ASTM_C_1816_-_16.pdf

Designation:C181616Standard Practice forThe Ion Exchange Separation of Small Volume SamplesContaining Uranium,Americium,and Plutonium Prior toIsotopic Abundance and Content Analysis1This standard is issued under the fixed designation C1816;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 practice is an alternative to Practice C1411 for theion exchange separation in small mass samples(5 g ofplutonium and up to 0.5 mg of uranium in 1 mL of solution)ofuranium and plutonium from each other and from otherimpurities for subsequent isotopic abundance and contentanalysis by thermal ionization mass spectrometry(TIMS).Inaddition to being adapted to smaller sample sizes,this practicealso avoids the use of hydrochloric acid(HCl)and hydrofluoricacid(HF)and does not require the use of two anion exchangecolumns as required in Practice C1411.1.2 In chemically unseparated samples isobaric nuclides atmass 238(238U and238Pu),and mass 241(241Pu and241Am)will be measured together thus compromising the accuracy ofthe results of isotopic composition of Pu.Therefore,chemicalseparation of elements is essential prior to isotopic analyses.Concentrations and volumes given in the paragraphs below canbe modified for larger sample sizes,different types of anionexchange resin,etc.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:2C698 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade Mixed Ox-ides(U,Pu)O2)C833 Specification for Sintered(Uranium-Plutonium)Diox-ide PelletsC859 Terminology Relating to Nuclear MaterialsC1008 Specification for Sintered(Uranium-Plutonium)DioxidePelletsFast Reactor Fuel(Withdrawn 2014)3C1168 Practice for Preparation and Dissolution of PlutoniumMaterials for AnalysisC1347 Practice for Preparation and Dissolution of UraniumMaterials for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 AlphaSpectrometryC1625 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 Water3.Terminology3.1 DefinitionsFor definitions of terms used in thispractice,refer to Terminology C859.4.Summary of Practice4.1 Solid samples are dissolved according to PracticesC1168 or C1347 or other appropriate methods.The resultingsolution is processed by this practice to prepare separatesolutions of plutonium and uranium for mass spectrometricisotopic abundance analysis using Test Method C698,C1625,or C1672.Appropriate portions are taken to provide up to 5 gof plutonium on the ion exchange column to be separated from0.5 mg or less of uranium.All dilutions should be performed by1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Jan.15,2016.Published February 2016.Originallyapproved in 2015.Last previous edition approved in 2015 as C1816 15.DOI:10.1520/C1816-16.2For 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 mass to ensure the smallest uncertainty possible.This practicecan be used for higher uranium to plutonium ratios,but columnrinsing volumes should be adjusted accordingly(see 10.1.3.8).Using the volumes proposed in this practice leads to aseparation efficiency of at least 99.999%between uranium andplutonium.Valence adjustment is obtained by using the proce-dure described in 4.1.1 or by an alternative method demon-strated by the user to perform the equivalent reduction/oxidation procedure.4.1.1 For any sample type,especially those containing largeamounts of impurities,ferrous sulfate may be used for reduc-tion.The sample is diluted in 1 M nitric acid(HNO3).Ferroussulfate is added to reduce all pluton