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Revision1U.S.NUCLEARREGULATORYCOMMISSIONJune1975REGULATORYGUIDEOFFICEOFSTANDARDSDEVELOPMENTREGULATORYGUIDE1.87GUIDANCEFORCONSTRUCTION1OFCLASS1COMPONENTSINELEVATED-TEMPERATUREREACTORS(SUPPLEMENTTOASMESECTIONIIICODECASES1592,1593,1594,1595,AND1596)A.INTRODUCTIONSection50.55a,CodesandStandards,of10CFRPart50,LicensingofProductionandUtilizationFacilities,requires,inpart,thatstructures,systems,andcomponentsbedesigned,fabricated,erected,tested,andinspectedto.qualitystandardscommensuratewiththeimportanceofthesafetyfunctionstobeperformed.GeneralDesignCriterion1,QualityStandardsandRecords,ofAppendixA,2GeneralDesignCriteriaforNuclearPowerPlants,to10CFRPart50permitsuseofrecognizedcodesandstandards,providedtheyareidentifiedandevaluatedtodetermineapplicability,adequacy,andsufficiencyandaresupplementedormodifiedasnecessarytoensureaqualityproductinkeepingwiththerequiredsafetyfunction.ThisguidedescribesinterimlicensingguidelinestoaidapplicantsinimplementingtheserequirementswithrespecttoASMEClass1componentsoperatingatelevatedtemperatures.Thisguideappliestohigh-temperaturegas-cooledreactors(HTGRs),liquid-metalfast-breederreactors(LMFBRs),andgas.cooledfast-breederreactors(GCFBRs).'AsdefinedinSectionIIIoftheAmericanSocietyofMechanicalEngineersBoilerandPressureVesselCode(ASMEB&PVCode),constructionisanall-inclusivetermcomprisingmaterials,design,fabrication,examination,testing,inspection,andcertificationrequiredinthemanufactureandinstallationofcomponents.2AppendixAto10CFRPart50isdirectlyapplicabletowater-coolednuclearpowerplants;however,asindicatedinthatappendix,theGeneralDesignCriteriaareconsideredapplicabletoothertypesofnuclearpowerunitsandareintendedtoprovideguidanceinestablishingprincipalcriteriaforsuchotherunits.B.'DISCUSSIONTherulesforconstructionofnuclearcomponentsgiveninSectionIIIoftheASMEBoilerandPressureVesselCode,includingClass1nuclearcomponentsthatarecoveredinSubsectionNBofSectionIII,applytocomponentsattemperatureswherecreepeffectsareinsignificant.Materialbehaviorconsiderationsarelimitedtoeitherelasticorelastic-plasticresponse,which,ineffect,providesprotectionagainstonlytimeindependentfailuremodessuchasductilerupture,grossdistortion,andfatigue.TheservicetemperaturesandloadconditionsforHTGRs,LMFBRs,andGCFBRsaresuchthattime-dependentphenomenasuchascreepandrelaxationareimportant.SubsectionNBofSectionIIIdoesnotprovideadequateguidanceforconstructionofcomponentssubjecttoelevated-temperatureservice.Therefore,asaninterimstep,theASMEhasdevelopedfiveCodeCases(1592,1593,1594,1595,and1596)toprovideguidanceinthisarea.CodeCases1593,1594,1595,and1596wereapprovedonNovember5,1973,asinterpretationsoftheASMEBoilerandPressureVesselCode.CodeCase1592wasapprovedonApril29,1974.TheseCodeCasescoverdesign,fabricationandinstallation,examination,testing,andprotectionagainstoverpressure.Theyreflectbothtime-independentandtime-dependentmaterialpropertiesandstructuralbehavior(elasticandinelastic)byconsideringthefollowingmodesoffailure:1.Ductilerupturefromshort-termloadings;2.Creeprupturefromlong-termloadings;USNRCREGULATORYGUIDESCommentsshouldbesenttotheSecretaryoftheCommission,U.S.NuclearRegulatoryGuidesareissuedtodescribeandmakeavailabletothepublicRegulatoryCommission,Washington.D.C.20555,Attention:DocketingandmethodsacceptabletotheNRCstaffofimplementingspecificpartsoftheServiceSection.Commission'sregulations,todelineatetechniquesusedbythestaffinevalu.atingspecificproblemsorpostulatedaccidents.ortoprovideguidancetoappli-Theguidesareissuedinthefollowingtenbroaddivisions:cants-RegulatoryGuidesarenotsubstitutesforregulations,andcompliance1.PowerReactors6.Productswiththemisnotrequired.MethodsandsolutionsdifferentfromthosesetOutin2ResearchandTestReactors7.Transportationtheguideswillbeacceptableiftheyprovideabasisforthefindingsrequisiteto3.FuelsandMaterialsFacilities8.OccupationalHealththeissuanceorcontinuanceofapermitorlicensebytheCommission.4.EnvironmentalandSiting9.AntitrustReviewCommentsandsuggestionsforimprovementsintheseguidesareencouraged5.MaterialsandPlantProtection10-Generalatalltimes,andguideswillberevised,asappropriate,toaccommodatecommentsandtoreflectnewinformationorexperience.ThisguidewasrevisedasaCopiesofpublishedguidesmaybeobtainedbywrittenrequestindicatingtheresultofsubstantivecommentsreceivedfromthepublicandadditionalstaffdivisionsdesiredtotheU.S.NuclearRegulatoryCommission.Washington.D.C.review20555.Attention:Director,OfficeofStandardsDevelopment.3.Creep-fatiguefailure;4.Grossdistortionduetoincrementalcollapseandratcheting;5.Lossoffunctionduetoexcessivedeformation;6.Bucklingduetoshort-termloadings;7.Creepbucklingduetolong-termloadings.Considerationofthesecomplexfailuremodesservesasabasisfordevelopingdesignmethodsandprocedurestoprovideadequateprotectionthroughoutareactorlifetimeof30to40years.TheCodeCasesunderdiscussionutilizerecentlyacquiredinformationonmaterialbehavior,extendeduseofacceptedpractice,andspecialconsiderationofsafety-relatedaspectsofthenuclearsystemtoestablishrulesofconstructionforcomponentsinelevatedtemperatureservice.These