RG1115低轨迹汽轮机发射物的防护1977

U.S.NUCLEARREGULATORYCOMMISSIONRevisom1July1977xREGULATORYGUIDEOFFICEOFSTANDARDSDEVELOPMENTREGULATORYGUIDE1.115PROTECTIONAGAINSTLOW-TRAJECTORYTURBINEMISSILESA.INTRODUCTION•GeneralDesignCriterion4,EnvironmentalandMissileDesignBases,ofAppendixA,GeneralDesignCriteriaforNuclearPowerPlants,to10CFRPart50,LicensingofProductionandUtilizationFacilities,requires,inpart,thatstructures,systems,andcomponentsimportanttosafetybeappropriatelyprotected,againsttheeffectsofmissilesthatmightresultfromequipmentfailures.Failuresthatcouldoccurinthelargesteamturbinesofthemainturbine-generatorsetshavethepotentialforproducinglargehigh-energymissiles.ThisguidedescribesmethodsacceptabletotheNRCstaffforprotectingsafety-relatedstructures,systems,andcomponentsagainstlow-trajectorymissilesresultingfromturbinefailurebyappropriateorientationandplacementoftheturbine-generatorset.TheAdvisoryCommitteeonReactorSafeguardshasbeenconsultedconcerningthisguideandhasconcurredintheregulatoryposition.B.DISCUSSIONAlthoughthereislittleinformationavailableonfailuresoflargeturbines,cumulativefailuredatabasedonoperatinghistoryforconventionalplants'indicatethattheprotectionofsafety-relatedportionsofnuclearpowerplantsfromturbinemissilesisanappropriatesafetyconsideration.Thetwobroadcategoriesofturbinefailuresareusuallyreferredtoasdesignoverspeedfailuresanddestructiveoverspeedfailures.Missilesresultingfromdesignoverspeedfailuresaretheresultofbrittlefractureofturbinebladewheelsorportionsoftheturbinerotoritself.FailuresofthistypeIcanoccurdduringstartupornor*•Linesindicatesubstantivechangesfrompreviousissue.'Bush,S.H.,ProbabilityofDamagetoNuclearComponents,NuclearSafety,Vol.14,No.3,May-June,1973.maloperation.Missilesresultingfromdestructive-overspeed-failureswouldbegenerated7-iftieoverspeedprotectionsystemmalfunctionsandtheturbinespeedincreasestoapointatwhichthelowpressurewheelsorrotorwillundergoductilefailure.Thekineticenergyofejectedmissilescanb'esufficienttodamageevensubstantialreinforcedconcreteslabsandpanels.Thusturbinemissileshavethepotentialfordamagingsafety-relatedstructures,systems,andcomponentsoftheplant.Missilesfromaturbinefailurecanbedividedintotwogroups:high-trajectorymissiles,whichareejectedupwardthroughtheturbinecasingandmaycausedamageifthefallingmissilestrikesanessentialsystemandlow-trajectoryordirectmissiles,whichareejectedfromtheturbinecasingdirectlytowardanessentialsystem.Thisguideoutlinesacceptablemethodsofprotectionagainstlow-trajectoryturbinemissiles.Considerationofturbinemissileprotectionisrelevantforessentialsystems,i.e.,thosestructures,systems,andcomponentsnecessarytoensure:1.Theintegrityofthereactorcoolantpressureboundary,2.Thecapabilitytoshutdownthereactorandmaintainitinacoldshutdowncondition,or3.Thecapabilitytopreventaccidentsthatcouldresultinpotentialoffsiteexposuresthatareasignificantfractionoftheguidelineexposuresof10CFRPart100,ReactorSiteCriteria.Thepotentialconsequencesofturbinemissilesincludedirecteffects(e.g.,damagetothespentfuelstoragepool)aswellasindirecteffects(e.g.,impairmentofvitalcontrolroomfunctions).Ineithercase,itisnecessarytoshowthattheriskfromturbinemis-USNRCREGULATORYGUIDESCommentsshouldbesenttotheSecretaryoftheCommission,U.S.NuclearRegulatoryCommission,Washington,D.C.20555,Attention:DocketingandServiceRegulatoryGuidetsareissuedtodescribeandmakeavailabletothepublicmethodsBranch.acceptabletotheNRCstaffofimplementingspecificpartsoftheCommission'sregulations,todelineatetechniquesusedbythestaffinevaluatingsOecificproblemsTheguidesareissuedinth?followingtenbroaddivisions:orpostulatedaccidents,ortoprovideguidancetoapplicants.RegulatoryGuidesarenotsubstitutesforregulations,andcompliancewiththemisnotrequired.1.PowerReactors6.ProductsMethodsandsolutionsdiffer.entfromthose4btoutintheguideswillbeaccept-2.ResearchandTestReactors7.Transportationableiftheyprovideabasisforthefindingsrequisitetotheissuanceorcontinuance3.FuelsandMaterialsFacilities8.OccupationalHealthofaitorolicensbytommissin.4.EnvironmentalandSiting9.AntitrustReviewapermitorliensebytheCommission.5.MaterialsandPlantProtection10.GeneralCommentsandsuggestionsforimprovementsintheseguidesareencouragedatallRequestsforsinglecopiesofissuedguides(whichmaybereproduced)orforplacetimes,andguideswillberevised,asappropriate,toaccommodatecommentsandmentonanautomaticdistributionlistforsinglecopiesoffutureguidesinspecifictoreflectnewinformationorexperience.ThisguidewasrevisedasaresultofdivisionsshouldbemadeinwritingtotheUS.NuclearRegulatoryCommission,substantivecommentsreceivedfromthepublicandadditionalstaffreview.Washington,D.C.20555.Attention:Director.DivisionofDocumentControl.silesisacceptablysmall,eitherbecausedesignfeaturesateprovidedtopreventdamageorbecausetheprobabilityofastrikebyaturbinemissileissufficientlylow.Turbineorientationandplacement,shielding,qualityassuranceindesignandfabrication,inspectionandtestingprograms,andoverspeedprotectionsystemsaretheprincipalmeansofsafeguardingagainstturbinemissiles.Thefirstofthese,turbineorientationandplacement,providesahighdegreeofconfid