ML080140077
| ML080140077 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/11/2008 |
| From: | Bischof G T Dominion, Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 07-0834E | |
| Download: ML080140077 (16) | |
Text
Dominion Nuclear Connecticut, Inc.
Dominion Boulevard, Glen Allen, Virginia 2.,060\X,*h\ddrcss:
www.dom.com January II, 2008 07-0834E RO 50-423 NPF-49SerialNo.:
NLOS/MAE:DocketNo.:LicenseNo.:U.S.NuclearRegulatoryCommissionAttention:DocumentControlDeskOneWhiteFlintNorth11555RockvillePikeRockville,MD20852-2378 DOMINION NUCLEAR CONNECTICUT, INC.MILLSTONE POWER STATIONUNIT3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING STRETCH POWER UPRATE LICENSE AMENDMENT REQUEST RESPONSE TO QUESTIONS SBPB-07-0082 THROUGH SBPB-07-0087DominionNuclearConnecticut,Inc.(DNC)submittedastretchpowerupratelicense amendmentrequest(LAR)forMillstonePowerStationUnit3(MPS3)inlettersdatedJuly13,2007(SerialNos.07-0450and07-0450A),andsupplementedthesubmittalbylettersdated September12,2007(SerialNo.07-0450B)andDecember13,2007(SerialNo.07-0450C).TheNRC staffforwardedrequestsforadditionalinformation(RAls)in October29,2007andNovember27,2007letters.DNCrespondedtotheRAlsinlettersdated November19,2007(SerialNo.07-0751)andDecember17,2007(SerialNo.07-0499).TheNRC staff forwardedanadditionalRAIinaDecember14,2007letter.TheresponsetoquestionsSBPB-07-0082throughSBPB-07-0087ofthisRAIisprovidedintheattachmenttothisletter.TheinformationprovidedbythisletterdoesnotaffecttheconclusionsofthesignificanthazardsconsiderationdiscussionintheDecember 13,2007DNCletter(SerialNo.07-0450C).Shouldyouhaveanyquestionsinregardtothissubmittal,pleasecontactMs.MargaretEarleat804-273-2768.
Sincerely,VicePresidentNuclearEngineering COMMONWEALTH OF VIRGINIACOUNTYOFHENRICOTheforegoing document was acknowledged before me,inandfortheCountyand Commonwealthaforesaid,todaybyGerald T.Bischof,whoisVice PresidentNuclearEngineeringofDominionNuclearConnecticut.Inc.Hehasaffirmedbeforemethatheisduly authorizedtoexecuteandfiletheforegoingdocumentin behalfofthatCompany,andthatthe statementsinthe documentaretruetothebestofhisknowledgeandbelief.
Acknowledgedbeforemethis 1/7JI day of(fm<"'0'2008.My Commission Expires: '1'J/0.&, t JIu YlCKll.HUll R f I Notafy PubUcNotaryPublic Comrnonweanh 0'Virginia 1-'2 My Conwnlnlan
.....May 31.2010 Commitmentsmadeinthisletter:None Attachmentcc:U.S.NuclearRegulatoryCommissionRegionI Regional Administrator 475 Allendale RoadKingofPrussia,PA19406-1415 Mr.J.G.Lamb U.S.NuclearRegulatoryCommission One WhiteFlintNorth11555RockvillePikeMailStop 0-8B1ARockville,MD20852-2738Ms.C.J.Sanders Project Manager U.S.NuclearRegulatoryCommission One WhiteFlintNorth11555RockvillePikeMailStop 0-8B3Rockville,MD20852-2738Mr.S.W.Shaffer NRC SeniorResidentInspectorMillstonePowerStation DirectorBureauofAir ManagementMonitoringandRadiationDivision Department of Environmental Protection79ElmStreetHartford,CT06106-5127SerialNo.07-0834E DocketNo.50-423SPUQues.SBPB-07-0082-SBPB-07-0087Page2of2 ATTACHMENT LICENSE AMENDMENT REQUEST STRETCH POWER UPRATE LICENSE AMENDMENT REQUEST RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RESPONSE TO QUESTIONS SBPB-07-0082 THROUGH SBPB-07-0087 MILLSTONE POWER STATIONUNIT3 DOMINION NUCLEAR CONNECTICUT, INC.
SeriaINo.07-0834EDocketNo.50-423Attachment,Page1of13 Balance-ot-Plant Branch SBPB-07-0082 In Attachment5,Section2.5.6.3,SolidWasteManagementSystems,thelicenseestates"ImplementationofSPUisanticipatedtoincreasethepotentialforoccurrenceofthecrudinducedpowershift(CIPS)phenomena.Detailsassociatedwiththefuelcleaningprocessproposedtomanageand/orprecludeCIPSrequirefinalization."Consistentwiththerequirementsof10CFR50.34a(c),describeanynewequipmentnecessaryforcontrolofliquideffluentsfromthecleaningprocessandtheeffectthattreatmentofthoseeffluentswouldhaveonthepackagingandstorageofsolidwaste.
ONe ResponseDominionNuclearConnecticut(DNC)iscurrentlyintheprocessofevaluationandselectionofthevendorthatwillprovidethefuelcleaningservices.Assuch,nodetailsabouttheequipmentareavailableatthistime.Thefuelcleaningsystemscurrentlyunderevaluationdonotincludeanypermanentlyinstalledequipmentandwouldnotinvolvethecreationofanyliquidradioactiveeffluents.Thecrudremovedfromthefuelwillbecollectedonfiltersandthefilterswouldrequiresubsequentdisposal.Itisexpectedthatthesefilterswouldnotbesignificantlydifferentfromotherfiltersthatcollectradioactive materials.Thenormalchangeprocesseswillbeappliedwhenthefuelcleaning equipmentisplacedintoservice(e.g.procedurechangesandtemporarymodifications).Thesechangeprocesseswillinsurethatthecontrolofliquidandsolidradioactivewasteswillcomplywithallapplicablerequlationsandrequirements.
SBPB-07-0083 In Attachment1,Section3.3,Demineralized WaterStorageTank(DWST)LicensingBasisChange,thelicenseeproposestochangethelicensingbasisfortherequiredlevelintheDWST.TheexistingbasisisfortheDWSTtoholdenoughwaterfor10hoursathotstandby.Thelicenseeproposedtochangethebasistoholdenoughwaterfor7hoursathotstandby.Tosatisfyaccidentanalysisassumptions,theDWSTmustcontainsufficientcoolingwatertoremovedecayheatfollowingareactortrip,andthentocooldownthereactorcoolantsystem(RCS)toresidualheatremovalentryconditions,assuminga coincidentlossofoffsitepowerandthemostadversesinglefailure.Provideanevaluation SerialNo.07-0834EDocketNo.50-423Attachment,Page2of13oftheproposedlicensingbasischange,includingthebasisforthecurrent10hourrequirementandthebasistoconcludethattheproposedsevenhoursadequatelyaddressesallaccidentanalysesandrequirements.
ONe Response 1.GeneralRegardingcoldshutdowncapabilities,theMPS3DWSTdesignandlicensingbasisconsidered,butdoesnotcomplywith,BranchTechnicalPosition(BTP)RSB5-1(seeFSARSection10.4.9,"AuxiliaryFeedwaterSystem").Furthermore,BTPRSB 5-1doesn'trequirethefunctionalcapabilityforcoldshutdown(withcreditingonlysafety-gradeSSC's)forallaccidents.ThisapproachwouldhavebeentheDWSTdesignandlicensingbasisifMPS3fullycompliedwithdraftRegulatoryGuide(RG)1.139,"GuidanceforResidualHeatRemoval"(May1978)whichcontainedthefollowingsentence:"Consequently,itisessentialthatapowerplanthavethecapabilitytogofromhot-standbytocold-shutdownconditions(whenthisisdeterminedtobethesafetycourseofaction)underanyaccidentconditions."R.G.1.139wasneverissuedbyNRC;butrather,BTPRSB5-1wasissuedanditdefinedamethodacceptabletotheNRCforcomplyingwithGDC19and34.BTPRSB 5-1PositionAspecifiesafunctionalcapabilityforthereactortobetaken"fromnormaloperatingconditions"tocoldshutdownusingonlysafetygradesystems.AsindicatedinFSAR5.4.7.2.3.5,"SafetyGradeColdShutdown",thedesignSafetyGradeColdShutdown(SGCS)assumesasafeshutdown earthquake(SSE)coincidentwithalossofoffsitepower.Thepostulatedseismiceventmayimpactalternatenon-seismicauxiliaryfeedwater(AFW)pumpsuctionsourcesorimpactlonger-termDWSTreplenishment activities/capabilities.LicenseReportTable2.5.4.5-2,"Demineralized WaterStorageTank-SGCSFunctionalRequirementsComparisonBeforeandAfterUprate"providesan assessmentofMPS3SGCSfunctionalrequirements.TheDWSTisrequiredtohavesufficientinventorytomitigatenumerousaccidents,butingeneralFSARChapter15accidentsaremitigatedrelativelyquickly.Forexample,thelicensingbasisforamainsteamlinebreak(MSLB)accidentishot-standbyandthisaccidentismitigatedusingonlyasmallportionoftheDWSTinventory.Amoredetailedaccident assessment isprovidedinSection3ofthisresponse.
SeriaINo.07-0834EDocketNo.50-423Attachment,Page3of13MPS3SPULicenseAmendmentRequest,Attachment1,page28providesatechnicalanalysisfortheDWSTlicensingbaseschangeanditcontainsthefollowingstatement:"Theproposedlicensingbasischangeprovidesadequateinventoryforaccidentanalysisprimarysuccesspathsandprovidesadequateinventorywhichoperatingexperienceand/orprobabilisticrisk assessment hasshowntoassurepublichealthandsafety." 2.Bases for Current DWST 10/6 Design CriterionThe10-hourathot-standby,followedbya6-hourcooldowntoRHRentryconditions(10/6)DWSTdesigncriterionforMPS3wasestablishedearlyinthelicensingprocess.TheMPS3PSAR(circa1973)describesagallonDWST(whichwouldhavebeenequivalenttoan approximate 2/5DWSTdesigncriterion).In1979,the10/6DWST SIZingcriterionwasselectedbytheAlE(inconsultationwiththeNuclearSteamSupplySystem(NSSS)vendorinexpectationofaSGCSdesignthatmightberequiredtocomplywithdraftRegulatoryGuide(RG)1.139(i.e.,underanyaccidentcondition).Specifically,internalcorrespondenceshowsthatplantdesignerswerecontemplatingaSGCSdesignthatincludedallConditionII,III,IVevents,includinganeventthatrequiredcontrolroomevacuation,whichwouldhaveresultedinsafeshutdownbeingconductedfromtheAuxiliaryShutdownPanel(ASP).AlEandNSSSvendorcorrespondencein1979showthatthe 1 O-hourhot-standbyperiodwascomprisedofthefollowingtimeintervals:C*1979Table1DWSTHStdbPhC't
-ot-an>y asenenon trca Design Consideration Time (Hours)"safetygradeshort-term 4 allowance""borationperiod" 6 Sub-total 10AstheSGCSdesignevolved,includingBTPRSB 5-1issuanceinlieuofRG1.139,theoutsidethecontrolroomandthe"underanyaccidentconditions"designaspectswereeliminatedfromtheSGCSdesign.TheMPS3SGCSdesignandlicensingbasesevolvedtoaddressonlyasafeshutdown earthquake(SSE)andcoincidentLossofNormalPower(LNP).SincetheSGCSdesignandlicensingbasisdoesn'tinvolveacontrolroomevacuationoraconcurrentdesignbasisaccidentthatcomplicatedoperatorresponse,thecurrentSGCSanalysisassumesoperatorsbeginborationwithout significant SerialNo.07-0834EDocketNo.50-423Attachment,Page4of13delay,iftheDWSTistheonlyavailableSGmakeupsource(i.e.,aseismiceventdamagestheCondensateStorageTank(CST)makingitunavailableasanalternateAFWpumpsuctionsource).Insummary,theDWSTsizingcriterionwasincreasedtothecurrent10/6criterionin1979baseduponpreliminaryactionsinexpectationoftheSGCSdesignbeingrequiredtocomplywithdraftRG1.139(i.e.,theSGCSdesignthatwasevolvingatthattimeandadesignthatwasn'tfullyimplemented).
3.Assessment of DWST AccidentMitigationFunctional Requirements Against the 7/6DesignCriterionTable2providesatechnicalbasistoconcludethattheproposedDWST7/6designcriterionadequatelysupportsallaccidentmitigationrequirements.Specifically,representativeFSARChapter15accidentsarereviewedagainsttheproposedDWST7/6designcriterion.Table2 FSAR Chapter 15 Accident Analysis Assessment AgainsttheProposedDWST7/6DesignCriterion(SelectedAccidents)
Accident Assessment 7/6 design criterionLBLOCASafeShutdownLicensingBasis:N/A AcceptableAFWsystemisn'tcreditedforLBLOCAmitigation.RecirculationSpray(RSS)system,viacoldlegandhotleginjectionpathways,supportthelong-termcoolingdesignfunctionrequiredby10CFR50.46.SBLOCASafeShutdownLicensingBasis:N/A AcceptableAFWsystemiscreditedintheSBLOCAanalysis.TheSBLOCAclassificationincludesabreakspectrumfrom13.5to3/8-inchdiameter.AsspecifiedinWCAP9600,"ReportonSmallBreakAccidentsforWestinghouseNSSSSystem"theSBLOCAlong-termcoolingdesignfunctionisperformedbysumprecirculationusingemergencycorecoolingsystem(ECCS)[i.e.,RecirculationSpraySystem(RSS)whichwillrejectdecayheattotheultimateheatsink(UHS)].Fromadesignandlicensingperspective,RSSsystem/ECCSisthecreditedlong-termpathwayandthe RHRsystemisa SerialNo.07
-0834E Docket No.50-423 Attachment,Page5of13 Accident Assessment 7/6 design criterion potentially availableSSGthatcanbeusedat operator discretion.Thespectrum upperend(i.e.,13.5to2-inch diameter)is mitigatedrelativelyquickly.TheSG's don'tperformany long-termheatremovalfunction becauseheatremovedbythebreakflowbecomes sufficient(orwithin1-houronlyaverysmallSGsteamrateisrequired)andtheRSSSystemisthelong-termheatremovalpathway.
SBLOGA'sonthelowerendofthe spectrum require operatoractiontoestablishalong-termcoolingmethod.If condensatemakeuporotherSSG availability becomes aconcern,plant operatorscanopenthesteam generator atmosphericdumpbypassvalves (SGADBV)and/or pressurizer power-operatedreliefvalve (PORV's)to establishthecreditedSBLOGAlong-termcoolingmethod(i.e.,EGGSsump recirculation).IfaPORVisopenedto establishthecreditedsumprecirculation long-term heatremovalpathway,theSGheatremoval pathway isn'trequiredbeyondthispoint.
The smallest un-isolable SBLOCAwouldhaveanRCS leakage rate greaterthan126-gpmat2250psia(Ref.FSARpage9.3-56).A complexanalysiswouldberequiredto determinelong-termDWSTusageinlightof the decayheatremovedby emergencycorecoolingsystem(EGCS)flow.However,DWST steaming support capability would significantlyextendbeyond 13-hours duetoheatremovedbythefeedandbleedheatremovalpathways.Thus,the 334,OOO-gallonDWSTlimiting conditionofoperationismorethan adequatetimeto ensure the SBLOCA'screditedlong-termcoolingmethodcanbe established,ifrequired.MainSteamSafe ShutdownLicensingBasis:Hot Standby AcceptableLineBreakFSARSection15.0definestheMainSteamLineBreak accidentasaConditionIVevent.
Secondarysidepiping failureeventsareexcludedfromtheSGCSdesignandlicensingbasis because subsequent cooldownisnotfrom[FSAR 15.1.5]"normal operating conditions".
SeriaINo.07-0834E Docket No.50-423 Attachment,Page6of13 Accident Assessment 7/6 design criterionMPS3wouldbe broughttocoldshutdownona schedule commensuratewithsafetyandusing available SSC's.[FSARSection15.1.5shows accident is mitigatedwithin1-hour]Feedwater Safe ShutdownLicensingBasis:Hot Standby AcceptableLineBreakFSARSection15.0definesthe FeedwaterLineBreak accidentasaConditionIVevent.
Secondarysidepiping failureeventsareexcludedfromtheSGCSdesignandlicensingbasisbecause subsequentcooldownisnotfrom
[FSAR15.2.8]"normaloperatingconditions".MPS3wouldbebroughttocold shutdownona schedule commensuratewithsafetyandusing available SSC's.[FSARFigure15.2.13to24show accident is mitigatedwithin1-hour]
Rod Cluster Safe ShutdownLicensingBasis:Hot Standby Acceptable Control Assembly This eventisclassifiedasaConditionIVevent.The Ejection, accident'sreactivitycontrolaspectsare mitigated relatively Spectrum ofquickly.The accident's primary system pressure boundary failureaspectswouldbe governedbythe SBLOCAanalysis,whichis addressed above.[FSAR 15.4.8]MPS3wouldbe broughttocoldshutdownona schedule commensuratewithsafetyandusing available SSC's.[FSARTable15.0-6 doesn'tlistthe AFWsystemasasystemrequiredfor accident mitigation]LossofNon-Safe ShutdownLicensingBasis:Cold Shutdown Acceptable emergency AC Power toTheLossofNon-emergencyACPower accidentiswithintheStationtheSGCSdesignbasis becauselossofnormal power Auxiliaries
&(LNP)eventis encompassedintheSGCSdesign scenarioLossof (seismiceventwith concurrentlossofnormalpower).
Normal Therefore,theSGCSdesignandlicensingbasis Feedwater encompassesthisaccident.TheSPU'sSGCS analysiswithLossof demonstratesthattheDWST7/6criterion provides Normal Power adequate condensate.
SerialNo.07-0834E Docket No.50-423 Attachment,Page7of13 Accident Assessment 7/6 design criterion[FSAR15.2.6ALNPcausesalossofnormal feedwater(LONF)eventand15.2.7]andFSARSection15.2.6saysthatSection15.2.7 addressesthelossof feedwater aspectofthelossofAC power events.Locked Rotor Safe ShutdownLicensingBasis:Hot Standby Acceptable[FSAR15.3.3]
This accidentismitigatedrelativelyquickly.FSARTable15.0-6,"PlantSystemand EquipmentRequiredfor Mitigation of Transient or Accident"showsthat AFWsystemisnotcreditedforlockedrotormitigation.FSARSection15.0definesthelockedrotor accidentasa ConditionIVevent.This accidentwouldbe outside theBTPRSB5-1's"fromnormalplantconditions"criterionand this accidentisoutsidetheMPS3SGCSdesign scenario(whichisbasesfor MPS3's degree of compliancetoBTPRSB5-1).MPS3wouldbebroughttocoldshutdownona schedule commensuratewithsafetyandusing available SSC's.SGTR Safe ShutdownLicensingBasis:Hot Standby/Hot Acceptable Shutdown[FSAR 15.6.3]AFWsystemiscreditedintheSGTRanalysis.This accidentinvolvesRCS cooldown/depressurization to terminatethebreakflowintotheimpactedSG.Thisoccurswithin 2-hoursandthe7/6criterionismorethan sufficient to support accidentmitigation.A complexanalysiswouldberequiredto determine long-term DWSTusageinlightofthedecayheatremovedby emergencycorecoolingsystem(ECCS)flowbuttheDWST capabilitywouldbeextendedbytheECCS decayheatremoval pathway.FSARSection15.0definestheSGTR accidentasa ConditionIVevent.Accidents involving primary system pressure boundary passive failuresarebeyondtheSGCSdesignandlicensingbecausethey don'tmeetthe"from normal operatingcondition"criterion.
SerialNo.07-0834EDocketNo.50-423Attachment,Page8of13 Accident Assessment 7/6 design criterionMPS3wouldbebroughttocoldshutdownonaschedulecommensuratewithsafetyandusingavailableSSC's.[FSARTable15.6.3-2showsbreakflowterminatedwithin2-hours.OffsiteradiationdoseforSGTRaccidentperformedwithmethodologydevelopedinWCAP10698,Supplement1]TheSGCSanalysisisbaseduponan11-hoursRHRentrytime(whichisdiscussedinthefollowingRAIresponse).Notwithstandingtheaccidentsafeshutdownmodes,theproposed7/6DWSTdesigncriterionaffordswaterforinexcessof13.7-hoursformostaccidentsbecausetheproposedDWSTdesign criterion conservativelyretainsafeedwaterlinebreakspillageallowance(whichisequivalentto0.7-hourssteamingtime).Therefore,anapproximate2.7-hourtimemarginisretainedbetweentheSGCSanalysisRHRentrytimeandDWST7/6designcriterion.Therefore,althoughbeyondtheplantdesignandlicensingbasis,itisreasonabletoconcludethatcoldshutdownconditionscanbeachievedformanyaccidentscreditingonlytheDWSTinventorybecausethedecisiontoinitiateRCSborationwouldlikelybemadewithin2.7-hours.AsstatedintheMPS3license amendment request (Attachment1,page28),theDWST7/6designcriterionalsoaffordsadequatetimeforDWSTreplenishmentactivities,ifadditionalcondensateisrequired.
4.SummarySPUSGCSassessmentshaveconcludedthatthe7/6DWSTdesigncriterionresultsinampleusablewaterforSGCSdesignscenarios.The7/6DWSTdesigncriterionprovidesamplewatertomitigateallFSARChapter15designbasisaccidents.TheMPS3licensingreportaddressesthestationblackoutandfireshutdowndesignrequirements.
SerialNo.07-0834EDocketNo.50-423Attachment,Page9of13 SBPB-07-0084 In Attachment5,Section2.8.4.4.2.2.2,SafetyGradeColdShutdown(SGCS)CooldownAnalysis,thelicenseestatesthatTS3.7.1.3ensuresanadequatevolumeintheDWSTtosupporthotstandbyconditionswithsubsequentRCScooldown.Thelicenseeproposestochangethereasonabletimeperiodto72hoursfrom76hours,butkeepsthe36-hourrequirementtoinitiationofresidualheatremoval.ThesafetyrelatedwatersourceistheDWST,whichatSPUconditionswillonlyhavethecapacityforapproximately13hours,asstatedinSection2.5.4.5,AuxiliaryFeedWater.SinceSGCStakescreditforonlyrelatedequipment,notcreditingtheuseofthenon-safety-relatedcondensatestoragetankandservicewater,explainhowthe36-hourrequirementwouldbemaintainedbysafety-relatedequipment.
ONe ResponseBranchTechnicalPosition(BTP)RSB 5-1(Rev.2,July1981)guidancedoesnotincludea36-hourfunctionalrequirementforasafety-relatedsteam generator(SG)inventorymakeupsupply.However,theregulatorypositioninBTPRSB5-1,PositionAprovidesthefunctionalrequirementtobringthereactortoacoldshutdownconditionwithinareasonableperiodoftimefollowingshutdown,assumingthemostlimitingsinglefailureandusingonlysafety-gradesystems.MPS3isproposingthefollowingchange:Table1Idhtd df blSGCS-reasonaetimepenoorcosu own Pre-SPU Post-SPUreasonabletimefromreactor66-hours72-hourstriptocoldshutdownTheproposedMPS3timewasdeterminedbasedonmeetingtheBTPRSB 5-1referencedtimefromreactortripto200°Fratherthanthecurrentreference,whichistoRHRentry.MPS3FSARSection5.4.7.2.5,"SafetyGradeColdShutdown"(page5.4-32,firstfullparagraph,lastsentence)reads:"Therefore,theMPS3licensingbasisistoachievecoldshutdownwithin66-hoursofreactortrip."SRP5.4.7,Section 111.5(reviewproceduresection)states:"thereviewer determinesthatthesystem(s)hasthecapabilitytobringthereactortoconditionpermittingoperationoftheRHRsysteminareasonableperiodoftime,...Forthe purposeofthisreview,36-hoursisconsideredareasonabletimeperiod".BetweentheStandardReviewPlan(SRP)andBTP,thereisaframeofreferencechange(Le.,RHRentrytimeversuscoldshutdowntime).
SeriaINo.07-0834EDocketNo.50-423Attachment,Page10of13Basically,theSRP5.4.7reviewproceduresectionissayingverifythatthereactorhasthecapabilitytobebroughttoRHRentryconditionswithin36-hours,butitneverdefineswhatisareasonabletimeperiodbetweenreactortripandthecoldshutdowncondition.The"broughttoRHRentryconditionswithin36-hours"wordingisusedintheMPS3SER(page5-23).SPUhasnoadverseimpactuponSGCSanalysisRHRentrytime.Table2summarizestheRHRentrytimereportedinLRTable2.8.4.4-5and2.8.4.4-6:nalysls-ntrvirnePre-SPUPost-SPURHREntryTime11-hours11-hours[timeafterreactortrip]Table2SGCSAIRH REt TTherefore,MPS3continuestosatisfythewithin36-hourRHRentrytimecriteriondelineatedinSRP5.4.7,Section 111.5.Additional Information1.MPS3SPULicenseAmendmentRequestSection2.8.7.2,"NaturalCirculationCooldown"reportsthatSPUhasnoimpactuponSGCSborationtimes.Section2.5.5.1,"MainSteam"(page2-5-113)reportsthatexisting steam generatoratmosphericreleasecapabilitycontinuestosatisfyfunctionalrequirementsinherentintheSGCSanalysis.ThesesectionssupporttheconclusionthatSPUhasnoimpactuponSGCSanalysisRHRentrytime.2.BTPRSB5-1,PositionGstates:TheseismicCategoryIwatersupplyfortheauxiliary feedwatersystemforaPWRshallhavesufficientinventorytopermitoperationathot-shutdownforatleast4-hours,followedbycooldowntotheconditionspermittingoperationoftheRHRsystem.Theinventoryneededforcooldownshallbebasedonthelongestcooldowntimeneededwitheitheronlyonsiteoronlyoffsitepoweravailablewithanassumedsinglefailure."Theproposed7-hourathot-standby,followedbya6-hourcooldowntoRHRentryconditions(7/6)DWSTdesignandlicensingbasessatisfiesthisregulatorypositionbaseduponnaturalcirculationcooldownandtheSGCSanalysis.NaturalcirculationcooldowntoRHRentryis consistent withMPS3'scommitmenttoBTPRSP5-1.
SerialNo.07-0834EDocketNo.50-423Attachment,Page11of13 SummaryThereisnofunctionalrequirementderivedfromBTPRSB5-1 guidance thatwouldrequireMPS3tohavea36-hoursafety-relatedSGinventorymakeupsupply.TheBTPRSB5-1derivedfunctionalrequirementistohave sufficient safety-relatedSGmake-upinventorytosupportachievingcoldshutdownina reasonabletimeperiod.TheonlySGinventorymake-upsourcecreditedintheMPS3SPUSGCSanalysisisthesafety-relatedDemineralized Water StorageTank(DWST).Thus,BTPRSB5-1RegulatoryPositionAandGaresatisfiedintheproposeddesign.MPS3continuestosatisfytheSRP5.4.7,Section 111.5 review procedure criteriabecausethecapabilitytobringthereactortoRHRentry conditionswithinhoursisunaffected.
SBPB-07-0085 In Attachment5,Section2.5.1.2,MissileProtection,undertheresultssubsection,thelicenseestates:"Forplantareascontaining safety-related Structures,Systems,andComponents(SSCs),theSPUwillnotresultinanychangestoexistingmissilesourcesoraddanynewcomponentsthatcouldbecomeanewpotentialmissilesource.TheSPUwillalsonotresultinanysystem configurationchangesthatwouldimpactanyexistingmissilebarrier considerations." However,thelicenseedeterminedtheneedtoincreasethe feedwaterpumpturbinespeedfrom4900revolutionsperminute(rpm)to5125rpminordertoprovide adequateflow,head,andnetpositivesuctionheadtosupportSPUconditions.Apotentialsourceofmissilesishighspeedrotatingcomponents.MissilesgeneratedinternallytothereactorfacilitymaycausedamagetoSSCsthatare necessaryforthesafeshutdownofthereactororforaccidentmitigationorforpreventionof a significantreleaseofradioactivity.Describehow equipment necessaryforsafeshutdownisprotectedfrommissilesgeneratedbyfailureofthe feedwater pumporitsturbine.Doestheincreasedfeedwaterpumpoperatingspeedaffectthis protection?
ONe ResponseTheexistingturbinedesignratingis12,000HPat5250rpm.The turbine rotorsarebeingreplacedwiththenewrotorsfortheSPU.Theredesignedrotorsand the turbinewillretaintheoriginalratingof12,000HPat5250rpm.The feedwaterturbineSPU horsepowerandoperatingspeedof5125rpmarewithintheoriginal feedwaterturbinedesignrating.Inaddition,the feedwaterturbinesarelocatedintheturbinebuildingnearthemainturbine.Thereisnosafetyrelated equipmentrequiredforsafereactor SerialNo.07
-0834EDocketNo.50-423 Attachment,Page12of13 shutdownlocatedinthevicinityofthe feedwater pump turbinesasindicatedbyMPS3FSARTable3.5-1.
SBPB-07-0086 In Attachment5,Section2.5.1,PipeFailures,thelicensee addresses impactfrommainsteamlinebreak,recirculationpump component cooling water piping,andfloodingfromthehighenergylinebreak(HELB)ofanSGblowdownsystemlineinthemainsteamvalvebuilding.Itmentionsthatmain feedwaterlinesgothroughthisarea.However,theevaluationdoesnot specifically address the increasedmassreleasefromaHELBinthe feedwatersystemanditseffectuponinternalflooding.Explaintheeffectsofincreased feedwaterflowfroma feedwaterbreakatSPUconditionsuponinternalflooding.
ONC Response The feedwaterlineintheMSVBfromthe containmentpenetrationtocolumnFwall(F-Wall)isabreakexclusionzone(MPS3FSARsection3.6.1.3.3).
Therefore,abreakisnotpostulatedinthislocationsothereisnofloodingconcern.FromtheF-Walltotheturbinebuildingabreakispostulated.
There isnoareaforflood accumulationbetweentheF-Wallandthe Turbine Buildingsincethegroundfloorisanopentruckbayandtheupperfloorsareallgrating.
Any dischargewouldquicklyleavethebuilding.
SBPB-07-0087 In Attachment5,Section2.5.5,Table2.5.5.1-1 describesthechangesinthe operating conditionsinthemainsteamsystemfrom current operating conditionstoSPUconditions.Provideanevaluationofthechangein pressure and setpointsfromthehighpressureturbinefirststagepressuretoreactor protection.
ONC ResponseAnewheatbalancehasbeendevelopedforMPS3baseduponthenewSPU100%powerlevel,NSSS3666MWt.TheheatbalancewasrunforaTavg temperatureof587.1°Fandpredictsanewturbinefirststage pressure of approximately712.2psiaforfullload.Theturbinefirststage pressure transmitterswillberescaledsuchthatthe transmitteroutputvalueforfullload impulse chamber pressure measurementwillbechangedfromits present scaledfullloadvalueof650psia(actualplantseasonal variations645to648psia)toanewscaledfullloadvalueof715psia.
Because the transmitterswillberescaledtoalignwiththenewpredictedfullload impulse chamberpressuretherewillbenoimpactonany protectionorcontrol SerialNo.07-0834EDocketNo.50-423Attachment,Page13of13setpointsthatusethetransmittersinput(ReferenceLARSection2.4.1.2.3.6forlistoffunctions),essentiallythetransmitteroutputfortheexistingfullloadpressurewillberescaledtobethesameoutputfortheSPUfullloadpressure.DuringtheMPS3SPUpowerascension,impulsechamberpressurewillbemonitoredforconsistencywiththepredictedheatbalancevalue.Ifatthenew100%SPUpowerleveltheimpulsechamberpressuredeviatesfromthepredictedvalue,thedeviationwillbeevaluatedandifnecessarytheturbinefirststagepressuretransmitterswillberescaledtoaccommodatethefinalobserved value.