1、Designation:C174217Standard Test Method forIsotopic Analysis of Uranium Hexafluoride by DoubleStandard Single-Collector Gas Mass Spectrometer Method1This standard is issued under the fixed designation C1742;the number immediately following the designation indicates the year oforiginal adoption or,in
2、 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 is a quantitative test method applicable to deter-mining the mass percent of uranium
3、 isotopes in uraniumhexafluoride(UF6)samples with235U concentrations between0.1 and 5.0 mass%.1.2 This test method may be applicable for the entire rangeof235U concentrations for which adequate standards areavailable.21.3 This test method is for analysis by a gas magnetic sectormass spectrometer wit
4、h a single collector using interpolation todetermine the isotopic concentration of an unknown samplebetween two characterized UF6standards.1.4 This test method is to replace the existing test methodcurrently published in Test Methods C761 and is used in thenuclear fuel cycle for UF6isotopic analyses
5、.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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-p
6、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Intern
7、ational Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3C761 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofUranium HexafluorideC787 Spec
8、ification for Uranium Hexafluoride for Enrich-mentC859 Terminology Relating to Nuclear MaterialsC996 Specification for Uranium Hexafluoride Enriched toLess Than 5%235UC1068 Guide for Qualification of Measurement Methods bya Laboratory Within the Nuclear Industry2.2 Other Document:USEC-651Uranium Hex
9、afluoride:A Manual of GoodHandling Practices,Latest Revisions3.Terminology3.1 Except as otherwise defined herein,definitions of termsare as given in Terminonlogy C859.4.Summary of Test Method4.1 The unknown sample and two standards,whose235Umass percent bracket that of the unknown,are introduced ins
10、equence into the mass spectrometer and measurements aremade that are a function of the mol ratio of235U to the total ofthe other isotopes of uranium.These measurements,togetherwith the known composition of the standards,permit calcula-tion of the235U composition of the sample by linear interpo-latio
11、n(1-6).4.2 The symmetrical sequence of sample-standard introduc-tions from low standard,sample,high standard,and thenreversed is designed to minimize biases resulting from instru-ment drift,sample interaction or memory,and the nonlinearityof the relationship between the measured resistance ratios an
12、dthe true sample mol ratios.Corrections generally are notrequired for instrument memory.1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1,2017.Published June
13、2017.Originallyapproved in 2010.Last previous edition approved in 2010 as C1742 10.DOI:10.1520/C1742-17.2This test method applies to the measurement of235U.It would also be able tomeasure minor isotopes using the same principle subject to appropriate validation bythe measurement laboratory.3For refe
14、renced 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshoh
15、ocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organiza
16、tion Technical Barriers to Trade(TBT)Committee.1 5.Significance and Use5.1 Uranium hexafluoride is a basic material used to preparenuclear reactor fuel.To be suitable for this purpose,thematerial shall meet the criteria for isotopic composition.Thistest method is designed to determine whether the materialmeets the requirements described in Specifications C787 andC996.5.2 Fitness for Purpose of Safeguards and Nuclear SafetyApplicationsMethods intended for use in safeguards andnuclear safety appli
