Managing naturally occuring radioactive material …

1 Managingnaturallyo ccurringradioactivematerial( norm )inminin gandmineralpro cessing guidelineNORM 5 DoseassessmentReferenceTherecommendedref erenceforthispublicationis:DepartmentofM inesandPetroleum, ccurringradioactivematerial( norm )inminin gandmineralpro cessing 5 Doseassessment:ResourcesSafety,Departmen tofMinesandPetroleum,WesternAustralia,71 pp.< >PublishedFebruary2010 GuidelineNORM osure(dustinhalation).. osure(inhalationofradon/thoronanddecaypr o ducts).. osure(ingestionofdrinkingwater).. osure(ingestionoffo o d,dustandsoil).. endixde ningtheICRP lungmo endixlistingthethorium/uraniumradionucli deactivitiesandcommittede endixlistingingestionradionuclideactivit iesandcommittede endixwithdoseconversionfactorcharts59 ResourcesSafety,DepartmentofMinesandPetr oleumiiiGuidelineNORM 5 DoseassessmentBibliography69 Index71ivManagingnaturallyo ccurringradioactivematerial( norm )inminin gandmineralpro cessingGuidelineNORM 5 DoseassessmentList of uenceofparticlesizeondep ,DepartmentofMinesandPetroleumvGuideline norm 5 DoseassessmentList of (IAEAB asicSafetyStandards).

2 (IAEAB asicSafetyStandards).. ectivedosefortheinhalationofthoriumoredu st(AMAD=1 m)bymemb ectivedosefortheinhalationofthoriumoredu st(AMAD=1 m) ectivedosefortheinhalationofthoriumoredu st(AMAD=3 m) ectivedosefortheinhalationofthoriumoredu st(AMAD=5 m) ectivedosefortheinhalationofthoriumoredu st(AMAD=10 m) ectivedosefortheinhalationofuraniumoredu st(AMAD=1 m)bymemb ectivedosefortheinhalationofuraniumoredu st(AMAD=1 m) ectivedosefortheinhalationofuraniumoredu st(AMAD=3 m) ectivedosefortheinhalationofuraniumoredu st(AMAD=5 m) Radionuclideactivitiesandcommittede ectivedosefortheinhalationofuraniumoredu st(AMAD=10 m) (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=1 mcontainingb oththoriumanduraniumindi erentratios,formemb ersofthegeneralpublic(doseconstraint= (DCF mSv/Bq ))

3 ,annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=1 mcontainingb oththoriumanduraniumindi erentratios,formemb ersofthegeneralpublic(exp osurelimit=1mSv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=1 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=1m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=1 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=5m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=1 mcontainingb oththoriumanduraniumindi erentratios,forworkers(exp osurelimit=20mSv/year)..39viManagingnatu rallyo ccurringradioactivematerial( norm )inminin gandmineralpro cessingGuidelineNORM (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=3 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=1m Sv/year).

4 (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m )forthedustwithAMAD=3 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=5m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=3 mcontainingb oththoriumanduraniumindi erentratios,forworkers(exp osurelimit=20mSv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=5 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=1m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=5 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=5m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=5 mcontainingb oththoriumanduraniumindi erentratios,forworkers(exp osurelimit=20mSv/year).

5 (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=10 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=1m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=10 mcontainingb oththoriumanduraniumindi erentratios,forworkers(doseconstraint=5m Sv/year).. (DCF mSv/Bq ),annuallimitsofintake(ALI Bq/year)andderivedairconcentrations(DAC Bq/m3)forthedustwithAMAD=10 mcontainingb oththoriumanduraniumindi erentratios,forworkers(exp osurelimit=20mSv/year).. lter(repro ducedfromIAEARS G ).. lter(repro ducedfromIAEARS G ).. ductsforworkers(repro ducedfromARPANSA`MiningCo de',2005).. ectivedosefortheingestionofradionuclides fromthoriumdecaychainbymemb ,DepartmentofMinesandPetroleumviiGuideli neNORM ectivedosefortheingestionofradionuclides fromuraniumdecaychainbymemb (DCF mSv/Bq),theoreticalannuallimitsofintake( ALI Bq/year)andderivedwaterconcentrations(DW C Bq/m3)fortheradionuclidesofradiologicals igni canceindrinkingwater,formemb ersofthegeneralpublic(exp osurelimit=1mSv/year).

6 (DCF mSv/Bq),theoreticalannuallimitsofintake( ALI Bq/year)andderivedwaterconcentrations(DW C Bq/m3)fortheradionuclidesofradiologicals igni canceindrinkingwater,forworkers(dosecons traint=5mSv/year) (DCF mSv/Bq),theoreticalannuallimitsofintake( ALI Bq/year)andderivedwaterconcentrations(DW C Bq/m3)fortheradionuclidesofradiologicals igni canceindrinkingwater,forworkers(exp osurelimit=20mSv/year)57viiiManagingnatu rallyo ccurringradioactivematerial( norm )inminin gandmineralpro cessingGuidelineNORM oseToprovideguidanceonmetho dsoftheassessmentofradiationexp osureofemployeesandmemb eThisguidelineappliestoallexploration,mi ningandmineralpro cessingop erationsinWesternAus-traliathatuseorhand lenaturallyo ccurringradioactivematerial( norm )andcome withinthescop eofPart16oftheMinesSafetyandInsp ectionRegulations1995[1]. nitionsActivityTheactivityofaradionuclid eAisthenumb erofsp ontaneousnucleartransformationsdNtakingp laceintherelevantnumb erofradionuclidesNinatimeintervaldt,divi dedbythistimeinterval:A=dNdtTheSIunitfor theactivityistheBecquerel(Bq).

7 ActivityConcentration/Sp eci cActivityTheactivityconcentrationCisthea ctivityAofaradioactivesubstanceinaliquid orair,dividedbythevolumeVoftheliquidorai r:C=AVThesp eci cactivityofthesolidmaterialisdeterminedi nasimilarway, eci cactivityvary,mostcommonlyusedareBecquer elp ercubicmetre(Bq/m3),Becquerelp erlitre(Bq/L),andBecquerelp ergram(Bq/g).Absorb edDoseTheabsorb eddoseDisthemeanenergyd impartedbyionisingradiationtoamasselemen tdminthematter,dividedbythismasselement: D=d dmTheabsorb :gray(symb olGy),1Gy=1joulep ,DepartmentofMinesandPetroleum1 GuidelineNORM 5 DoseassessmentEquivalentDoseTheequivalen tdoseHT,RofatissueororganTistheaverageab sorb eddoseDT,Rinthetissueororgan,multipliedb ytheradiationweightingfactorwR:HT,R=wRDT ,Rwhere:wRistheradiationweightingfactorf ortheradiationqualityR;andDT,Ristheavera geabsorb osedofseveralradiationqualitieswithdi erentwRvalues,theequivalentdoseHTis:HT= RwRDT,RUnit:Sievert(symb olSv)RadiationWeightingFactorRadiationwe ightingfactor(wR)isafactor,whichmo di esabsorb eddoseinanorganortissuetoyieldequivalent doseandwhichisdeterminedbythetyp eandenergyoftheradiationtowhichtheorgano rtissueisexp ectiveDoseThee ectivedoseEisthesumoftheequivalentdosesH T,multipliedbytissueweightingfactorswT:E = TwTHT= TwT RwRDT,RUnit:Sievert(symb olSv)TissueWeightingFactorTissueweightin gfactorisafactor,whichmo di esequivalentdoseinanorganortissuetoyield tissuee ( )ofatissueTistheequivalentdosecausedtoth istissueasaresultofanintake:HT( ) =t0+ t0HT(t)dtwhere:HT(t)istheequivalentdoser ateinatissueTattimet.

8 :Sievert(symb olSv)Theintegrationtime ,itshouldb eassumedthatitis50yearsforadultsandthenu mb ccurringradioactivematerial( norm )inminin gandmineralpro cessingGuidelineNORM 5 DoseassessmentCommittedE ectiveDoseThecommittede ectivedoseE( )isthesumofthecommittedequi-valentdosesH T( ),multipliedbythetissueweightingfactorsw T:Unit:E( ) = TwTHT( )Sievert(symb olSv)CollectiveE ectiveDoseCollectivee ectivedoseisthesum,overallsubgroupsiinap opulation,ofthepro ductoftheaveragee ectivedose,Ei,receivedbythememb ersofeachsubgroupandthenumb erofp eopleinthesubgroupNi:S= iEiNiUnit:man-Sievert(symb olman-Sv)IntakeIntakeis,accordingtotheco ntext,eitherthepro cessofaradioactivesubstanceenteringtheb o dyortheactivityoftheradioactivesubstance ,whichhasenteredtheb o o dythroughinhalation,theintakemeanstheinh aledactivity,irresp o dythroughingestion, :Becquerel(Bq)AnnualLimitofIntakeTheAnnu alLimitofIntake(ALI)istheintake,whichwil lcauseacom-mittede :ALI=DALhjwhere:DAListheannualdoselimit; andhjisthedoseconversionfactoroftheradio nuclideinquestion(thecommittede ectivedosep erunitactivity).

9 EndicesC,D,F, (DAC)istheaverageactivityconcentrationof theradionuclideinairinwhichitisp ossibletoworkfor2000hoursp ,theDerivedAirConcentrationDACiscalculat edfromtheALIvalueasfollows:DAC=ALIV where:ResourcesSafety,DepartmentofMinesa ndPetroleum3 GuidelineNORM ersonengagedinlightworkisab , ersofthegeneralpublic, 26intheApp otentialalphaenergyofradonprogenyandthor onprogenyisthetotalalphaenergyultimately emittedinthedecayofradonprogenyandthoron progenythroughthedecaychain, osurestoradonprogenyandthoronprogenymayb edeterminedfromtheconcentrationsofradona ndthorongasintheairbyusingthefollowingfo rmula' 47[6]andparagraph15ofICRP 65[7]:PRnP= 10 6 t FRnP CRnPTnP= 10 5 t FTnP CTnwhere:PRnP,PTnParethep otentialalphaenergyexp osurestoradonprogenyandthoronpro-geny,re sp ectively(mJh/m3);tistheexp osuretime(hours);FRnPistheequilibriumfac torforradonprogeny( ors);FTnPistheequilibriumfactorforthoron progeny( ors);CRnistheradongasconcentration(Bq/m3 );andCTnisthethorongasconcentration(Bq/m 3).

10 TheSIunitofp otentialalphaenergyisthejoule(J).Owingto theshorthalf-lifeofthoron( ),theequilibriumb etweenthoronanditsprogenycanb ,acalculationofexp osurefromtheinhalationofradonandthoronpr ogenyiscarriedoutasfollows:ERn=EECRn fRn T,ETn=EECTn fTn T,where:theconversionfactorsfRnandfTnwer eadoptedas9and40[nSv/(Bq h m 3)]forradonandthoron,resp ectively[17,18].4 Managingnaturallyo ccurringradioactivematerial( norm )inminin gandmineralpro cessingGuidelineNORM :RelationshiptootherNORM guidelinesSystem of radiation protection in mines ( norm -1)MonitoringNORM ( norm -3)ControllingNORM ( norm -4)Dust controlstrategies ( )Management of radioactive waste( )Transport of norm ( )Assessingdoses( norm -5)Dose assessmentReporting andnotifying ( norm -6)Reporting requirementsPre-operationalmonitoring ( )Operational monitoring ( )Air monitoring strategies ( )Airborne radioactivity sampling ( )Measurement of particle size ( )Preparation of a radiation management plan ( norm -2)Exploration ( ) mining and processing ( )BOSWELL assessment and reporting database ( norm -7)Electronic data management systemResourcesSafety,DepartmentofMinesa ndPetroleum5 GuidelineNORM ductionTheob jectivesofradiationprotectionare: topreventacuteradiatione ects.