Designation:C1475−17StandardGuideforDeterminationofNeptunium-237inSoil1ThisstandardisissuedunderthefixeddesignationC1475;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisguidecoversthedeterminationofneptunium-237insoilbymeansofradiochemicalseparationsandalphaspectrometry.Thisguideprovidesoptionsintheselectionofsamplepreparation,separation,andmeasurement.Althoughneptunium-237isnotacomponentofglobalfallout,itisaproductofproductionreactorsandspentfuelprocessing.ThisguideisdesignedforanalysisoftengramsofsoilpreviouslycollectedandtreatedinaccordancewithPracticesC998andC999.Larger-sizesamplesofenvironmentalsoilmayalsobeanalyzed,aslongastheconcentrationsofinterferencessuchasuraniumandthoriumareatornearenvironmentalconcentra-tions.Dependingonthechoiceofasampledissolutionmethod,allchemicalformsofneptuniummaynotbecompletelysolubilized.Thisguideshouldallowthedeterminationofneptunium-237concentrationsfromsubbecquerelpergramlevelstoapplicablestandardsdependingoncounttime,samplesize,detectorefficiency,background,andtraceryield.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.Specificprecau-tionarystatementsaregiveninSection9.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2C859TerminologyRelatingt...