Potential health hazard associated with handling pipe used in oil and gas production that may be contaminated with radioactive scale from naturally occurring radioactive materials (norm).

1. Potential healthhazard of naturally-occurringradioactive materials (NORM).
The concern isthe possible inhalationand/oringestionof scale particlescontaminatedwithradium-226and possibly
otherradioactive material thatmaybecome airborne during welding,cuttingorreamingof pipe containingthe
radioactive scale.
UncontrolledworkactivitiesinvolvingNORMcanleadto unwantedexposure and dispersal posingariskto human
healthandthe environment.These risks –or dosesstemmingfromthe exposure toionizingradiationemergingfrom
NORM– can be reducedbythe adoptionof appropriate controlstoidentifyif andwhere NORMispresent.The general
principlesof protectionagainstthe hazardsof ionizingradiationare primarilyimplementedbyutilizingbestworking
practicesat NORMwork areas.Inthis respectexposurecontrol andadequate dosimetryare the mostcritical
componentsof a healthandsafetyprogramme inthe protection of workers.The protectionof the environment,and
subsequentlythe publicatlarge,isachievedbycontrolleddisposalof NORM-waste andthe adoptionof emission
controls.
Key unitsare:
Activity (becquerelorBq) solelyindicatesthe numberof nucleardisintegrations persecondbutisalsoencounteredas
derivedunitssuchasactivitypermassor volume (Bq/g[solid],Bq/L[liquid] andBq/Nm3[gas]). Absorbeddose(grayor
Gy) denotesthe amountof energy(J) impartedperunitof mass(kg).Thisdose doesnotaccountfor the biological harm
done to the human body.
Effective dose (sievertorSv) isa derivedSIunitintroducedbyhealthphysicsand accountsfor the type of radiationand
the sensitivityof the tissue exposed. Asionizingradiationcannotbe detectedbyhumansenses,radiationmonitoring
instrumentshave tobe used.The operatingprinciplesinthese instrumentsare separatelytreatedinsection5(NORM
monitoring).
Radiation characteristics
There are three typesof radiationof interestthatare emittedinvariousamounts
by NOR4:
• Alpha(α) particles
• Beta(β) particles
• Gamma (γ) photons.
atoms. Theyare large subatomicfragmentsconsistingof twoprotonsandtwo neutronsidentical toaheliumnucleus
strippedfromitselectrons.Theyare a relativelyheavy(mass4),highenergy(MeV) particlesthatare doubly(positively)
chargedand lose energyveryquicklyinmatter.α-particleswill onlytravelabout 2 cm inair and onlyabout10 μm or
lessinsolidmaterial likehumantissue. Theycaneasilybe shieldedwithapiece of paper,gloves,disposablecoverall or
the deadouterlayerof yourskin.The primaryhealthconcernisinhalationand ingestionof α-particlesintothe body
whichplacesthemindirectcontact with essentiallayersof livingtissue(e.g.oxygenornutrientsexchangelayersin
lungor intestine).
β-particles are subatomicparticlesejectedfromthe nucleusof some radioactive atoms.Theyare equivalentto
electrons.The difference isthatβ-particlesoriginate fromthe nucleusandelectronsoriginate fromelectronicshells
(orbitals) outside the nucleus.β-particleshave anegative charge of –1 and a mass whichisabout 1/2000 of the massof
a proton or neutron.The speedof individualβ-particles dependsonhow muchenergytheyhave,andvariesovera
wide range. Itis theirexcessenergy,whichcausesharmtolivingcells.Whentransferred,this energycanbreak
chemical bondsandformions.β-particlesmaytravel uptoabout 1 m inair and the maximumrange for500 keV β
particlesintissue isabout1 mm. Theycan be effectivelyshieldedwith athinpiece of aluminium, steel orplasticbut
unlike alphaparticleswill notbe fullyshieldedbycoverallsandgloves.
Accumulation of NOR in oil and gas production
In a gas/oil reservoirthathasnotbeenproducing,boththe 232Thand238Udecayseriesare insecularequilibrium.For
reservoirsinproductionchemical partitioningequilibriumbetweenNORspresentinreservoirrockand reservoir
fluidswill be dependentonthe elemental properties: Th& U: as a gas/oil reservoirisareducingenvironmentbothTh
and U preferthe solidrockphase and do notdissolve inthe aqueousoroilyphase.Consequently the topof bothseries
remainswithreservoirrockand can onlyappearinnatural concentrations at the surface duringdrillingoperations.

2. Ra: the partitioningof Ra(228Ra, 226Ra, 224Ra) isspecial astheyare formedby α-decayfromtheirimmediateparentand
may be injectedfromrock/fluid interface intowell fluidsbyso-calledα-recoil.Inaddition,Raprefersthe aqueous
phase,leadingto somewhatnaturallyenhancedconcentrations.Thereforeupon productionthe Rawill follow the
aqueousproducedwaterstream.Rais chemically similartobarium(Ba),strontium(Sr),calcium(Ca) andmagnesium
(Mg) andbecomesincorporatedingroupIIsulfate orcarbonate depositsandscale.Once depositedinside installations
or producedat the surface due to theirradiation characteristicsall three RaNORsshow differentbehaviour:
• 228Ra is veryquickly(withintwodays) insecularequilibriumwith 228Ac(denotedas 228Raeq),afterwhichinamuch
slowerprocess(about10 years) 228Th,thatwasabsentin(depositsfrom) producedwater,growsin(transient
equilibrium).Withthe appearance of 228Thall NORsuntil 208Pb.
• 226Ra starts a secularequilibrium(withintwoweeks) of short-livedNORs (222Rn,218Po, 214Pb, 214Biand214Po) of itsown
denotedas 226Raeq.The ingrowth of 210Pboccursata muchslowerrate (about100 years).
• 224Ra appearsin producedwaterorits depositswithoutitsimmediate parent228Th,soitdoesnotgrow in anymore
and quickly(withintwoweeks) diesout. Thisimpliesthatonlyinfreshlysampledfreshproducedwater 224Ramaybe
detected.Withthe reappearance of 228Th,224Rawill alsoreappearinmore agedsamples asmemberof the 228Theq
subseries.
Radon(Rn) isotopesare special asthey,beinganoble gaselement,preferthe (natural)gasphase fortransportfrom
the subsurface tothe surface.As 220Rn(alsoknownasthoron) onlylivesforminutesbythe time thatthisNORreaches
the surface,itwill have decayed. 222Rnwithahalf-lifeof aboutfourdaysmay appearin Natural Gas Liquids(NGL)
processinginstallations(particularlythe C3 processstream),inthe gascap of crude oil storage tanks(associated gas) or
inNatural Gas (NG) transmissionlines.Ultimatelyitwilldecayto 210Pb,butas 222Rnisshort-livedwithrespectto 210Pb,
no equilibriumstatuswill be reached. 210Pb
depositsoriginatingfrominitial relativehigh 222Rnconcentrationsmayappeardue toprolongedprocessingindeposits
inNGL processinstallations,intank bottomsludge of crude oil storage tanksandin sludge fromboosterstationsinNG
transmissionlines. Pb:Ingasor oil fields,where stablePbispresentinproducedwaters, 210Pbmay
be incorporatedinanyformeddepositaswell7.Inthiskindof deposit 210Pbactivity concentrationswillbe substantially
higherthan 226Raactivityconcentrations, indicatingthataseparate andindependentmechanismforPbtransportis
present(unsupported 210Pb).
The leachingandoccurrence NORsalwaysleadto chemical trace concentrations; e.g.1Bq[226Ra] correspondstoabout
30 pg[226Ra].
The level of NORMaccumulationcan varysubstantiallyfromone facilitytoanother dependingongeological formation
and operational conditionsandwillalso change overthe lifetimeof asingle well.NORMcannotbe readily
differentiated fromotheroilfieldmaterialsandwastesexceptbyspecialistmeasurement.The quantityof materialdoes
not necessarilydictatethe amountof NORMpresentor the radiological riskthatitmayrepresent.Todetermine
whetherornot a facilityis accumulatingNORM,aperiodicNORMsurveywithlikelysubsequentsamplingand
analysisneedstobe conducted.
NOR in oil and gas industry – solid waste streams
Under certainconditions,NORcanbecome depositedoraccumulatedinside productionortreatmentinstallationsas
scale or sludge therebymakingtheseotherwiseroutineoilfieldby-productsandwaste materialsradioactive (NORM).
It isimportantto stressthat NORoccur as impuritieswithinbulkmaterialsand minerallattices.AsRa(226Raand228Ra) is
chemicallysimilartoBa,Sr, Ca and Mg, the use of scale inhibitorsplaysakeyrole inthe reductionof NORM.
Changesin operatingconditionsthatcanleadtoNORMaccumulationinclude:
• temperature andpressure variations
• varyingflow(transitionbetweenlaminarandturbulent)
• gas expansiondue toapipeline diameterchange
• pH variation(increase insulphate concentrationdue toinjectionof fluidsrich
insulphates,ormixture of differentproducedwaters)
• presence of seedcrystalsonthe innersurface of the equipmentandrough surfaces,(forexample,insourgaswells,
the presence of NORMscale is enhancedbythe presence of gypsum).
The main typesof scale encounteredinthe oil andgasfacilitiesare sulphate scale suchasBaSO4,andcarbonate scale
such as CaCO3.Ra ischemicallysimilartoBa and Ca and co-precipitatesformingincorporatedtrace impuritieswithin
the bulk mineral matrices.
There are a numberwaysinwhichnormal oil fieldoperationscaninduce scaling, some of whichmaycontainNORM.
For example,the mixingof seawater, whichisrichinsulfate,withformationwater,whichisrichinbrine,increasesthe

3. scalingtendency.The suddenchange inpressureandtemperature orevenacidity of the formationwater,asitis
broughtto the surface,contributestoscale build-up.
The build-upof scale onthe interiorof a pipe isphenomenonhas implicationsforthe productionof oil andgas;inthis
case,the capacity of the pipe totransferoil andgas wouldbe reducedsignificantly.Scalesare rarelyhomogeneousand
so the abundance of NORcontaminantswill vary.
Verythinfilmsof 210Pbmaybe observedinthe innersurfacesof gastransmission lines,linkedtothe presence of
relative high 222RnconcentrationsinNGandprolongedexploitationof the lines.
NOR in oil and gas industry – sludge and scrapings
Sludge andscrapingsmayalso containNORsoccurringwithinoil-wetfinemineral
grainsof sulfatesandcarbonatesthathave theirorigininthe same processes
that leadto hardscales.OtherNORssuch as 210Pbeq mayalsobe foundinpipeline
scrapingsas well assludge accumulatingintankbottoms,gas/oil separators,
dehydrationvessels,NGLstorage tanksandin waste pitsas well asincrude oil
pipelinescrapingsorpiggingdebris.
Some gas fieldsmayproduce Pb-compoundsorevenalmostpure Pb
contaminatedwith 210Pbeq (upto1,000 Bq/g).The fingerprintof stable Pbisotopes
formingthiskindof depositsisverytypical forgas/oil fields.
Alongside NORMcontaminationandthe heavyhydrocarbonswithinwhichitiscomingled,
there are frequentlyelevatedlevelsof otherpollutantse.g.mercury(Hg),
whichhas an associatedenvironmental andhealthrisksof itsown.The issues
relatedtoNORMmanagementshouldthereforenotbe consideredinisolation,but
take in to accountall of the componentspresent.
Health hazards of NORM
The healtheffectsof NORMare a functionof the energytransmittedtothe bodyas
the α, β or γ radiationdissipatesexcessenergyintolivingcells,whichmayresultin
cellulardamage andgeneticmutation.
In the presentframeworkof radiationprotection,effectsoriginatedbyexposure
of humanstoradiationare groupedin:
• deterministiceffects (harmful tissue reactions)due inlarge partto the killing/
malfunctionof cellsandinsome instanceslarge quantitiesresultinginorgan
damage followinghighdoses
• stochasticeffects,i.e.cancerandheritable effectsinvolvingeithercancer
developmentinexposedindividualsowingtomutationof somaticcellsor
heritable disease intheiroffspringowingtomutationof reproductive (germ)
cells.Thisisusuallyassociated withlong-term, low-level exposure.
Deterministiceffectsoccurat dosesexceeding0.5 – 1 Gy. These thresholdsvary
withdose rate and withradiationquality.The severityof the effectincreaseswith
increasingdose anddose rate.Deterministiceffects are mainlyassociatedwith
incidentscenariosinnuclearindustry,industrialandmedical use of highactivity
sourcesand X-raygeneratorsandparticle accelerators.
Sources of exposure
There are twowaysin whichpersonnel canbe exposedtoradiationemittedby
radioactive material, includingNORM.Irradiationfromexternal sourcesand
contaminationfrominhaledandingestedsources
Irradiationfromexternal sourcesoccurswhenthe material emittingradiation
islocatedoutside the humanbody.Irradiationfrominternalsourcesoccurs
whenthe material emittingradiationislocatedinsidethe humanbody.Internal
contaminationcanoccur mainlydue toinhalationoringestionof material
containingradionuclidessuchasdust particles.
Irradiationfromexternal sourcesoccurinthe proximityof the source and
decreaseswithdistance,droppingtoeffectively‘zero’atasufficientdistance.In

4. the case of NORM, thisis usuallyafewmetresfromcontaminatedequipmentand
will followthe ‘inverse square law’wherebyintensityisinverselyproportional to
the square of the distance fromthe source.Absolute exposureatone
metre will be fourtimesgreaterthanexposure attwometres.However,such
modelsassume asingle point-source forthe radiationwhereas,in real-life,NORM
may be encounteredoveralarge area.Thishas directbearinguponthe size of the
controlledareaarounda NORMcontaminatedsite
Internal sourcesleadtoirradiationof tissuesandorgansandpersistafterthe
introduction of radionuclidesinthe body.Reductionof irradiationdependsmainly
fromthe intrinsicproprietyof the radionuclide (half life time) andexcretionrate
(dependingof chemical compositionof the contaminant).Control of dustand
protectionfrominhalationduringthe handlingof NORMis therefore one of the
principal mechanismsbywhichexposure canbe limited.
For a pointsource,absolute exposure atone metre will be fourtimesgreaterthan
exposure attwometres.However,pointsourcesare rarelyencounteredunder
operational conditionswhere NORMgenerallyaccumulatesacrossanarea.
NORM management cycle
Where managementof NORMisexpectedtoformpart of oil andgas production
operations,amanagementplanisrequiredtomonitorandcontrol the risk in
an appropriate andproportional mannercomplyingwithrelevantnational and
international legislation.
The flowchartisgenericandrequires
manytasks,documentsandsupportsystemstoenable itto functioneffectively.
The remainderof thisreportworksthroughthiscycle.
The processbeginswiththe needtoroutinelymonitorandtestforthe presence
of NORM.NORMcannot be directlyobserved,ithasto be measured.Thisis
not alwayseasyandmusttherefore be factoredintooperational cyclesand
maintenance schedules.NORMaccumulationmayoccurin equipmentthat
isfrequentlyinaccessible.Surfacesmaybe irregular,makingconventional
instrumentationhardtouse.Self-absorbance canmaskthe true abundance of
NORMor it mightbe co-mingledwithotherwastesandhazardousmaterials.The
selectionof instrumentationwill affectthe abilitytodetectNORMof differenttypes
and indifferentcircumstances.The monitoringplanmusttherefore be appropriate
for the settingandrefreshedregularly,especiallywhenotherchangesare made to
an operation(suchasnewdrilling).
It isimportantthat NORMmanagementisplannedandcarriedoutwith
considerationof consultationandengagementof stakeholders.Specifically,the
approval of the regulatoryauthoritiesmaybe required.Giventhe contentious
nature of radioactivityandradioactivematerial,andthe highdegree of technical
knowledge thatissometimesrequired,itmaybe necessarytoengage independent
specializedcontractors withinthe monitoringplan.
NORM Regulations
NORMregulationsvarybetweencountries.Itisimportantthatanyspecificplansreflectthe locationof the NORM
(e.g.spotsinoperational installations,whereNORMmaypreferablydeposit) and
all applicable nationalandinternational regulationsorlaws.
NORM monitoring
The energyof ionizingradiationismeasuredinelectronvolts(eV).One
electronvoltisanextremelysmall amountof energyandsoismost
commonlyencounteredasmultiple unitskiloelectron(keV)
Variousinstrumentsare available foronsitemonitoringof ionizingradiationor

5. radioactive contaminationincludingsome developedspecificallyforuse atoil and
gas productionandprocessingfacilities.However,thereisnosingle instrument
capable of detectingall typesof radiation(α,β, γ) andenergiesof the particles
(α,β) or photons(γ) emittedbyNORM.It istherefore importanttocarefullyselect
and make instrumentsavailablethatare appropriate andefficientforthe NORM
detectionunderoperational andmaintenance conditions.
The essential partof a radiationmonitoristhe detector,inwhichthe ionization
occurs due to the absorptionstoppingpowerof α/β-particlesorγ-photons.
Detectorsshouldbe focusingonthe characteristicsof the radiationemittedby
NORsencounteredinthe oil andgasindustry.
Under operational conditions,all α- andβ-particleswillbe absorbedbythe wall
of pipelinesandotherfacilities,sothatonlyγ-photons(“externalradiation”) may
be detected.However,γ-photonsuntilabout200 keV will alsobe mostlyabsorbed
ina 1.5 cm thicksteel wall.Onlyγ-photonswithenergiesexceeding200 keV may
escape froman operational facility,sothatdepositsincludingthe 228Raeq (via228Ac)
and 226Raeq (via214Pb, 214Bi)subseriesmaybe detectedbydose rate
metersinan external NORMsurvey.If these depositsare
aging,thenradiationlevelswill increasenotnecessarilydue tothe build-upof
more Ra-includingdeposits,butalsodue tothe ingrowthof the 228Theq subseries
(via212Pb, 212Bi, 208Tl;).Itshouldbe notedthat 210Pbdeposits(excluding 226Raeq) or
internal contaminationby 210Pbcannotbe detectedbyanexternal NORMsurveyas
onlylowenergyγ-photonsare emitted.
To determine whetherornot a facilityisaccumulatingNORM,aNORMsurvey
withlikelysubsequentsamplingandanalysisneedstobe conducted.Locations
where NORMmay potentiallyaccumulate (e.g.nearthe perforationatwellheads
as scale or inside gas/oil separatorsassludge) are indicatedbythe radiation
trefoil.
Dose rates measured
close to the circumference of the installationsshouldbe usedtodetermineif there
isNOR-contaminatedscale orsludge presentinthe installations(inpreparation
of cleanoutjobs),while doseratesmeasuredat1 m heightand1 m distance from
the installationcanbe usedfor(operational) industryworkerdose assessment
purposes.
Radiation monitoring instruments
Four distincttypesof radiationmonitorsmaybe distinguished:
1) Dose rate meters– measurespotentialexternal exposure,readsinμSv/h(or
μGy/h).
2) Dosimeters –indicatescumulative externalexposure,readsinμSv(ormSv)
perexposure period.
3) Surface contaminationmeters –measuresthe amountof radioactive
material distributedoverasurface,readsincountspersecond(c/s or cps)
or per minute (c/minorcpm).
4) Airborne contaminationmetersandgasmonitors – measures(indirectly)
airborne particulate NORMor radonconcentrationinair;indicatespotential
internal exposure.
Several typesof detectorsare available:ionizationchambers(gasfilled,
response proportionaltoβ/γ-energyabsorbed),proportional counters(gasfilled,
response proportionaltoβ/γ-energyabsorbed),Geiger-Muller(GM) counters(gas-filledcountrate relatestoradiation
fluence,independentof energyabsorbed),scintillationcounters(extremelysensitivetoγ-photons,thoughthere are β-
scintillatorsonthe marketaswell),solidstate counters(highresolutionγ-spectrometer).
Doserate meters
The response of anydose rate meterisdependentonthe characteristicsof
the detectoritcontainsand inparticularitsdetectionefficiencyatenergiesof
the radiationto whichitisexposed.Aninstrumentmayhave gooddetection

6. efficiencyoverarange of radiationenergies,reducingto(nearly)zeroefficiency
at the detectionrange extremes.If the detectionefficiencyispoor,the instrument
will indicate zeroreadingswhateveractual dose ratesthose radiationsmaybe
producing.Forexample,aninstrumentthatprovidesanaccurate indicationof dose
ratesdue to 214Bi γ-photons(Eγ =609 keV) maybe insensitivetodose ratesdue to
210Pbγ-photons(Eγ =47 keV).
Surfacecontamination monitors
Surface contaminationmonitorsusuallyare designed tomeasure specifictypes
of radiationandoftenhave optimumdetectionefficiencyoveralimitedrange of
radiationenergies.Forexample the detectormayrespondonlytoγ-photonsorβ/γ
radiation.Itmay alsoperformbetterindetectinghighenergyβ- particlesrather
than those of lowenergy;orit may be designedtodetectlow energyγ-photons
but nothighenergy.Instrumentsare beingmarketedthat
have beenoptimizedtodetectNOR-contamination.Mostsurface contamination
monitors needtobe calibratedforthe type and energyof the radiation(e.g.a
single radionuclide) tobe detected,beforethe readingcanbe convertedinto
meaningful units(Bq/cm2).AsNORMisalwaysconstitutedfromasuitof NORs
appearingindifferentproportions,itisimpossible toconvertthe acquire readings
intoaccurate Bq/cm2,soin general the readingwillbe incountspertime interval,
where fora β/γ sensitive contaminationmonitorthe countmaybe causedby
β-particle orγ-photonabsorption.
Contamination monitors for airborne radioactivity
Instrumentsformeasuringairborne contaminationneedspecialistassessment
and consequentlyare rarelyusedinthe oil andgas industry.These instruments
normallydrawpotentiallycontaminatedair(e.g.dusty scale removal treatments)
at a constantrate througha filtermainlytomonitorairborne α-emitters,including
radon progeny.Personal airsamplersbasedonthe use of a filtermayalsoserve
as personal (inhalation)dosimeters,butthe filterneedstobe assessedbyan
external laboratory,where the resultsonlyprovidearetrospectiveassessmentof
the workingconditions.
Monitoring in practice
Undernormal operational conditions
An explosion-proof orintrinsicallysafedose rate meter should
be applied formonitoringthe external dose rate around(potentially) contaminated
installationparts.Nowadays,suchdose rate meterscanalsobe usedas EPD. Applicationsand/ormeasurement
conditionsare,forexample:
jobpreparedness:measure dose rate atthe outercircumference
of operatinginstallations.If measureddose rate exceedstwicethe
backgrounddose rate due to the natural radiationenvironment,thenthe
inside of the monitoredinstallationpartiscontaminatedwithNORsand
any jobto be carriedout inside thisinstallationshouldbe classifiedas
NORMwork.NOTE: 210Pbeq cannotbe measuredinthiswayandwhere PB
isanticipated,measurementsshouldbe takeninternallywithadetector
sensitivetobetaemissionspriortoconductingwork.
workerdose assessment: measure dose rate at1 m distance from
circumference of installationpartswithNORMand at 1 m height –in
combinationwithassessedresidence timespotential external dose of
industryworkerscanbe pre-assessed(‘radiationriskassessment’);
judgingthe outcome of the pre-assessment,itmaybe decidedif the
workershouldweara TLD badge duringhis/herjob.
workerdose monitoring: duringhis/herworkthe operatormayweara
TLD or EPD duringall his/herworkrelatedoccupations –afterabout one
monthhis/heroccupational dose associatedwiththe jobcarriedoutcan
be derived(bysubtractingthe natural backgrounddose).AsmanyEPDs

7. are equippedwithloggingoptions,these are excellentlysuitedtoanalyse
whatthe actual exposure causingstepsof aparticularjobare, so that
dosescan be keptALARP.
Undermaintenance and/or cleaningconditions
An explosion-proof orintrinsicallysafedose rate meterand
surface contaminationmonitorshouldbe appliedformonitoring
the external dose rate andcontaminationlevel insideinstallationparts.
Applicationsand/ormeasurementconditionsare
jobpreparedness: measure dose rate andcontaminationlevelsatthe
innersurfacesof operatinginstallations.If measureddose rate exceeds
twice the backgrounddose rate due to the natural radiationenvironment
samplesshouldbe takenandsubmittedforγ-spectrometricanalysisfor
transportationanddisposal classification.Basedonthe analysisresults
a radiationriskassessmentshouldbe carriedouttakingall potential
exposure pathways(external,inhalation,ingestion,skincontamination)
intoaccount and a strategyshouldbe developedforanymaterial removed
fromthe installation.If onlysurface contaminationreadingsexceedthe
natural background,the workerwill notbe at risk,buta strategyshould
be determinedshouldbe developedforanyinstallationpartsormaterial
removedfromthe installation.
workerdose assessment: basedonmeasureddose rate inside
installationsandtakingintoaccountpotential formationof airborne
contaminatedmaterial,the dose forthe jobshouldbe assessed
beforehand.If the assessmentindicatesthatthe potentiallycontracted
dose will be well below 1mSv/year,the jobmaybe carriedout.If the
assessmentindicatesthatthe potentiallycontracteddose willexceed
1 mSv,itmay be necessaryto hire a specialistNORMdecontamination
contractor PPEsprescribedforjobsinconfinedspaceswill alsoprotect
the workeragainstany inhalation,ingestionorskincontaminationdose.
workerdose measurement: Where aworkerdose assessmentindicates
the likelihoodfoexposure,the onlydose componentthatcannotbe
circumventedisthe externaldose,whichmaybe monitoredbyan
intrinsicallysafe EPDandof course the authorityprescribedTLD.Asmany
EPDs are equippedwithloggingoptions,these are excellentlysuitedto
analyse whatthe actual exposure causingstepsof aparticularjobare, so
that dosesforthe nextsimilarjobcanbe minimized.Itisadvisedto keep
dose records(evenif nodosesare recorded) forthe varioustypesof jobs
to be carriedout.
Training and awareness
Trainingandawarenessare majorcomponentsof a NORMmanagementsystem.
Workersneedtobe made aware of:
• the hazardsassociatedwithNORM
• procedurestoidentifyNORM(andthe challengesherein)
• controlsthatare requiredfortheirpersonal protection
• methodsforpreventingenvironmentalcontamination
• local documentationrequirementsandhowtoescalate actionsover
uncontrolledrisksornon-conformantoperations.
Trainingshouldfocusonoperational personnelwhoare potentiallyexposedto
NORMand directlyinvolvedinmaintenance operations.However,basic awareness
shouldalsobe giventoall the personnel involvedinthe facility,eventhoughthey
are notinvolveddirectlyorhave lowimmediate riskof beinginvolved.
Basic trainingshouldbe refreshedatregularintervalsandwheneverasignificant
change is encountered –suchas the introductionof new equipment.

8. Keypersonnel shouldbe identifiedandprovidedwithtrainingthatwill permitthem
to ensure thatthe work theydopays due regardto the NORMhazards and prevent
spreading.Trainingshouldbe tailoredtothe specificpotential hazardassociated
withNORMto whichthe personnel isexposedto.
NORMtrainingisreadilyavailable bothasclassroomandvirtual learning.Some
trainingleadstospecificqualifications,whichmaybe specifiedinlocal guidelines
or legislation.Examplesinclude‘Radiological ProtectionAdvisor’,‘Radiological
ProtectionSupervisor’and‘SuitablyQualifiedPerson’butthere isnouniversal
standardas to the contentof trainingor capability.
Control of NORM sites
The followingare basiccontrol proceduresthatshouldbe practisedwhen
operatinginor aroundpotentiallyNORMsites:
• Identifyanappropriatelytrainedandqualifiedpersonresponsiblefor
managingthe riskand ensure thattheyoperate withinawiderNORM
managementsystemandcontrol of work.
• Establishaboundaryaroundthe work areaand post radiationwarningsigns.Thisshouldbe proportionaltothe level
of contaminationandreevaluatedwheneverthe level of informationspecifictothe locationchanges.
The boundaryshouldbe as small asreasonablypractical,butlarge enough
to allowforpersonnel andequipmentaccessfromthe workarea and toallow
for all workto be accomplishedinasafe manner.Aneffective barrierdefines
the extentof the contaminatedareaandcontrolsexposure tothe regulatory
limitsformembersof the public.
 Boundarywarningsignswiththe internationallyrecognizedradiation
‘tri-foil’sign
• Considerwhether:
a) the pre-existingcontrols,whichare usuallydirectedatcontrolling
chemical contamination,are sufficienttoaddressthe NORMissue,
b) the pre-existingcontrolsneedsome minorimprovements,or
c) the pre-existingcontrolsneedconsiderable improvementtoproperly
addressthe NORMissue.
• Containersorplasticbagsshouldbe providedfordiscardedprotective
clothingandcontaminatedtrashat the exitof the workarea.
• Onlyessential personnel shouldbe allowedinthe NORMworkareas.They
shouldhave appropriate traininginkeepingwithlocal lawsandsuitable
measuresandrecordkeepingestablishedtotrackexposure dosage relative
to pre-determinelimitswithinagivenperiod.
• Priorto maintenance of contaminatedequipmentoropeninginspection
hatches,sludge trapsor pigreceivers,sufficientgroundcovershouldbe
placedbelowthe iteminthe workarea.The ground covershouldbe made
of a plastic,waterproof type material capable of withstandingthe work
activitiesinvolvedwithouttearingorripping.Alternatively,asuitable drip-tray
or catch-panmay be used.The groundcovershouldbe sizedtoprovide for
the containmentof leakage andwaste andto allow ample roomforrelated
peripheral work.
• Holda safetymeetingforall personnel performingwork.Radiological items
whichshouldbe addressedduringthe meetingare,butare notlimitedto,
protective clothingandrespiratoryprotectionrequirements,radiationand
contaminationlevels,maintenanceactivitieswhichcancause radioactive
material tobecome airborne,requirementsforwaste generatedandactionto
be takenin the case of emergencies.
• Commence maintenance activity;anydrymaterial thatisNOR-contaminated
shouldwheneverpractical be wetteddowntopreventthe generationof
airborne radioactive materials.Drymaterial shouldbe wettedperiodically

9. throughoutthe maintenance work.
• Openingsof equipmentorpipesthathave internal NORcontaminationshould
be sealedorwrappedbyplasticor othersuitable materials.
• Obsolete NOR-contaminatedpipesorequipment shouldbe clearlylabelledas“NORMContaminated
Material”and removedtoa designatedarea.The areashouldbe labelledas“CautionNaturally
OccurringRadioactive Materials”andrestrictedforthe general public.
• All NORMwaste generatedduringmaintenance shouldbe drummedorputintocontainersandmarked
or labelled.Representative samplesshouldbe collectedfromthe waste andanalysedforradioactivity.
• Upon completionof maintenance,personnel shouldremove theirprotective clothingshouldbe
assessedforcontamination,if necessarywashed-downandremovedbefore leavingthe workarea.
• All material,equipmentandtoolsnotplacedincontainersordrummedshouldbe surveyedforbothloose
contaminationandexposure rate levelsuponexitfromthe workarea.
A readinggreaterthantwice backgroundlevelsispositive indicationof
contamination,andshouldbe handledassuch.
Upon jobcompletion,the accessibleareasof the workarea shouldbe surveyedfor
loose contamination.Anyloose surface contaminationfoundshouldbe promptly
cleanedupanddrummed.
Once the work area hasbeenverifiedfree of loose surfacecontamination,the
boundaryandpostingsmaybe takendown.
NOR contaminated equipment
Basicsof control and managementapplicable toNORcontaminatedthatare small enoughtobe isolated,cleanedor
disposedof.
Examplesincludetubulars,valves,vessels,pipesormachinery
Control
Beyondmanagementof the equipment in situation NORMcontaminatedequipmentmustbe handled,transported,
stored,maintainedordisposedinacontrolledmannerproportional totheiractivityandcompliantwithlocal or
international guidelines.Protocolsare neededtoensure thatequipmentisnotreleasedorhandledwithoutcontrolsto
protectthe workerand prevent
contaminationof the environment.Therefore,itiscritical tounderstandand
control howand where NORmaterialscanbe transported.Forexample,drilling
pipe thatcontainslow-levelNORcontaminatedscalecanbe unrecognizedand
transportedtoa varietyof secondarypipe reprocessingfacilitieswithsubsequent,
inadvertentexposureandspreadof NORM.
The followingshouldbe consideredthe minimumrequirementsforthe control of
NOR-contaminatedequipmentwithactivityabove exemptionthresholds.
Equipmentshould:
• be decontaminatedpriortoreleaseforunrestricteduse
• be storedonlyindesignatedstorage areas
• be taggedor clearlymarkedas NORcontaminated.
• be handledonlybyemployeestrainedinNORMhazardsandis usingPPE
• notbe sentformaintenance/repairtoworkshopswithoutinformingthe
workshopthatthe componentiscontaminatedwithNORM.
• be disposedof onlyinanapprovedNORMdisposal facility.
• be decontaminatedonlyinanapprovedNORMdecontaminationfacilityor
accordingto an approveddecontaminationprotocol.
• opensectionsof equipment,i.e.,flange orpipe ends,etc.,shouldwherever
possible be adequatelycoveredbyheavy-gaugeUV-stabilizedplasticorother
suitable materialstoensure thatNORMmaterial does notleakfromthe item.
• routine checksonall storedNOR-contaminatedequipmentshouldbe
undertakentoensure thatthe integrityof the protective measuresisadequate.
• detailedandverifiablerecordsshouldbe maintainedof all storedNOR
contaminatedequipment
Once verifiedasfree fromNORcontamination,the equipmentmaybe re-usedsent

10. for repair/servicinginthe normal mannerorsoldor disposedof asscrap.
Local decontamination of equipment
Where regulationspermitandothercontrol measureshave beenestablished,it
may be preferable todecontaminate equipmentlocally,either in situ or without
transportation.Thisshouldbe conductedonlybyadequatelytrainedpersonnel.
Decontaminationof equipmentwhichiscontaminatedwithNORMshouldbe
undertakeninacontrolledmannertoensure workerprotection,preventthe
spreadof NORMcontamination,andtominimize the waste arisingfromthe
decontaminationprocess.Simple mechanical/abrasive,i.e.highpressurewater
jetting(HPWJ) inconjunctionwithothermechanical/abrasivemethodsremain
the most commontechniquesadoptedbutchemical cleaningsolutionsare
increasinglyavailable.All formsof decontaminationhave the potential tospread
NORMand inthe case of abrasive cleaningincrease the likelihoodof NORM
becomingairborne asdust.A full riskassessmentistherefore required.
Whensuch methodsare used,considerationsinclude:
• changingfacilitiesforworkers
• operatingareastocarry outwork
• handling/receivingareas
• stripdownareas
• waterjettingareas
• liquidre-circulationsystem
• ventilationsystem
• control of equipment(administrationsystem)
• inspectionof equipment
• monitoringof equipment
• safetyrelatedsystems.
The decontaminationplanshouldconsiderother hazardsassociatedwiththe
material includingintrinsichazards(shape,weight,etc.) andotherformsof
contaminant(hydrocarbons,heavymetals,etc.) Wherepossible,decontamination
systemsshouldbe automated.
Operating areas
Main change room Thiswill allowaccesstothe (supervisedorcontrolled)
NORMworkareas where decontaminationwill take place.
HandlingareaThiswill be fora) checkingthe inventory/material being
sentfor decontamination;b) carryingoutradiationsurveys
of decontaminatedequipment;c) providingasegregation
systemtokeepincoming‘dirty’itemsseparate foroutgoing
‘cleanitems’;d) aquarantine areafor itemsthatrequire
furtherdecontamination.
Stripdownarea To allowthe stripdownof componentssuchas valves,
wellheadsandothercomponents.
Burningbay Forhighlevelsof activity,toallowforoxy-propane
cutting,grindingetc.of equipmentthisisanarea where
NORMmay become airborne andthereforerequirestotal
containmentwithaventilationsystemequippedwith high
efficiencyparticulatearrester(HEPA) orHEPA filter.
Local extractventilation(i.e.elephanttrunks) will also
be available inthe areato control/removeairborne
contaminateddustatsource
Workerswill needtowearrespiratoryprotectiveequipment
(RPE) inthisarea; therefore the supplyof breathingairfor
RPE isneeded.
The floorand surfacesshouldbe of an impermeable nonflammable
surface capable of withstandingheavyloads.

11. Water jettingareaThis isa (supervisedorcontrolled) NORMworkarea
where NORMmay become airborne andtherefore requires
total containmentwithaHEPA-filteredextractventilation
system.Inthisarea,workerswill be requiredtowearRPE
inthisarea; therefore the supplyof breathingairforRPE is
required.
The floorand surfacesshouldbe of an impermeable nonflammable
surface capable of withstandingheavyloads,
and the impactof HPWJ
LiquidrecirculationAllprocessliquidusedindecontaminationoperations
shouldbe filteredandre-used.There shouldbe no
connectiontoany external drainagesystem.The following
elementswill be requiredinthe system:
The systemneedstoseparate NORM-contaminated
sedimentandoilywaste materialfromthe processwater.
Water fromthe HPWJ area will be circulatedbacktothe
systembyan enclosedanddoublycontaineddrainage
system.A leakdetectionsystemshouldbe includedinthe
watercirculationsystem.The settlingtankshouldbe able
to be readilyaccessibleandable tohave any sediment
removed/decantedintowaste containers.The system
shouldhave capacityto allowthe transferof waterfrom
the settlingtanktoanotherholdingtankto allowsediment
removal.
Control of works
• Anadministrativesystemisrequiredtocontrol andtrack the progressof all
equipmentandcomponentsenteringthe decontaminationfacility.
• Inspectionof all equipmentandcomponentsshouldbe carriedoutonreceipt.
The status of the equipmentshouldbe loggedandanydamage notlogged
on the documentationshouldimmediatelybe broughttothe proponent’s
attentionandthe componentshouldbe quarantinedpendingfurther
instructionfromthe proponent.
• Monitoringof equipmentforclearance shouldonlybe carriedoutbytrained
operators.
• All monitoringequipmentshouldbe fullyoperationalandwithinits
calibrationperiod.A checkonthe operational statusof all radiological
monitoringequipmentshouldbe maintained.
• Anadministrativesystemshouldbe implementedtoidentifyitemswhichare
NOR-contaminatedfromthose thathave beencleaned.
The acceptance criteriafor successful decontaminationshouldbe:
a) All equipmentmustbe visuallyclearof scale,sludge orotherdeposits(such
as blackpowder).
b) All equipmentmustbe free of detectable radioactivecontamination,asper
section5 (i.e.lessthandouble background).
Worker protection
The underlyingprinciplesof workerprotectionare derivedfromthe
propertiesof radiationwhichcanbe controlledthroughacombinationof:
• shielding:providingappropriateshielding
• distance:increasingthe separationof workersfromthe source
• time: reducingthe periodof exposurereducesthe dose
Under normal operatingconditions,the greatestriskassociatedwithNORM
comesfromworkers operatinginclose proximitytoNORMfor extendedperiods
such as duringdecontamination.

12. WorkersenteringconfinedspacescontainingNORM(e.g.vessel tanks) or
conductingintrusive workonNOR-contaminatedequipmentshouldadhere tothe
followingguidance:
• Personnel requiredtoworkwithNORMshouldbe trainedinthe associated
hazardsand local procedures.
• Anappropriate monitoringandcumulative dosage recordingprotocol should
be established.
• All NORMoperationsshouldbe coveredbyasafe systemof workwhich
shouldidentifythe hazardsandhighlightthe precautionstobe taken.
• Anyitemor areawithdetectable levelsof loose NORcontaminationshouldbe
subjecttoappropriate radiological controls.
• Appropriate PPEshouldbe worn(whichmayincludebutnotbe restrictedto):
–– ‘Tyvek’style coverallsorchemical suits
–– Neoprene,PVC,nitrile ornitrilerubber(NBR) gloves
–– RespiratorswithHEPA cartridges
• Eating,drinking,smokingandchewingare notallowedinworkareaswhere
there ispotential NORM.
• Onlyessential personnel shouldbe allowedinthe workareaswhere NORMis
potentiallypresent.
• Personnel shouldwashupthoroughlywithcopiousquantitiesof soapand
water,afterworkingwithcontaminatedequipment,andbefore eating,
drinking,orsmoking,andat the endof the workday.
• Use systemsof workthat minimize the generationof waste PPE.
Confined space entry
Personnel shouldadhere toapplicable regulationsandguidelinesforconfined
space entry.In addition,before enteringvessels/tanksorotherconfinedspaces
knownor suspectedtobe NOR-contaminated,the workers’protectionmeasures
shouldbe implemented.
Furthermore,beforeenteringtanksorvesselsingasplants,especiallyin
propane andmethane streams,vessels/tanksshouldbe emptiedandmayneed
to be ventilated,throughforcedventilation,foratleastfourhourspriorto entry
for cleaningormaintenance.Ventilationwill force anytrappedradongasout
of the vessel,whilethe delayedentrywill allowadequatetime forthe decayof
short-livedradondaughters(progeny).Radonisnotthe most significanthazard
associatedwithconfinedspace entryandall otherlosspreventionchecksmust
alsobe completed. Radondoesnotpresentanacute hazard to health,andthe
requirementtoventthe tankfor fourhours isa meansof minimizingpotential
dose uptake and,as such,shouldbe includedaspartof the full safetyjobrisk
assessment.
All personnel andequipmentexitingavessel shouldbe subjectedtoaNORM
contaminationsurvey.Personnel orequipmentfoundtobe contaminatedshould
be segregatedanddecontaminated.
Transport of NOR contaminated
equipment (NORM)
Adequate precautionsare neededforthe safe and traceable transportationof
NORMcontaminatedequipmentandNORMwastesincludingscales,sludgesand
contaminatedpersonal protectionequipment(PPE) suchasglovesandcoveralls.
Thisis to ensure thatno NORMcan contaminate eitherthe transportationvehicle
or route.
Transportationcan include awide varietyof vehiclesincludingshipping,roadand
rail and unlike manyotherhazardousmaterialstrans-national shippingispossible

13. eitherduringthe servicingof equipmentand/orfordisposal.Radioactive waste is
not coveredbythe Basel conventionwhichprohibitsthe internationalshippingof
hazardousgoodsfor the purpose of disposal.
The followingguidance provideskeyprinciplesof safe transportation,butare not
a replacementforlocal lawsandpractises.Where regulationsorcodesare not
inuse by a country the IAEA SafetyStandardsSeries‘Regulationsforthe Safe
Transport of Radioactive Material’shouldbe consulted.
Dependingonactivityandquantityandlocal andinternationalrequirements,
NORMundertransportationmayrequire labellingwithanappropriate UN
numbers.Thisisa four-digitnumbersthatidentifyhazardoussubstances,and
articles(suchas explosives,flammable liquids,toxicsubstances,etc.) inthe
frameworkof international transport.UN numbersare assignedbythe United
NationsCommitteeof Expertsonthe Transportof DangerousGoods.Theyare
publishedaspartof theirRecommendationsonthe Transportof Dangerous
Goods,alsoknownas the ‘Orange Book’.These recommendationsare adoptedby
the regulatoryorganizationresponsibleforthe differentmodesof transport.NOR
materialsfall predominatelyunder‘class7’e.g.UN 2912 (Low SpecificActivity).
NORMmustbe packagedandpreparedforshippinginorderto complywith
the latesttransportregulationsforthe mode of transportbeingused,e.g.the
International Maritime DangerousGoodsCode (IMDGCode) forseafreight.IMDG
Code isintendedtoprotectcrewmembersandto preventmarine pollutionin
the safe transportation of hazardousmaterialsbyvessel.Itisrecommendedto
governmentsforadoptionorforuse as the basisfor national regulations.The
implementationof the Code ismandatoryinconjunctionwiththe obligationsof the
membersof unitednationgovernmentunderthe International Conventionforthe
Safetyof Life at Sea(SOLAS) andthe International Conventionforthe Preventionof
PollutionfromShips(MARPOL)
NORcontaminatedequipment/itemsshouldfirstbe wrapped/baggedtoprevent
the escape of NORM, labelled,thensecuredinatransportcontainer.Where items
are toolarge tobe placedina transportcontainer,or itis impractical todo so
such as a large oilfield‘Christmastree’,itmayundercertaincircumstancesbe
acceptable toshipthese itemsas‘unpackaged’solongasthere isno escape of
material duringtransport.
NORcontaminatedsand/scale/sludgemustbe packagedfortransportinsuitable
drumsor skips,withthe endstorage/disposal route oftendictatingwhichtype
are used.The specificactivitiespresentinthe waste,alongwiththe presence of
any otherhazards,will alsoinfluencethe choice of container.The aimisalways
to ensure thatthere isno escape of material duringtransport,thereforechecks
shouldbe made that sealsare intactand lidsfitcorrectlyNORcontaminatedsand/scale/sludge mustbe packagedfor
transportin suitable
drumsor skips,withthe endstorage/disposal route oftendictatingwhichtype
are used.The specificactivitiespresentinthe waste,alongwiththe presence of
any otherhazards,will alsoinfluencethe choice of container.The aimisalways
to ensure thatthere isno escape of material duringtransport,thereforechecks
shouldbe made that sealsare intactand lidsfitcorrectly.
Before shippingNORM,consignorsmustensurethatstaff are trainedto
understandthe hazards,risksandrequirementsof the appropriate regulations/
codes/safetystandards.Asaminimum,general awarenesstrainingshouldbe
providedtoall personnel involved.However,thiswill alsodependonthe UN
numberandmode of transportbeingused.Trainingmayalsobe neededfor
drivers,ship’sCaptains,etc.toensure thatcontingencyarrangementswill be
followed.A writtencontingencyplanmustbe available,definingthe actionstobe
takeninthe eventof anincidentduringthe transportof NORM.
Labellingof NORMpackages/equipmentisthe responsibilityof the consignorand

14. musttake accountof the latestIAEA standardsand/orlocal Regulations.Where
equipmentisunpackagedshippinglabelsmuststillbe attachedtothe item, its
cradle,or itsliftingdevice.
Some countriesrequire vesselstobe licensedtocarry radioactive material,
includingNORMandconsignorsmustalwayscheckto ensure theyare complying
withlocal requirements.
Transport documentation,e.g.dangerousgoodstransportdocuments,mustbe
completedandsignedbythe consignor’srepresentative,withthe documents
accompanyingthe shipment.
Notification/agreementstoshipwill be requiredbythe receivingsite,and
considerationshouldalsobe giventootherlocal requirements,e.g.24hour
notificationgiventoaharbour authority,shippingagentand/orcrane company.
The followingrecordsmustbe keptbythe consignor:
• description of items/waste beingshipped
• no.of items/packages
• weight/volume
• identificationof NORs,theiractivityconcentrationsandtotal activity
• transportroute,destinationandstatementfromthe receivingsite confirming
that NORMwill be accepted
• copyof all shippingpaperwork
• anyotherrelevantinformation,e.g.acceptance/disposal certificate
Duringtransport,items/packagesmayrequiresegregationfromothertypesof
cargo, e.g.photographicfilm,orothertypesof dangerousgoods.Therefore,the
relevantstowage andsegregationtablesmustbe consulted,thiswill usuallybe the
responsibilityof the carrier.
NORMwaste isnearlyalwaysaccumulated/shipped/disposed-of througha
systemof permitsandlicensesissuedbythe countriesregulators.Exporting
and importingof NORMmay alsobe acceptable insome countries,butonlywith
the approval of the regulatorsfrombothcountries.Itistherefore importantthat
specialistadvice issoughtfromasuitablyqualifiedexpert.
Remediation of NORM
contaminated land
Land whichisNORMcontaminatedasa resultof oil and gas relatedoperations,
such as an evaporationpondorlandfarm,shouldbe remediatedpriorto
release forunrestricteduse.Remediationisthe systematicremoval of NORM
contaminationfromthe areaina controlledmanner,withthe contaminatedsoil/
material becomingpartof the NORMwaste stream.It iscrucial to establishclear
release criteriawiththe regulatorbefore startinglandremediation.
Priorto any remediationoperations, carefulanalysisof the overall risksshould
be completedtoensure thatthere isbenefittobe gainedbycarryingoutthe
operation.
It isimportantto stressthat a NORMmanagementplanshouldalsoconsiderthe context
withinwhichthe material hasbeen found.NORMcontaminatedsitesmayalso
be contaminatedwithotherhazardousmaterialssuchasheavymetalsand
hydrocarbons,whichwill require separateriskassessments.
One of the greatestchallengesinassessingNORMwaste aspart of a remediation
planliesinthe selectionof representativesamplesandappropriate survey
techniques.The selectionof instrumentationcanhave
a significantbearinguponthe levelsandoriginsof NORMidentified.NORMwill
not be foundevenlyacrossmostsites,butwill occuras‘hot spots’samplesof
elevatedactivity.Moreover,laboratorybasedassaysindevelopingcountriesand
remote locationscanbe hamperedbythe availabilityof in-countryfacilitieswith

15. the capabilitytoassesssamplesadequately.Suchissuesshouldformpartof a
remediationprotocol.
Permanent disposal options
Giventhe longhalf-livesof several NORs,(mostnotably 226Rat. =1604 y),the
provisionof longtermdisposal optionsthatprovide adequateprotectiontoboth
humanhealthandthe environmentovercomparabletimescalesneedscareful
consideration.Forexample,apermanentdisposalprotocol shouldbe designed
to preventcontaminationof natural resourcessuchasundergroundwater,or
contaminationof soil thatcouldinfuture become residential oragricultural areas
evenalthoughthe areaiscurrentlyremote oruninhabited.
It isessential toconsultthe national regulationswhenconsideringNORMdisposal
routesas these differbetweencountries.Insome countries,it isacceptable
that an oil companymay propose disposal options(workedoutinternally) tothe
national competentauthoritywhilst,inothercountries,the approvedoptionsare
more prescriptive.Inaddition,hazardouswastesof all kindscanbe an emotive
subjectandconsiderationshouldalsobe takenof local opinionandpublic
awarenessof the issuesandrelative risks.
The preliminaryselectionforadisposal methodmayinclude:
• radiological riskduringactive use of adisposal site
• radiological risk overthe effective lifespanof the waste
• technical feasibility,includinggeographical location
• general acceptance (regulatoryandpublic)
• cost
Popularmethodsof NORMdisposal currentlyusedinthe oil andgasindustry
include offshoredisposal,landfill,undergroundinjectionanddedicatedwaste
facilitiessuchassubsurface saltcaverndisposal.