1、Designation:C1455141Standard Test Method forNondestructive Assay of Special Nuclear Material HoldupUsing Gamma-Ray Spectroscopic Methods1This standard is issued under the fixed designation C1455;the number immediately following the designation indicates the year oforiginal adoption or,in the case of
2、 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.1NOTE10.4.1.1 editorially corrected in July 2015.1.Scope1.1 This test method describes gamma-ray methods used to
3、nondestructively measure the quantity of235U or239Pu presentas holdup in nuclear facilities.Holdup may occur in anyfacility where nuclear material is processed,in processequipment,in exhaust ventilation systems and in building wallsand floors.1.2 This test method includes information useful formanag
4、ement,planning,selection of equipment,considerationof interferences,measurement program definition,and theutilization of resources(1,2,3,4).21.3 The measurement of nuclear material hold up in processequipment requires a scientific knowledge of radiation sourcesand detectors,transmission of radiation
5、,calibration,facilityoperations and uncertainty analysis.It is subject to the con-straints of the facility,management,budget,and schedule;plushealth and safety requirements.The measurement processincludes defining measurement uncertainties and is sensitive tothe form and distribution of the material
6、,various backgrounds,and interferences.The work includes investigation of materialdistributions within a facility,which could include potentiallylarge holdup surface areas.Nuclear material held up in pipes,ductwork,gloveboxes,and heavy equipment,is usually dis-tributed in a diffuse and irregular man
7、ner.It is difficult to definethe measurement geometry,to identify the form of the material,and to measure it without interference from adjacent sources ofradiation.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the us
8、er 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:3C1490 Guide for the Selection,Training and Qualification ofNondestructive Assay(NDA)PersonnelC1592 Guide for Non
9、destructive Assay MeasurementsC1673 Terminology of C26.10 Nondestructive Assay Meth-ods2.2 ANSI Standards:4ANSIN15.36 MeasurementControlProgramNondestructive Assay Measurement Control and Assur-ance SystemsANSI N15.56 Nondestructive Assay Measurements ofNuclear Material Holdup:General Provisions2.3
10、U.S.Nuclear Regulatory Commission RegulatoryGuides:5Regulatory Guide 5.23,In SituAssay of Plutonium ResidualHoldup3.Terminology3.1 Refer to Terminology C1673 for definitions used in thistest method.4.Summary of Test Method4.1 IntroductionHoldup measurements range from thesolitary assay of a single i
11、tem or routine measurement of apiece of equipment,to an extensive campaign of determiningthe total SNM in-process inventory for a processing plant.Holdup measurements differ from other nondestructive mea-surement methods in that the assays are performed in situ onequipment or items instead of on mul
12、tiple items with similarcharacteristics measured in a specialized,isolated room.Oftenthe chemical form and geometric distribution of the SNM are1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.10 on NonDestruct
13、ive Assay.Current edition approved Jan.1,2014.Published March 2014.Originallyapproved in 2000.Last previous edition approved in 2007 as C1455 07.DOI:10.1520/C1455-14E01.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards,visi
14、t 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.4Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036
15、,http:/www.ansi.org.5Available from the U.S.Nuclear Regulatory Commission,Washington,DC,20555.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 not well known.These challenges require unique preparationfor every measurement to obtain a qual
16、ity result.Unknownmeasurement parameters can lead to large measurement uncer-tainties.4.2 Definition of RequirementsDefinition of the holdupmeasurement requirements should include,as a minimum,themeasurement objectives(that is,criticality control,SNMaccountability,safety,or combinations thereof);the desiredmeasurement sensitivity,measurement uncertainty,and avail-able resources(schedule,funds,and subject matter experts).The customer,the measurement organization,and appropriateregulatory authorit
