ASTM_D_3454_-_11.pdf

Designation:D345411Standard Test Method forRadium-226 in Water1This standard is issued under the fixed designation D3454;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 measurement of soluble,suspended,and total radium-226 in water in concentrationsabove 3.7 103Bq/L.This test method is not applicable tothe measurement of other radium isotopes.1.2 This test method may be used for quantitative measure-ments by calibrating with a radium-226 standard,or for relativemeasurements by comparing the measurements made witheach other.1.3 This test method does not meet the current requirementsof Practice D2777.1.4 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.5 Hydrofluoric acid(HF)is very hazardous and should beused in a well-ventilated hood.Wear rubber gloves,safetyglasses or goggles,and a laboratory coat.Avoid breathing anyHF fumes.Clean up all spills promptly and wash thoroughlyafter using HF.1.6This standard does not purport to address all of theother safety 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:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3648 Practices for the Measurement of RadioactivityD3649 Practice for High-Resolution Gamma-Ray Spectrom-etry of WaterD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis of WaterD4448 Guide for Sampling Ground-Water Monitoring WellsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6001 Guide for Direct-Push Groundwater Sampling forEnvironmental Site CharacterizationD7282 Practice for Set-up,Calibration,and Quality Controlof Instruments Used for Radioactivity Measurements3.Terminology3.1 For definitions of terms used in this test method,refer toTerminology D1129.For terms not defined in this test methodor in Terminology D1129,reference may be made to otherpublished glossaries.4.Summary of Test Method4.1 This test method3is based on the emanation andscintillation counting of222Rn,a gaseous daughter productof226Ra,from a solution.4.2226Ra is collected from water by coprecipitation on arelatively large amount of barium sulfate.The barium-radiumsulfate is decomposed by fuming with phosphoric acid,and theresulting glassy melt is dissolved by evaporation with dilutehydrochloric acid to form soluble barium-radium phosphatesand chlorides.These salts are dissolved and the solution isstored for ingrowth of222Rn.After a suitable ingrowth period,the radon gas is removed from the solution by purging with gasand transferred to a scintillation counting chamber.About 4 hafter222Rn collection,the scintillation chamber is counted foralpha activity.The226Ra concentration is calculated from thealpha count rate of222Rn and its immediate daughters.Theradioactive decay characteristics of226Ra and its immediatedecay progeny are listed in Table 1.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-cal Analysis.Current edition approved June 15,2011.Published July 2011.Originallyapproved in 1975.Last previous edition approved in 2005 as D3454 05.DOI:10.1520/D3454-11.2For 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.3This test method is based on a previously published method by Rushing,D.E.,Garcia,W.J.,and Clark,D.A.“The Analysis of Effluents and EnvironmentalSamples from Uranium Mills and of Biological Samples for Radium,Polonium andUranium,”Radiological Health and Safety in Mining and Milling of NuclearMaterials,Vol.II,IAEA,Vienna,Austria,1964),p.187.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 The most prevalent of the five radium isotopes in groundwater,having a half life greater than one day,are226Ra and228Ra.These two isotopes also present the greatest health riskcompared to the other naturally occurring nuclides of equalconcentrations if ingested via the water pathway.5.2 Although primarily utilized on a water medium,thistechnique may be applicable for the measurement of the226Racontent of any