1、Designation: C 1347 08Standard 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 () 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 forcharacterizi
3、ng 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 Ur
4、anium 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 F
5、usion8.4Dissolution 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 asstandard. No other units of measure
6、ment are included in thisstandard.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 limita
7、tions prior to use. Specific hazardsstatements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2C 753 Specification for Nuclear-Grade, Sinterable UraniumDioxide PowderC 776 Specification for Sintered Uranium Dioxide PelletsC 1168 Practice for Preparation and Dissolution of Pluto-niu
8、m Materials for AnalysisD 1193 Specification for Reagent Water3. 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 refractory m
9、aterials 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.3,4,5Alternatively, thecombination of acids and a high pressure microwave have beenfound to be effective with
10、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 factor
11、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 samples ar
12、e 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 increase
13、the level of impurity beingdetermined significantly.NOTE 1The use of double distilled acids may be necessary for lowlevel trace impurities. The use of plastic labware will be necessary so thedissolution does not increase the level of impurities being determined.This may be necessary in Section 8.6.3
14、.4 These dissolution procedures are written for the com-plete or nearly complete dissolution of samples to obtain1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Dec.
15、 1, 2008. Published December 2008. Originallyapproved in 1996. Last previous edition approved in 2002 as C 1347 02.2For 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 t
16、he standards Document Summary page onthe ASTM website.3Selected Measurement Methods for Plutonium and Uranium in the NuclearFuel Cycle, Second Edition, C. J. Rodden, ed., U.S. Atomic Energy Commission,1972.4Analysis of Essential Nuclear Reactor Materials, C. J. Rodden, ed., U.S.Atomic Energy Commiss
17、ion, 1964.5Larsen, R. P., “Dissolution of Uranium Metal and Its Alloys,” AnalyticalChemistry , Vol 31, No. 4, 1959, pp. 545549.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.destructive assay results on as near to 100 % of the sampl
18、e aspossible. When sample inhomogeneity is determined to be amajor contributor 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;the contribution of the error to the total assay may bepro
19、pagated using the NDA assay value and errors for theresidue, and it may be determined that the error contributed 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 sam
20、pleis required for difficult to dissolve matrices.4. Significance and Use4.1 The materials covered that must 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 uraniumconten
21、t, uranium-235 enrichment, and impurity content, asdescribed in Specifications C 753 and C 776. The material 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 w
22、hich the user must determine the applicability of thispractice. In general, these unique uranium materials 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
23、 mixer,as appropriate; riffle splitter, stainless steel.5.3 FurnaceMuffle furnace, with fused silica tray to holdcrucibles, capable of operation to 1200C.5.4 Heating EquipmentAsteam bath in a hood; hot plates;infrared lamps; Bunsen and blast burner, with provision forboth gas and compressed air supp
24、ly; microwave oven6andhigh-pressure, heavy duty dissolution vessels.5.5 HardwareMetal weighing scoop; funnel 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
25、 recommended. However, the analyst shouldbe sure that safety and sample contamination are consideredwhen choosing appropriate containers. If the background levelsof impurities such as boron, iron and sodium are beingdetermined, then polypropylene or polytetrafluoroethylenecontainers and labware will
26、 be necessary in place of borosili-cate glass.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 dish
27、es; narrow mouth 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 Pa
28、per Pulp.5.13 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, ma
29、yrequire that all reagents and standards be prepared usingPlasma grade, trace metal grade (TMG), double distilled, orbetter. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch spe
30、cifications are available.7Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofmeasurements made on the prepared materials.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall b
31、e understood to mean laboratory-accepteddemineralized or deionized water. For impurities analyses,Type 1 Reagent Grade8water 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 concentra
32、ted HNO3(sp gr1.4) to approximately 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 (
33、HCI), concentrated 12 M (sp gr1.2).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).6The sole source of supply
34、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 will receive careful consideration at a meeting of theresponsible
35、 technical committee which you may attend.7Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dors
36、et, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.8See Specification D 1193.C13470826.11 Sulfuric Acid,9MAdd 500 mL of concentrated (spgr 1.8) H2SO4to approximately 400 mL of water, cool anddilute to 1 L. Store in a glass bot
37、tle.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 handling techniques, must be used inworking with samples containing these material
38、s. A detaileddiscussion of all 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 safetyp
39、rocedures in the laboratorys safety 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
40、addition of acid orwater, or even spontaneously. The reaction of uranium alloyswith acides may create an explosive mixture.37.4 WarningHydrofluoric acid is highly corrosive acidthat can severly burn skin, eyes, and mucous membranes.Hydrofluoric acid is similar to other acids in that the initialexten
41、t of a burn depends on the concentration, the temperature,and the duration of contact with the acid. Hydrofluoric aciddiffers from other acids because the fluoride ion readilypenetrates the skin, causing destruction of deep tissue layers.Unlike other acids that are rapidly neutralized, hydrofluorica
42、cid reactions with tissue may continue for days if leftuntreated. Due to the serious consequences of hydrofluoric acidburns, prevention of exposure or injury of personnel is theprimary goal. Utilization of appropriate laboratory controls(hoods) and wearing adequate personnel protective equipmentto p
43、rotect from skin and eye contact is essential. Acuteexposure to HF can cause painful and severe burns upon skincontact that require special medical attention. Chronic orprolonged exposure to low levels on the skin may causefluorosis.8. Procedures8.1 Dissolution of Uranium Metal and Oxide with Nitric
44、Acid: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 the 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 ap
45、propriate container, and rinse the metal twice withdistilled water into the container.8.1.1.1 Dry the metal by rinsing twice with acetone orethanol. 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
46、 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 metal (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 co
47、ncentration).NOTE 2Measure and record the room temperature, barometric pres-sure, and percent relative humidity if performing buoyancy corrections.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 t
48、o 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 since 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 le
49、ft unstoppered due to gas generation,but it may be covered by an inverted beaker).NOTE 3If desired, up to 20 mL of concentrated H2SO4may be 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 byadding distilled water in 200 to 300-mL portions and swirlingafter each addition. Allow the solution to cool to roomtemperature,
