風險評估方法程序

1、風險評估方法程序風險評估方法程序13/13風險評估方法程序ContractTitleShanghaiSeccoPetrochemicalsCompanyLimitedShanghaiEthyleneCrackerComplexCaojing,Shanghai,PRChinaDocumentTitleQUANTITIVERISKASSESSMENTPHILOSOPHYDOCUMENTNUMBERPH-00-TSC-SE-0008A02APPROVEDMCR30/08/02PS30/08/02JEF30/08/02AS19/11/02A01FORAPPROVALRM18/06/02JEF21/06

2、/02JEF21/06/02RJCTD22/8/02A00FORAPPROVALRM08/05/02MR08/05/02JEF08/0502RJCTDRJCTDP00PRELIMINARYFORREVIEWRM10/04/02JEF10/04/02IssueIssueorRevisionDescriptionOriginDateCheckDateApproveDateApproveDateRevbybybybyThisDocumentisOwnedbyAdrianSambrook(AS)IPMTAuthorityHARDCOPIESAREUNCONTROLLEDPage1of13SECCOQu

3、antitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A02QUANTITIVERISKASSESSMENTPHILOSOPHYTABLEOFCONTENTS1.0INTRODUCTION1.1GENERAL1.2INTEGRATEDPROJECTMANAGEMENTTEAM(IPMT)STRATEGY1.3PROJECTDOCUMENTS2.0SCOPEOFWORK2.1GENERAL2.2APPROACHTOWORK3.0QRAMETHODOLOGY3.1RATIONALEFORQRA3.2METHODOLOGYHazardIdentifica

4、tionandScreeningIncidentScenarioDevelopmentFrequencyandProbabilityAnalysisConsequenceModellingFatalityEstimationRiskEvaluationWhatif?AnalysisHumanFactors3.3COSTBENEFITANALYSISANDDEMONSTRATIONOFALARPApproachMethodology3.4QRAFLOWCHARTFlowChart4.0DOCUMENTATIONDELIVERABLES5.0QRAREPORTATTACHMENTSQuantiti

5、veRiskAssessmentPhilosophyPage2of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A021.0INTRODUCTION1.1GENERALThepurposeofthisdocumentistosetoutthemethodologyofQuantitiveRiskAssessmentapproachforallProcessUnitsoftheSECCOfacility.Thedocumenthasbeendevelopedinordertocreateaglobalcros

6、s-disciplineguideforthedevelopmentoftheprocessderivativesplantsandoffsitesinvolvedinthisproject.ThePhilosophyshallbeusedasaguidebyallcontractorsintheSECCOdevelopmentandassuchwillbesubjectofinputfromallconcerned.ItwillbearrangedasasupportfortheShanghaiSeccoPetrochemicalCompanyLtd,SECCOIPMTandChineseL

7、egislativerequirementstoensurethatthedesignprocessincorporatesthebestavailablepracticewiththeoptimisationofresourceandcost.AsalinktotheresponsibilitiesoftheOperator,ShanghaiSeccoPetrochemicalCompanyLtdanIntegratedProjectManagementTeam(IPMT)hasbeenestablishedtomanagetheShanghaiEthyleneCrackerComplex(

8、SECCO)projectanditsengineeringcontractors.TheQRAdocumentshalllinkthefirehazardassessmentrequirements,andanyQuantitativeRiskAssessmentprocess,tothedesigndevelopmentbyensuringthatreliableandeffectivesafetyandemergencysystemsareincorporated.Thiswillprovideanoverallsystem,whichwillhelptominimisethelosso

9、flife,production,capitalinvestmentanddamagetotheenvironmentshouldanaccidentaleventoccur.ThisdocumentwhileprovidingthebasicsafetydesignguidelinesfortheProjectdoesnotattempttocoverindetaileveryaspectofsafetydesign.Referenceshouldbemadetherefore,tospecificdisciplinephilosophiesandspecificationsasapprop

10、riate.ThephilosophydoesnotrelievepersonnelofShanghaiSeccoPetrochemicalCompanyLtd.SECCOIPMT,theMainEngineeringContractorsandtheirsub-contractorsandSuppliersfromtheirresponsibilitiesforthesafedevelopmentofthedesignundercurrentapplicablelegislativerequirementspertainingtothedevelopment.1.2INTEGRATEDPRO

11、JECTMANAGEMENTTEAM(IPMT)STRATEGYTheIPMTstrategyforQuantitiveRiskAssessmentinaccordancewiththeConceptSafetyEvaluationshallbeistodevelop,withinaHealth,SafetyandEnvironmentalbackground,aphilosophy,incorporatingstandardsandspecificationsinorderthatacommonanduniformapproachisadoptedtoensureacrosstheplots

12、tandardisation.Byadoptingacommonstandarditisintendedtocreateasituationwherefacilitiesare,assessed,engineeredandsupplied/installedonauniformbasisandhencenegateasituationwhichhasarrivedatadifferingengineeringsolutionanddifferingcomponentparts.QuantitiveRiskAssessmentPhilosophyPage3of1330/08/02SECCOQua

13、ntitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A021.3PROJECTDOCUMENTSActiveandPassiveFireProtectionPhilosophyPH-00-TSC-TE-0003ConceptSafetyEvaluationReportRE-00-TSC-SE-0001TechnicalHSEPlanPL-00-TSC-SE-0001HazardousAreaClassificationPhilosophyPH-00-TSC-SE-0001EnvironmentalAssuranceStrategyST-00-TSC

14、-SE-0004InstrumentandControlPhilosophyPH-00-TSC-CI-0003DistributedControlSystemSD-00-TSC-CI-0004PlantLayoutPhilosophyPH-00-TSC-PP-0001GeneralSiteInformation:Meteorological,SP-00-TSC-PR-0001Geological&UtilitiesDataUnitEquipment,Line&InstrumentPR-00-TSC-PR-0001NumberingProcedureFire:&GasSystemSpecific

15、ationSD-00-TSC-0010RiskAcceptabilityCriteriaST-00-TIJ-SE-0001QuantitiveRiskAssessmentPhilosophyPage4of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A022.0SCOPEOFWORK2.1GENERALQuantifiedRiskAssessments(QRA)aretobeperformedfortheSECCOProjectmainprocessISBLTeams,Olefins,Styrenics,P

16、oleolefins,AcrylonitrileandMethylMethacreylatetoassesstheconsequencesofidentifiedmajorhazardsparticularly,thosewhichcouldresultinharmtopeopleandortheenvironment.TheanalysisshallbebasedontheupdatedApprovedforDesign(AFD)informationforeachunitoftheproject.TheConceptSafetyEvaluation(CSE)Reportshallbecon

17、sideredastheinitialpre-assessmentdocumenttoanyQRAReport.TheQRAReportsshalldetermineIndividualRisk(IR)andpotentiallossoflifefortoAsLowAsReasonablyPracticable(ALARP).TheindividualQuantitiveRiskAssessmentsshallbepreparedinaccordancewiththefollowingparameters.HazardIdentificationandScreeningIdentificati

18、onofthepotentialhazardsbasedontheConceptSafetyEvaluation,HAZOPSandpreliminarydesigndocumentationprovidedfromtheindividualcontractorsdesignandproductionofahazardlist.IncidentScenarioDevelopmentBasedontheProcessUnithazardlistdevelopdefinitiveeventscenariosforsubsequentanalysis.FrequencyandProbabilityA

19、nalysisAssessthefrequencyandprobabilityofeacheventscenariousingpublisheddataandanyotherapplicabledata.Datawillencompassasaminimumreleasefrequencydataasafunctionofholesizefromequipmentandpipeworkandfittingsandignitionprobabilitiesderivedfromvalidatedhistoricalsourcesandmodels.ConsequenceModellingDeve

20、lopmodelstoestablishtheconsequencesforeacheventscenario.SafetyFunctionImpairmentEstimationFromeacheventestablishthelikelyimpairmentorvulnerabilityofthefunctionalityofsafetysystemsbySIL(SafetyIntegrityStudies)andshallincludeUninterruptedPowerSupply(UPS)Integrity.QuantitiveRiskAssessmentPhilosophyPage

21、5of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A02FatalityEstimationEstimatelikelyfatalitiesarisingfromeachidentifiedevent.RiskEvaluationDetermineindividualriskandpotentiallossoflifefromthefatalitiesandeventprobabilities.Whatif?Analysis(FundamentalsofQRA)QuantifiedRiskAssessme

22、nt(QRA)maybeinitiallydefinedasthequantitiveevaluationofthelikelihoodofundesiredeventsandthelikelihoodofharmordamagebeingcaused,togetherwiththevaluejudgementsmadeconcerningthesignificanceoftheresults.Thisprocedureinvolvesaseriesofspecificstages,asfollows:Identificationofundesiredevents.Analysisofthem

23、echanismsbywhichundesiredeventscouldoccur.Considerationoftheextentofanyharmfuleffects.Considerationofthelikelihoodoftheundesiredeventsandthelikelihoodofspecificdetrimentaloutcomes.Judgementsaboutthesignificanceoftheidentifiedhazardsandestimatedrisks.Inthisextentconsequenceshallrefertoahazardouscondi

24、tion,egatoxicgasconcentrationordose,thermalradiation,explosionoverpressure,andtheirresultanteffectsonpeopleandpropertyetc.Riskreferstothelikelihoodofastatedlevelofharmordamagearisingandisacombinationoffrequencyandconsequence,takingintoaccounttheprobabilityofexposure(sayofaperson,orgroupofindividuals

25、)andvulnerabilitytothehazard.DemonstrationofALARP(AsLowAsReasonablePracticable)EachQRAreportshallcontainasectiontodemonstratethatriskstopeopleandortheenvironmentareALARP.PresentationofResultsThepresentationofresultsshallbeinaspreadsheetformatwiththeusualfacilitytoproduceresultsasbarcharts,piecharts,

26、riskcontours,methodsofconsequencemodelling.Ahard(paper)copyoftheQRAmodelincludinganelectronicversion(Word)ofthefinalreportshallbeprovidedasadeliverablewiththefinalreportsproducedbyindividualcontractors.QuantitiveRiskAssessmentPhilosophyPage6of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TS

27、C-SE-0008-A02TheQRAReportsshallbeissuedduringthedetaildesignphaseoftheprojecttoenableincorporationofanydesignchangesduringthedesignphaseoftheprojectunits.2.2APPROACHTOWORKTheworkshallbecarriedoutintwoparts:Theinitialanalysisanddraftreportshallbecarriedoutfollowinganinitiationmeetingandcollectionofth

28、enecessarydatacollatedfromtheConceptSafetyEvaluationandprocessinformation.AfinalanalysisandreportshallthenbepreparedduringthedetaileddesignphaseforeachProcessUnit(egOlefins)bytheDesignContractorforthatunit.3.0QRAMETHODOLOGY3.1RATIONALEFORQRAQRArepresentsasystematicapproachtotheidentification,estimat

29、ionandevaluationofhazardsassociatedwithparticularindustrialinstallations,processesandoperations.TheoverallprocessofQRAisnotaprecisescientificexercise.Thenumericalrisklevelspredictedareestimates,subjecttoinherentuncertainties.QRAisnotintendedasamechanisticnorautomatictechnicalmeansofdecisionmaking.In

30、stead,itsproperroleisasadecision-aidingtool,tocollateandstructuretechnicalinformationonthelikelihoodandconsequencesofpotentialaccidentaleventsandtopermitvaluejudgementsontheirsignificance.Bythismeans,thetechniqueimprovestheconsistencyandqualityofriskmanagementinselectedareasofapplication.TheQRAshall

31、betoquantifyandassesstheriskstopersonsinaccordancewiththedirectivesofSecco,establishedfromtheConceptSafetyEvaluationinthefollowingProcessUnits:OlefinsStyrenicsPolyolefinsAcrylonitrileMethylMethacrylatearisingfrommajorhazardsandtoensurethattheycomplywiththeRiskAcceptabilityCriteriaasstatedinDocumentN

32、o.ST-00-TIJ-SE-0001andcanbedemonstratedtobeAsLowAsReasonablyPracticable(ALARP).TheDesignContractorforeachpartoftheProcessshallberesponsibleforproducingtheQuantitiveRiskAssessmentforthatpartoftheprocess.ThisgenericmethodologyindicatestheapproachtotheworkrequiredineachQRAReport.QuantitiveRiskAssessmen

33、tPhilosophyPage7of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A023.2METHODOLOGYThemethodologyshallinvolvethefollowingnumberoflogicalsequentialstepsasexplainedinSection2:HazardIdentificationandScreening.IncidentScenarioDevelopment.FrequencyandProbabilityAnalysis.ConsequenceMode

34、lling.SafetyFunctionImpairmentEstimation.FatalityEstimation.RiskEvaluation.Whatif?analysis.DemonstrationofALARP.PresentationofResults.HazardIdentificationandScreeningPotentialhazardsshallbeidentifiedandrankedaccordingtotheseverityoftheirconsequencesandpotentialforescalation.TheTopEventsshallbedeterm

35、inedfromtheConceptSafetyEvaluationbySeccoandindicatedtotheContractorsDesignSafetyEngineers.Minorhazardsareexcludedfromfurtheranalysis.MajorhazardsformasetofTopEventstobeanalysedbyQRA.TechniquessuchasHAZOP(HazardandOperabilityStudy)orFMEAmayproveusefulinidentifyingpossibleTopEvents.However,experience

36、andjudgementarebyfarthemosteffectivemethodsforgeneratingthem.TopEventsareexpectedtoinclude,butnotbelimitedto:Leaksfromprocessequipmentorpipework.,egflammablehydrocarbonvapoursandliquids,toxicvapours.VehiclecollisionwithpiperacksorsimilarincidentsDroppedobjects.Occupationalaccidents.IncidentScenarioD

37、evelopmentEachTopEventisfurtherdevelopedintoIncidentScenariosresultinginafullrangeofpossibleoutcomes(EndEvents).ThisdevelopmentprocessshallbecarriedoutbymeansofEventTrees.QuantitiveRiskAssessmentPhilosophyPage8of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A02Theeventtreesareco

38、nstructedbyconsideringanumberofintermediateeventssuchas:Immediateignition?GasdetectionfailureFiredetectionfailureESDfailureBlowdownfailureEachoftheseevents(questions)canhavetwooutcomes(answers),yesorno,givingtwobranchestowhichprobabilitiesareassigned.Formodellingpurposes,TopEvent-to-EndEventpathstha

39、thavesimilarultimateconsequencesmaybeaggregatedandrepresentedbysingleincidentscenarios.Frequenciesofmultipleeventsmay,bythismeans,besummatedandassignedtoarelativelysmallnumberofdistinctandrepresentativescenarios.FrequencyandProbabilityAnalysisThefrequenciesoftopeventsmaybeobtainedfromstatisticaldata

40、havingahistoricalbasissuchasE&PForumData.Alternatively,wherehistoricaldataisabsent,thesefrequenciescanbederivedbymeansofFaultTrees,usinggenericequipmentfailureratesfromtheOREDAandSRDDatabases.Frequenciesorprobabilitiesofequipmentfailureorincidentoccurrence,usedinfaultandeventtrees,areeitherextracted

41、fromgenericdatabasessuchasOREDAorderivedfromengineeringjudgement.Assumptionsregardingtheoperationandmaintenanceofthefacilitiesthataffecttheconstructionoffaultoreventtreesshouldbelisted.ConsequenceModellingHazardregionsforeachincidentscenarioshallbecalculatedusingappropriateconsequencemodels.Forhydro

42、carbonevents,theseregionsequatetolevelsofgasorsmokeconcentration,fireradiationorexplosionover-pressure,dependingontheincidentscenario.Theescalationpotentialofincidentscenariosshallthenbeestimatedtakingintoaccountthecorrespondingfailurecriteriaforprocessequipmentandstructuresunderthermalorblastloadin

43、g.QuantitiveRiskAssessmentPhilosophyPage9of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A02FatalityEstimationTheprobabilityofdeathandnumberoffatalitiesatrepresentativelocationsisestimatedforeachincidentwhichshallalsoincludeanysubsequentescalation.Theseshallbebasedonpersonnelexp

44、osurecriteria,whichshalldefinetheeffectsofthermalradiation,overpressure,smokeandgasonhumans.Thefatalityestimationshalltakeintoaccounttheprobablepersonneldistributionandtheintendedplantoperatingprocedures.RiskEvaluationThefrequenciesandtheconsequencesofeachscenarioshallbecombinedtoformtherequiredmeas

45、ureofrisk.Individualrisk(SiteOperativeonSite)Individualonsiteriskistheriskthatwillbeexperiencedbyanindividualworkerinagiventimeperiod.Itshallreflecttheseverityofthehazardsandtheamountoftimetheindividualspendsinproximitytothem.Theindividualriskshallbepresentedas:Individual-specificIndividualRisk(deri

46、vedfromLocation-specificIndividualRisk).Thisindicatestheriskforparticulargroupsofworkers(e.g.operators,maintainers,clerical),takingintoaccountthetimetheyspendonsite.Individualrisk(offsite)riskispresentedas:Individual-specificRisk(derivedfromLocation-specificIndividualRisk).Individual-specificRisksha

47、llindicatetheriskforparticularsectionsofthepublic(e.g.thoselivingorworkingneartheplant,thosepassingbytheplantboundary),takingintoaccountthetimetheyareexposed.SocietalriskSocietalriskistheriskexperiencedbyallpersonsonandoffsite.Itshallreflecttheseverityofthehazardsaswellasthenumberofpeopleexposedtoth

48、em.Societalriskshallbepresentedas:PotentialLossofLife(PLL)calculatedforbothonsiteandoffsite.ManningdistributionsusedtoassessthelivesatriskonsitefromanygivenscenarioshallbeextractedtakenfromthePlantManningPhilosophydocuments.Whatif?AnalysisTheeffectsofdesignoptionsonthesummatedrisksshallthenbeassesse

49、d.Atthisstage,theresultingriskmeasuresmaynotbetheonlyfactorsusedinreachingdecisions.QuantitiveRiskAssessmentPhilosophyPage10of1330/08/02SECCOQuantitiveRiskAssessmentPhilosophyPH-00-TSC-SE-0008-A02ThevariationsoftheQRAprocessshallbeassessedbyconsideringpessimisticandoptimisticinput(upperandlowerbound

50、)valuesforthemajorcontributorstorisk.Uncertaintyanalysisshouldprovideanindicationoftheconfidencelimitsoftherisksummationandmayalsobeusedtoensuretheresultsarestable,i.e.asmallchangeinoneoftheinputvariablesdoesnotcauseadisproportionatelylargechangeinanyofthefinalriskmeasures.HumanFactorsTheeffectofHum

51、anFactorsisanissuethatshallbeaddressedbytheQRAmodel.Itisacceptedthatthisisparticularlydifficultinviewofthelimiteddataavailable,however,itissuggestedthattheissueisdealtwithqualitativelyineachrelevantstudythatinputsdataintotheQRAmodel.TheQRAreportitselfwillincorporatetheissueofhumanerrorwhenassessingp

52、rocessleakageratesanddamagepotentialduringescalationmodelling.3.3COSTBENEFITANALYSISANDDEMONSTRATIONOFALARPApproachTheriskcalculatedusingthemethodologydescribedaboveshallbecomparedwithRiskAcceptanceCriteriaST-00-TIJ-SE-0001.Iftheriskislowerthanthebroadlytolerablelimitthenitisacceptableandnofurtherac

53、tionwillbenecessary.Iftheriskishigherthantheintolerablelimitthenitisunacceptableandriskreductionmeasuresmustbeimplemented.Iftheriskisbetweentheabovelimits(theALARPregion)thenitshouldbedemonstratedthatitisaslowasreasonablypracticable.Thisimpliesriskreductionmeasurestobeadoptedunlesscostbenefitanalysi

54、s(CBA)showsthecostofimplementationisgrosslydisproportionatetothepotentialbenefits.MethodologyThemethodologyforcarryingoutCostBenefitAnalysis(CBA)anddemonstratingALARPisbasedontheJustifiableExpendituremethod.Thismethodidentifiesthemaximumexpenditurethatwouldbereasonabletoreduceagivenriskbyasufficientamounttoavertonefatality.Itleavesthechoiceofsafetymeasureandpotentiallivessavedopenfordiscussion.Themethodrequiresknowledgeofthescenariooreventthatmaycausethefatality,itsfrequencyandwhetherornotmorethanonefatalitymayoccursimultaneously.Toascertainjustificat