RADIATION SAFETY MANUAL辐射安全手册英 文版.docx

RADIATION SAFETY MANUAL辐射安全手册英 文版.docx

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RADIATIONSAFETYMANUAL辐射安全手册英文版

RADIATIONSAFETYMANUAL

Revision6.16June2014

Contents

Page

Introduction3

1General4

2NormalOperatingProcedures5

2.1BasicPrinciplesofControl5

2.2GeneralProceduresforWorkingwithRadioactiveMaterials5

2.3MethodsofProtection5

2.3.1TheExternalRadiationHazard6

2.3.2TheInternalRadiationHazard7

2.4ProcedurefortheProcurementandUseofRadioactive8

2.5ScanningElectronMicroscopes–MSTDepartment9

2.6PHILIPSX-RayDiffractionSpectroscope–MSTandCESDept.9

2.7DualEnergyX-RayAbsorptiometerDXA10

2.8SealedRadioactiveSources–PhysicsDepartment10

2.9UnsealedRadioactiveSources–CESDept.11

2.10SecurityandSafetyofLicensedItems12

3EmergencyOperatingProcedures13

3.1PersonalContamination13

3.2EmergencyContactDetails（outofhours）13

4MonitoringforRadiationandContamination14

4.1MonitoringtheWorkplace14

4.2PersonalRadiationMonitoring14

4.3PortableRadiationMonitoringEquipment15

4.4PortableSurfaceContaminationMonitoringEquipment15

4.5WipeTestingofSealedSources15

4.6MaintenanceProceduresfortheIrradiatingEquipment16

4.7MonitoringofI-125Contamination16

4.8Wipe-testingofSealedI-129Source18

4.9StorageanddisposalofRadioactiveWaste19

I-125LaboratorySafetyPoster21

5RadiologicalProtectionAdministration22

5.1RoleoftheHeadsofDepartment22

5.2RoleoftheRadiologicalProtectionAdvisor22

5.3RoleoftheRadiologicalProtectionOfficer22

5.4RoleoftheDepartmentalRadiologicalProtectionSupervisors22

5.5AdministrationforRadiologicalProtectionattheUniversityofLimerick23

6InterventionPlanandEmergencyPlanforRadiologicalAccidents

6.1Introduction26

6.2Purposeofplan26

6.3Organisationalstructureandresponsibilities26

6.4Teamresponsibilities29

6.5CrisisscenariosinvolvingradioactivesourcesorX-rayapparatus30

6.6Calloutprocedures32

References33

Tables

Table1Maintypesofionisingradiation’sandtheirhazards

Introduction

TheStatutoryrequirementsfortheprotectionofworkersandgeneralpublicagainstthedangerofradiationarebasedonthefollowingthreefundamentalprinciples:

-

（a）everyactivityresultinginanexposuretoionisingradiationshallbejustifiedbytheadvantageswhichitproduces;

（b）allexposuresshallbeaslowasreasonablyachievable（theALARAprinciple）;

（c）thedoseequivalenttoindividualsshallnotexceedtheprescribedlimits.

Forthepurposesofthismanualradioactivematerialscanbeclassifiedintotwogroups-unsealeddispersibleradioactivematerialandsealedsources.Thefollowingdefinitionsapply:

-

（a）aradioactivesubstanceisanysubstancewhichissuspectedtohaveanactivityconcentrationgreaterthanthevaluestatedinSI125of2000;

（b）asealedsourceisaradioactivematerialwhollybondedwithinasolidinactivematerialorencapsulatedinareceptaclesothatnoleakagecanoccurduringstorageorforeseeableconditionsofuse（RefertoISO2919）;

（c）unsealeddispersibleradioactivematerialisradioactivematerialnotconsideredtobeasealedsource.

Workwithradioactivesubstancesisperhapsmorestringentlycontrolledthansomeaspectsofchemicalresearch,andthisisreflectedinIrishlegislationforthehandlingofradioactivematerials.

Section1

1.General

1.1TheUniversityofLimerickacademicDepartmentsshallcomplywiththeconditionsoftheRPIILicenseinthecontrolanduseofradioactivesubstancesandirradiatingapparatus.

1.2TheRadiationSafetyManualisfortheuseandguidanceofallUniversitystaffforwhomitisrelevant.TheprovisionsoftheRadiationSafetyManualaretosupplementtherequirementsoftheRPIILicenceandshallbeobservedinfull.

Section2

2NormalOperatingProcedures

2.1BasicPrinciplesofControl

Therearethreemainprinciplesofcontrolagainsttheinternalradiationhazard:

（a）containment;

（b）cleanliness;

（c）useoftheleasttoxicradioactivematerialthatissuitable,andtheminimumquantitiesinallexperiments.

Thetwomethodsofcontainmentofoperationsmostwidelyusedarepartialcontainmentbymeansoffumecupboards,andcompletecontainmentbymeansofgloveboxes.

2.2GeneralProceduresforWorkingwithRadioactiveMaterials

Thefollowingworkingpracticesandproceduresshouldbeadopted:

（a）thelaboratorybenchshouldbemaintainedinatidyandorderlystate;

（b）thereshouldbenounnecessaryaccumulationofradioactivematerials;

（c）anysurfacecontaminationarisingduringanoperationshouldbecleaned-upimmediately;

2.3MethodsofProtection

Everyattemptmustbemadetolimitthedegreeofexposureachievedthroughworkingwithradioactivematerialsorradiationsources.Table1liststhetypesofradiationwhichmaybeencountered.Theirrangeinairvarieswiththeirnatureandenergyandgivesrisetotwotypesofradiologicalhazard-internalandexternal.

Radiationtype

Mainhazardtopersonnel

Protection

Alphaparticles

Internal

Containment

Betaparticles

Internalandexternalskindose

Containment,localshieldingandexposuretime

Gamma&X-rays

External

Distances,shieldingandexposuretime

Neutrons

External

Specialshieldingandexposuretime

Table1Maintypesofionisingradiation’sandtheirhazards

2.3.1TheExternalRadiationHazard

Thebasicmethodsofprotectionagainstexternalradiationare:

-

（a）restrictionofthestrengthofeverysourcetotheminimumnecessaryforthetaskinhand;

（b）theuseofthemaximumamountofdistancebetweenthesourceandtheoperator,compatiblewiththesatisfactoryandsafeperformanceofthework;

（c）restrictionoftheperiodofexposuretotheminimumcompatiblewithsafeworking;

（d）theuseofsuitableshielding.

Theprotectionnecessaryinanyparticularsituationtoensurethatdosesarekeptbelowtherelevantlimitmaybeachievedbyacombinationofthesemethods.

（b）TheUseofDistance

Theintensityofradiationfromaradioactivesourcedecreaseswithincreasingdistance.Forapointsource（andwherethedimensionsofthesourcearesmallcomparedwiththedistancefromthesourcetothepointofinterest）,thedoserateisinverselyproportionaltothesquareofthedistance,i.e.,bydoublingthedistancethedoserateisreducedbyafactorof4andsoon.Forexample,thegammadoseratefroma1GBqcobalt-60sourcedecreaseswithincreasingdistanceasfollows.

at1cm~3.5Svh-1

at10cm~35mSvh-1

at100cm~350Svh-1

Radioactivesourcesshouldthereforeneverbehandledwithbarehands,orwithglovedhandsunlessthethicknessofthegloveissufficienttoreducetheradiationtoreasonablelevels.

（c）TheUseofTime

TheacceptabledosemustbekeptbothwithinstatutorydoselimitsandALARA-AsLowasReasonablyAchievable.

Exposuretohighdoseratescallsforcarefulpre-planning,andsometimesfor'dummy'runs.'Onthejob'discussionsinaradiationfieldshouldbeavoided.

（d）TheUseofShielding

BetaRadiation.ThemostsuitableshieldingmaterialsforbetaradiationaresheetsoflightmetalssuchasaluminiumorPerspex.Theabsorptionofbetaparticlesinmattergivesrisetobremsstrahlungradiation（electromagneticradiationresultingfromtheretardationofchargedparticles）.Forsourcesofenergeticbetaradiation,acombinationofPerspexandleadmakesthebestshieldingmaterial.

Gammarayscannotbecompletelyabsorbedbyashield;theyareonlyreducedinintensity.Ofcourse,anydegreeofattenuationispossibleiftheshieldismadethickenough.Theapproximatethicknessesofvariousmaterialsrequiredtoattenuate1MeVgammaraysbyafactorof10are:

LEAD

IRON

CONCRETE

WATER

3.5cm

6cm

20cm

40cm

（Thesefiguresrefertobroadbeamgeometry）

2.3.2TheInternalRadiationHazard

RoutesofEntry:

（a）Ingestion.Contaminationonsurfacesmayleadtoingestionofactivitythroughthemouth.Controlisbasedonacombinationofrulesandproceduresandstrictlaboratorydiscipline,e.g.inthecorrectuseandremovalofgloves,correctmonitoringproceduresafterworkingincontaminatedareas,andnoeating,smoking,drinking,orapplyingmake-upincontamination-controlledareas.

（b）Inhalation.Workcarriedoutinalaboratoryorworkshopcanbeaccompaniedbytheformationofairbornecontamination.Theassessmentofthesignificanceofradioactiveairbornecontaminationisadifficultproblemduetotheinfluenceofmanyfactorssuchasbreathingcharacteristics（rateofbreathing,whethertheindividualbreathesthroughthenoseorthemouthetc.）,thesize,shapeanddensityandthechemicalpropertiesoftheairborneparticles（whichwillaffectlungdepositionandsubsequentmetabolism）,andtheventilationpatternintheworkingarea.Controlislargelybasedonpropercontainmentandventilationcoupledwithcorrectworkingdiscipline.Beforeajobiscarriedoutconsiderationmustbegiventothepossibilityofairbornecontamination.

（c）Absorption.Radioactivecontaminationmaypenetratetheskinbydiffusionthroughtheskinbarrierorviacutsandwounds.Radioactivematerialsdepositedontheskinandabsorbedthroughtheskinmaysubsequentlydisperseviathebloodstream.Organicsolventsareparticularlydangerousinthattheycanpenetratetheskineasily.Ingeneral,however,theskinformsanefficientbarriertocontamination.Controlisbasedlargelyoncorrectlaboratorydisciplineandtechniques,e.g.whenusing