ASTM_C_1268_-_15.pdf

Designation:C126815Standard Test Method forQuantitative Determination of241Am in Plutonium byGamma-Ray Spectrometry1This standard is issued under the fixed designation C1268;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 quantitative determinationof241Am by gamma-ray spectrometry in plutonium nitratesolution samples that do not contain significant amounts ofradioactive fission products or other high specific activitygamma-ray emitters.1.2 This test method can be used to determine the241Am insamples of plutonium metal,oxide and other solid forms,whenthe solid is appropriately sampled and dissolved.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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:2C758 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofNuclear-Grade Plutonium MetalC759 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofNuclear-Grade Plutonium Nitrate SolutionsC859 Terminology Relating to Nuclear MaterialsC1009 Guide for Establishing and Maintaining a QualityAssurance Program forAnalytical Laboratories Within theNuclear IndustryC1168 Practice for Preparation and Dissolution of PlutoniumMaterials for AnalysisC1592/C1592M Guide for Making Quality NondestructiveAssay MeasurementsE181 Test Methods for Detector Calibration and Analysis ofRadionuclides2.2 U.S.Nuclear Regulatory Commission RegulatoryGuides:3Regulatory Guide 5.9,Rev.2Guidelines for GermaniumSpectroscopy Systems for Measurement of SpecialNuclear MaterialsRegulatory Guide 5.53,Rev.1Qualification,Calibration,and Error Estimation Methods for Nondestructive Assay33.Terminology3.1 Except as otherwise defined herein,definitions of termsare as given in Terminology C859.4.Summary of Test Method4.1 An aliquot of the sample that contains about 10 to 100ng of241Am is analyzed by measuring the intensity of thecharacteristic 59.5 keV gamma ray emitted by241Am.4.2 Multiple sample geometries may be used if an appro-priate calibration for each geometry is made.4.3 The sample geometry must be reproducible.This in-cludes the physical characteristics of the sample container,thepositioning of the sample,and the volume of sample viewed bythe gamma-ray detector.4.4 Electronic corrections are made,if required,for theeffects of pulse pile-up and dead time losses due to the activityof the sample.The necessity of dead time and pulse pile-upcorrections can be reduced by sample dilution to control countrates.4.5 Acorrection is made for the contribution to the 59.5 keVintensity due to gamma rays produced in the decay of237U.4.6 The relationship between the measured gamma-rayintensity and the241Am content is determined by the use ofappropriate standards.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 1,2015.Published July 2015.Originally approvedin 1994.Last previous edition approved in 2008 as C1268 94(2008).DOI:10.1520/C1268-15.2For 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.3Available from U.S.Nuclear Regulatory Commission,One White Flint North,11555 Rockville Pike,Rockville,MD 20852.Also through www.nrc.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 This test method allows the determination of241Am in aplutonium solution without separation of the americium fromthe plutonium.It is generally applicable to any solutioncontaining241Am.5.2 The241Am in solid plutonium materials may be deter-mined when these materials are dissolved(see Practice C1168).5.3 When the plutonium solution contains unacceptablelevels of fission products or other materials,this method maybe used following a tri-n-octylphosphine oxide(TOPO)extraction,ion exchange or other similar separation techniques(see Test Methods C758 and C759).5.4 This test method is less subject to interferences fromplutonium than alpha counting since the energy of the gammaray used for the analysis is better resolved from other gammarays than the alpha particle energies used for alpha counting.5