverthe beaker with a watch glass.NOTE 4Caution: Do not wash down the walls of the beaker becausethe powder may creep up the sides of the beaker and be lost.8.2.2 Acid Dissolution:NOTE 5Caution: Do not wet the beaker walls with the acid. A
49、ddapproximately 100 mL of 8 M HNO3to the sample carefully in order tocontrol the reaction rate.NOTE 6Caution: Powders may react very rapidly. If the reaction istoo rapid, add distilled water to decrease the reaction rate.8.2.2.1 Allow the reaction to subside; then heat on asteambath or hot plate (A1.1.2). Add additional 8 M HNO3asnecessary, until dissolution is complete.8.2.2.2 When the dissolution appears to be complete, washdown the walls of the beaker with distilled water and heat foran additional 30 min.8.2.2.3 Allow the solution to cool; then filter (
