ASTM_C_1625_-_12.pdf

Designation:C162512Standard Test Method forUranium and Plutonium Concentrations and IsotopicAbundances by Thermal Ionization Mass Spectrometry1This standard is issued under the fixed designation C1625;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 covers the determination of the con-centration and isotopic composition of uranium and plutoniumin solutions.The purified uranium or plutonium from samplesranging from nuclear materials to environmental or bioassaymatrices is loaded onto a mass spectrometric filament.Theisotopic ratio is determined by thermal ionization massspectrometry,the concentration is determined by isotope dilu-tion.1.2 The values stated in SI units are to be regarded as thestandard.Values in parentheses are for information only.1.3 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 safetyand health practices and determine the applicability of regu-latory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C753 Specification for Nuclear-Grade,Sinterable UraniumDioxide PowderC757 Specification for Nuclear-Grade Plutonium DioxidePowder,SinterableC776 Specification for Sintered Uranium Dioxide PelletsC833 Specification for Sintered(Uranium-Plutonium)Diox-ide PelletsC859 Terminology Relating to Nuclear MaterialsC1008 Specification for Sintered(Uranium-Plutonium)Di-oxide PelletsFast Reactor FuelC1068 Guide for Qualification of Measurement Methods bya Laboratory Within the Nuclear IndustryC1156 Guide for Establishing Calibration for a Measure-ment Method Used to Analyze Nuclear Fuel Cycle Mate-rialsC1168 Practice for Preparation and Dissolution of PlutoniumMaterials for AnalysisC1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisC1411 Practice for The Ion Exchange Separation of Ura-nium and Plutonium Prior to Isotopic AnalysisC1415 Test Method for238Pu Isotopic Abundance By AlphaSpectrometryC1614 Practice for the Determination of237Np,232Th,235Uand238U in Urine by Inductively Coupled Plasma-MassSpectrometry(ICP-MS)and Gamma Ray SpectrometryD3084 Practice for Alpha-Particle Spectrometry of Water2.2 Other DocumentsInternational Target Values 2010 for Measurement Uncer-tainties in Safeguarding Nuclear Materials33.Terminology3.1 For definitions of pertinent terms not listed here,seeTerminology C859.3.2 Definitions of Terms Specific to This Standard:3.2.1 isotope dilution mass spectrometry(IDMS)isotoperatio measurements,using mass spectrometry,of samplesspiked with accurately known weights of individual lowabundance isotopes(adapted from Practice C1614).4.Summary of Test Method4.1 The uranium and plutonium are separated from eachother and purified from other elements by selective extraction,anion exchange(such as in C1411)or extraction chromatog-raphy.The uranium and plutonium fractions are individuallymounted on filaments of rhenium,tungsten,or tantalum,andare analyzed by thermal ionization mass spectrometry todetermine the relative abundance of the isotopes.If a known233U or242Pu(or244Pu)spike is added prior to chemicalseparation the corresponding elemental concentration may alsobe determined by isotope dilution mass spectrometry(IDMS).1This test method is under the jurisdiction ofASTM CommitteeC26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1,2012.Published July 2012.Originally approvedin 2005.Last previous edition approved in 2005 as C162505.DOI:10.1520/C1625-12.2For 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.3K.Zhao et.al.,“International Target Values 2010 for Measurement Uncertain-ties in Safeguarding Nuclear Materials,”International Atomic Energy AgencySTR-368,2010.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 Uranium and plutonium oxides can be used as a nuclear-reactor fuel in the form of pellets.In order to be suitable for useas a nuclear fuel the starting material must meet certainspecifications,such as found in Specifications C757,C833,C753,C776,C1008,or as specified by the purchaser.Theuranium and/or plutonium concentration and isotopic abun-dances are measured by mass spectrometry following this testmethod.5.2 The separated heavy element fractions placed on massspectrometric filaments must be very pure.The quantityrequired depends upon the sensitivity of the instrument detec-tion system.If an electron multiplier dete