1、Designation:C170308(Reapproved 2013)Standard Practice forSampling of Gaseous Uranium Hexafluoride1This standard is issued under the fixed designation C1703;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A n
2、umber 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 covers methods for withdrawing represen-tative sample(s)of uranium hexafluoride(UF6)during atransfer occurring in the gas phas
3、e.Such transfer in the gasphase can take place from a mother cylinder,for example in anautoclave to a receiving cylinder.It can also occur during thefilling in the gas phase of a cylinder during a continuousproduction process,for example centrifuge enrichment facilityor the distillation column in a
4、conversion facility.Suchsample(s)may be used for determining compliance with theapplicable commercial specification,for example SpecificationC996 or Specification C787.1.2 Since UF6sampling is taken during the filling process,this practice does not address any special additional arrange-ments that m
5、ay be agreed upon between the buyer and theseller when the sampled bulk material is being added toresidues already present in a container(“heels recycle”).Sucharrangements will be based on QA procedures such as trace-ability of cylinder origin(to prevent for example contaminationwith irradiated mate
6、rial).1.3 If the receiving cylinder is purged after filling andsampling,special verifications must be performed by the userto verify the representativity of the sample(s).It is thenexpected that the results found on volatile impurities with gasphase sampling may be conservative.1.4 This practice is
7、only applicable when the transfer occursin the gas phase.When the transfer is performed in the liquidphase,Practice C1052 should apply.This practice does notapply to gas sampling after the cylinder has been filled sincethe sample taken will not be representative of the cylinder.1.5 The scope of this
8、 practice does not include provisionsfor preventing criticality incidents.1.6 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 th
9、e applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C761 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofUranium HexafluorideC787 Specification for Uranium Hexafluoride for Enrich-mentC996 Specification f
10、or Uranium Hexafluoride Enriched toLess Than 5%235UC1052 Practice for Bulk Sampling of Liquid UraniumHexafluoride2.2 Other Document:ISO/DIS 7195 Packaging of Uranium Hexafluoride(UF6)for Transport33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 containera vessel either holding
11、or receiving bytransfer,the UF6to be sampled;it may consist of,for example,a fixed vessel in a UF6handling plant or a cylinder to be usedfor the transport of UF6.3.1.2 sample vesselthe small vessel into which the sampleof UF6is withdrawn for analysis in the laboratory for charac-terization.It can be
12、 a 1S or 2S bottle or a PCTFE(polydifluorodichloroethylene)/PTFE(polytetrafluoroethyl-ene)pot or tube or any other type of cylinder compatible withUF6.4.Summary of Practices4.1 Two methods of withdrawing gas UF6for sampling arepossible,namely:(1)continuous withdrawal using for examplea capillary and
13、 producing only one sample,or(2)sequentialwithdrawals producing a composite sample.Depending on the1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.02 on Fuel andFertile Material Specifications.Current edition ap
14、proved Jan.1,2013.Published January 2013.Originallyapproved in 2008.Last previous edition approved in 2008 as C1703 08.DOI:10.1520/C1703-08R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume
15、 information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United
16、States1 pressure and temperature conditions during the transfer,thesampled UF6is either liquefied or solidified in the samplevessel.4.2 An example of(1)is the sampling of UF6coming froma distillation column.In such case,the sampled gas UF6can becondensed in the liquid phase in the sampling vessel.Therepresentative sample is then homogenized before analysis atthe laboratory.It is assumed that the flow rate from thedistillation is either constant(for example using a mass flowcontroller)or that the
