RG1.209 安全相关的基于计算机的仪控系统的环境鉴定导则 2007

TheU.S.NuclearRegulatoryCommission(NRC)issuesregulatoryguidestodescribeandmakeavailabletothepublicmethodsthattheNRCstaffconsidersacceptableforuseinimplementingspecificpartsoftheagency’sregulations,techniquesthatthestaffusesinevaluatingspecificproblemsorpostulatedaccidents,anddatathatthestaffneedinreviewingapplicationsforpermitsandlicenses.Regulatoryguidesarenotsubstitutesforregulations,andcompliancewiththemisnotrequired.MethodsandsolutionsthatdifferfromthosesetforthinregulatoryguideswillbedeemedacceptableiftheyprovideabasisforthefindingsrequiredfortheissuanceorcontinuanceofapermitorlicensebytheCommission.Thisguidewasissuedafterconsiderationofcommentsreceivedfromthepublic.TheNRCstaffencouragesandwelcomescommentsandsuggestionsinconnectionwithimprovementstopublishedregulatoryguides,aswellasitemsforinclusioninregulatoryguidesthatarecurrentlybeingdeveloped.TheNRCstaffwillreviseexistingguides,asappropriate,toaccommodatecommentsandtoreflectnewinformationorexperience.WrittencommentsmaybesubmittedtotheRulesandDirectivesBranch,OfficeofAdministration,U.S.NuclearRegulatoryCommission,Washington,DC20555-0001.Regulatoryguidesareissuedin10broaddivisions:1,PowerReactors;2,ResearchandTestReactors;3,FuelsandMaterialsFacilities;4,EnvironmentalandSiting;5,MaterialsandPlantProtection;6,Products;7,Transportation;8,OccupationalHealth;9,AntitrustandFinancialReview;and10,General.Requestsforsinglecopiesofdraftoractiveregulatoryguides(whichmaybereproduced)shouldbemadetotheU.S.NuclearRegulatoryCommission,Washington,DC20555,Attention:ReproductionandDistributionServicesSection,orbyfaxto(301)415-2289;[e-mail]ideandotherrecentlyissuedguidesareavailablethroughtheNRC’spublicWebsiteundertheRegulatoryGuidesdocumentcollectionoftheNRC’sElectronicReadingRoomat’sAgencywideDocumentsAccessandManagementSystem(ADAMS)at(DraftwasissuedasDG-1142,datedOctober2006)GUIDELINESFORENVIRONMENTALQUALIFICATIONOFSAFETY-RELATEDCOMPUTER-BASEDINSTRUMENTATIONANDCONTROLSYSTEMSINNUCLEARPOWERPLANTSA.INTRODUCTIONTitle10,Part50,oftheCodeofFederalRegulations(10CFRPart50),“DomesticLicensingofProductionandUtilizationFacilities”(Ref.1),delineatesthedesign-andqualification-relatedregulationsthattheU.S.NuclearRegulatoryCommission(NRC)hasestablishedforcommercialnuclearpowerplants.Inparticular,GeneralDesignCriterion4inAppendixA,“GeneralDesignCriteriaforNuclearPowerPlants,”to10CFRPart50requiresthatstructures,systems,andcomponents(SSCs)importanttosafetyshallbedesignedtoaccommodatetheeffectsof,andtobecompatiblewith,theenvironmentalconditionsassociatedwithnormaloperation,maintenance,testing,andpostulatedaccidents,includingloss-of-coolantaccidents(i.e.,theequipmentshallremainfunctionalunderpostulatedaccidentconditions).Thefollowingsectionsof10CFRPart50specifygeneralrequirements:•10CFR50.55a,“CodesandStandards”•AppendixA,GeneralDesignCriteria1,2,4,13,21,22,and23•AppendixB,“QualityAssuranceCriteriaforNuclearPowerPlantsandFuelReprocessingPlants,”specificallyCriterionIII,“DesignControl,”CriterionXI,“TestControl,”andCriterionXVII,“QualityAssuranceRecords”RG1.209,Page2Accordingto10CFR50.55a(h)(2),protectionsystemsshallmeettherequirementssetforthintheInstituteofElectricalandElectronicsEngineers(IEEE)Standard(Std.)603-1991,“CriteriaforSafetySystemsforNuclearPowerGeneratingStations”(Ref.2),andthecorrectionsheetdatedJanuary30,1995,orIEEEStd.279-1971,“CriteriaforProtectionSystemsforNuclearPowerGeneratingStations”(Ref.3),contingentonthedatethattheNRCissuedtherelatedconstructionpermit.Thedesign-basiscriteriaidentifiedbythosestandardsorbysimilarprovisionsinthelicensingbasisforsuchfacilitiesincludetherangeoftransientandsteady-stateenvironmentalconditionsthroughoutwhichtheequipmentshallperformduringnormal,abnormal,andaccidentoperationalevents.AsreportedinNUREG/CR-5904,“FunctionalIssuesandEnvironmentalQualificationofDigitalProtectionSystemsofAdvancedLight-WaterReactors,”issuedApril1994(Ref.4),safety-relatedmicroprocessor-basedelectricequipmentcanposeuniquefunctionalandqualificationissues.Traditionaltestingandevaluationapproachesdevelopedprimarilyforanalogequipmentmaynotfullyaddressthesedigitalissues.TheprimaryfocusofIEEEStd.323,“IEEEStandardforQualifyingClass1EEquipmentforNuclearPowerGeneratingStations”(Refs.5,6,and7),isthereliableoperationofsafety-relatedequipmentundernormal,abnormal,design-basisaccident,post-design-basisaccident,andcontainmenttestconditions.Atpresent,computer-basedinstrumentationandcontrol(I&C)systemsareprimarilyimplementedinnuclearpowerplantlocationsthatarecharacterizedasmildenvironmentsthatarenotaffectedbydesign-basisaccidentconditions.Thus,thedesign-basisaccidentelementoftypetestingforqualificationdoesnotapplytocomputer-basedI&Csystemsinmildenvironments.Inaddition,becauseofreadyaccessibilityformoni