ML17037B598

Nine Mile Point Unit 1 - Letter Regarding Mark I Containment Short Term Program Safety Evaluation Report and a Sample Federal Register Notice

ML17037B598
Person / Time
Site:	Nine Mile Point
Issue date:	02/28/1978
From:	Stello V Office of Nuclear Reactor Regulation
To:	Niagara Mohawk Power Corp
References
NUREG-0408
Download: ML17037B598 (14)

Text

8REGOg~oCyAO+~O~+*+<<IUNITEDSTATESNUCLEARREGULATORYCOMMlsslONWASHINGTON,D.C.20555February28,1978AllOperatingBWRLicensees(ExceptforHumboldt)Gentlemen:TheNRCstaffhascompleteditsreviewofthegenericMarkIContainmentShortTermProgramconductedbytheMarkIOwnersGroup'ndtheassociatedplant-uniqueinformationwhichyouprovidedwithrespecttoyourfacility'scontainmentsystem.Theresultsofourreviewaredocumentedinthestaff's"MarkIContainmentShortTermProgramSafetyEvaluationReport,"NUREG-0408,December1977.Acopy.ofthisdocumentisenclosedforyourinformation.Baseduponourreview,wehaveconcludedthatlicensedMarkIBWRfacilitiescancontinuetooperatesafely,withoutunduerisktothehealthandsafetyofthepublic,duringaninterimperiodofapproximatelytwoyearswhileamethodical,comprehensiveLonqTermProgram(LTP)isconducted.Thisconclu-sionhasbeenmadebasedonourdetermination(1)thatthemagnitudeandcharacterofeachofthehydrodynamicloadsresultingfromapostulatedde-signbasislossofcoolantaccident(LOCA)havebeenadequatelydefinedforuseintheShortTermProgram(STP)structuralassessmentoftheMarkIcontainmentsystem;and(2)that,forthemostprobableloadsinducedbyapostulateddesignbasisLOCA,asafetyfactortofailureofatleasttwoexistsfortheweakeststructuralormechanicalcomponentinthecontain-mentsystemforeachoperatingMarkIBWRfacility.AsdescribedinSectionIVofNUREG-0408,ourevaluationofthecapabilityofyourfaci'lity'sMarkIcontainmentsystemtowithstandtherecentlyidentified'OCA-relatedhydrodynamicsuppressionpoolloadsindicatesthat,althougheachofthestructuralandmechanicalcomponentsofyourcontain-mentsystemmeettheSTPstructuralacceptancecriteria(i.e.,asafetyfactortofailureofatleasttwo),thedemonstratedsafetymarginsofcertaincomponentsundertheseloadingconditionsislessthan.thatwhichisnecessarytosatisfytherequirementsofSectionIIIoftheASMEBoilerandPressureVesselCode.Consequently,wehaveconcludedthatthe

demonstratedsafetymarginofyourfacility'scontainmentsystemwithrespecttosuchloadingconditionsdoesnotcomplywithourcurrentinterpretationof"sufficientmargin"asprescribedinGeneralDesignCriterion(GDC)50,"ContainmentDesignBasis",ofAppendixAto10CFRPart50.Forlongtermoperationofyourfacility,wewillrequirethatthestructuralandmechanicalcomponents-ofyourfacility'scon-tainmentsystemmeettheacceptancecriteriaoftheASMEBoilerandPressureVesselCodetothemaximumextentpracticablefortheloadsandloadingcombinationsidentifiegjntheMarkIContainmentLongTermProgramandapprovedbytheNRCstaff.However,wefindthat:(1)yourfacility'scontainmentsystemdesignstillretainssufficientmarginunderpresentconditionstoprecludefailureandthusprovidesreasonableassuranceofnounduerisktothehealthandsafetyofthepublic,(2)theobjectiveoftheHarkICon-tainmentLTP,i.e.,torestoretheoriginallyintendeddesignsafetymarginsforeachHarkIcontainmentsystem,isacceptable,and(3)theHarkIOwner'sProgramActionPlanfortheLTPisreasonablydesignedtosatisfytheLTPobjectives.Therefore,wefindthatoperationofyourfacility,inconformancewiththeconditionsspecifiedinNUREG-0408,willnotendangerlifeorpropertyorthecommondefenseandsecurity.IntheabsenceofanysafetyproblemassociatedwithoperationofyourfacilityuntiltheLTPiscompleted,thereappearstobenopublicinterestconsiderationfavoringrestrictionoftheoperationofyourfacility.Accordingly,pursuantto10CFRPart50,Section50.12,you'rehereby.grantedanexemptionfromGDC-50,withrespecttoLOCA-relatedhydrodynamicsuppressionpoolloads,foraninterimperioduntilcompletionoftheLTP(approximatelytwoyears),providedthattheconditionsspecifiedinNUREG-0408andanyresultingTechnicalSpecificationrequirementsaremaintained.Tothisextent,thisexemp-tionencompassesanyrelatedrequirementsof10CFRPart50,Section50.55(a),andGDC-l.AsampleFEDERALREGISTERNoticerelatedtothisactionisalsoenclosedTheNoticethatisfiledwiththeOfficeoftheFederalRegisterforeachindividualplantwillbeprovidedatalaterdate.AsdiscussedinSectionIII.C.ofNUREG-0408,operatingandsurveillancerequirementsondrywe11/wetwelldiffere'ntialpressureandtoruswaterlevelswillbeincorporated,bylicenseamendment,intoyourfacilityTechnicalSpecificationsinthenearfuture

Enclosures:

SeePage3VorStell,Jr.,rectorDivisionopenReactorsOfficeofNuclearReactorRegulation

Enclosures:

l.NUREG-0408,"NarkIContainmentShortTermProgramSafetyEvaluationReport"2.FederalReisterNotice

+C SAMPLEFEDERALREGISTERNOTICEUNITEDSTATESNUCLEARREGULATORYCOMMISSIONDOCKETNO.LICENSEENOTICEOFGRANTINGANEXEMPTIONFROMTHEREUIREMENTSOFENERALDESIGNCRIER050CONTAINMENTDESIGNBASISOFAPPENDIATO1CFRPART5TheU.S.Nuclear.RegulatoryCommission(TheCommission)hasgrantedanexemptionfromtherequirementsofGeneralDesiqnCriterion50,"Contain-mentDesignBasis",ofAppendixAto10CFRPart50to(Licensee)(theLicensee).ThisexemptionrelatestothedemonstratedsafetymarginoftheMarkIcontainmentsystemfor(FacilitName)forrecentlyidentifiedhydrodynamicsupppressionpoolloadsassociatedwithapostulateddesignbasislossofcoolantacci.dentandprovidesforoperationundertheconditionsspecifiedintheNRCstaff's"MarkICon-tainmentShortTermProgramSafetyEvaluationReport"andunderanyresultingTechnicalSpecificationrequirements.Tothisextent,thisexemptionencompassesanyrelatedrequirementsof10CFRPart50,Sec-tion50.55(a),andGeneralDesignCriterion1.Thisexemptioniseffectiveasofthedateofitsissuance.TheCommissionhasevaluatedthedemonstratedsafetymarginofthecontainmentsystemfor(FacilitName)underpresent

conditionsandhasconcludedthatsufficientmarginexiststoprecludeunduerisktothehealthandsafetyofthepublic.Thisevalua-tionisdocumentedinthestaff's"HarkIContainmentShortTermProgram.SafetyEvaluationReport,"NUREG-0408,Pecember1977.Thisexemptionisgrantedforaninterimperiodofapproximatelytwoyearswhileamoredetailedreviewi'sconducted.Attheconclusionofthisre-view,thedesignsafetymarginofthecontainmentsystemfor(FacilitNamewillberestoredtothatwhichwasoriginallyintendedatthetime(FacilitName)waslicensedforoperation.Thebasisforthisexemptionissetforthinthelettertothelicenseegrantingtheexemption,datedFebruary,1978.TheCommissionhasdeterminedthatthegrantingofthisexemptionwillnotresultinanysignificantenvironmentalimpactandthatpursuantto10CFRSection51.5(d)(4)anenvironmentalimpactstatementornegativedeclara-tionandenvironmentalimpactappraisalneednotbepreparedinconnectionwiththisaction.Forfurtherdetailswithrespecttothisaction,see(1)theCommission'slettertothelicenseedatedFebruary,1978,and(2)theCommission'

)~H,~"1IllII "MarkIContainmentShortTermProgramSafetyEvaluationReport,"NUREG-0408,December1977.TheseitemsareavailableforpublicinspectionattheCommission'sPublicDocumentRoom,1717HStreet,N.W.,Washington,D.C.andatthe(LPDR)Acopyofitem(1)maybeobtaineduponrequestaddressedtotheU.S.NuclearRegulatoryCommission,Washinq-ton,D.C.20555,,Attention:Director,DivisionofOperatingReactors.Acopyofitem(2)maybeobtaineduponrequestaddressedtotheNationalTechnicalInformationService,Sprinqfield,Virginia22161.DatedatBethesda,MarylandthisFORTHENUCLEARREGULATORYCOMMISSION,ChiefOperatinqReactorsBranchDivisionofOperatingReactors Cl NiagaraMohawkPowerCorporationcc:EugeneB.Thomas,Jr.,EsquireLeBoeuf,Lamb,Leiby5MacRae1757NStreet,N.W.Washington,D.C.20036AnthonyZ.RoismanNaturalResourcesDefenseCouncil91715thStreet,N.W.Washington,D.C.20005OswegoCountyOfficeBuilding46E.BridgeStreetOswego,NewYork13126