1、Designation:C151408(Reapproved 2017)Standard Test Method forMeasurement of235U Fraction Using Enrichment MeterPrinciple1This standard is issued under the fixed designation C1514;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the yea
2、r 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 quantitative determinationof the fraction of235U in uranium using measurement of the185.7
3、keV gamma-ray produced during the decay of235U.1.2 This test method is applicable to items containinghomogeneous uranium-bearing materials of known chemicalcomposition in which the compound is considered infinitelythick with respect to 185.7 keV gamma-rays.1.3 This test method can be used for the en
4、tire range of235Ufraction as a weight percent,from depleted(0.2%235U)tohighly enriched(97.5%235U).1.4 Measurement of items that have not reached secularequilibrium between238U and234Th may not produce thestated bias when low-resolution detectors are used with thecomputational method listed in Annex
5、A2.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This standard may involve hazardous materials,operations,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.I
6、t is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C1030 Test Method for Determination of Plutonium IsotopicComposition by Gamma-Ray
7、 SpectrometryC1490 Guide for the Selection,Training and Qualification ofNondestructive Assay(NDA)PersonnelC1592 Guide for Nondestructive Assay MeasurementsC26.10 Terminology Guide2.2 ANSI Standard:N42.14 Calibration and Use of Germanium Spectrometersfor the Measurement of Gamma-Ray Emission Rates of
8、Radionuclides33.Terminology3.1 For definitions of terms used in this test method,refer toTerminology C26.10.4.Summary of Test Method4.1 The test method consists of measuring the emission rateof 185.7 keV gamma-rays from an item in a controlledgeometry and correlating that emission rate with the enri
9、ch-ment of the uranium contained in the item.4.2 Calibration is achieved using reference materials ofknown enrichment.Corrections are made for attenuating ma-terials present between the uranium-bearing material and thedetector and for chemical compounds different from thecalibration reference materi
10、als used for calibration.4.3 The measured items must completely fill the field ofview of the detector,and must contain a uranium-bearingmaterial which is infinitely thick with respect to the 185.7 keVgamma-ray.If the field of view is not filled,a correction factormust be applied.5.Significance and U
11、se5.1 The enrichment meter principle provides a nondestruc-tive measurement of the235U fraction of uranium-bearingitems.Sampling is not required and no waste is generated,minimizing exposure to hazardous materials and resulting inreduced sampling error.5.2 This method relies on a fixed and controlle
12、d geometry.The uranium-bearing materials in the measured items andcalibration reference materials used for calibration must fill thedetector field of view.1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.10 on
13、NonDestructive Assay.Current edition approved Jan.1,2017.Published January 2017.Originallyapproved in 2002.Last previous edition approved in 2008 as C1514 08.DOI:10.1520/C1514-08R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.
14、For Annual Book of ASTMStandards volume 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,
15、West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Tr
16、ade Organization Technical Barriers to Trade(TBT)Committee.1 5.3 Use of a low resolution detector(for example,NaIdetector)to measure uranium with235U fraction approximately10%which is contained in a thin-walled container can providea rapid(typically 100 s),easily portable measurement systemwith precision of 0.6%and bias of less than 1%.5.4 Use of a high resolution detector(for example,high-purity germanium)can provide measurement with a precisionbetter than 0.2%and a bias less than 1%within a 30
