ASTM_C_1236_-_99_2005.pdf

Designation:C 1236 99(Reapproved 2005)Standard Guide forIn-Plant Performance Evaluation of Automatic Vehicle SNMMonitors1This standard is issued under the fixed designation C 1236;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 special nuclear material(SNM)monitors and their performance evaluation.Others inthe series provide information on SNM monitoring,monitorcalibration,and methods of evaluation(see 1.3),but GuideC 993,in particular,provides much of the basis for this guide.The purpose for a guide to in-plant performance evaluation isto provide a comparatively rapid way to verify whether SNMmonitors perform as expected for detecting SNM or analternative test source.1.2 Guide C 993 points out that in-plant evaluation is onepart of a program to keep SNM monitors in proper operatingcondition and that in-plant evaluation can be used as a routineoperational evaluation or can be used to verify performanceafter a monitor is calibrated.1.3 This guide is based on ASTM standards that describeapplying and evaluating SNM monitors.2.Referenced Documents2.1 ASTM Standards:2C 993 Guide for In-Plant Performance Evaluation of Auto-matic Pedestrian SNM MonitorsC 1112 Guide for Application of Radiation Monitors to theControl and Physical Security of Special Nuclear MaterialC 1189 Guide to Procedures for Calibrating AutomaticPedestrian SNM Monitors3.Terminology3.1 Definitions:3.1.1 vehicle monitoring stationa type of vehicle SNMmonitor that monitors vehicles while they are stopped,await-ing clearance at an entry/exit station.3.1.1.1 DiscussionThese monitors are described in 5.3.2of Guide C 1112.3.1.2 vehicle portal monitoran automatic vehicle SNMmonitor that monitors moving vehicles as they pass throughradiation detectors during their approach to an entry/exitstation.3.1.2.1 DiscussionThese monitors are described in 5.3.1of Guide C 1112.3.2 Terminology for confidence coefficient,confidence in-terval,detection probability,evaluations,nuisance alarm,SNM,SNM monitor,and test sources is defined or described inSection 3 of Guide C 993.4.Summary of Guide4.1 The monitor to be evaluated is a vehicle SNM portalmonitor(see 3.1.1)or a vehicle SNM monitoring station(see3.1.2).4.2 As a first step,the monitors indicated backgroundmeasurement value is recorded for possible future use introubleshooting.4.3 If the monitor is being evaluated in routine operation,the number of nuisance alarms since the last evaluation isexamined for evidence of possible misoperation.4.4 The detection probability for a test source is evaluatedby repeatedly transporting a test source through the monitor.4.5 The results of the evaluation are analyzed and recorded.5.Significance and Use5.1 SNM monitors are an effective and unobtrusive meansto search for concealed SNM,and facility security plans usethem to prevent SNM theft or unauthorized removal from SNMaccess areas.Functional testing of monitors on a daily basiswith radioactive sources can assure that they are in goodworking order.The significant use of a less frequent,in-plantevaluation of an SNM monitor is to verify that the monitor1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommittee C26.05 on Methods of Tests.Current edition approved June 1,2005.Published October 2005.Originallyapproved in 1993.Last previous edition approved in 1999 as C 1236-99.2For 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.1Copyright 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.achieves an expected probability of detection for an SNM oralternative test source.NOTE1An SNM test source used for in-plant evaluation is normallyshielded only by protective encapsulation and the parts of a vehicle thatmay lie between the source and the monitors detectors.However,theevaluation procedure could just as well be used to verify an expected levelof detection for SNM inside of containers or shields.6.Apparatus6.1 Gamma-RaySurveyMeter(NonmandatoryInformation)Historical records of gamma-ray backgroundintensity may provide useful information for troubleshootingfuture monitoring problems.An evaluation offers a goodopportunity to record both the monitors indicated backgroundcount and the gamma-ray background intensity.If desired,gamma-ray intensity can be measured with a survey meter an