ASTM_C_1832_-_16.pdf

Designation:C183216Standard Test Method forDetermination of Uranium Isotopic Composition by theModified Total Evaporation(MTE)Method Using a ThermalIonization Mass Spectrometer1This standard is issued under the fixed designation C1832;the number immediately following the designation indicates the year 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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes the determination of theisotope amount ratios of uranium material as nitrate solutionsby the modified total evaporation(MTE)method using athermal ionization mass spectrometer(TIMS)instrument.1.2 The analytical performance in the determination of the235U/238U major isotope amount ratio by MTE is similar to the(“classical”)total evaporation(TE)method as described in TestMethod C1672.However,in the MTE method,the evaporationprocess is interrupted on a regular basis to allow measurementsand subsequent corrections for background form peak tailing,perform internal calibration of a secondary electron multiplier(SEM)detector versus the Faraday cups,peak centering,andion source refocusing.Performing these calibrations and cor-rections on a regular basis during the measurement,improvesprecision,and significantly reduces uncertainties for the minorisotope amount ratios234U/238U and236U/238U as compared tothe TE method.1.3 In principle,the MTE method yields major isotopeamount ratios without the need for mass fractionation correc-tion.However,depending on the measurement conditions,small variations are seen among sample turrets;therefore,asmall correction based on measurements of a certified refer-ence material is recommended to improve consistency.Theuncertainty around the mass fractionation correction factorusually includes unity.1.4 UnitsThe values stated in SI units are to be regardedas the standard.When non-SI units are provided,they are forinformation only.1.5 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C753 Specification for Nuclear-Grade,Sinterable UraniumDioxide PowderC776 Specification for Sintered Uranium Dioxide PelletsC787 Specification for Uranium Hexafluoride for Enrich-mentC833 Specification for Sintered(Uranium-Plutonium)Diox-ide PelletsC859 Terminology Relating to Nuclear MaterialsC967 Specification for Uranium Ore ConcentrateC996 Specification for Uranium Hexafluoride Enriched toLess Than 5%235UC1008 Specification for Sintered(Uranium-Plutonium)DioxidePelletsFast Reactor Fuel(Withdrawn 2014)3C1068 Guide for Qualification of Measurement Methods bya Laboratory Within the Nuclear IndustryC1128 Guide for Preparation of Working Reference Materi-als for Use in Analysis of Nuclear Fuel Cycle MaterialsC1156 Guide for Establishing Calibration for a Measure-ment Method Used to Analyze Nuclear Fuel Cycle Mate-rialsC1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisC1411 Practice for The Ion Exchange Separation of Ura-nium and Plutonium Prior to Isotopic AnalysisC1625 Test Method for Uranium and Plutonium Concentra-tions and Isotopic Abundances by Thermal IonizationMass SpectrometryC1672 Test Method for Determination of Uranium or Pluto-nium Isotopic Composition or Concentration by the TotalEvaporation Method Using a Thermal Ionization MassSpectrometerD1193 Specification for Reagent Water1This 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 Jan.15,2016.Published January 2016.DOI:10.1520/C1832-16.2For 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 the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 E2655 Guide for Reporting Uncertainty of Test Results andUse of the Term Measurement Uncertainty in ASTM TestMethodsE2586 Practice for Calculating and Using Basic Statistics3.Terminology3.1 The terminology standard C859 contains terms,definitions,descriptions of terms,nomenclature,and explana-tions of acronyms and symbols specifically associated withstandards under the jurisdiction of Committee C26 on NuclearFuel Cycle.3.2 Definitions:3.2.1 abundance sensitivity,nin isotope amount ratiomeasurements,the ratio of the measured intensity of an ionbeam at a mass,m,to the measured intensity from the sameisotope measured at on