1、Designation:C138004(Reapproved 2011)Standard Test Method forthe Determination of Uranium Content and IsotopicComposition by Isotope Dilution Mass Spectrometry1This standard is issued under the fixed designation C1380;the number immediately following the designation indicates the year oforiginal adop
2、tion or,in the 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 This test method covers a method for the determinationof the uranium concentrat
3、ion in uranium oxides by isotopedilution mass spectrometry(IDMS).The isotopic compositionof the oxide is measured simultaneously.1.2 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 ap
4、pro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Water3.Summary of Test Method3.1 For measurement of the elemental uranium concentra-tion of uranium oxides by IDMS,
5、a representative and accu-rately measured aliquot of the sample is prepared.A knownquantity of233U(“spike”)is added to an aliquot of the sample.The sample aliquot and spike are taken to dryness,redissolvedin dilute nitric acid,and loaded on a filament for analysis in athermal ionization mass spectro
6、meter(TIMS).After measure-ment of the isotopic ratios in the spiked sample,the uraniumcontent and isotopic composition of sample are calculated.4.Significance and Use4.1 Determination of percent uranium content and235Uabundance in oxides and other materials containing highconcentrations of uranium i
7、s required for special nuclearmaterials accountability,regulatory requirements,and processcontrol.5.Interferences5.1 The calculations assume any233U in the sample isnegligible.If the sample contains significant233U,the samplemust be analyzed for isotopic composition with and withoutadded spike,and t
8、he calculations adjusted accordingly.6.Apparatus6.1 Thermal ionization mass spectrometer(TIMS)config-ured with Faraday cup detectors and an automated operatingsystem.6.2 Preconditioning unit for the TIMS.6.3 Filament loading assembly for the TIMS.6.4 Balance,analytical,with five-place range.6.5 Vial
9、s,glass,disposable with plastic caps.6.6 Pipet,automatic,Ranin or equivalent,variable to 1000L.6.7 Pipet tips,disposable plastic,1001000 L.6.8 Liquid dispenser,Repipette or equivalent.7.Reagents and Materials7.1 Purity of MaterialsReagent grade chemicals shall beused in all tests.Unless otherwise in
10、dicated,it is intended thatall reagents conform to the specification of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be usedprovided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its u
11、se without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherwise indicated,referencesto water shall mean reagent water in conformance withSpecification D1193.7.3 Nitric Acid,HNO3,concentrated(70%).1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFue
12、l Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1,2011.Published June 2011.Originallyapproved in 1997.Last previous edition approved in 2004 as C1380 04.DOI:10.1520/C1380-04R11.2For referenced ASTM standards,visit the ASTM website,www.a
13、stm.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.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,D.C.For suggestions on the te
14、sting of reagents notlisted by the American Chemical Society,Washington,D.C.For suggestions on thetesting of reagents not listed by the American Chemical Society,see AnalarStandards for Laboratory Chemicals,BDH Ltd.,Poole,Dorset,U.K.,and theUnited States Pharmacopeia and National Formulary,U.S.Pharm
15、acopeial Con-vention(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.4 Nitric Acid,0.8 M(5%v/v)Cautiously add 50 mL ofconcentrated nitric acid to 950 mL of water.7.5 Nitric Acid,0.1 MAdd 6.5 mL concentrated nitric aci
16、dto 900 mL of water,mix,and bring to 1000 mL with water.7.6 Hydrogen Peroxide H2O2,30%.7.7 Elemental and Isotopic Uranium Standards(NewBrunswick Laboratory CRM 114,CRM 116,CRM 129,orequivalent4).7.8 Uranium-233 spike assay and isotopic standard(NBLCRM 111A4or equivalent)Dilute NBLCRM 111A1:50 byweight with a 5%nitric acid to give a233U concentration ofapproximately 10 g233U/g solution.NOTE1An exact 1:50 dilution is not required.The requirement is forprecise and accurate weights of standard and d
