ASTM C1514-2008 用同位素浓缩度计原理测定铀235微粒的标准试验方法

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【英文标准名称】:StandardTestMethodforMeasurementof235UFractionUsingEnrichmentMeterPrinciple
【原文标准名称】:用同位素浓缩度计原理测定铀235微粒的标准试验方法
【标准号】:ASTMC1514-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C26.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:enrichment;UF6;uranium,Calibration--nuclearanalysisinstrumentation;Enrichmentmeterprinciple;Lowresolutiondetector;Nondestructiveevaluation(NDE)--nuclearapplications;Uranium-235
【摘要】:Theenrichmentmeterprincipleprovidesanondestructivemeasurementofthe235Ufractionofuranium-bearingitems.Samplingisnotrequiredandnowasteisgenerated,minimizingexposuretohazardousmaterialsandresultinginreducedsamplingerror.Thismethodreliesonafixedandcontrolledgeometry.Theuranium-bearingmaterialsinthemeasureditemsandcalibrationreferencematerialsusedforcalibrationmustfillthedetectorfieldofview.Useofalowresolutiondetector(forexample,NaIdetector)tomeasureuraniumwith235Ufractionapproximately10%whichiscontainedinathin-walledcontainercanprovidearapid(typically100s),easilyportablemeasurementsystemwithprecisionof0.6%andbiasoflessthan1%.Useofahighresolutiondetector(forexample,high-puritygermanium)canprovidemeasurementwithaprecisionbetterthan0.2%andabiaslessthan1%withina300-smeasurementtimewhenmeasuringuraniumwith235Ufractionintherangeof0.711%orabovewhichiscontainedinthin-walledcontainers.Inordertoobtainoptimumresultsusingthismethod,thechemicalcompositionoftheitemmustbewellknown,thecontainerwallmustpermittransmissionofthe185.7keVgamma-ray,andtheuranium-bearingmaterialwithintheitemmustbeinfinitelythickwithrespecttothe185.7keVgamma-ray.Allitemsmustbeinidenticalcontainersormusthaveaknowncontainerwallthicknessandcomposition.Itemstobemeasuredmustbehomogeneouswithrespecttoboth235Ufractionandchemicalcomposition.Whenmeasuringitems,usinglow-resolutiondetectors,inthin-walledcontainersthathavenotreachedsecularequilibrium(morethanabout120daysafterprocessing),eitherthemethodshouldnotbeused,additionalcorrectionsshouldbemadetoaccountfortheageoftheuranium,orhigh-resolutionmeasurementsshouldbeperformed.Themethodisoftenusedasaenrichmentverificationtechnique.1.1Thistestmethodcoversthequantitativedeterminationofthefractionof235Uinuraniumusingmeasurementofthe185.7keVgamma-rayproducedduringthedecayof235U.1.2Thistestmethodisapplicabletoitemscontaininghomogeneousuranium-bearingmaterialsofknownchemicalcompositioninwhichthecompoundisconsideredinfinitelythickwithrespectto185.7keVgamma-rays.1.3Thistestmethodcanbeusedfortheentirerangeof235Ufractionasaweightpercent,fromdepleted(0.2%235U)tohighlyenriched(97.5%235U).1.4Measurementofitemsthathavenotreachedsecularequilibriumbetween238Uand234Thmaynotproducethestatedbiaswhenlow-resolutiondetectorsareusedwiththecomputationalmethodlistedinAnnexA2.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thisstandardmayinvolvehazardousmaterials,operations,andequipment.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:F46
【国际标准分类号】:
【页数】:8P.;A4
【正文语种】:英语