ASTM_C_1001_-_11.pdf

Designation:C100111Standard Test Method forRadiochemical Determination of Plutonium in Soil by AlphaSpectroscopy1This standard is issued under the fixed designation C1001;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 plutoniumin soils at levels of detection dependent on count time,samplesize,detector,background,and tracer yield.This test methoddescribes one acceptable approach to the determination ofplutonium in soil.1.2 This test method is designed for 10 g of soil,previouslycollected and treated as described in Practices C998 and C999,but sample sizes up to 50 g may be analyzed by this testmethod.This test method may not be able to completelydissolve all forms of plutonium in the soil matrix.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.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.Specific hazardstatements are given in Section 9.2.Referenced Documents2.1 ASTM Standards:2C859 Terminology Relating to Nuclear MaterialsC998 Practice for Sampling Surface Soil for RadionuclidesC999 Practice for Soil Sample Preparation for the Determi-nation of RadionuclidesC1163 Practice for Mounting Actinides for Alpha Spectrom-etry Using Neodymium FluorideC1284 Practice for Electrodeposition of the Actinides forAlpha SpectrometryD1193 Specification for Reagent WaterD3084 Practice for Alpha-Particle Spectrometry of WaterD3648 Practices for the Measurement of RadioactivityD7282 Practice for Set-up,Calibration,and Quality Controlof Instruments Used for Radioactivity Measurements3.Summary of Test Method3.1 Plutonium is extracted from the soil with a mixture ofnitric,hydrofluoric,and hydrochloric acids in the presence of242Pu or236Pu isotopic tracer(See Appendix for purificationand standardization of236Pu tracer).Plutonium is isolated byanion exchange,then electrodeposited onto a polished metaldisk for determination by alpha spectrometry.As an option,theplutonium may be prepared for alpha spectrometry measure-ment by using coprecipitation with neodymium fluoride.Therange of chemical yield is between 40 and 90%.The testmethod is based on a published procedure(1).34.Significance and Use4.1 A soil sampling and analysis program provides a directmeans of determining the concentration and distribution ofradionuclides in soil.A soil analysis program has the mostsignificance for the preoperational monitoring program toestablish baseline concentrations prior to the operation of anuclear facility.Soil analysis,although useful in special casesinvolving unexpected releases,is a poor technique for assess-ing small incremental releases and is therefore not recom-mended as a method for routine monitoring releases ofradioactive material.Nevertheless,because soil is an integratorand a reservoir of long-lived radionuclides,and serves as anintermediary in several of the plutonium pathways of potentialimportance to humans,knowledge of the concentration ofplutonium in soil is essential.5.Apparatus5.1 Electrodeposition Apparatus(2),see Practice C1284.5.2 Alpha Spectrometer,capable of 40 to 50 keV resolutionon actual samples electrodeposited on a flat,mirror-finishedmetal planchet,and a fractional counting efficiency greaterthan 17%,and a background less than 0.010 cpm over each1This 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 Feb.15,2011.Published February 2011.Originallyapproved in 1983.Last previous edition approved in 2005 as C1001 05.DOI:10.1520/C1001-11.2For 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 boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 designated energy region.Resolution is defined as the fullwidth half maximum(FWHM)in keV,the distance betweenthose points on either side of the alpha peak where the count isequal to one-half the maximum count.Also see PracticesD3084 and D3648.NOTE1A regular program of measurement control operations shouldbe conducted for the alpha spectrometry system,such as regular back-ground checks,source check to determine system stability,contr