ML17216A456
| ML17216A456 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 03/18/1986 |
| From: | WOODY C O FLORIDA POWER & LIGHT CO. |
| To: | THADANI A C Office of Nuclear Reactor Regulation |
| References | |
| TASK-2.D.1, TASK-TM L-86-114, NUDOCS 8603240265 | |
| Download: ML17216A456 (46) | |
Text
REGULATORY,JFORIJATIONDISTRIBUTION~cN(RIDS)ACCESS'I'OR-NBR:8'F2+0%.T~'E76"J71~10TA~~FACIL:50-335St.LuciePlantiUnitiiFloridaPower5LightCo.50-389St.LuciePlantiUnit2iFloridaPower5LightCo.AUTH.MANEAUTHORAFFILIATIONMOODY>C.O.FloridaPoeerKcLightCo.RECIP.NANERECIPIENTAFFILI*TIQNTHADANIiA.C.PWRProspectDirectorate80500033505000389
SUBJECT:
SubmitsaddiinforeS507268c1018commitmentstorespondtoTNIItemII.D.1onrelief-5safetyvalvetestrequirements.DISTRlBUTIONCODE:A046DCOPIESRECEIUED:LTRICL4IZE:TITLE:ORSubmittal:TMIActionPlanRgmtNUREG-07378cNUREG-Ohb0NOTES:RECIPIENTIDCODE/NANEPMR-8ADTSPMR-8PEICSBPMR-8PDSPD01PMR-8PEICSBINTERNAL:*DN/LFMBIE/DEPERDIR33NRRBMRADTSNRRPMR-A*DTS04COPIESLTTRENCL1122551110111111111RECIPIENTIDCODE/NANEPMR-8EBPMR-8FOBSELLS>DPMR-8RSBELD/HDS2IE/DEPER/EPBNRRPAULSON>M.NRRPMR-8ADTSNRR/DSROENRITRGN2COPIESLTTRENCL1111111033111111EXTERNAL:24XNRCPDR02111LPDRNSIC03051111Q6TOTALNUMBEROFCOPIESREQUIRED:LTTR31ENCL
,J(<<pl,jO'J'>,[Yl(',fpi<~"$qlln~<<l~:!~7$s,iga*r>>i~<<3stsJ~r' P~OX14000,JUNOBEACH,FL3340~pili&)-Alki.zlLXWFLORIDAPOWER&LIGHTCOMPANYttrgg1818%L-86-II4OfficeofNuclearReactorRegulationAttention:Mr.AshokC.Thadani,DirectorPWRProjectDirectorate88DivisionofPWRLicensing-BU.S.NuclearRegulatoryCommissionWashington,D.C.20555
DearMr.Thadani:
Re:St.LucieUnitsIand2DocketNos.50-335and50-389ReliefandSafetValveTestReuirementsByletterdatedJune2l,l985(NRCTACNo.446I7),theNRCstaffrequestedadditionalinformationontheSt.LucieUnitIdocketregardingTMIActionItemII.D.I.AsimilarrequestwasmadeontheSt.LucieUnit2docketbyNRCletterdatedJulyII,l985(NRCTACNo.5I605).BylettersL-85-29I(July26,l985)andL-85-397(OctoberI8,l985),FloridaPower8LightCompanycommittedtorespondtobothinformationrequestsbyMarchl5,l986.Incompliancewithourcommitment,therequestedinformationisattached.Verytrulyyours,C.O.WoodyGroupVicsidentNuclearErgyCOW/MAS/gpAttachmentcc:Dr.J.NelsonGrace,USNRC,RegionIIHaroldReis,Esquire,Newman&HoltzingerPDR0>~S8603188603p4PO~<0800033'DRMAS2/0I2/IPEOPLE...SERVINGPEOPLE
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TMIACTIONITEMH.D.1ST.LUCIE1uestionsrelatedtotheselectionoftransientsandvalveinletconditions:Question1.TheCombustionEngineeringReportonoperabilityofPORV'sinCEPlantsindicatedthatthelimitinginletfluidconditionsduringlowtemperaturepressurizationtransientsareawaterdischargeevent.TheCEInletFluidConditionsReportstatedthatthepressurizerwatersolidconditionandresultingPORVliquiddischargecasewaschosenforthecoldoverpressurizationeventsinceitgavethemostseverepressurizationtransients.ThereportfurtherstatesthatasteambubblecanalsoexistinthepressurizerduringlowtemperatureoperationwherebythePORVcouldliftonsteam.NolowpressuresteamtestswereperformedbyEPRIontheDresserPORV.ProvideverificationthattheSt.Lucie1PORVswilloperatesatisfactorilyonlowpressuresteam.Also,sincethesubmittaldoesnotidentifythePORVsetpointsforeithernormaloperationorlowtemperatureoverpressureprotection,pleaseprovidethisinformation.Resonsetouestionl.TheEPRItestsdemonstratedthatDresserPORVsoperatesatisfactorily,i.e.,openandcloseondemand,underawiderangeofinletfluidconditions.Theseconditionsincludedsteamathighpressures(2000-2500psia),wateratpressuresof2000-2500psia,andwateratlowpressure(630-700psia).Additionally,aseriesofsaturatedsteamtestswithvariousPORVsetpressureswereconductedbythemanufacturer(Reference1).Inthesetests,thePORVopenedandclosedwithoutfailureandwithnoapparentleakage.PORVopeningpressuresof00psigto1960psigwererecordedinthesetests.Consequently,DresserconservativelyconcludedthattheminimumoperatingpressureforthesePORVsis75psig.ThePORV'stestedinbothprogramswererepresentativeofthoseatSt.LucieUnit1.SincetheinletfluidconditionsintheirtestseitherenvelopedorapproximatedSt.LucieUnit1plant-specificinletfluidconditionspresentedinReference2,itisconcludedthatthePORVsinSt.LucieUnit1areexpectedtooperatesatisfactorilyunderallanticipatedinletfluidconditionsincludinglowpressuresteam.BothPORVsinSt.LucieUnit1havethesamesetpoints,namely:ahighpressuresetpointof2900psiaforhotstandbyandpoweroperation,andalowpressuresetpointof065psiaforlow,temperatureoverpressureprotection.
uestionsrelatedtovalveoerabilit:Question2.NUREG-0737,ItemII.D.lrequiresthattheplant-specificPORVControlCircuitrybequalifiedfordesign-basistransientsandaccidents.Provideinformationwhichdemonstratesthatthisrequirementhasbeenfulfilled.Resonsetouestion2.DesinBasisforPower0cratedReliefValves(PORV)1.RCSOverressureProtection{HPRO)ThereactorcoolantsystemisprotectedagainstoverpressurebycontrolandprotectivecircuitssuchasthehighpressurereactortripandbyASMEcodesafetyvalvesandPowerOperatedReliefValves(PORVs)connectedtothetopheadofthepressurizer.ThePORV'saredesignedtorelievesufficientsteamduringabnormaltransientstopreventactuationofthecodesafetyvalves.ThecombinedcapacityofthePORV'sislargeenoughtorelievethemaximumsurgevolumeassociatedwiththecontinuousControlElementAssembly(CEA)withdrawalstartingfromlowpower.Thetotalreliefcapacityisalsolargeenoughtopreventopeningofthepressurizercodesafetyvalvesduringalossofloadfromfullpower.Thesetwodesignrequirementsassumenormaloperationofthepressurizerspraysystemandareactortriponhighpressurizerpressure.ThePORV'saresolenoid-actuated,pilotoperated,balancedvalves,operatedautomaticallyorbyremotemanualcontrol.ThePORVisopenedbyenergizingasolenoidwhichopensthepilotvalvecausingadifferentialpressureacrossthemaindiscwhichforcesthevalveopen.Thevalveisshutbyde-energizingthesolenoidandallowingsteampressureandspringforcetoshutthepilotvalve.Thiscreatesadifferentialpressureacrossthemaindiscwhichforcesthevalveshut.EachPORVhasahandcontrolswitchonRTGBl03.Theyarethreepositionswitches,eachhavingLOWRANGE-NORMALRANGE-OVERRIDEpositions.ByselectingtheOVERRIDEposition,allotherinputsignalstothePORVareblockedandthevalveremainsshut,orwillshutifintheprocessofopeningoralreadyopened.ThismanualcontrolfeatureisprovidedtoshuttheassociatedPORVduringanundesiredopening{oruponfailuretoshutafterproperactuation).Thetworemainingpositionsselectthe,operatingmodeofthePORV.'srelativetoRCSoperatingconditions.NORMALRANGEisselectedanytimeRCStempe'ratureandpressureisabove279oF(TC)and035psia,respectively.InthismodeeachPORVwillopenwhenthefollowingconditionsaresatisfied:a)PORVhandswitchisinNORMALRANGEb)ANDaHighPressureReliefOpen(HPRO)signalfromtheReactorProtectiveSystem(RPS)ispresent(RCS.pressure~greaterthan2000psia).
Resonsetouestion2.(continued)Theopensignaloriginatesfromfourredundantpressuretransmitters,PT-1102A,B,C,dcD,whichprovideinputsignalstotheRPScomparatorcircuits.Whenanytwoofthefoursenses2000psiaincreasingpressure,theHPROsignalisgeneratedtoopenthePORV's.Additionally,thissamesignalisusedtogeneratethereactorhighpressuretrip.TheLOWRANGEpositionactivatesaspeciallowtemperatureoverpressuremitigationsystemthatprotectstheRCSfrompressurizationbeyondthelimitdefinedbytheMinimumPressurizationTemperature(MPT)curvesoftheTechnicalSpecifications,whiletheRCSisatlowtemperatures.2.TheOverressureMitiationSstem(OMS)TheOverpressureMitigationSystem(OMS)protectstheRCSfrombeingpressurizedbeyondthelimitdefinedbytheMinimumPressurizationTemperature(MPT)curvesoftheTechnicalSpecifications,whiletheRCSisatlowtemperatures.TheOverpressureMitigationSystem(OMS)achievesitspurposebypressurecomparisonintwoindependentredundantOMStrains,oneforeachPORV.TheOMSgeneratesanopenPORVsignalfrompressurecomparatorPC-1103and/orPC-1100whenpressurereaches065psiaincreasing.Theactuationpointof065psiaisdesignedtopreventthepressuretransientinasolidRCS(pressurizersteamvolumefullofwater)fromexceedingthepressure-temperaturerelationshipdefinedbythe10EFPYheatupcurveintheeventofeitherofthebelowtransients.a)ARCPstartwhensteamgeneratortemperatureexceedsreactorvesseltemperatureby50oForless(maximum4T,50oF).b)Inadvertentsafetyinjectionbytwohighpressuresafetyinjectionpumpsandthree,chargingpumps.NotethattheLTOPanalysisispresentlybeingre-evaluatedforusebeyondthepresentcurves.Assumptions,setpointsandhardwarechangesmaybeimplementedtoincreasethepresentoperatingwindow.The.LOWRANGEpositionisselectedanytimeRCStemperatureandpressureisbelow275oFor015psia,respectively.Inthismode,eachPORVwill,openwhenthefollowingconditionsaresatisfied:.a)AssociatedPORVhandswitchisinLOWRANGE.b)ANDanopensignalfromtheassociatedOMSpressurecomparatorispresent(pressuregreaterthan065psia).OMSopensignalsoriginateintworedundanttrainswithpressurecomparatorsPC-1103andPC-1100supplyingopensignalstoV1002andV1000,respectively.
Resonsetouestion2.(continued)3.PORVPosition'IndicationInTheControlRoomRed(open)andgreen(closed)lampsonRTGB103inthecontrolroomprovidePORVpositionindicationderivedfromlimitswitchesoperatedbythevalvesolenoid.Inadditiontothevalvepositionindicatinglights,anacousticmonitorsystemisprovided.TheacousticmonitorsystemprovidespositivecontrolroomindicationofsafetyvalveandPORVposition.Theparameteractuallymonitoredisflow.Thesafetyvalveshavenootherpositivepositiondetectorssuchasswitchesoperatedbythevalvestem.WhilethePORV'shavepositionindication,itisnotpositivebecausetheirindicationisactuatedbyenergizingtheoperatingPORVsolenoid.Thevalvemaynotoperateifamechanicalfailureoccurs,'eventhoughthesolenoidisenergized.Therefore,onepiezoelectricaccelerometerisclampedtotheoutsideofeachcodesafetyvalveandPORVtailpipe.Flowthroughthetailpipe,whichconstitutespositiveindicationthatthe'valveisopen,causesacousticalaccelerations(flownoiseandpipevibrations).Theaccelerometerproducesapiezoelectricchargeproportionaltoacceleration(g's);thischargeisthenconvertedtovoltagebyaremotechargeconvertermountedinsidethecontainment.Thisvoltageisthenappliedtothevalveflowmonitormodule,locatedinthecontrolroom.ThevalveflowmonitormoduleprocessesthevoltagesignalandindicatestherelativevalueofflowonabargraphdisplayofLightEmittingDiodes(LED's)calibratedinincrementsoffullflow,whichis1.0.ThediscreteflowvalueLED'sare:0.01,0.00,0.09,0.16,0.25,0.36,0.09,0.81,and1.0.Themonitormodulecontainsasignalprocessingchannelanddisplayforeachmonitoredvalve.TheflowindicatorsandrecorderFR-1200arelocatedonthePost-AccidentPanel(PAP)inthecontrolroom.Acommonalarmisactuatedbyanyoneofthefiveflowindicatorsifindicatedflowexceedsapproximately00gpm.ThealarmislabeledSAFETYRELIEFVALVEOPEN,locatedonRTGB103annunciatorinthecontrolroom.Inaddition,atemperaturedetector(RTD),installedinthecombinedPORVreliefline,indicatesthatoneorbothPORV'shaveliftedorareleaking.Thedetectorsuppliesaninputtoatemperatureindicator-controllerinthecontrolroom.Thisactuatesanalarm"PressurizerReliefLineHighTemperature"towarnofPORVactuationorle'akage.I0.10CFR50Aendix"R"ConsiderationsAfireinthecontrolroomand/orcablespreadingroommaycausecontrolroomevacuationandtheplantmustbeplacedinasafeshutdownconditionbyutilizingalternateshutdownequipment.TopieventspuriousPORVopeningduringafire,selectorswitches Resonsetouestion2.(continued)outsidethecontrolroomareprovidedforeachPORV.Theselectorswitchesarelocatedintheelectricalcablepenetrationrooms.Theseswitcheswhenplacedinthe"Isolate"positionwilldisconnectspurioussignalsgeneratedbythefireandde-energizePORVsolenoidscausingPORV'stoclose.5.ElectricalPowerSuliesThePORV'sareoperatedfromClass1E125VDCredundantbusesformaintainingoperabilityofthesevalvesfollowingoff-sitepowerloss.ThePORV'saredesignedtofailclosedonvalvesolenoiddeenergization.MotoroperatedblockingvalvesareoperatedfromClass1E080V,3PHredundantMCC's;TheseMCC'sarepoweredfromtheEmergencyDieselGeneratorsfollowingoff-sitepowerloss.6.EnvironmentalCriteriaTheenvironmentalconditionsunderwhichequipmentmustfunction,areprovidedintheSt.LucieUnit1FSARSection3.11.ThefollowingsafetyrelatedelectricalequipmentlocatedintheReactorContainmentBuilding(RCB)isqualifiedforuseunderthespecifiedenvironment:PT-1102A,B,C,DPT-1103PT-1100PORVAcousticFlowMonitoringSystemElectricalcablesElectricalpenetrationsThisequipmentcanbefoundlistedintheSt.LucieUnit1EnvironmentalQualification(EQ)listforIOCFR50.09.CompleterecordofthisdocumentationcanbefoundattheSt.LucieRecordsVaultattheplantsite.4Allotherelectricalcomponentsforindicationandcontrol,arelocatedinmildenvironmentareasintheReactorAuxiliaryBuilding.Thesecomponentshavebeeninstalledtakingintoconsiderationtheirspecificationandtheavailableenvironmentaldatatoassuretheadequacyoftheinstallationforthespecifiedenvironmentalservice.7.SeismicCriteriaClass1Eelectricalequipmentsuchasswitches,electronicdevices,cablesandpowersupplies,includingtheirsupports,areseismicallyqualifiedtoIEEE-323.TheseismicqualificationcriteriaofClassIinstrumentationandelectricalequipmentisdescribedinSt.LucieUnit1UpdatedFinalSafetyAnalysisReport(UFSAR)Section3.10.
Question3.Theinformationreferencedbythesubmittalstatesthatbendingmomentsimposedbythedischargepipingdidnotimpairvalveoperability.Thermalexpansionofthepressurizercausingdisplacementofthepipingnozzlesandthermalexpansionofthepipingfromthenozzlestothevalvescancontributetothebendingmomentinducedinthevalvebody.ThesubmittaldoesnotmakeclearwhatloadswereconsideredincalculatingthebendingmomentsappliedtotheplantsafetyvalvesandPORVs.Provideadditionaldiscussioncomparingthemeasuredmomentonthetestedvalvestothecalculatedinducedmomentsfromalleffectsincludingthosedescribedaboveontheplantspecificvalves.Verifythatthebendingmomentswouldhavenoadverseeffectontheoperabilityoftheplantvalves.Resonsetouestion3.Forthesakeofdeterminingtheeffectsofpipingloadsontheoperabilityofpressurizersafetyandpoweroperatedreliefvalves,onlythebendingmomentsimposedonthevalvedischargeflangewereevaluated.Toevaluatetheimpactofthesecalculatedloadsonvalveoperability,theemergencyconditionwasutilized.Theemergency'onditionincludestheconservativeloadcombinationofpressure,deadweight,DBEandvalvedischargeloads.1.SafetValves(CrosbHB-BP-363K6)ThebendingmomentsrecordedduringtheEPRISafetyValveTestProgramrepresentanas-testedvalveloadingwherebothvalveoperabilityandstructuralintegrityweredemonstrated.Withthemeasuredbendingmomentactingonthesafetyvalve,thevalveopened,discharged,andclosedinasatisfactorymanner.Thesetestsdemonstratedthatallvalvebodyorcomponentdistortionduetothisbendingmomentwassmallanddidnotcausebindingorinterference.Themeasuredbendingmomentswhichactonthesafetyvalvecanbedirectlycomparedtoanalyticallycalculatedmomentssincebothchallengevalveoperabilityandstructuralintegrity.Notethatthetestedloadacceptancecriterionisnotanupperlimitloadbasedonfailurecriteria.Thisacceptancelimitrepresentsthehighestmeasuredloadwithacceptablevalveoperabilityduringthetestprogram.Duringtheentiretestprogram,themeasuredbendingmomentsnevercausedavalvetomalfunction.Thistestrecordindicatesthatvalveoperabilityisnotsensitivetobendingmomentsandthatactualbendingmomentlimitsarehigherthanthemeasuredvalues.The.resultsofthe-EPRISafetyValveTestProgramdemonstratethatthebendingmomentsonthesafetyvalveflangesduetothermalexpansionofthepressurizerandpipingandbythedischargeloadswillnotimpairvalveoperabilityprovidedthattheanticipatedloadsarelessthanthesemeasuredinthetests.
Resonsetouestion3.(continued)ForSt.LucieUnit1,themaximumcalculatedbendingmomentactingonthesafetyvalvedischargeflangeis60,068in-lbs.Themaximumas-testedbendingmomentforthistypeofvalvewas133,000in-lbs(seeReference33.Thistestedvalueistwotimesgreaterthanthemaximumcalculatedvalue.Itisthereforeconcludedthattheplant-specificbendingmomentswillhavenoadverseeffectontheoperabilityoftheSt.LucieUnit1safetyvalves.2.PORV's(Dresser31533VX-30)ThemaximumcalculatedbendingmomentimposedontheSt.LucieUnit1PORVis25,808in-lbs.TheEPRItestprogram(Reference3)providedonlyonetestpointforasimilarPORVinwhichameasuredbendingmomentof25,500in-lbswasobserved.Althoughvalveoperabilitywasnotimpairedbythisinducedmoment,aformalconclusionbetweencalculatedandtestvaluescouldnotbemadeduetoinsufficienttestdata.However,becausethemaximumcalculatedmomentisnearlyidenticaltothetestedmoment,itcanbeinferredthattheplant-specficbendingmomentwillhavenoadverseeffectontheoperabilityoftheSt.LucieUnit1PORV's.Questiono.Basedoninformationobtained,onotherplants,themanufactureroftheDresserPORVrecommendsthataheavierspringbeinstalledinbothmainvalveandthepilotvalveinordertopreventleakageatlowerpressures.Provideverificationthatthismodificationhasbeenmadeorotherinformationwhichdemonstratesthevalvewillnotexcessivelyleakcausingvalveseatdamageduringlowpressurefluidinletconditions.Resonsetouestion0.AccordingtoDresser(Reference0);theheavierspringsarenecessaryforvalveoperabilitybelow100psig,whenthedeadweightoftheactivatinglevermaycausethepilotvalvetoopenortoremainopen.Accordingly,themainvalve,mayalsopartiallyopen.HeavierspringshavenotbeenprovidedtotheSt.LucieUnit1PORVs."However,evenwiththeexistingsprings,ifinletpressureincreasesrapidlytoabove100psig,thevalve(pilotandmain)shouldproperlyloadandsealoffwithoutleakage.Fromcoldstart,theremaybesomecyclictypeleakageuntilthevalvecomesthermallystable.Toimprove.seattightnessatpressuresof,100.to1000psig,Dresserrecommendedthattheoriginalvalvetype1designbemodifiedintotype2(sometimescalledDash2)design.BothEPRIandDressertestswereperformedwithDresserPORVsofthetype2design.TheoriginalSt.LucieUnit1type1PORV'sweremodifiedtothetype2designpriortotheEPRItestprogram.
uestionsonthermohdraulicanalsis:Question5.Thesubmittalstatesthatathermal-hydraulicanalysiswasperformedusingRELAP5andtheresultsinputintothepostprocessorcodeCAPLOTFIIIforthedevelopmentoftheappropriateforcingfunctionsandtimehistories.Somedetailsoftheanalyseswerenotprovided.Toallowforanevaluationofthemethodsusedprovideasketchofthemodelandidentifythevalveopeningtimesusedintheanalysis.ThecodeCAPLOTFIIIisaspecialpurposecodewithoutwideuse.Provideadiscussiononhowthiscodehasbeenverifiedtoprovideconfidencethatitcomputescorrectforcingfunctions.Also,sincetheASMECoderequiresderatingofthesafetyvalveto90%ofexpectedflowcapacity,theactualflowwouldbeexpectedtoexceedtheratedflow.FlowsmeasuredduringtheEPRItestsconfirmedthisexpectation.Thesehigherflowswouldproducehigherpipingloads;therefore,explainthemethodusedtoestablishtheflowratesofthesafetyvalvesandthePORVsusedintheanalyses.Resonsetouestion5.ThemodelsusedinthethermalhydraulictransientanalysesareshowninFigures1and2.AlsoattachedisacopyofthemodelutilizedbyEDSintheirpipinganalysis(Figure3).Thevalveopeningtimesusedintheanalysesare6msecfortheSRVand110msecforthePORV.AsdescribedintheReference5report,theyaretheshortestopeningtimesmeasuredintheEPRIsafetyandreliefvalvetestprogram(Reference3).ThepostprocessorCALPLOTFIIIwasprogrammedtoconvertthetransientflowconditions(calculatedbyRELAP5/MOD1)intotransientforcesonthepipingsystem.ThederivationofthegoverningequationsareshowninAppendixl.Thevalidityoftheprogramcodingwasverifiedbycomparinghandcalculationresultsagainstthevaluescomputedbytheprogram.TheprogramwasfurtherassessedwiththeGE0-inchpipeblowdowntestresults.Favorablecomparisonswereobservedincomparingthecomputedresultsagainstthetestdata.DuetothediscrepancyintheRELAP5/MOD1chokeflowmodel,aswasdemonstratedinEPRIRELAP5/MODlapplication(Reference6),adjustedvalveflowareashavetobeusedtogeneratetherequiredflowrates.TheactualcalculatedflowratesfortheSRVactuationcaseareshowninTablel.\
uestionsonstructuralanalsis:Question6.Thesubmittalstatesthattheresultsofthethermal-hydraulicanalysiswerecomparedwiththeanalysiswhichhadresultedinthepresentdesignandtheconclusionwasreachedthatthepipingandsupportsareadequateforthecalculatedhydraulicloads.Sincetheloadingisatimedependentloadingatnumerouslocations,dynamicconsiderationsarenecessaryinmakingthecomparison.Detailsofthecomparisonwerenotprovided.Toallowanevaluationofthecomparisonexplainhowthecomparisonwasmade.Ifcomputerprogramswereusedinthecomparisonidentifytheprogramsandexplainhowtheyhavebeenverifiedforthisapplication.Identifytheloadcombinationsconsideredandtheallowablestresscriteriaforeachcombination.Ifthecombinationsandacceptancecriteriadifferfromthoserecommendedinthe"EPRISafetyandReliefValveTestProgramGuideforApplicationofValveTestProgramResults"providetherationalefortheselection.Resonsetouestion6.Thecomparisonofthehydrodynamicloadswasbasedontheapproximatepeakvaluesofthesegmentforcingfunctions.Inestimatingthereactionloadsontherestraints,itwasobservedthatthecharacteristictimedurationofeachoscillationintheloadwasshorterthanthefundamental'eriodwithwhichthepressurizerreliefpipingsystemwouldrespond.Itwasconcluded,therefore,thattheexpecteddynamicamplificationfactorintheresponseofthepipingsystemshouldbeclosetounity.Therefore,theexpectedhydrodynamicloadingswerecalculatedwithadynamicloadfactorof1.0.Thecomparisonofthehydrodynamicloadscalculatedinthereportwiththoseusedin'theoriginalstressanalysisandpipesupport/restraintdesignwasbasedsolelyonbasicengineeringprinciplesandgoodengineeringjudgement.Nocomputerprogramswereusedinthisprocess.TheloadcombinationusedintheEDSstressanalysisareconsistentwithSRP3.9.3Revision1requirements,whichareasormoreconservativethanthoserecommendedbyEPRI;namelyOBEcombinedwiththemaximumvaluesofPORVandSRVloadshavebeenevaluatedusingLevelBlimits,andDBEcombinedwiththemaximumvaluesofPORVandSRVloadshavebeenevaluatedusingLevelClimits.Theloadingusedinthedesignoftherestraintswasthecombinationoftheworstthermal,deadweight,seismicandPORV/SRVdischargeloads.Therestraintdesignconsideredthiscombinationandnormalallowablestressvalues.
TMIACTIONITEMILD.IST.LUCIE2uestionsrelatedtotheselectionoftransientsandvalveinletconditions:Questioni.TheCombustionEngineeringReportonoperabilityofPORVsinCEPlantsindicatedthatthelimitinginletfluidconditionsduringlowtemperaturepressurizationtransientsisawaterdischargeevent.TheCEInletFluidConditionsReportstatedthatthepressurizerwatersolidconditionand.resultingPORVliquiddischargecasewaschosenforthecoldoverpressurizationeventsinceitgavethemostseverepressurizationtransients.ThereportfurtherstatesthatasteambubblecanalsoexistinthepressurizerduringlowtemperatureoperationwherebythePORVcouldliftonsteam.NolowpressuresteamtestswereperformedbyEPRIontheDresserPORV.ProvideverificationthattheSt.Lucie2PORVswilloperatesatisfactorilyonlowpressuresteam.Also,sincethesubmittaldoesnotidentifythePORVsetpointsforeithernormaloperationorlowtemperatureoverpressureprotection,pleaseprovidethisinformation.Resonsetouestion1.St.LucieUnit2doesnotutilizeDresserPORV's,butratherGarretPORV's.AccordingtotheGarretTechnicalManualtheSt.Lucie-2PORVswilloperatesatisfactorilywithaninletsteampressureaslowas100psigwithzerobackpressure.Duringhotstandbyandpoweroperations,thePORVswillopenatahighpressuresetpointof2000psia.Forlowtemperatureoverpressureprotectionduringheatupandcooldownandduringextendedperiodsofcoldshutdown,lowpressuresetpointsareincorporatedinthePORVcircuitry.Theselowpressuresetpointsarestaggeredasfollows:060psiainPORVV-1070and090psiainPORVV-1075.-10-uestionsrelatedtovalveoerabilit:Question2.NUREG0737,ItemII.D.lrequiresthattheplant-specificPORVControlCircuitrybequalifiedfordesign-basistransientsandaccidents.Provideinformationwhichdemonstratesthatthisrequirementhasbeenfulfilled.Resonsetouestion2.DesinBasisforPower0cratedReliefValves(PORV)l.RCSOverressureProtection(HPRO)ThePORV'sare'designedtorelievesufficientsteamduringabnormaltransientstopreventactuationofthecodesafetyvalves.ThecombinedcapacityofthePORV'sislargeenoughtorelievethemaximumsurgevolumeassociatedwithacontinuousControlElementAssembly(CEA)withdrawalstartingfromlowpower.Thetotalreliefcapacityisalsolargeenoughtopreventopeningofthepressurizercodesafetyvalvesduringalossofloadfromfullpower.Thesetwodesignrequirementsassumenormaloperationofthepressurizerspraysystemandareactortriponhighpressurizerpressure.BecauseonePORVissufficienttomeetthedesignrequirementsforUnit2,onePORVisisolatedduringnormalplantoperation.ThePORV'saresolenoid-actuated,pilotoperated,balancedvalves,operatedautomaticallyorbyremotemanualcontrol.ThePORVisopenedbyenergizingasolenoidwhichopensthepilotvalvecausingadifferentialpressureacrossthe.maindiscwhichforcesthevalveopen.Thevalveisshutbyde-energizingthesolenoidandallowingsteampressureandspringforcetoshutthepilotvalve.Thiscreatesadifferentialpressureacrossthemaindiscwhichforcesthevalveshut.EachPORVhastwoassociatedhandcontrolswitchesonRTGB203.Thereisanindividualthree-position,OFF-OVERRIDE-TESTswitchandatwo-position,LTOP-NORMALmodeselectorswitchforeachPORV.Thetwo-positionmodeselectorswitch,HS-1070(HS-1075),selectstheoperatingmodeofthePORV'srelativetoRCSoperatingconditions.TheNORMALpositionisselectedanytimeRCStemperatureisabove320oF.InthismodeeachPORVopenswhenallof,thefollowingconditionsaresatisfied:a)ModeselectorswitchinNORMAL.eb)PORVoverride/testswitchinOFF.c)ANDaHighPressureReliefOpen(HPRO)signalfromRPSpresent(RCSpressuregreaterthan2000psia).-11-Resonsetouestion2.(continued)TheHPROsignalorginatesfromfourredundantpressuretransmitters,PT-1102A,B,CRD,whichprovideinputsignalstotheRPScomparatorcircuits.Whenanytwoofthefoursense2000psiaincreasingpressure,theHPROsignalisgeneratedtoopenthePORV's.Additionally,thissamesignalis,usedtogeneratereactorhighpressuretrip.TheLTOPpositionactivatesaspeciallowtemperatureoverpressuremitigationsystemthatprotectstheRCSfrompressurizationbeyondthelimitdefinedbytheMPTcurvesoftheTechnicalSpecificationswhiletheRCSisatlowtemperatures.2.LowTemeratureOverressureProtectionSstem(LTOPS)TheLowTemperatureOverpressureProtectionSystem(LTOPS),achievesitspurposebypressurecomparisonintworedundantLTOPchannels,AandB,oneforeachPORV.TheLTOPSgeneratesopensignalsfrompressurecomparatorsPC-1103,PC-1100,PC-1105,andPC-1106toactuatethePORV'satstaggeredsetpoints.Theactuationpointsof060and090psiaaredesignedtopreventthepressuretransientinasolidRCS(pressurizersteamvolumefullofwater)fromexceedingthecurvesthatdefineallowablepressure-temperaturerelationships,intheeventofeitherofthebelowtransients:a)AnRCPstartswhensteamgeneratortemperatureexceedsreactorvessel.temperatureby100oForless(maximum>T,100oF).b)Inadvertentsafetyinjectionbytwohighpressuresafetyinjectionpumpsandthreechargingpumps.NotethattheLTOPanalysisispresentlybeingre-evaluatedforusebeyondthepresentcurves.Assumption,'setpointsandhardwarechangesmaybeimplementedtoincreasethepresentoperatingwindow.SinceeachPORVhassufficientcapacitytomitigateeitherofthetransientsdiscussedabove,staggeredsetpointscanbeusedtoavoidopeningofthesecondPORV(V1075at090psia)duringminorpressureexcursionsthatareimmediatelyarrestedbyactuationofthefirstPORV(V1070at060psia).Thus,theLTOPSprovidestotallyredundantprotectionwhileminimizingthepossibilityofunnecessaryRCSdepressurization.TheLTOPpositionisselectedany.timeRCStemperatureisbelow280oF(TC).Inthismode,PORVV1070(V1075)openswhenallofthefollowingconditionsaresatisfied:a)PORVmodeselectorswitchisinLTOP.b)PORVoverride/testswitchisinOFF.-12-Resonsetouestion2.(continued)c)TCisnotabove320oF.d)ANDaLowPressureReliefOpen(LPRO)signalispresent.TheLPROsignaloriginatesfromtworedundantchannelswithfourpressurecomparators;PC-1103andPC-1105supplytheinputsignaltoopenPORVV1070,PC-1100andPC-1106supplytheoutputsignaltoopenPORVV1075.AtemperatureinterlockpreventsPORVactuationabove320oF,(TC)ifthemodeselectorswitchisinadvertentlypositionedtotheLTOPposition.Thenormal2000psiasetpointremainsineffectwhenthisinterlockisineffect.ThisfeatureprovidesPORVoverpressureprotectionevenifthemodeselectorswitchesweretobeleftintheLTOPposition.TheLTOPSprovidestwoinstructivealarmsandtwowarningalarmsfortheoperator.TheyareSELECTLTOP,SELECTNORMAL,andLTOPTRANSIENTCHANNELA(B)alarms,locatedonRTGB203,-annunciatorsH-02,H-06,H-03andH-07,respectively.ThetwoinstructivealarmsdirecttheoperatortomakeselectionsonthePORVmodeselectorswitches.ThesealarmsarecommontobothLTOPchannels.Also,bothLTOPchannels'providetransientalarmswhichwarntheoperatorwhenactualpressureis060psiaassensedbychannelA;thechannelBtransientalarmisactuatedat090psia.Thethree-positionoverride/testselectorswitchprovidesthecapabilitytooverrideactuatingsignalsandtotestactuatingcircuitswithoutoperatingvalves.ThisswitchisnormallyintheOFFposition.TheOVERRIDEpositionshutsthePORVifitisopenandoverridesanysignaltoopenthevalve.ThismanualcontrolfeatureisprovidedtoshutthePORVduringanundesiredopening(oruponfailuretoshutafterproperactuation).TheTESTpositionsimulatesanopensignaltothePORV,totestthecircuit,withoutphysicallyopeningthevalve.TheswitchisspringreturnedtoOVERRIDEfromTESTwhenreleased(OFFandOVERRIDEaremaintaincontacts).TheoperatorisalertedbyaPORVTESTCONDITIONindicatinglightonRTGB203,whenevertheoverride/testswitchisintheOVERRIDEorTESTposition.3.PORVPositionIndicationintheControlRoomRed(open)andgreen(closed)lampsonRTGB203inthecontrolroomprovidepositivePORVpositionindicationderivedfromlimitswitchesopera'tedby'thevalveoperator.Inadditiontothevalvepositionindicatinglights,an'cousticmonitorsystemisprovided.TheacousticmonitorsystemprovidespositivecontrolroomindicationofsafetyvalveandPORVposition.Theparameteractuallymonitoredisflow.Thesafetyvalveshavenootherpositivepositiondetectorssuchasswitchesoperatedbythevalvestem.WhilethePORV'shavepositionindication,itisnotpositivebecausetheirindicationisactuatedbyenergizingtheoperatingPORVsolenoid.Thevalvemaynotoperateifamechanical-13-Resonsetouestion2.(continued)failureoccurs,eventhoughthesolenoidisenergized.Therefore,onepiezoelectricaccelerometerisclampedtotheoutsideofeachcodesafetyvalveandPORVtailpipe.Flowthroughthetailpipe,whichconstitutespositiveindicationthatthevalveisopen,causesacousticalaccelerations(flownoiseandpipevibrations).Theaccelerometerproducesapiezoelectricchargeproportionaltoacceleration(g's);thischargeisthenconvertedtovoltagebyaremotechargeconvertermountedinsidethecontainment.ThisvoltageisthenappliedtotheTECvalveflowmonitormodule,locatedinthecontrolroom.TECisjustthemanufacturer'sacronym.Thevalveflowmonitormoduleprocessesthevoltagesignalandindicatestherelativevalueofflowonabargraphdisplayoflightemittingdiodes(LED's)calibratedinincrementsoffullflow,whichis1.0.ThediscreteflowvalueLED'sare:0.01,0.00,0.09,0.16,0.25,0.36,OA9,0.81,and1.0.Themonitormodulecontainsasignalprocessingchannelanddisplayforeachmonitoredvalve.TheflowindicatorsandrecorderFR-1200arelocatedonthePost-AccidentPanel(PAP)inthecontrolroom.Acommonalarmisactuatedbyanyoneofthefiveflowindicatorsifindicatedflowexceedsapproximately00gpm.ThealarmislabeledSAFETYRELIEFVALVEOPEN,locatedonRTGB203annunciatorinthecontrolroom.Inaddition,St.LucieUnit2hasatemperatureelementlocatedineachPORVdischargepipe.Theysupplyindependent'temperatureindicatorsonRTGB203.EachtemperatureindicatoractuatesacommonalarmlabeledPRESSURIZERRELIEFLINEHIGHTEMPERATURE.0.10CFR50Aendix"R"ConsiderationsAfireinthecontrolroomandorcablespreadroommaycausecontrolroomevacuationandtheplantmustbeplacedinasafeshutdownconditionbyutilizingalternateshutdownequipment.TopreventspuriousPORVopeningduringafire,keyoperatedselectorswitchesareprovidedforeachofPORV.Theselectorswitchesarelocatedinthephysicallyseperatedelectricalcontainmentcablepenetrationrooms.Theseswitcheswhenplacedinthe"ISOLATE"positionwilldisconnectspurioussignalsgeneratedbythefireanddeenergizePORVsolenoidscausingPORV'stoclose.50ElectricalPowerSuliesThePORV's'areoperatedfromClassIE125VDCredundantbusesformaintaining'operabilityofthesevalvesfollowingoffsitepowerloss.ThePORV'saredesignedtofailclosedonvalve,solenoiddeenergization.
ResponsetoQuestion2.(continued)MotoroperatedblockingvalvesareoperatedfromClasslE080V,3PH,60HZredundantMCC's.TheseMCC'sarepoweredfromtheEmergencyDieselGeneratorsfollowingoff-sitepowerloss.Themotoroperatedvalvesfail"asis"uponpowerfailure.6.EnvironmentalCriteriaTheenvironmentalconditionsunderwhichequipmentmustfunction,areprovidedintheSt.LucieUnit2FSARSection3.11.ThefollowingsafetyrelatedelectricalequipmentlocatedintheReactorContainmentBuilding(RCB)isqualifiedforuseunderthespecifiedenvironment:oPT-1102A,B,C,DoPT-1103oPT-1100oPT-1105oPT-1106o-PORVAcousticFlowMonitoringSystemoElectricalCablesoElectricalPenetrationsThisequipmentcanbefoundlistedintheSt.LucieUnit2EnvironmentalQualification(E.Q.)listforIOCFR50.09.AcompleterecordofthisdocumentationcanbefoundattheSt.LucieRecordsVaultattheplantsite.Allotherelectricalcomponentsforindicationandcontrol,arelocatedinmildenvironmentareasintheReactorAuxiliaryBuilding.Thesecomponentshavebeeninstalledtakingintoconsiderationtheirspecificationandtheavailable'nvironmentaldatatoassure,theadequacyoftheinstallationforthespecifiedenvironmentalservice.7.SeismicCriteriaTheseismicdesignofequipmentpresentlyinstalledismaintained.ThePORV'sweredesignedandmanufacturedinaccordancewithASMEBoilerandPressureVesselCodeSectionIIIandareClassIvalves.Class1Eelectricalequipmentsuchasswitches,electronicdevices,cables,powersupplies,includingtheirsupports,areseismicallyqualifiedtoIEEE-300-75.TheseismicqualificationcriteriaforClass1E,SeismicCategoryIelectricaland.inst'rumentationisdescribedinSt.LuciePlantUnitNo.2Updated~~FinalSafetyAnalysisReport(UFSAR)Section3.10,and.Appendix'.10A.Question3.TheCEownersgroupsummar'yreportontheoperabilityofPressurizerSafetyValvesinCEDesignedPlants(CEN-227)identifiedthreequalifiedringsettingsforthetwoSt.Lucieplantsafetyvalves.Theseare-55,-10;.-05,-10;and-95,-10whichresultedinprojectedblowdownfrom8.9to15.79o.Thesubmittaldoesnotstatewhatringsettingsareactuallyusedontheplantvalves.Thelicenseeshouldidentifywhatringsettingsareused,andjustifyanydeparturefromtherecommendedsettings.-15-Resonsetouestion3.AtthecompletionoftheEPRISafetyValveTestProgram,CombustionEngineering,recommendedringsettingsof(-55,-10)forthepressurizersafetyvalves.ThisringsettingadjustmentwasperformedbyaCrosbyrepresentativeduringconstructionofSt.LucieUnit2.Additionally,plantmaintenanceproceduresensurethattheringsettingsareproperlyadjustedtothisvalueanytimemaintenanceisperformedonthepressurizersafetyvalves.~uestion0.Theinformationreferencedbythesubmittalstatesthatbendingmomentsimposedbythedischargepipingdidnotimpairvalveoperability.'hermalexpansionofthepressurizercausingdisplacementofthepipingnozzlesandthermalexpansionofthepipingfromthenozzlestothevalvescancontributetothebendingmomentinducedinthevalvebody.ThesubmittaldoesnotmakeclearwhatloadswereconsideredincalculatingthebendingmomentsappliedtotheplantsafetyvalvesandPORVs.Provideadditionaldiscussioncomparingthemeasuredmomentonthetestedvalvestothecalculatedinducedmomentsfromalleffectsincludingthosedescribedaboveontheplantspecificvalves.Verifythatthebendingmomentswouldhavenoadverseeffectontheoperabilityoftheplantvalves.Resonsetouestion0.ThegeneraldiscussionincludedintheSt.LucieUnit1responsetoQuestion3isapplicabletoSt.LucieUnit2andisomittedfromthisreponsetoavoidrepetition.1.SafetValves(CrosbHB-BP-363K6)AmaximumcalculatedbendingmomentactingontheSt.Lucie2safetyvalvedischargeflangeis72,718in-lbs.Sincethismomentissignificantlylowerthanthemaximumas-testedbendingmomentof133,000in-lbs(Reference3)andtheas-statedmomentdidnotimpairvalveoperability,itisconcludedthatplant-specificbendingmomentswillhavenoadverseeffectontheoperabilityoftheSt.LucieUnit2safetyvalves.2.PORV's(Carrett3750010)ThemaximumcalculatedbendingmomentactingontheSt.LucieUnit2PORVdischargeflangeis83,635in-lbs.TheEPRITestProgram(Reference3)providedonlyone.testpointforasimilar.PORV:inTest98-GA-2S,a'bending.-momentof33,200in-lbswasinducedonthevalvedischargeflange.Althoughthevalveoperabilitywasnotimpairedbytheinducedmoment,aformal'conclusionbasedonacomparisonbetweentheas-testedandcalculatedvaluescouldnotbemadebecauseofinsufficienttestdataandalsothefactthattheas-testedbendingmomentislessthantheplant-specificcalculatedbendingmoment.-16-Resonsetouestion4.(continued)Thesubjectvalvedesignreport(Reference5),however,providesamaximumallowabledesignvalueofthebendingmoment.Comparisonofthisvalue,whichisequalto193,200in-lbs,withtheplant-specificcalculatedbendingmomentof83,635in-lbsdemonstratesthattheSt.Lucie2PORVdischargeflangeswillbesubjectedtoananticipatedbendingmomentoflessthanone-halfofthemaximumallowabledesignvalue.Itisconcluded,therefore,thattheanticipatedbendingmomentswillhavenoadverseeffectontheoperabilityoftheSt.Lucie2PORVs.Question5.TheMarshallsteamtestsprovedthattheoriginalmethodforcompensatingforthermalgrowthinthe'arrettPORVwasinadequate.Anumberofdesignchangesweremadetothetest'valve.Provideinformationaddressingthisconcern.VerifythattherecommendedchangesofthemanufacturerhavebeenincorporatedintothePORVvalvesusedatSt.Lucie2.Resonsetouestion5.TheinternaldesignoftheGarrettPORV,part3220718-1,testedintheEPRITestProgramatMarshallSteamStationincludedasingle-piececageandseatassemblyhelddownbymeansofaflexitallicspringgasket.Althoughthevalveoperatednormallythroughout77cycleswithdrysaturatedsteamat2000psig,aseatleakageof0.006gpmaftertwocyclesand0.01gpmduringtheremainderofthetestwasdetected.Uponvalvedisassemblyandinspection,theseatgasketwasfoundtohavebeencompletelywashedout,whichwasconsideredtohavebeenthecauseoftheleakage.,AccordingtoReference7,post-testanalysisshowedthattheproblemwascausedbydifferentialthermalgrowthduringthefirstopeningcycle.Aflexitallicgasketbetweenthecageandbonnethadthedualfunctionofholdingthecagedownagainsttheseatgasketandcompressingsufficientlytocompensatefordifferentialthermalgrowth.Thegasketprovedunabletowithstandtheappliedloadandtookapermanentset,thusallowingthecagetobecomeunloadedandliftupofftheseatgasket.Theseatjacketwas,therefore,exposedtothescouringactionofthesteamandalloftheasbestoswaswashedoutduringthefirstcycleofoperation.1AtthetimeoftheMarshalltest,Garrettintendedto'utilizethesingle-piececageandseatasse'mblydesigninproductionPORVsincludingthosesuppliedto'St.LucieUnit2.However,uponreviewingthetestresults,Garrettconcludedthatanimproveddesignwaspossible'andchangedboththetestandproductionvalvedesignstoincorporatethesedesignimprovements.Testvalve3220718-Iwasmodifiedtothe3220718-2configurationwhichincorporatedallthedesignfeaturesoftheimprovedSt.Lucie2valvedesign.NotethattheGarretttestFORV,Part3220718-2,wassubsequentlytestedatV/yleLaboratories.-17-Resonsetouestion5.(continued)ThefollowingdesignchangesweremadetothetestPORVPart3220718-2,andtheSt.Lucie2PORVsPart3750010:a)Designingaseparate,bolteddownseat,b)allowingthevalvecagetofloat,independentoftheseat,forthermalcompensation,c)replacingtheseatandbody/bonnetflexitallicswithasheetmetal/graphoil-typeSelcoseal,andd)changingthecage-to-bonnetsealfromaflexitallictoacarbonpistonringboreseal.Compensationforthermalgrowthcausedbydifferentheatingratesbetweenthevalvecageandbodyisprovidedbyagapwhichismaintainedbetweenthebottomofthecageandthetopoftheseat.Whenthevalveisclosed,thecageisheldupagainstthebonnetbyalightspring.Whenthevalveopens,pressureforcesthecageupintothebonnetwithahighload,thusmaintainingthegapbetweenthebaseofthecageandtheseat.Evenunderworst-casethermalgrowthconditionsthethermalcompensatorgapisneverreducedtozero.Thus,thermalgrowthhasnoeffeetonoperabilityofthevalve.SomeadditionaldesignchangeshavebeenincorporatedintotheSt.'Lucie2PORVssincetheMarshallsteamtests.Theyareasfollows:a)InstallationofGarrettdesignedandmanufactured,direct-acting,integral,IEEEQualifiedthree-waysolenoids.b)Installationofflexitallicgasketsatthebody-to-bonnetjointsandthebody-to-solenoidjoints.ThisredesigncorrectedslightexternalsteamleakageproblemsencounteredduringthefirstfuelcycleatSt.Lucie2.c)Installationofmagnetsstabilizedat300oCforthemainvalvepositionindicatingswitches.Thispreventslossofmagnetstrengthatoperatingtemperaturesandthuslossofpositionindication.ThisproblemwasencounteredduringthefirstfuelcycleatSt.Lucie2andresultedfrommagnetsbeingstabilizedattoolowatemperature(200oC).Installationoflongermagnetrodstoallowadditionalrangeofadjustmentof.themainvalvepositionindicatingswitches.During=initialswitchadjustmentsat'St.Lucie2,itwasfoundthat'theclosedpositionindicationswitcheshadtobesetclosetotheendoftheadjustmentrange.-18-uestionsrelatedtotheblockvalves:~uestion6.TheMarch22,1983submittalstatesthatthePORVblockvalvesatSt.LucieUnit2areWestinghouse0306GM88FNH(88Series)motoroperatedgatevalves.ThisinformationdoesnotagreewiththeinformationtransmittedbyR.C.YoungdahlonbehalfofmemberutilitieswhichindicatesthattheblockvalvesatSt.Lucie2are2I/2inchmodel75-L-012TargetRockGateValves.TheYoungdahltransmittaltestresultsindicatethatsomeproblemshavebeenidentifiedrelatingtothetorquerequirementstooperatetheWestinghousevalve.Thetestsindicatedthatthemodel3GM88valvewiththevendor-recommendedactuatorand-torqueswitchsettingwasinsufficienttoreliablyclosethevalve.PleaseconfirmwhatPORVblockvalvesandactuatorsareactuallyusedatSt.Lucie2.IfthevalvesareWestinghouseseries88,thenprovideinformationtoidentifyhowthespecialtorquerequirementsofthisvalvehavebeenaccommodated.IftheblockvalvesusedatSt.Lucie2areTargetRock,theninformationshouldbeprovidedtomeettherequirementsofNUREGItemII.D.Iregardingtheblockvalves.TheTargetRockValvewasnotincludedinEPRIMarshallblockvalvetests.Resonsetouestion6.TheSt.LucieUnit2PORVblockvalvesareWestinghouseModel0300GM88FNH(Series88)gatevalveswithLimitorqueModelSB-00-15operators.PriortotheactualWestinghouseblockvalvetesting(duringcalibrationandcheckoutactivities),thevalvefailedtocloseagainstflowanddifferentialtestconditions.SubsequentinvestigationandtestingperformedbyWestinghouseanddetailedinReference8indicatedthatthestemthrustrequiredtoclo'sethevalveunderdesignconditionswasunderpredicted.Toassurefullclosureofthevalve,Westinghouserecommendedagearratiochangeandarewireofthe'motoroperatortoachievelimitswitchclosurecontrolinlieuofthestandardtorqueswitchcontrol.BothofthesemodificationswereimplementedontheSt.LucieUnit2PORVblockvalvesbyLimitorquepriortoinstallation.Westinghousehasfurthercertifiedthattheseblockvalveswillfullyopenandcloseunderdesigndifferentialpressureandfullflowconditions.uestionsonthermohdraulicanalsis:Question7..Thesubmittalstatesthatathermal-hydr'aulicanalysiswasperformedusing"RELAP5andtheresultsinputinto.thepostprocessorcodeCAPLOTFIIIforthedevelopmentoftheappropriateforcingfunctionsandtimehistories.Somedetailsoftheanalyseswerenotprovided.Toallowforanevaluationofthemethodsusedprovideasketchofthemodelandidentifythevalveopeningtimesusedintheanalysis.ThecodeCAPLOTFIIIisaspecialpurposecodewithoutwideuse.Provideadiscussiononhowthiscodehasbeenverifiedtoprovideconfidencethatitcomputescorrectforcingfunctions.Also,sincetheASMECoderequiresderatingofthesafetyvalveto90%ofexpectedflowcapacity,theactualflowwouldbeexpected-19-toexceedtheratedflow.FlowsmeasuredduringtheEPRItestsconfirmedthisexpectation.Thesehigherflowswouldproducehigherpipingloads;therefore,explainthemethodusedtoestablishtheflowratesofthesafetyvalvesandthePORVsusedintheanalyses.Resonsetouestion7.AThemodelsusedinthethermalhydraulictransientanalysesareshowninFigures0and5.ThestressanalysismodelshavealsobeenattachedtothisresponseasFigures6thru8.Also,attachedasFigure9isthepressurizermodelincludedinthepipingstressanalysis.Thevalveopeningtimesusedintheanalysesare6msecfortheSRVand130msecforthePORV.Asdescribedinthereport,theyaretheshortestopeningtimesmeasuredintheEPRIPWRsafetyandreliefvalvetestprogram(Reference3).ThepostprocessorCALPLOTFIIIwasprogrammedtoconvertthetransientflowconditions(calculatedbyRELAP5/MODl)intotransientforcesonthepipingsystem.ThederivationofthegoverningquestionsareshowninAppendix1.Thevalidityoftheprogramcodingwasverifiedbycomparinghandcalculationresultsagainstthevaluescomputedbytheprogram.TheprogramwasfurtherassessedwiththeCE0-inchpipeblowdowntestresults.Favorablecomparisonswereobservedincomparingthecomputedresultsagainstthetestdata.DuetothediscrepancyoftheRELAP5/MOD1chokeflowmodel,aswasdemonstratedintheEPRIRELAP5/MOD1application(Reference6),adjustedvalveflowareashavetobeusedtogeneratetherequiredflowrates.TheactualcalculatedflowratesfortheSRVactuationcaseareshowninTable2.uestionsonstructuralanalsis:uestion8.Thesubmittalstatesthattheresultsofthethermal-hydraulicanalysiswerecomparedwiththeanalysiswhichhadresultedinthepresentdesignandtheconclusionwasreachedthatthepipingandsupportsareadequateforthecalculatedhydraulicloads.Sincetheloadingisatimedependentloadingatnumerouslocations,dynamicconsiderationsarenecessaryinmakingthecomparison.Detailsofthecomparisonwerenotprovided.Toallowanevaluationofthecomparisonexplainhowthecomparisonwasmade.Ifcomputerprogramswereusedinthecomparisonidentifytheprogramsandexplainhowtheyhavebeenverifiedforthisapplication.Identifytheloadcombinationsconsideredandtheallowablestresscriteriaforeachcombination.Ifthecombinationsandacceptance.criteriadifferfromthoserecommendedinthe,"EPRISafetyandReliefValve..Test'ProgramCuideforApplicationofValveTestProgramResults"providetherationalefortheselection.-20-ResonsetouestionS.AdynamicanalysishasbeenperformedfortheSt.LucieUnit2pressurizerPORVandsafetyvalvedischargepiping.Therefore,nocomparisonofhydraulicforceswasnecessarysincethepipingandsupportshavebeenqualifiedusingcalculatedloads.TheprogramusedforthedynamicanalysisisPIPESTRESS2010whichisabenchmarkedprogramdiscussedintheSt.LucieUnit2FSAR.Thespecifictechniqueusedwasgeneralizedresponseanalysiswherethetimehistoryoftheappliedloadisusedtocalculateamodelboundsolution.ThepipestressloadcombinationsareconsistentwithSRP3.9.3Revision1requirements,whichareasormoreconservativethantheEPRIrecommendations;namely,OBEcombinedwiththemaximumvaluesofPORVandSRVloadshavebeenevaluatedusingLevelBlimitsandDBEcombinedwiththemaximumvaluesofPORVandSRVloadshavebeenevaluatedusingLevelDlimits.Theloadingusedinthedesignoftherestraintswasthecombinationoftheworstthermal,deadweight,seismicandPORV/SRVdischargeloads.Therestraintdesignconsideredthiscombinationandnormalallowablestressvalues.-21-
REFERENCES1.DresserReportSV-203A,datedJune30,1983.2.SummaryReportontheOperabilityofPowerOperatedReliefValvesinCEDesignedPlants,CEN-213,datedJune,1982.3.EPRISafetyandReliefValveTestProgram,EPRIReportNP-2628-SR,December,1982."0.HeavierRateSpringsfor31533VX-30Electromatic,DresserTechnicalReviewNo.32-85-65-RSH,October29,1985.5.GarrettEngineeringReport10-3135B,EndLoadAnalysisfortheSolenoidOperatedReliefValvesforCEPowerSystems,May,1983.6.ApplicationofRELAP5/MODlforCalculationofSafetyandReliefValveDischargePipingHydrodynamicLoads,EPRIReportNP-2079,December,1982.7.EPRISafetyandReliefValvesTestProgram,ValveSelection/JustificationReport,EPRIReportNP-2292,datedDecember,1982.8.EPRISummaryReport:WestinghouseGateValveClosureTestingProgram,preparedbyWestinghouseElectro-MechanicalDivision,March31,1982.-22-WP/DISCj/PSL0005/TMIActionNUREG/0286/L TABLElStLucieUnit1SteadyStateBackpressureCalculationsSRVDownstreamPressure(psia)Valve/PressureSRVFlowrate(ibm/sec)CalculatedFlowrate*PressurizerRatedFlowratePressure(psia)a)3SRV's(atendofRELAP5run.time=0.6sec)V-1200/351Y-1201/362V-1202/33771.171.171.11.2021.2021.2022528.7b)2PORV's(atendofRELAP5runtime~0.6sec)V-1200/125Y-1201/124V-1202/1230.00.00.02434.7SRVRatedFlowrateis2i3000ibm/hr(Crosby3K6)
TABLE2.ST,LUCIEUNIT2STEAOYSTATEBACKPRESSUREANDFIOWRATECALCULATIONSCASEVALVENUMBERDOWNSTREAMPRESSUREsiaFLOWRATE1bmsecCALCULATEDFMWRATEa)PORVactuation(atendofRELAP5runtime~0.6sec)V-1200V-1201,V-1202V-1474V-14752052012003183210.00.00.0116.0115.01.061.05b)SRVactuation.V-1200(atendofRELAP5V-120106,)V-1474.V-147530830629818618472.272.272.20.00.01.221.221.22*SRVRatedFlovrateis2130001bm/hrPORVRatedFlovrateis3950001bm/hr psR4LSl~Cgtk>>XeSoi00I)rlerl~4.~4<<1I'Pgt+f.77+Q,r~eI~r=C~11'ri'rq.qlISt~rSp~Ie4I00112,o~~tI~Ie~-.IlaCALpLo7FXKG'--IP~~gR~IEeeHFA'eC~.s',gL'IPCS.IelII4~0~JrrPII%17Orerg~<<'frL'I7Pprt~gp.<<II~ePPle~')t.~c(5Q71Rs..+2'.+C+~iPey;'0>>~>>oP.>>tgA>tp,>>,~~.IgeIe/,.r.b'I~tll>>g0l'lrL)~~r'.$'~~~7g2f-RC~escaIS~S3/54.$00.f37'0%$$675653TOO615"1CISPO'~r~4)'Og.i.7~It)41fctgSI'I~ED~2<~gSSeI0tat~7Sre~lo42tit4.rtl04'4.P-~C>>r+r.~IQl'.IS~rCj>>4etI'Q~r4'>>IttI'Al,I'rIet~et~I~rtvIs.-ST.LUCIEURIyIPRESSURIZERRKI,IEFSySml.RC.RSte~12'I,ll~1stia:e~.a22>>vee14.TCO~I~2.IaOICII.~eeeeett>>'RSTR>>PCPEttCII7III'eIAL.4R~IIII:0N~eoQML01lLRSr.
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J4$gC-Z'I)-O.eT.~'~.gLtr5rrs'gC'4)S,'>pfyll.C'g4:~vP>>S5~ic'gHOCICeyCeS~"1lsCs<<.goo"'C<)gO~ppISg/qPlrrr))~rr~IgSIIo".ICQC)O.<0')QrIgfgc'pitI-j))010)>qC~~4.4402~Ejgt~I,~tU.~ci1~EHit7$031.7/$-3$o0octrr<<IIpopN.3lN4ISIv.Oaso~T(NICE~i)IJr)L)IIIICLAIIIptlOISC<<inr<<II~MSCOSCNIICNSosCORSOOATEO<<IrVOaaSCV.o)saTritw)ailet.~It))r)K)r~)I~0%kVIttILal1iDrtNl.~aliistaticPIrrsw)aglltsOtwalterstIIfrI%all,ItaCINaltrWILIsail/err~-a-r(),'rir'L~IISOIIIT<<SCSSO.Mlr,~rlJr-earlAE~'ralZER4t;GAEL APPENDIXIDESCRIPTIONOFCALPLOTFIII B-I.MathematicalModelTheCALPLOTFIXIcomputercodehasbeenwrittentoconvertthetransientflowconditionscalculatedinapipingsystembytheRELAP5H)D1Computercodeintotransientforcesonthepipingsystem,Specifically~CALPLOTFIIIcalculatesandplotstheforcesonstraightlengthsofpipebetweenchangesinpipedirection(bends)~orbetweenachangeindirectionandapipebreak,Thederivationoftheequationsusedinthecodearegivenbelow.B-I-lStraihtLenthsofPiesBetweenDirectionalChanesTheforceonastraightlengthofpipebetweendirectionchanges(FigureB.l)iscalculatedusingthemomentumequation:F+Bpdv~V(pV~dA)+-V(pdv)(Bl)cvcscvIfthegravitytermisassumednegligible,thefollowingequationresults:F~~V(pV~dA)+-/V(pdv)Btcv(B2)Sincetheforceonthestraightpipelengthonlyexistsinonedimension,theaboveequationcanbewritteninascalarform:F~V(pV~dA)+-satVpdv(B3)cscvSincetheRELAP5MOD1i',Computercodecalculatesthepressuresandtheflowrates.atdifferentphysicalpositionsinthepipingsystem,it.isnecessarytosubdivideapipinglengthintotwocontrol'volumetypesforapplicationofthemomentumequationThefirstdivision~createsthepressurecontrolvolumes;Thedivisionsforthepressure'ontrol,volumesarethepositions'in'hepipelengthwherethepressuresarecalculatedbythecomputercode,andserveastheboundariesacrosswhichthecontrolvolumesurfaceforcesarecalculated.ThesecondcontrolvolumedivisionsareduetoflowconditionsTheboundariesoftheflowcontrolvolumesarelocatedatthepipelengthlocationswhereflowsarecalculatedbythecomputercode.Theforcesinthepipelengthwhichareduetotherateofeffluxofmomentumacrossacontrolvolumeandthechangeofmomentuminacontrolvolumearecalculatedusingtheflowboundariesasflowcontrolvolumedivisions Theresultantforceonthefluidacrosstheboundaryofthepressure.controlvolumes1~2~and3,showninFigureB.l,are:F~-(P-P)AA+RSlAa2AABB(BA)2FS3"B')"B'3FThenetsurfaceforceonthestraightpipelengthisobtainedbysummingequationsB4,B5,andB6:(B4)(B5)(B6)SlS2S3123F~RS(B7)(Bg)Therefore,theforceonthestraightpipelengthduetosurfaceforcesisequaltothenetnormalandshearstressesonthepipewalllength+TherightsideofequationB3cannowbeevaluatedforeachoftheflowcontrolvolumesAandB:2P22BMAF-h+Sl,gAae,2p>VgA<8+S28+~thB(B9)(Blo)SincetheRELAP5computercodecalculatesnonthermalequlibriumconditionsfortwophaseflowconditionsandallowsthetwophasestopossessdifferentvelocities,theparametersofequations(B9),(B10)aredefinedas:MA1A1A~AAA(B11)2P22lB1BB'+~BBB)"B2l2122g2g22(B12)(BX3)
SummingequationsB9andB10,andusingequationBS,thenetfluidforceonthepipelengthcanbeobtained:-aae,K>-F~<<R~-hA--hBSBtBe(B14)Ifthestraightlengthofpipeconsideredisboundedbyadirectionalchangeandanopenend,abreak,theforcesobtainedusingequationBllmustbemodifiedtoaccountfortheforcedevelopedatthepipeexitplane.Consequently,usingthemomentumequation,theforceonthestraightpipelengthshownonFigureB.2,forunchokedbreakflow,canbewrittenas:2-p2V2A2BMAKhAUnc8Be(B15)Ifchokedbreakflowisdeterminedtocomputercode,thenequationB15mustpressureunbalancethatoccursattheoftheequationforthestraightpipethefollowingrelation:existbythefluidtransientbemodifiedtoaccountforthepipeexitplane.Arederivationlengthforthiscaseresultsin<<p2-BAK--(P-P)AA-hAhch2agBe(B163orKh~K-(P-P)Achunc2a(Blgwhere:'2~'Ah'222+h2gY2P222gQp-4P-hP(Blg)faccelV2V2P=P+PAh-222A2g2g(B19)pAVA-pv(1-a)+pv22AgAgAA(B20)
NomenclatureBPRflowareabodyforceofacontrolvolumesurfaceforceresultantonacontrolvolumegravitationalconstantforceoffluidonpipingcontrolvolumeflowratepressurepressureoutsidepipecontrolvolumesnormalandshearstressesinacontrolvolumetimevolumeofacontrolvolumevelocityoffluidinacontrolvolumeGreekLettersPadensityin'ontrolvolumevoidfractionSubscriptsacc,'hcselunc1iccelerationfrictionchokedflovcontrolsurfacecontrolvolteeIevationunchokedliquidgas
'VOL.2IIIIIIIlIII+FORCEIIIIBLEGEND:----PRESSUREBOUNDARY----FLONBOUNDARY PiqueB.2VOL.1VOL.2I+FORCEILEGEND:PRESSUREBOUNDARY-----FLOWBOUNDARY