ML20104A307

From kanterella
Jump to navigation Jump to search

Draft NEI 20-05, Methodological Approach and Considerations for a Security Assessment to Demonstrate Compliance with the Performance Criteria of 10 CFR 73.55(TBD)
ML20104A307
Person / Time
Site: Nuclear Energy Institute
Issue date: 04/10/2020
From: Young D
Nuclear Energy Institute
To: Dennis Andrukat
NRC/NMSS/DREFS/RRPB
Andrukat D
Shared Package
ML20104A306 List:
References
10 CFR Part 73, CAC 001625, EPID U-2019-RU7-0000, NRC-2017-0227, RIN 3150-AK19 NEI 20-05
Download: ML20104A307 (12)
v • d • e


Text

©NEI2020.Allrightsreserved.

    • DRAFTA**nei.org NEI2005 MethodologicalApproachandConsiderationsfora SecurityAssessmenttoDemonstrateCompliancewith thePerformanceCriteriaof10CFR73.55(TBD)

PreparedbytheNuclearEnergyInstitute

[Month]2020

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**nei.org

Acknowledgements ThistechnicalreportwaspreparedbytheNuclearEnergyInstitute(NEI).Wegreatlyappreciate theeffortsbyourmembersandotherorganizationsthatcontributedtothepreparationand reviewthisdocument.

NEIProjectLead:DavidYoung

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**nei.org

TableofContents 1

Purpose.....................................................................................................1 2

SecurityAssessmentGuidelines................................................................1 2.1 ThreatCharacteristics.......................................................................1 2.2 ProbabilisticRiskAssessmentInformation........................................1 2.3 PlantConfiguration/ModeChanges..................................................2 2.4 DefinitionofTargetSetandRelationshiptoPerformanceCriteria....2 2.5 CreditforManualActions.................................................................3 2.6 CreditforLawEnforcementSupport.................................................3 2.7 Safety/SecurityInterface..................................................................3 2.8 HazardsfromAdjacentFacilitiesandTransportationRoutes.............4 2.9 NUREG/CR7145................................................................................4 2.10 UseofSecurityModellingTools.....................................................4 3

PerformanceCriteria.................................................................................5 3.1 PerformanceCriterion[#1](regulatoryreferencelater)....................5 3.2 PerformanceCriterion[#2](regulatoryreferencelater)....................5 3.3 PerformanceCriterion[#3](regulatoryreferencelater)....................6 4

ConsequenceAnalysisGuidelines..............................................................7 4.1 GeneralInstructionsandAssumptions..............................................7 4.2 MeteorologicalParameters...............................................................8 4.3 AtmosphericTransportModeling......................................................9 4.4 ExposureParameters........................................................................9 5

Updates....................................................................................................9

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page1 1 PURPOSE Thistechnicalreportprovidesguidanceforperformingasecurityassessmenttodemonstrate thatanuclearpowerreactorapplicantqualifiesforthevoluntary,performancebased alternativestocertainphysicalsecurityrequirementscontainedinTitle10oftheCodeof FederalRegulations(10CFR)73.55,Requirementsforphysicalprotectionoflicensedactivities innuclearpowerreactorsagainstradiologicalsabotage.Toqualifyforthealternative requirements,anapplicantmustdemonstratethatthenuclearpowerreactorfacilitymeetsone oftheperformancecriteriaspecifiedin10CFR73.55(TBD).Theguidanceinthisreport addressessecurityassessmentstargetedatanyofthethreeperformancecriterialistedin10 CFR73.55(TBD).

2 SECURITYASSESSMENTGUIDELINES 2.1 ThreatCharacteristics Thethreattobeconsideredinasecurityassessmentisthedesignbasisthreatofradiological sabotageasstatedin10CFR73.1,Purposeandscope,andreferredtoastheDBT.1 AssessmentelementsinvolvingconsiderationofspecificDBTcapabilitiesandtacticsshouldbe informedbytheguidanceinRegulatoryGuide(RG)5.69,GuidancefortheApplicationof RadiologicalSabotageDesignBasisThreatintheDesign,DevelopmentandImplementationofa PhysicalSecurityProgramthatMeets10CFR73.55Requirements.2Anapplicantmayusean alternativeapproachtoagivencapabilityortacticintheirassessment;however,thealternative approachshouldbeclearlyidentifiedandsupportedwithatechnicalbasis.

2.2 ProbabilisticRiskAssessmentInformation Asecurityassessmentmayconsiderinformationavailablefromaprobabilisticriskassessment (PRA)developedtomeetfacilitylicensingrequirements(e.g.,evaluationofsevereaccidents) establishedbytheU.S.NuclearRegulatoryCommission(NRC).Priortobeginningthe assessment,anapplicantisencouragedtobecomefamiliarwiththeguidanceinRG5.81, TargetSetIdentificationandDevelopmentforNuclearPowerReactors.RG5.81includesa discussionontheuseofPRAinformationandinsightstoassistwiththeidentificationoftarget sets.Thismaterialcanhelpinformthecontentofasecurityassessmentperformedto demonstratecompliancewith10CFR73.55(TBD).

RG1.200,AnApproachforDeterminingtheTechnicalAdequacyofProbabilisticRisk AssessmentResultsforRiskInformedActivities,providesanapproachthattheNRChasfound acceptablefordevelopingaprobabilisticriskassessment(PRA)suitableforriskinformed regulatorydecisions.TheguidanceinRG1.200shouldbefollowedtotheextentpracticaland applicablewhenassessingtheacceptabilityofprobabilisticriskinformationusedinasecurity 1 An applicant planning to assess a threat with characteristics different than the DBT (e.g., one with less capabilities) should also seek an exemption from this requirement as part of the facilitys licensing process.

2 RG 5.69 contains Safeguards Information (SGI) and is therefore not publicly available.

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page2 assessment.

2.3 PlantConfiguration/ModeChanges Asapplicabletothefacilitydesignandfeatures,asecurityassessmentshouldconsiderthe effectsfromplanned(routine)changestotheplantconfiguration,ormodeofoperation,onthe abilitytocontinuouslymeetatargetedperformancecriterion.Ifneeded,theassessment shoulddescribethecontrolsthatwillbeimplementedtoensurethattheperformancecriterion willalwaysbemet.Alternatively,asecurityassessmentcouldbedirectedattwo(orallthree) performancecriteriawherebyoneperformancecriterionismetinoneplantconfigurationor mode,andanothercriterionismetinadifferentconfigurationormode.

2.4 DefinitionofTargetSetandRelationshiptoPerformanceCriteria Asusedinthisdocument:

Atargetsetistheminimumcombinationofequipmentoroperatoractionswhich, ifallarepreventedfromperformingtheirintendedsafetyfunctionorprevented frombeingaccomplished,wouldlikelyresultinoffsitedosesgreaterthanthe referencevaluesin10CFR50.34and52.79.

AnachievabletargetsetmeansatargetsetthatiswithintheabilityoftheDBTto compromise,destroy,orrendernonfunctional,absentactionsbyanonsitearmed responseforce.

Therelationshipofatargetsettothethreeperformancecriteriapresentedin10CFR 73.55(TBD)isshownbelow.

Performance Criterion FacilityTargetSet?

AchievableTarget Set?

MitigationMeasures forLossofTarget Set?

[#1]

No N/A N/A

[#2]

Yes No N/A

[#3]

Yes Yes Yes

ThematerialinRG5.81canhelpinformtheidentificationanddevelopmentoftargetsets.

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page3 2.5 CreditforManualActions Amanualactionperformedbythefacilitystaffmaybecredited3inasecurityassessment intendedmeetPerformanceCriterion[#2]orPerformanceCriterion[#3],includingactionsto preventormitigateoffsiteradiologicalconsequences.Thebasisforassumingaction performanceshouldprovidereasonableassurancethattheactioncouldbecompletedunder thepostulatedattackconditionsandbedocumentedintheassessment.Forexample,an actiontoenableaphysicalprotectionelement,suchaschangingthepositionofabarrieror armingadelayfeature,couldbecreditedprovidedthefacilityslayout,staffingandphysical securityfeaturesgivereasonableassuranceofitscompletionduringanattack.Guidancefor assessingthecredibility(andthusacceptability)ofaproposedmanualactioncanbefoundin RG5.81.4 Manualactionsinitiatedfromaremotelocationmayalsobecredited.Inthesecases,thebasis shouldalsoaddresspotentialchallengestotimelyperformanceoftheactionandmitigative measures.Topicstoconsiderincludecyberattacks,reliabilityandredundancyof communicationssystems,andpotentialcollateraldutiesofpersonnelattheremotelocation.

2.6 CreditforLawEnforcementSupport Asecurityassessmentmaycreditanonsiteresponsefromalawenforcementagencyto neutralizethethreat;thiscreditmaybeappliedinanassessmenttargetedatanyofthethree performancecriteria.Thescopeandtimingofthelawenforcementresponseshouldbe consistentwiththeReasonableAssuranceofProtectionTime(RAPT)describedinRG5.76, PhysicalProtectionProgramsatNuclearPowerReactors.Itispossiblethataresponsetime shorterthantheRAPTcouldbeused;however,thesecurityassessmentwouldneedtoinclude asitespecificbasisfortheshortertime.[Augmentthisinformationwithdiscussioninpending SECYonRAPT/SBT.]

2.7 Safety/SecurityInterface Theperformanceofphysicalprotectionelementsdescribedinasecurityassessmentmustbe consistentwiththerequirementsin10CFR73.58,Safety/securityinterfacerequirementsfor nuclearpowerreactors.Morespecifically,thedesignandperformanceoftheseelements cannotadverselyaffectreactorsafetyand,conversely,plantandoperatorresponsestothe event(e.g.,changesinequipmentconfiguration)cannotadverselyaffectphysicalprotection elements.FurtherguidanceonthistopiccanbefoundinRG5.74,Managingthe Safety/SecurityInterface.

3 For the purpose of this document, credit means a determination that a proposed action or activity can be performed during an attack, thereby permitting the action or activity to be relied upon to support conclusions in the assessment. The determination should meet a reasonable assurance standard.

4 RG 5.81 uses the term operator action.

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page4 2.8 HazardsfromAdjacentFacilitiesandTransportationRoutes Whenapplicable,thesecurityassessmentshouldidentifyandevaluatehazardsfroman adjacentnonnuclearfacilitythatcouldpotentiallyaffectthesafetyorsecurityfeaturesrelied upontomeetaperformancecriterion.Theassessmentshouldalsoexaminesimilarhazards emanatingfromanonsiteornearbytransportationroute(e.g.,aroadwayorrailline).

ConsiderationshouldbegiventohazardousconditionscreatedbytheDBTaswellasthose arisingfromothercauses.Potentialhazardstoconsiderinclude:

Steamreleases Chemicalexplosions,releasesorspills Fires Misuseofindustrialradiationsources Thecharacteristicsofeachhazard,suchastiming,severity,andpersistence,shouldbe determined.Theassessmentshouldthendescribethedesignprovisionsand/orresponse actionsthatwillmitigatetheimpactsofeachhazardandensurethatthecapabilitytomeetthe performancecriterionismaintained.HazardanalysesperformedtomeetotherNRClicensing requirements(e.g.,reactorsitingcriteria)maybereferencedasapplicable;thereisnoneedto performduplicativeanalyses.

2.9 NUREG/CR7145 Priortobeginningasecurityassessment,anapplicantisencouragedtobecomefamiliarwith theguidanceinNUREG/CR7145,NuclearPowerPlantSecurityAssessmentGuide.

NUREG/CR7145providesguidancetodesigncertificationandcombinedlicenseapplicantsfor optimizingphysicalsecurityduringthedesignphaseandminimizingrelianceonoperational programs(humanactions).ThematerialinNUREG/CR7145canhelpinformthecontentofa securityassessmentperformedtodemonstratecompliancewith10CFR73.55(TBD).

2.10 UseofSecurityModellingTools Anapplicantmayemployacomputerapplicationinasecurityassessmenttomodelthe securityrelatedaspectsofanattackonthefacility.Forexample,anapplicationcouldbeused toevaluatethedetectionanddelaycapabilitiesdescribedintheassessment.Foradditional informationonsecurityassessmentmodelingtools,seeSandiaNationalLaboratoriesReport SAND20075591,NuclearPowerPlantSecurityAssessmentTechnicalManual.

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page5 3 PERFORMANCECRITERIA 3.1 PerformanceCriterion[#1](regulatoryreferencelater)

Performancecriterion[#1]states:

Theradiologicalconsequencesfromahypothetical,unmitigatedeventinvolvingtheloss ofengineeredsystemsfordecayheatremovalandpossiblebreachesinphysical structuressurroundingthereactor,spentfuel,andotherinventoriesofradioactive materialsresultinoffsitedosesbelowthereferencevaluesdefinedin10CFR50.34and 52.79.

Tomeetthisperformancecriterion,afacilitymusthavenocombinationofequipmentor operatoractionsthat,ifpreventedfromperformingtheirintendedsafetyfunctionorprevented frombeingaccomplished,wouldlikelyresultinoffsitedosesexceedingthecitedreference values(i.e.,thefacilitydoesnothaveatargetset).Anapplicantcandemonstratecompliance withthiscriterionthroughasecurityassessmentbasedonaconsequenceanalysisthat determinesoffsitedosesforthepostulatedsecurityevent.Theassessmentmayconsiderall engineeredsafetyandsecurityfeaturesinplaceatthebeginningoftheevent;manualactions tooperatethesefeaturesaftertheattackhasbegunshouldnotbeconsidered.

Guidelinesforperformingaconsequenceanalysisarepresentedinsection4ofthisdocument.

3.2 PerformanceCriterion[#2](regulatoryreferencelater)

Performancecriterion[#2]states:

Theplantfeaturesnecessarytomitigateaneventandmaintainoffsitedosesbelowthe referencevaluesin10CFR50.34and52.79cannotreasonablybecompromisedbythe designbasisthreatofradiologicalsabotage.

Tomeetthisperformancecriterion,afacilitymusthavenoachievabletargetsetthatwould likelyresultinoffsitedosesexceedingthecitedreferencevalues;inotherwords,thefacility doesnothaveatargetsetthatcanbecompromisedbytheDBT(giventheircapabilities)toan extentnecessarytoresultinoffsitedosesexceedingthecitedreferencevalues.Anapplicant candemonstratecompliancewiththiscriterionthroughasecurityassessmentthatidentifies planttargetsetsanddemonstratesthecapabilityofsafetyandsecurityfeaturestopreventthe DBTfromcompromisinganytargetset.Tomeetthiscriterion,theassessmentresultscannot relyuponactionsbyanonsitearmedresponseforce.

Securityfeaturesthatmaybeconsideredintheassessmentinclude:

  • Accesscontrolmeasures
  • Detectionandassessmentcapabilities

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page6
  • Delayandbarrierfeatures
  • Actionsbythefacilitystafforperformedremotely
  • Insiderthreatmitigation 3.3 PerformanceCriterion[#3](regulatoryreferencelater)

Performancecriterion[#3]states:

Plantfeaturesincludeinherentreactorcharacteristicscombinedwithengineeredsafety andsecurityfeaturesthatallowforimplementationofamitigationstrategyifatarget setiscompromised,destroyed,orrenderednonfunctional,suchthatoffsiteradiological consequencesaremaintainedbelowthereferencevaluesdefinedin10CFR50.34and 52.79.

Tomeetthisperformancecriterion,afacilityshouldhaveareactordesignwithalargeheat capacityandslowprogressionfromlossofsafetyequipmenttodegradationoffissionproduct barriersandreleaseofradionuclidesfromthefacility.Anapplicantcandemonstrate compliancewiththiscriterionthroughasecurityassessmentbasedonaconsequenceanalysis thatdeterminestheshortestelapsedtimefromeventinitiationtotheonsetofconditionsthat wouldproduceareleasewithradiologicalconsequencesexceedingthecitedreferencevalues.

Theassessmentwillalsoneedtodescribetheplannedmitigationstrategiesthatwouldbe implemented,withinthetimeavailable,topreventtheconditionsleadingtotheradiological release.

Guidelinesforperformingaconsequenceanalysisarepresentedinsection4ofthisdocument.

Astrategyshouldbeunderstoodasaplanofactionformaintainingorrestoringasafety functionthatischallengedduetothelossofatargetelementortargetset.Astrategycanbe implementedbyoneormoremethods.Amethodisaseriesofactionsdesignedto implementaspecificstrategy.Asanillustrativeexampleoftheseterms,considerthatplacinga portablepumpinservice(amethod)toinjectwaterintoareactorvessel(astrategy)would maintainorrestorethecorecoolingsafetyfunction.

Thedescriptionofamitigationstrategyshouldidentifythesafetyfunctionperformed,the eventsthatwouldpromptimplementation,theanticipatedtimeforperformance(with considerationofreasonablyexpectedconditionsprevailingduringanattack),andthefollowing elementsneededforexecution,asapplicable.

  • Equipment(e.g.,portablepumps,generators,hoses,cables,etc.)
  • Storagelocations(onsiteand/oroffsite)
  • Transportanddeploymentarrangements(i.e.,provisionsformovingtheequipment fromastoragelocationtothelocationwhereitwillbeplacedintoservice)

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page7
  • Keyactionstoplaceequipmentinservice
  • Staffing
  • Communications Afacilitymeetingperformancecriterion[#3]willneedtoperformperiodicadministrativeand maintenanceactivitiesthatsupporttheongoingcapabilitytoimplementmitigationstrategies.

Tothisend,thesecurityassessmentshoulddiscussthefollowingitems.

  • Anticipatedoractualdocumentationofsupportfromoffsiteresourceproviders (e.g.,letterofagreement,memorandumofunderstanding,contract,etc.)andhow thisdocumentationwillbeperiodicallyverifiedandupdated.
  • Plantdesignchangeandconfigurationcontrolmeasurestoensurethatcredited strategiescanbereadilyimplementedormodifiedasneeded.
  • Maintenanceandtestingofequipment.
  • Traininganddrillstovalidatestrategiesandmaintainproficiencyofpersonnel.

Anapplicantcomplyingwiththerequirementsof10CFR50.155,Mitigationofbeyonddesign basisevents,isencouragedtobecomefamiliarwiththeguidanceinRG1.226,Flexible MitigationStrategiesforBeyondDesignBasisEvents.RG1.226identifiesmethodsand procedurestheNRCstaffconsidersacceptablefornuclearpowerreactorapplicantsand licenseestodemonstratecompliancewithNRCregulationscoveringplanningandpreparedness forbeyonddesignbasisevents.ThematerialinRG1.226canhelpinformthecontentofa securityassessmentperformedtodemonstratecompliancewithperformancecriterion[#3].

4 CONSEQUENCEANALYSISGUIDELINES 4.1 GeneralInstructionsandAssumptions Forthepurposeofthisdocument,aconsequenceanalysisisanactivityperformedbythe applicanttodetermineradiationdosesattheboundaryoftheexclusionareaandtheboundary ofthelowpopulationzone.Asnotedabove,aconsequenceanalysiswillbeneededtosupport demonstrationofcompliancewithPerformanceCriteria[#1and#3].Theanalysisshould describetheinitiatingevent(i.e.,theactionstakenbytheDBT),thecompromisedtargetset (forassessmentsdirectedatPerformanceCriterion[#3]),andthesubsequentresponsesbythe plant,facilitystaffandsupportingorganizationsandagencies,includinglawenforcement.With thisinformation,theanalysisshouldthendeterminethetypeandamountofradioactivity releasedtotheenvironment.

Thefollowingassumptionsshouldbeemployedinaconsequenceanalysis.

a. Bothactiveandpassivesafetyfeaturesmaybeconsideredintheanalysis.

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page8
b. Theatmosphericreleasepathwayistheriskdominantcontributortooffsitedoses(i.e.,

noconsiderationofdirectexposuresfromthefacilityorreleasestoliquidpathwaysis necessary).

c. Theatmosphericreleaseconsistsofaerosolsorgasses(withradioactivedecayandin growthcorrectionsasappropriate).Ifareleasepathwayrequiresmorecomplex atmospherictransportmodeling,additionalanalysesmaybeneeded.
d. AstraightlineGaussianplumesegmenttypeatmosphericdispersionmodel,with modificationsasneededtoaccountfornearfielddispersionphenomena,isusedto estimateatmosphericconcentrations.Suchmodelsaregenerallymostsuitablefor relativelysimpletransportsituations,suchasopenandlevelterrain,relativelysteady meteorology,andrelativelyclosedistances(<10km).Useofamoreadvanced dispersionmodelmayrequireadifferentsetofassumptionsormethodologicalsteps thanthosedescribedinthisdocument.

Forfacilitieswithrelativelysmallexclusionareas,astraightlineGaussianplumemodel mayoverestimatenearfieldradiologicalconsequences.Inthesecases,other consequenceanalysismodelsmaybeused.

e. Thereisnocreditforpreplannedoffsiteprotectiveactionssuchasevacuationor sheltering.
f. Theexposuredurationsshouldbeconsistentthedurationsspecifiedin10CFR 50.34(a)(1)(ii)(D)(1)and(2),or10CFR52.79(a)(1)(vi)(A)and(B).
g. Theanalysisneednotpostulatecoincidentevents(e.g.,aseismicorfloodingevent),or failuresofstructures,systemsorcomponentsunrelatedtotheevent.

Forthereleasescenarioanddoseprojections,aquantitativeradiologicalsourcetermshouldbe developedbyspecifyingatmosphericreleasecharacteristicssuchasthetimedependent isotopicreleaseratestotheatmosphere,releasedurations,releaselocations, physical/chemicalform,plumebuoyancy,etc.Theradiologicalsourcetermshouldbeestimated usinganalysismethodsandcodesevaluatedbyanNRCacceptedprocess.Incaseswheremore thanonereleasescenarioisidentified,theconsequenceanalysisshouldusethescenario(i.e.,

theeventsequence)thatproducesthegreatestoffsitedoseattheboundariesoftheexclusion areaandlowpopulationzones.

4.2 MeteorologicalParameters Ananalysistodevelopmeteorologicaldatamaybeneededtoevaluatearangeof meteorologicalconditionsinaprobabilisticfashion.Alternately,conservativetransportand dispersionconditionsmaybeassumed,althoughtheconservatismoftheselectedconditions shouldbeevaluatedtoensurethatthecombinationofparametersselectedfortransportand dispersionmodelingwasinfactconservative.Forexample,withappropriatejustification,site

[Month]2020

©NEI2020.Allrightsreserved.

    • DRAFTA**Page9 specificmeteorologicalinformationcouldbeusedtodevelopaverageexpectedatmospheric dispersioncharacteristics(i.e.,50thpercentilemeteorologyforthesite),whichwouldthenbe employedintheanalysis.

Selectionofasourceofmeteorologicaldatawouldincludeanevaluationofdataneedssuchas windspeeds,atmosphericstability,precipitation,mixingheight,etc.,fortemporaland geographicalrepresentativeness.Thequalityandcompletenessofthemeteorologicaldata shouldbeassessed,andsignificantuncertaintiesidentifiedandcharacterized.Itisexpected thatsitespecificmeteorologicaldatawillbeused;however,theremaybeinstanceswheresite specificdataisnotavailableorofsufficientqualityandcompleteness.Inthesecases,there shouldbeanexplanationoftheappropriatenessofthemeteorologicaldatausedforthe analysis.

4.3 AtmosphericTransportModeling Anatmospherictransportmodelappropriatefortherangeofdistancesunderconsideration shouldbeidentified.ForGaussiantypemodels,dispersionparametersappropriatetothe characteristicsoftheareaanddistancerangesunderconsiderationshouldbeidentified,and conceptualapproachesforthetreatmentofnearfieldeffectssuchaselevatedreleases, buildingwakeeffects,plumemeander,plumerise,etc.shouldalsobeidentified.Theselection ofanatmospherictransportmodelshouldalsoinvolveselectionofaconceptualapproachfor treatmentofwetanddrydeposition.Anyassumptionsmadeintheatmospherictransport modelshouldbeidentified.

4.4 ExposureParameters Therelevantexposurepathwaysshouldbeidentified;forexample,exposuretobothairborne anddepositedradioactivityfromatmosphericreleaseswouldinvolvebothexternal (groundshineandcloudshine)andinternal(inhalationofairbornematerialduringcloud passageorasaresultofresuspension)exposure.Inordertoassessthedose,theexposure parameters(e.g.,shieldingfactors,breathingrates,exposuredurations,etc.)wouldneedtobe characterized.Doseestimationsshouldbecarriedoutbycombiningtheresultsoftherelease, transport,andexposureassessmentwitharecognizedsourceofdoseconversionfactors(such asFederalGuidanceReportsissuedbytheU.S.EnvironmentalProtectionAgency)toestimate thedosesattheboundariesoftheexclusionareaandlowpopulationzone.

5 UPDATES Asneeded,asecurityassessmentshouldbeupdatedtoreflectchangestofacilityfeaturesor offsitesupportresourcesdescribedintheassessment.TheNRCshouldbenotifiedofachange thataffectscompliancewithanapplicableperformancecriterion(e.g.,ananticipatedchange willresultintheperformancecriterionnolongerbeingmet).

Documentationofsupportfromoffsiteresourceprovidersshouldbeverifiedonanannual basis.

Retrieved from "https://kanterella.com/w/index.php?title=ML20104A307&oldid=4303300"