RG1.182 维修活动前的风险评估和管理 2000

U.S.NUCLEARREGULATORYCOMMISSIONREGULATORYGUIDE44COFFICEOFNUCLEARREGULATORYRESEARCHREGULATORYGUIDE1.182(DraftwasissuedasDG-1082)ASSESSINGANDMANAGINGRISKBEFOREMAINTENANCEACTIVITIESATNUCLEARPOWERPLANTSA.INTRODUCTIONTheU.S.NuclearRegulatoryCommission(NRC)hasamendedtheMaintenanceRule,10CFR50.65,byaddinganewparagraph(a)(4):Beforeperformingmaintenanceactivities(includingbutnotlimitedtosurveillances,post-maintenancetesting,andcorrectiveandpreventivemaintenance),thelicenseeshallassessandmanagetheincreaseinriskthatmayresultfromtheproposedmaintenanceactivities.Thescopeoftheassessmentmaybelimitedtostructures,systems,andcomponentsthatarisk-informedevaluationprocesshasshowntobesignificanttopublichealthandsafety.[64FR38551,July19,1999,MonitoringtheEffectivenessofMaintenanceatNuclearPowerPlants]AsofJuly1998,MaintenanceRuleBaselineInspectionsatallU.S.nuclearpowerplantsiteswerecomplete.NRCstaffexperienceduringthebaselineinspectionsindicatedthatalllicenseeshavedevelopedprogramstoimplementtherecommendedpre-maintenanceassessmentprovisionoftheoriginalparagraph(a)(3).However,thebaselineinspectionsidentifiedanumberofinstancesinwhichtheseassessmentswerenotperformed(includingsomethatcausedasignificantincreaseinrisk)andidentifiedweaknessesinlicensees'programsthatcouldresultinfailurestoperformadequateassessmentspriortomaintenanceactivities.Partlybecauseoftheseinspectionfindings,theCommissionapprovedtheRegulatoryguidesareissuedtodescribeandmakeavailabletothepublicsuchinformationasmethodsacceptabletotheNRCstaffforimplementingspecificpartsoftheNRC'sregulations,techniquesusedbythestaffinevaluatingspecificproblemsorpostulatedaccidents,anddataneededbytheNRCstaffinitsreviewofapplicationsforpermitsandlicenses.Regulatoryguidesarenotsubstitutesforregulations,andcompliancewiththemisnotrequired.MethodsandsolutionsdifferentfromthosesetoutintheguideswillbeacceptableiftheyprovideabasisforthefindingsrequisitetotheissuanceorcontinuanceofapermitorlicensebytheCommission.Thisguidewasissuedafterconsiderationofcommentsreceivedfromthepublic.Commentsandsuggestionsforimprovementsintheseguidesareencouragedatalltimes,andguideswillberevised,asappropriate,toaccommodatecommentsandtoreflectnewinformationorexperience.WrittencommentsmaybesubmittedtotheRulesandDirectivesBranch,ADM,U.S.NuclearRegulatoryCommission,Washington,DC20555-0001.Regulatoryguidesareissuedintenbroaddivisions:1,PowerReactors;2,ResearchandTestReactors;3,FuelsandMaterialsFacilities;4,EnvironmentalandSiting;5,MaterialsandPlantProtection;6,Products;7,Transportation;8,OccupationalHealth;9,AntitrustandFinancialReview;and10,General.Singlecopiesofregulatoryguides(whichmaybereproduced)maybeobtainedfreeofchargebywritingtheDistributionServicesSection,U.S.NuclearRegulatoryCommission,Washington,DC20555-0001,orbyfaxto(301)415-2289,[e-mail]lsoavailableontheinternetatNRC'shomepageat(May1993).Revision2ofNUMARC93-01waspreparedbytheNuclearEnergyInstitute(NEI)andisendorsedbyRevision2ofRegulatoryGuide1.160,MonitoringtheEffectivenessofMaintenanceatNuclearPowerPlants.2Basedinpartonthesediscussionswithindustryrepresentatives,thisRegulatoryGuide1.182providesguidanceonimplementingtheprovisionsof10CFR50.65(a)(4)byendorsingarevisedSection11toNUMARC93-01.RegulatoryGuide1.182willbeusedasacompanionguidetoRegulatoryGuide1.160asguidanceonmethodsacceptabletotheNRCstaffforassessingandmanagingtheincreaseinriskthatmayresultfrommaintenanceactivitiesandforimplementingtheoptionalreductioninscopeofSSCsconsideredintheassessments.Theinformationcollectionscontainedinthisregulatoryguidearecoveredbytherequirementsof10CFRPart50,whichwereapprovedbytheOfficeofManagementandBudget,approvalnumber3150-0011.IfameansusedtoimposeaninformationcollectiondoesnotdisplayacurrentlyvalidOMBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformationcollection.B.DISCUSSIONTheobjectiveoftheMaintenanceRule,10CFR50.65,istorequiremonitoringoftheoverallcontinuingeffectivenessoflicenseemaintenanceprogramstoensurethat(1)safety-relatedandcertainnonsafety-relatedstructures,systems,andcomponents(SSCs)arecapableofperformingtheirintendedfunctions,(2)fornonsafety-relatedequipment,failureswillnotoccurthatpreventthefulfillmentofsafety-relatedfunctions,and(3)failuresresultinginscramsandunnecessaryactuationsofsafety-relatedsystemsareminimized.(Notethat,forMaintenanceRulepurposes,thetermSSCmaydenoteastructure,system,ortrain.Althoughcomponentsmaybemonitoredindividuallyatthelicensee'sdiscretion,theRuleanditsguidancegenerallydonotrequiremonitoringtothatlev