RG1.176 电厂特定风险预知决策的分级质量保证方法 1998

NRCRegulatoryGuide1.17619981/31August1998U.S.NRCRegulatoryGuide1.176AnApproachforPlant-Specific,Risk-InformedDecision-making:GradedQualityAssurance(Withdrawn--See73FR7766,02/11/2008)(DraftwasissuedasDG-1064)ContentsA.INTRODUCTION............................................................................................................2Background....................................................................................................................2B.DISCUSSION...................................................................................................................3PurposeandScope.........................................................................................................4RelationshiptoOtherGuidanceDocumentApplications..............................................4OrganizationandContent...............................................................................................5PROCESSOVERVIEW.......................................................................................................5Element1:DefinetheProposedChange........................................................................6Element2:PerformEngineeringAnalysis.....................................................................7Element3:DefineImplementationMonitoringProgram..............................................7Element4:SubmitProposedChange.............................................................................8C.REGULATORYPOSITION.............................................................................................81.ELEMENT1:DEFINETHEPROPOSEDCHANGE..............................................82.ELEMENT2:ENGINEERINGEVALUATION.......................................................93.ELEMENT3:DEVELOPIMPLEMENTATIONANDMONITORINGSTRATEGIES..............................................................................................................194.ELEMENT4:DOCUMENTATION........................................................................27References...........................................................................................................................30REGULATORYANALYSIS..............................................................................................30NRCRegulatoryGuide1.17619982/31A.INTRODUCTIONBackgroundTheNRChasestablisheddeterministiccriteriafordeterminingwhichcommercialnuclearpowerplantequipmentisconsideredsafety-related(seeSection50.2,Definitions,of10CFRPart50,DomesticLicensingofProductionandUtilizationFacilities;AppendixA,SeismicandGeologicSitingCriteriaforNuclearPowerPlants,to10CFRPart100,ReactorSiteCriteria;Section50.65,RequirementsforMonitoringtheEffectivenessofMaintenanceatNuclearPowerPlants,of10CFRPart50;andSection50.49,EnvironmentalQualificationofElectricEquipmentImportanttoSafetyforNuclearPowerPlants,of10CFRPart50).Becauseoftheimportanceofthesafety-relatedequipmenttoprotectingpublichealthandsafety,theNRChasadditionallyrequiredthataqualityassurance(QA)program(describedinAppendixB,QualityAssuranceCriteriaforNuclearPowerPlantsandFuelReprocessingPlants,to10CFRPart50)beappliedtoallactivitiesaffectingthesafety-relatedfunctionsofthatequipment.TheoverallpurposeoftheQAprogramistoestablishasetofsystematicandplannedactionsthatarenecessarytoprovideadequateconfidencethatsafety-relatedplantequipmentwillperformsatisfactorilyinservice.TherequirementsdelineatedinAppendixBto10CFRPart50recognizethatQAprogramcontrolsshouldbeappliedinamannerconsistentwiththeimportancetosafetyoftheassociatedplantequipment.Inthepast,engineeringjudgmentprovidedthegeneralmechanismtodeterminetherelativeimportancetosafetyofplantequipment.Inrecognitionofadvancesmadeinthestateoftheartintheprobabilisticriskassessment(PRA)technologyarea,theNRChasmadethedecisiontoexpandtheuseofPRAintheregulatoryprocess.PRAprovidesinsightsthatmaybeutilizedbylicenseestosupportthedeterminationoftherelativesafetysignificanceofplantequipment.Theprobabilisticinsightshelpidentifylowsafety-significantstructures,systems,andcomponents(SSCs)thatarecandidatesforreductionsinQAtreatment.Theendresultofthisprocesscouldbethatlicenseeswouldhaveplantequipmentthatiscategorizedassafety-relatedandhighsafety-significant;safety-relatedandlowsafetysignificant;non-safety-relatedandhighsafetysignificant;andnon-safety-relatedandlowsafety-significant.GradingofQAcontrolswouldvarycommensuratewiththesecategorizations.ThisregulatoryguideprovidesguidancethatcouldbeusedbylicenseesbothtodeterminetherelativesafetysignificanceofplantequipmentandtoadjusttheapplicationofQAcontrolsaccordingly.RequirementsrelatedtoQAprogramsfornuclearpowerplantsaresetforthinAppendixBto10CFRPart50.ThegeneralrequirementscontainedinAppendixBaresupplementedbyindustrystandardsandNRCregulatoryguidesthatdescribespecificpracticesthathavebeenfoundacceptablebytheindustryandtheNRCstaff.AlthoughbothAppendixBandtheassociatedindustrystandardsallowalargedegreeofflexibility,thelicenseesandtheNRCstaffhavebeenreluctanttomakemajorchangesinestablishedQApractices.Recently,how