ASTM_C_1507_-_12.pdf

Designation:C150712Standard Test Method forRadiochemical Determination of Strontium-90 in Soil1This standard is issued under the fixed designation C1507;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 is applicable to the determination ofstrontium-90 in soil at levels of detection dependent on counttime,sample size,detector efficiency,background,and chemi-cal yield.1.2 This test method is designed for the analysis of tengrams of soil,previously collected and treated as described inPractices C998 and C999.This test method may not be able tocompletely dissolve all soil matrices.The values stated in SIunits are to be regarded as the standard.1.3 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:2C859 Terminology Relating to Nuclear MaterialsC998 Practice for Sampling Surface Soil for RadionuclidesC999 Practice for Soil Sample Preparation for the Determi-nation of RadionuclidesD1193 Specification for Reagent WaterD7282 Practice for Set-up,Calibration,and Quality Controlof Instruments Used for Radioactivity Measurements3.Terminology3.1 For definitions of terms used in this standard,refer toTerminology C859.4.Summary of Test Method4.1 Strontium is extracted from soil with a mixture of nitric,hydrochloric,and hydrofluoric acids in the presence of stron-tium carrier.Strontium is isolated by extraction chromatogra-phy and evaporated on a planchet for recovery determinationand subsequent beta counting.This test method describes oneof the possible approaches to determine strontium-90 in soil.The chemical yield is typically 95%with a detection limit ofabout 0.004 Bq/g for a ten gram sample.5.Significance and Use5.1 Because soil is an integrator and a reservoir of long-lived radionuclides,and serves as an intermediary in severalpathways of potential exposure to humans,knowledge of theconcentration of strontium-90 in soil is essential.A soilsampling and analysis program provides a direct means ofdetermining the concentration and distribution of radionuclidesin soil.A soil analysis program has the most significance forthe preoperational monitoring program to establish baselineconcentrations prior to the operation of a nuclear facility.Soilanalysis,although useful in special cases involving unexpectedreleases,may not be able to assess small incremental releases.6.Interferences6.1 The presence of strontium-89 in the sample may bias thereported strontium-90 results using this method.6.2 Large concentrations of strontium,calcium,barium,orlead in the soil sample could interfere with the extractionchromatographic separation by loading the column with theseelements.Section 12.1 discusses procedures for accounting forthe stable strontium.6.3 The final strontium form is a nitrate salt and it ishygroscopic.Care must be taken when determining the mass ofthe final precipitate to avoid mass fluctuations and changes inphysical form or self-absorption due to water absorption fromthe atmosphere.7.Apparatus7.1 Beta Particle CounterA shielded low-backgroundproportional detector with appropriate electronics and compu-tational capabilities to control operations.The efficiency of thesystem should be greater than 35 percent for strontium-90 witha background of less than a few counts per minute.PracticeD7282 may contain other useful information on the set-up,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 1,2012.Published June 2012.Originallyapproved in 2001.Last previous edition approved in 2007 as C1507 07E01.DOI:10.1520/C1507-12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 calibration,and usage of such instrumentation.The measure-ment of strontium-90 and yttrium-90 can also be conducted byliquid scintillation spectrometry provided equivalency is dem-onstrated.7.2 Counting DishesTypically,50 mm diameter,6 mmdeep,stainless steel counting dishes,although other sizes maybe used that are compatible with the measurement instrumen-tation.7.3 Heat Lamp.7.4 Muffle Furnace.7.5 Whatman#2 Filter Paper or equivalent.7.6 Borosilicate Glass Erlenmeyers Flasks and Beakers.7.7 PTFE Beakers.7.8