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;orbyemailtoDistribution@nrc.gov.ElectroniccopiesofthisguideandotherrecentlyissuedguidesareavailablethroughtheNRC’spublicWebsiteundertheRegulatoryGuidesdocumentcollectionoftheNRC’sElectronicReadingRoomat’sAgencywideDocumentsAccessandManagementSystem(ADAMS)at(DraftwasissuedasDG-1159,datedOctober2006)DESIGNLIMITS,LOADINGCOMBINATIONS,MATERIALS,CONSTRUCTION,ANDTESTINGOFCONCRETECONTAINMENTSA.INTRODUCTIONThisregulatoryguidedescribesanapproachthatthestaffoftheU.S.NuclearRegulatoryCommission(NRC)considersacceptableforuseinsatisfyingtherequirementsofGeneralDesignCriteria(GDC)1,2,4,16,and50,asspecifiedinAppendixA,“GeneralDesignCriteriaforNuclearPowerPlants,”toTitle10,Part50,oftheCodeofFederalRegulations(10CFRPart50),“DomesticLicensingofProductionandUtilizationFacilities”(Ref.1).Specifically,GDC1,“Qualitystandardsandrecords,”requires,inpart,thatstructures,systems,andcomponents(SSCs)importanttosafetybedesigned,fabricated,erected,andtestedtoqualitystandardscommensuratewiththeimportanceofthesafetyfunctionstobeperformed.Toaugmentthoserequirements,GDC2,“Designbasesforprotectionagainstnaturalphenomena,”requiresthatSSCsimportanttosafetybedesignedtowithstandtheeffectsofexpectednaturalphenomenawhencombinedwiththeeffectsofnormalandaccidentconditions.Similarly,GDC4,“Environmentalanddynamiceffects,designbases,”requiresthatnuclearpowerplantSSCsimportanttosafetybedesignedtoaccommodatetheeffectsofandtobecompatiblewithenvironmentalconditionsassociatedwithnormaloperation,maintenance,testing,andpostulatedaccidents,includingloss-of-coolantaccidents(LOCAs).Rev.3ofRG1.136,Page2Inaddition,GDC16,“Containmentdesign,”requiresthatareactorcontainmentanditsassociatedsystemsbeprovidedtoestablishanessentiallyleaktightbarrieragainstuncontrolledreleaseofradioactivitytotheenvironmentandtoensurethatdesignconditionsimportanttosafetyarenotexceededforaslongasrequiredforpostulatedaccidentconditions.Finally,GDC50,“Containmentdesignbasis,”requiresthatthereactorcontainmentstructure(includingaccessopenings,penetrations,andcontainmentheatremovalsystems)bedesignedsothatthestructureanditsinternalcompartmentscanaccommodate,withoutexceedingthedesignleakagerateandwithsufficientmargin,thecalculatedpressureandtemperatureconditionscausedbyanyLOCA.10CFR50.44providestherequirementsforcombustiblegascontrolforcurrentlylicensedreactorsandforfuturewater-cooledreactorapplicantsandlicensees.ThisregulatoryguidedescribesanapproachacceptabletotheNRCstafftoconsiderthestructuralloadsinvolvedanddeterminethecontainmentresponseinordertodemonstratethecontainmentstructuralintegrity.Inaddition,forcertainreactorsspecifiedin10CFR50.34,“Contentsofapplications:technicalinformation,”requiresthatplantdesignsmustaccommodateloadingsassociatedwithhydrogengenerationthatresultsfrommetal-waterreactionofthefuelcladdingaccompaniedbyhydrogenburningortheaddedpressureofinertingsystemactuation.Inaddition,AppendixB,“QualityAssuranceCriteriaforNuclearPowerPlantsandFuelReprocessingPlants,”to10CFRPart50requires,inpart,thatmeasuresmustbeestablishedtoensurematerialscontrolandcontrolofspecialprocesses,suchaswelding,andpropertestingmustbeperformed.Thisregulatoryguidecontainsinformationcollectionscoveredb