U.S.NUCLEARREGULATORYCOMMISSIONREGULATORYSeptember1997GUIDEOFFICEOFNUCLEARREGULATORYRESEARCHREGULATORYGUIDE1.173(DraftwasDG-1059)DEVELOPINGSOFTWAREUFECYCLEPROCESSESFORDIGITALCOMPUTERSOFTWAREUSEDINSAFETYSYSTEMSOFNUCLEARPOWERPLANTSA.INTRODUUTIONIn10CFRPart50,DomesticLicensingofProductionandUtilizationFacilities,paragraph55a(a)(1)requires,inpart,1thatsystemsandcomponentsbedesigned,tested,andinspectedtoqualitystandardscommensuratewiththesafetyfunctiontobeperformed.Criterion1,QualityStandardsandRecords,ofAppendixA,GeneralDesignCriteriafor-NuclearPowerPlants,to10CFRPart50requires,inpart,1thataqualityassuranceprogrambeestablishedandimplementedinordertoprovideadequateassurancethatsystemsandcomponentsimportanttosafetywillsatisfactorilyperformtheirsafetyfunctions.AppendixB,QualityAssuranceCriteriaforNuclearPowerPlantsandFuelReprocessingPlants,to10CFRPart50describescriteriathataqualityassuranceprogramforsystemsandcomponentsthatpreventormitigatetheconsequencesofpostulatedaccidentsmustmeet.Inparticular,besidesthesystemsandcomponentsthatdirectlypreventormitigatetheconsequencesofpostulatedaccidents,thecriteriaofAppendixBalsoapplytoallactivitiesaffectingthesafety-relatedfunctionsofsuchsystemsandcomponentsasdesigning,purchaslInthisregulatoryguide,manyoftheregulationshavebeenparaphrased;see10CFRPart50forthefulltext.ing,installing,testing,operating,maintaining,ormodifying.Aspecificrequirementiscontainedin10CFR50.55a(h),whichrequiresthatreactorprotectionsystemssatisfythecriteriaofIEEEStd279-1971,CriteriaforProtectionSystemsforNuclearPowerGeneratingStations.2Paragraph4.3ofIEEEStd279-19713statesthatqualityofcomponentsistobeachievedthroughthespecificationofrequirementsknowntopromotehighquality,suchasrequirementsfordesign,inspection,andtesting.InAppendixBto10CFRPart50,manyofthecriteriacontainrequirementscloselyrelatedtosoftwarelifecycleactivities.CriterionI,Organization,describestheestablishmentandexecutionofaqualityassuranceprogram.CriterionII,QualityAssuranceProgram,states,inpart,thatactivitiesaffectingqualitymustbeaccomplishedundersuitablycontrolledconditions,whichincludeassurancethatallprerequisitesforagivenactivityhavebeensatisfied.Thiscriterionalso2RevisionIofRegulatoryGuide1.153,CriteriaforSafetySystems,endorsesIEEEStd603-1991,CriteriaforSafetySystemsforNuclearPowerGeneratingStations,asamethodacceptabletotheNRCstaffforsatisfyingtheNRC'sregulationswithrespecttothedesign,reliability,qualification,andtestabilityofthepower,instrumentation,andcontrolportionsofthesafetysystemsofnuclearpowerplants.31EEEpublicationsmaybeobtainedfromtheIEEEServiceCenter,445HoesLane,Piscataway,NJ08854.USNRCREGULATORYGUIDESTheguidesweissuedInthefollowingtonbroadivasions:RegulatoryGuidesweIssuedtodescribeandmakeavailabletothepublicsuchInformetlionasmethodsacceptabletotheNRCstaffforImplementingspecificpartsofteCom-1.PowerReactors6.Productsmission'sregulations,rtechiquesusedbythestinevaluatingspecificproblemsorpos-2.ResearchandTestReactors7.Transportationtuiatedaccidents,anddataneededbytheNRCstaffInitsreviewofapplicationsforper-IFuelsandMaterialsFacilities8.OccupationalHealthmitsndlicenses.Regulatoryguidesaenotsubstitutesforregulations.andcomp~lance4EnvironmetalandSiting9.AntitrustandFinancialReviewwiththemIsnotreqird.Methodsandsolutionsdifferentfromthosesetoutinteguides5.MaterasandPlantProtection10.GeneralwillbeacceptableIftheyprovideabasisforthefindingsrequisitetotheissuanceorcontInuenceofapermitorlicensebytheCommission.SinglecopiesofregulatoryguldesmaybeobtainedfreeofchargebywritingthePrinting,Thsguidewasissuedafterconsiderstionofcommentsreceivedfromthepublic.Corn-GraphicsandDistributionBranch,OficeofAdmrinistiaon,U.S.NuclearRegulatoryCommentsandsuggestionsforlmprovementsIntheseguidesareencouragedatalltimes,andmission,Washington,OC20555-0001;orbytaxat(301)415-5272.willberevised,asappropriate,toaccommodatecommentsandtoreflectnewInonorexpeience.IssuedguidesmayalsobepurchasedfromtheNationalTechnicalInformationServiceonWrittencorrenantsmaybesubmittedtotheRulesReviewarndDirectivesBranch.DFIPS,asteandingorderbasis.DetailsonthisservicemaybeobtainedbywrltingNTIS.5285PoitADM,U.S.NuclearRegulatoryCommission,Waeslington.DC20555-0001.RoyalRoad,Springfield,VA22161.callsfortakingintoaccounttheneedforspecialcontrolsandprocessestoattaintherequiredquality.CriterionIII,DesignControl,states,inpart,thatmeasuresmustbeestablishedfortheidentificationandcontrolofdesigninterfacesandforcoordinationamongparticipatingdesignorganizations.CriterionXV,NonconformingMaterials,Parts,orComponents,requiresmeasurestobeestablishedtocontrolmaterials,parts,orcomponentsthatdonotconformtorequirementsinordertopreventtheirinadvertentuseorinstallation.Finally,CriteriaVI,DocumentControl,andXVII,QualityAssuranceRecords,provideforthecontroloftheissuanceofdocuments,includingchangesthereto,thatprescribeallactivitiesaffectingqualityandprovideforthemaintenanceofsufficientrecordstofurnishevidenceofactivitiesaffectingquality.ThisregulatoryguideendorsesIEEEStd1074-1995,IEEEStandardforDevelopingSoftwareLif