Designation:C1539−08(Reapproved2014)StandardTestMethodforDeterminationofTechnetium-99inUraniumHexafluoridebyLiquidScintillationCounting1ThisstandardisissuedunderthefixeddesignationC1539;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisaquantitativemethodusedtodeterminetechnetium-99(99Tc)inuraniumhexafluoride(UF6)byliquidscintillationcounting.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C787SpecificationforUraniumHexafluorideforEnrich-mentC996SpecificationforUraniumHexafluorideEnrichedtoLessThan5%235UC1215GuideforPreparingandInterpretingPrecisionandBiasStatementsinTestMethodStandardsUsedintheNuclearIndustry2.2OtherDocument:USEC-651UraniumHexafluoride:AManualofGoodHandlingPractices33.Terminology3.1Definitions:3.1.1quenchstandardcurve—arelationshipbetweensamplequenchanddetectionefficiency.Aquenchcurveforanisotopeinagivencocktailandvialcombinationisdevelopedbycountingaseriesofstandardscontainingthesameactivityofthatisotope,buteachwithdifferentquench.Samplequenchistypicallyquantifiedbyavarietyofparameters.4.SummaryofTestMethod4.1Ameasuredportionofhydrolyzeduraniumhexafluoride(UF6)containingapproximately0.8to1.2gofuraniumoravolumeofsamplelessthanorequalto30mListransferredtoacentrifugetube.Theuraniumisprecipitatedusingammo-niumhydroxide.Aftercentrifuging,thedecantedsupernatantisacidifiedwithsulfuricacidandextractedwithtributylphos-phate.Analiquotoftheextractistransferredtoascintillationvial,wherestannousc...
