ASTM_D_7362_-_14.pdf

Designation:D736214Standard Guide forRapid Screening of Vegetation for Radioactive StrontiumAerial Deposition1This standard is issued under the fixed designation D7362;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 guide provides a rapid procedure by which vegeta-tion samples may be screened for surface contamination ofradioactive strontium(89Sr and90Sr,collectively referred to asradiostrontium)following an airborne radioactive dispersalevent.It provides a conservative estimate of radiostrontiumdeposition that can be used by decision makers for immediateactions prior to obtaining definitive results from a fixedlaboratory asset.1.2 Insoluble forms of radiostrontium,such as the strontium(90Sr)titanate(SrTiO3)used in radio-isotope thermal-electricgenerators(RTGs),will not be measured by this method.1.3 Non-SI units are used in the calculations of this guidefor ease of use during the emergency phase of an event.Theinstrumentation used typically provides count rates in countsper minute(cpm)rather than per second(s1,the SI unit),thusactivity is expressed in dpm(decays per minute)rather thanBq.Additionally,US EPA protective guidelines for surfacecontamination are expressed in dpm/100 cm2.1.4 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:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD3648 Practices for the Measurement of Radioactivity2.2 Other Documents:EPA Protective Action Guidelines33.Terminology3.1 DefinitionsSee Terminology D1129 for terms relatedto water.3.2 Definitions of Terms Specific to This Standard:3.2.1 ROI,nregion of interest;the span of channels,orregion,in the spectrum in which the counts due to a specificradioisotope appear on a functioning,calibrated liquid scintil-lation spectrometry system.3.3 Acronyms:3.3.1 RLS,nrapid liquid sampler3.3.2 SPE,nsolid phase extraction4.Summary of Guide4.1 Vegetation is collected from an area equivalent to 100cm2.The leafy material is shaken with pH=2 water tosolubilize radiostrontium deposited on the vegetation.Theradiostrontium is then extracted onto a solid phase extraction(SPE)disk for counting and quantification.4.2 Testing has shown that chemical recoveries for90Srunder these extraction conditions average 3050%,withsimilar recoveries expected for89Sr.4.3 Acounting efficiency of 8085%can be achieved usingliquid scintillation spectrometry.4.4 Quantification may also be accomplished using a simplegas-filled count rate meter(a“pancake probe”);however thepresence of other beta-emitting radionuclides can not bediscerned when using such a non-discriminatory detector.5.Significance and Use5.1 Strontium-90 is a major component of nuclear waste andis also a potential radioisotope for use as a weapon of massdestruction in a radiological dispersal device.It is a beta-emitting radioisotope with moderate half-life(30 years).1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.04 on Methods of RadiochemicalAnalysis.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 2007.Last previous edition approved in 2007 as D7362 07.DOI:10.1520/D7362-14.2For 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 United States Environmental Protection Agency(EPA),ArielRios Bldg.,1200 Pennsylvania Ave.,NW,Washington,DC 20460,http:/www.epa.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Strontium-89 is also a beta emitting radionuclide,but with ahalf-life of only 50 days it is not usually present in significantquantities.If ingested the radiostrontium may deposit in thebone of an individual and thus can contribute a significantradiological dose to an affected person.5.2 Following an explosion in which radioactive materialwas present,the potential exists for the material to becomeairborne.It will quickly attach to atmospheric particles and bedeposited on surfaces as the plume passes.This guide providesa rapid procedure by which vegetation can be screened todetermine if radiostrontium is present and to provide a conser-vative estimate of its deposition on vegetation.5.3 This guide is intended to be used in a field portable lab,or if needed,can be performed completely in the field;therefore no