ASTM_C_1237_-_99_2005.pdf

Designation:C 1237 99(Reapproved 2005)Standard Guide toIn-Plant Performance Evaluation of Hand-Held SNMMonitors1This standard is issued under the fixed designation C 1237;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide is one of a series on the application andevaluation of special nuclear material(SNM)monitors.Otherguides in the series are listed in Section 2,and the relationshipof in-plant performance evaluation to other procedures de-scribed in the series is illustrated in Fig.1.Hand-held SNMmonitors are described in of Guide C 1112,and performancecriteria illustrating their capabilities can be found in AppendixX1.1.2 The purpose of this guide to in-plant performanceevaluation is to provide a comparatively rapid procedure toverify that a hand-held SNM monitor performs as expected fordetecting SNM or alternative test sources or to disclose theneed for repair.The procedure can be used as a routineoperational evaluation or it can be used to verify performanceafter a monitor is calibrated.1.3 In-plant performance evaluations are more comprehen-sive than daily functional tests.They take place less often,atintervals ranging from weekly to once every three months,andderive their result from multiple trials.1.4 Note that the performance of both the hand-held monitorand its operator are important for effective monitoring.Opera-tor training is discussed in Appendix X2.1.5 The values stated in SI units are to be regarded asstandard.1.6 This standard does not purport to address all of thesafety problems,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 The guide is based on ASTM standards that describeapplication and evaluation of SNM monitors,as well astechnical publications that describe aspects of SNM monitor-ing.2.2 ASTM Standards:2C 859 Terminology Relating to Nuclear MaterialsC 1112 Guide for Application of Radiation Monitors to theControl and Physical Security of Special Nuclear MaterialC 1189 Guide to Procedures for Calibrating AutomaticPedestrian SNM Monitors1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommittee C26.12 on SafeguardApplications.Current edition approved June 1,2005.Published November 2005.Originallyapproved in 1999.Last previous edition approved in 1999 as C 123799.2For 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.NOTE1The procedures shown“above”the user provide the user withinformation before acquiring a monitor,and those“below”assist the userto obtain continuing acceptable performance from the monitor.FIG.1 The Relationship of In-plant Evaluation to OtherProcedures Described in Guides for SNM Monitors1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.Copyright by ASTM Intl(all rights reserved);Thu Apr 16 08:43:16 EDT 2009Downloaded/printed byLaurentian University pursuant to License Agreement.No further reproductions authorized.3.Terminology3.1 Definitions:3.1.1 alarmthe audible sound made by a hand-held SNMmonitor to indicate that it has detected radiation intensity at orabove the alarm threshold.3.1.1.1 DiscussionOne or more closely spaced alarmsmay be chosen to signify detection of SNM.3.1.2 alternative test sourceAlthough no other radioactivematerials individually or collectively duplicate the radioactiveemissions of uranium or plutonium,some materials havesimilar attributes and are sometimes used as alternative testsources.3.1.2.1 alternative gamma-ray test sourcesExamples ofalternative gamma-ray sources are highly enriched uranium(HEU)or133Ba used in place of plutonium when a plutoniumsource is not readily available or is prohibited.3.1.2.2 DiscussionTable 1 tabulates amounts of HEUmass,plutonium mass,and133Ba source activity that produceequal response in two different types of monitor.3.1.2.3 alternative neutron test sourceA common alterna-tive neutron source used in place of plutonium is252Cf,whichemits neutrons from spontaneous fission as does plutonium.3.1.2.4 DiscussionAlternative test sources may have shortdecay half-lives in comparison to SNM isotopes,for examplethe half-life of133Ba is 10.7 years and252Cf 2.64 years.Largersource activities than initially needed are often purchased toobtain a longer working lifetime for the source.3.1.3 confidence coeffcientthe approximate percentage ofconfidence intervals from a large nu