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{{#Wiki_filter:ATTACHMENTlMarked-upTechnicalSpecificationPages3/47-I0B3/47-3(withinsert)87i2300081871222iDa.~DOCK-O500OZ89---IDI9EJW4/0I7/2 I4II tPLANTSYSTEMSMAINFEEDWATERLINEISOLATIONVALVESLIMITINGCONDITIONFOROPERATION3.7.1.6EachmainfeedwaterlineisolationvalveshallbeOPERABLE.APPLICABILITY:MODES.1,2,3,and4.ACTION:MODE1Withonemainfeedwaterlineisolationlveinoperablebutopen,POWEROPERATIONmaycontinuep'rovidedheinoperablevalveisrestoredtoOPERABLEstatuswithinhours;otherwise,beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing24hours.MODES2,3-Withonemainfeedwaterlineisolationvalveinoperable,and4subseqentoperationinMODE2,3,or4mayproceedprovided::a.Theisolationvalveismaintainedclosed.b.The'p>ovisionsofSpecification3.0.4arenotapplicable.Otherwise,beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing24hours.SURVEILLANCEREUIREMENTS4.7.1.6EachmainfeedwaterlineisolationvalveshallbedemonstratedOPERABLEby:a.Part-strokeexercisingthevalveatleastonceper92days,a'ndb.Verifyingfullclosurewithin5.15secondsonanyclosureactuationsignalwhileinHOTSTANDBYwithTavg>515'Fduringeachreactor"shutdowne'xceptthatverificationoffullclosurewithin5.15secondsneednotbedeterminedmoreoftenthanonceper92days.ST.LUGIE-UNIT23/47-10AmendmentNo.B  
{{#Wiki_filter:ATTACHMENT lMarked-up Technical Specification Pages3/47-I0B3/47-3(withinsert)87i2300081 871222iDa.~DOCK-O500OZ89-
.PLANTSYSTEMSBASES3/4.7.1.4.ACTIVITYThelimitationsonsecondarysystemspecificactivityensurethattheresultantoffsiteradiationdosewillbelimitedtoasmallfractionof10CFRPart100limitsintheeventofasteamlinerupture.Thisdosealsoincludestheeffectsofacoincident1.0gpmprimaryto.secondarytubeleakinthesteamgeneratoroftheaffectedsteamlineandaconcurrentlossofoffsiteelectricalpower.Thesevaluesareconsistentwiththeassumptionsusedinthesafetyanalyses'/4.7.1.5MAINSTEAMLINEISOLATIONVALVESTheOPERABILITYofthemainsteamlineisolationvalvesensuresthatnomorethanonesteamgeneratorwillblowdownintheeventofasteamlinerupture.Thisrestrictionisrequiredto(1)minimizethepositivereactivityeffectsoftheReactorCoolantSystemcooldownassociatedwiththeblowdown,and(2)limitthepressurerisewithincontainmentintheeventthesteamlineruptureoccurswithincontainment.TheOPERABILITYofthemainsteamisolationvalveswithintheclosuretimesoftheSurveillanceRequirementsisconsistentwiththeassumptionsusedinthesafetyanalyses.3/4.7.1e6MAINFEEDWATERLINEISOLATIONVALVESThemainfeedwaterlineisolationvalvesarerequiredtobeOPERABLEtoensurethat(1)feedwateristerminatedtotheaffectedsteamgeneratorfollowingasteamlinebreakand(2)auxiliaryfeedwaterisdeliveredtotheintactsteamgeneratorfollowingafeedwaterlinebreak.Iffeedwaterisnotterminatedtoasteamgeneratorwithabrokenmainsteamline,twoseriouseffectsmayresult:(1)thepost-tripreturntopowerduetoplantcooldownwillbegreaterwithresultanthigherfuelfailureand(2)thesteamreleasedtocontainmentwillexceedthedesign.utoreovaofthminfeecckvalfromthelantdesgnanditreplaentwitsecondinfeedwaerline'tionaltheistngothertantheinfeedwelineotionalvesoreventckflowoWfolwinafednebrak.hismayre1ina1ofconensinntoryathepeialrotbeingletofethestamgeror.Theconcernisthefailureofonemainfeedwaterlineisolationvalvetoclosewiththeothermainfeedwaterlineisolationvalveinthatlinebeinginoperable(i.e.,stuckopen).Itisthusdesiredtoprecludeoperationforextendedperiodswithamainfeedwaterlineisolationva'.veknowntobestuckinthe'openposition.~X~Scnf+gs~n,k+I83/47"3 INSERT8'1Tworedundantmainfeedwaterisolationvalves(MFIV's)areprovidedineachmainfeedlinetoassurefeedwaterisolationintheeventofasteamlinebreakwithasinglefailure.Also,redundantMFIV'sassurethatbackflowinthefeedlinesispreventedfollowingafeedlinebreak.INSERTP2Atimelimitof72hoursonoperationswithaninoperablemainfeedwaterisolationvalveprovidesassurancethatoperationswillnotcontinueforanextendedperiodwithafailed,openMFIV.
--IDI9EJW4/0I7/2 I4II tPLANTSYSTEMSMAINFEEDWATER LINEISOLATION VALVESLIMITINGCONDITION FOROPERATION 3.7.1.6Eachmainfeedwater lineisolation valveshallbeOPERABLE.
ATTACHMENT2SAFETYEVALUATIONI.INTRODUCTIONTheexistingACTIONstatementfortheSt.LucieUnit2TechnicalSpecificationsSection3/4.7.1.6,MainFeedwaterIsolationValves(MFIV)allowsoperationstocontinuefour(4)hourswithaninoperable,openMFIV.ThisACTIONstatementdoesnotprovideadequatetimetoanalyzeanMFIVproblemandeffectrepairs.Asaresult,thereexiststhepotentialforunnecessaryplantshutdowns.ThisproposedchangetotheTechnicalSpecificationswillmodifytheSection3/4.7.1.6ACTIONStatementforaninoperable,openMFIVtoallowoperationstocontinueforupto72hoursinsteadofthepresentfour(4)hourlimit.IfthevalvecannotberestoredtoOPERABLE,theplantwouldbeplacedinHOTSTANDBYinthenext6hoursandCOLDSHUTDOWNwithinthefollowingtwenty-four(24)hours.II.DISCUSSIONANDANALYSISTheMPIVsarerequiredtobeOPERABLEtoensurethatfeedwaterflowtotheaffectedsteamgeneratoristerminatedintheeventofamainsteamlinebreak(MSLB).Ifmainfeedwaterflowisnotterminated,twoeffectsmayresult:(1)thepost-tripreturntopowermaybegreate'rwithresultanthigherfuelfailureand,(2)thesteamreleasetothecontainmentmayexceedcontainmentdesignpressureifthebreakisinsidecontainment.Additionally,theMFIVsfunctiontoensurethatauxiliaryfeedwater(AFW)canbedeliveredtotheintactsteamgeneratorintheeventofamainfeedlinebreak(MPLB).BackflowoftheAFWtotheMainFeedwaterSystemfollowingafeedlinebreakcouldresultinalossofcondensateinventoryandthepotentialfornotbeingabletofeedtheintactsteamgenerator.TheclosureofasingleMPIVineachfeedline,asrequiredbythesafetyanalysis,providesisolationofmainfeedwaterandavailabilityofAFWfollowingasteamlineorfeedlinebreak.ThesecondMPIVensuresthatasinglefailurewhichprecludesclosureofonevalvewillnotprecludemainfeedwaterisolationorAFWavailability.Theproposedchangeisacceptableforthefollowingreasons:(A)UndercurrentTechnicalSpecifications,operationwithaninoperable, yC~1 ATTACHMENT2Page2of3openMFIVisallowedforfourhours.IntheeventofaDesignBasisEvent(DBE)duringthisperiod,failuretoterminatefeedflowwouldrequirethat:1)thesecondMFIVinthesamelineasthefirstvalvemustalsofailopen,2)amainsteamline(orfeedline)breakmustoccurandtheaffectedsteamgenerator(orfeedline)mustbetheonefedbythelinewhichhastwofailedMFIVs,and3)thisseriesofeventsmustoccurduringtheactiontime(4.hours)identifiedintheLCO.Thelikelihoodofthissequenceofeventsoccurringisverylow.Inordertogainperspectiveonthesignificanceoftheproposedchange,from4to72hours,1)anestimatedMFIVfailopenfrequencyperNUREG2728(lE-3perdemand)canbecombinedwith2)anestimateofthefrequencyofMSLBasgivenintheZionPRA(9.4E-04)toprovideaconservativeestimateofthefailuretoterminateflowgivenaMSLBeventoccursduringoperationwithoneMFIVinoperable,open.ReviewofNPRDSdataforJanuary,1985toMay,1987revealedoneLERwrittenontheMFIVs.Therefore,anassumptionofenteringanLCOonceperyearisconservative.Usingthedescribedrationaleprovidesaconservativeestimatewhichcanhelpillustratetherelativesignificanceofachangefroma4hourtoa72houractiontime.(MFIVfailsopen)x(MSLB)x(LCOActionTime)=frequencyoffailuretoterminateflowduringMSLB(1E-03/d)x(9.4E-4/Rxyr)x(4hr)(1/8760yr/hr)=4.3E-10/d(1E-03/d)x(9'E-4/Rxyr)x(72hr)(1/8760yr/hr=7.7E-09/dTherangesof.0000000077and.00000000043aresuchlowoccurrenceeventsthatforpracticalpurposesthedifferencebetweenthetwo(7.3E-09)isnotsignificant.Asimilarargumentandlowfrequencyofoccurrencecanbedemonstratedforthefeedlinebreakscenario.B)IfanMFIVbecomesinoperableandisopen,thepresentTechnicalSpecificationSection3/4.7.1.6allowsoperationstocontinueforonlyfour(4)hourspriortoproceedingtoHOTSTANDBY.AsstatedinNUREG1024,TechSpecallowableoutagetimesforinoperableequipmenthavebeenestablishedonthebasisofengineeringjudgmentconsideringtheuseofstandardintervals(e.g.1hour,4hours,72hours,etc.).Itisalsostatedthat ATTACHMENT2Page3of3outagetimesthataretooshortcanresultinunnecessaryplanttrips,transientsandfatiguecycling.Theproposed72hourallowableoutagetimeforaninoperable,openMFIVisconsistentwiththestandardtimeintervalselectedforothersafeguardssystems.Forexample,withaninoperableEmergencyCoreCoolingSystem(ECCS)subsystem,Section3/4.5.2allowsoperationstocontinuefor72hourswhiletheredundantsubsystemisrestoredtoOPERABLE.SimilarsituationsexistwiththeContainmentSpraySystems(Section3/4.6.2)ContainmentFanCoolers(Section3/4.6.2.3),IntakeCoolingSystem(Section3/4.7.4)andComponentCoolingWaterSystem(Section3/4'.3).Ineachcase,theabovesystemshaveredundantsubsystemsandtheACTIONtimeineachTechSpecallowsoperationstocontinueforupto72hourswhileaninoperablesubsystemisrestoredtoOPERABLE.Also,theMFIVsfunctionasaportionoftheflowboundaryoftheAFWandtheproposedchangeisconsistentwiththeAFWTechSpecACTIONTIME(Section3/4.7.1.2)givenasingleinoperablecomponentinredundanttrains.Thus,anextensionoftheMFIVACTIONTIMETO72hoursprovidesthesametimetorepairaninoperablesubsystemasothersafeguardssystems.
APPLICABILITY:
ATTACHMENT3DETERMINATIONOFNOSIGNIFICANTHAZARDSCONSIDERATIONThestandardsusedtoarriveatadeterminationthatarequestforamendmentinvolvesnosignificanthazardsconsiderationareincludedintheCommission'sregulations,IOCFR50.92,whichstatesthatnosignificanthazardsconsiderationsareinvolvediftheoperationofthefacilityinaccordancewiththeproposedamendmentwouldnot(I)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated;or(2)createthepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated;or(3)involveasignificantreductioninamarginofsafety.Eachstandardisdiscussedasfollows:(I)Operationofthefacilityinaccordancewiththeproposedamendmentwouldnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.Theproposed72hourACTIONstatementwithaninoperableMainFeedwaterIsolationValve(MFIV)isconsistentwithothersafeguardsequipmentoutagetimes.Thelikelihoodofafeedlineorsteamlinebreakwithaconcurrentfailureofthesecondvalveinthesamefeedlineisremoteduringtheoutagetime.Thus,theproposed72hourallowableoutagetimewillnotsignificantlyincreasetheprobabilityorconsequencesofanaccidentpreviouslyevaluated.(2)Useofthemodifiedspecificationwouldnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.Thischangewillnotcreatethepossibilityofanewordifferentkindofaccidentfromanypreviouslyanalyzedbecauseitdoesnotintroduceanewmodeofnormaloremergencyplantoperation.Inadditiontheproposedchangedoesnotinvolveaphysicalmodificationtotheplant.(3)Useofthemodifiedspecificationwouldnotinvolveasignificantreductioninamarginofsafety.BecausefailureofthesecondMFIVinthesamefeedlinewithasimultaneousfeedlineorsteamlinebreakduringtheseventy-two(72)hourallowableoutagetimeisunlikely,thischangedoesnotinvolveasignificantreductioninamarginofsafety.Basedontheabove,wehavedeterminedthattheamendmentrequestdoesnot(I)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated,(2)createtheprobabilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated,or(3)involveasignificantreductioninamarginofsafety;andthereforedoesnotinvolveasignificanthazardsconsideration.EJWI/035/3 1H~y"~44CtI'I"'PVPPPIPUIh.~IIIJPIJU'~PJIII1h'Iy4VE1fh..d~I4~tl'It4<~PV"tPrIP>>I~4~VP~I','IP'1411~IdA1~,a'a1I44I44~1P'h4h41tV(td-1'"41hd4tld4IIPHtlIIth~.Itk4"84((~'EHItadl,ydJPPlftl.4.14'4yP~41PP>>I4~~1,V1.~I4Il'4,-ya'P~>~~\M'IVIIflhht11PPUP"~*aTtMaltI'~IddtlI>>'1JltaII3*t4Ett441aadltItta>>C~Jr1t41I'P~E4~gPJdfya:1~I4VCtPlaJtrP~P,U,'lHIJUa411~yd'Ua,fh=I~'4n>>a4tl~~~~CPllv.P~Jiay4444't'PPl4}}
MODES.1,2,3,and4.ACTION:MODE1Withonemainfeedwater lineisolation lveinoperable butopen,POWEROPERATION maycontinuep'rovided heinoperable valveisrestoredtoOPERABLEstatuswithinhours;otherwise, beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing 24hours.MODES2,3-Withonemainfeedwater lineisolation valveinoperable, and4subseqent operation inMODE2,3,or4mayproceedprovided:
:a.Theisolation valveismaintained closed.b.The'p>ovisionsofSpecification 3.0.4arenotapplicable.
Otherwise, beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing 24hours.SURVEILLANCE REUIREMENTS 4.7.1.6Eachmainfeedwater lineisolation valveshallbedemonstrated OPERABLEby:a.Part-stroke exercising thevalveatleastonceper92days,a'ndb.Verifying fullclosurewithin5.15secondsonanyclosureactuation signalwhileinHOTSTANDBYwithTavg>515'Fduringeachreactor"shutdowne'xceptthatverification offullclosurewithin5.15secondsneednotbedetermined moreoftenthanonceper92days.ST.LUGIE-UNIT23/47-10Amendment No.B  
.PLANTSYSTEMSBASES3/4.7.1.4.ACTIVITYThelimitations onsecondary systemspecificactivityensurethattheresultant offsiteradiation dosewillbelimitedtoasmallfractionof10CFRPart100limitsintheeventofasteamlinerupture.Thisdosealsoincludestheeffectsofacoincident 1.0gpmprimaryto.secondary tubeleakinthesteamgenerator oftheaffectedsteamlineandaconcurrent lossofoffsiteelectrical power.Thesevaluesareconsistent withtheassumptions usedinthesafetyanalyses'/4.7.1.5 MAINSTEAMLINEISOLATION VALVESTheOPERABILITY ofthemainsteamlineisolation valvesensuresthatnomorethanonesteamgenerator willblowdownintheeventofasteamlinerupture.Thisrestriction isrequiredto(1)minimizethepositivereactivity effectsoftheReactorCoolantSystemcooldownassociated withtheblowdown, and(2)limitthepressurerisewithincontainment intheeventthesteamlineruptureoccurswithincontainment.
TheOPERABILITY ofthemainsteamisolation valveswithintheclosuretimesoftheSurveillance Requirements isconsistent withtheassumptions usedinthesafetyanalyses.
3/4.7.1e6MAINFEEDWATER LINEISOLATION VALVESThemainfeedwater lineisolation valvesarerequiredtobeOPERABLEtoensurethat(1)feedwater isterminated totheaffectedsteamgenerator following asteamlinebreakand(2)auxiliary feedwater isdelivered totheintactsteamgenerator following afeedwater linebreak.Iffeedwater isnotterminated toasteamgenerator withabrokenmainsteamline,twoseriouseffectsmayresult:(1)thepost-trip returntopowerduetoplantcooldownwillbegreaterwithresultant higherfuelfailureand(2)thesteamreleasedtocontainment willexceedthedesign.utoreovaofthminfeecckvalfromthelantdesgnanditreplaentwitsecondinfeedwaerline'tionaltheistngothertantheinfeedwelineotionalvesoreventckflowoWfolwinafednebrak.hismayre1ina1ofconensinntoryathepeialrotbeingletofethestamgeror.Theconcernisthefailureofonemainfeedwater lineisolation valvetoclosewiththeothermainfeedwater lineisolation valveinthatlinebeinginoperable (i.e.,stuckopen).Itisthusdesiredtoprecludeoperation forextendedperiodswithamainfeedwater lineisolation va'.veknowntobestuckinthe'openposition.
~X~Scnf+gs~n,k+I83/47"3 INSERT8'1Tworedundant mainfeedwater isolation valves(MFIV's)areprovidedineachmainfeedlinetoassurefeedwater isolation intheeventofasteamlinebreakwithasinglefailure.Also,redundant MFIV'sassurethatbackflowinthefeedlines isprevented following afeedlinebreak.INSERTP2Atimelimitof72hoursonoperations withaninoperable mainfeedwater isolation valveprovidesassurance thatoperations willnotcontinueforanextendedperiodwithafailed,openMFIV.
ATTACHMENT 2SAFETYEVALUATION I.INTRODUCTION TheexistingACTIONstatement fortheSt.LucieUnit2Technical Specifications Section3/4.7.1.6, MainFeedwater Isolation Valves(MFIV)allowsoperations tocontinuefour(4)hourswithaninoperable, openMFIV.ThisACTIONstatement doesnotprovideadequatetimetoanalyzeanMFIVproblemandeffectrepairs.Asaresult,thereexiststhepotential forunnecessary plantshutdowns.
ThisproposedchangetotheTechnical Specifications willmodifytheSection3/4.7.1.6 ACTIONStatement foraninoperable, openMFIVtoallowoperations tocontinueforupto72hoursinsteadofthepresentfour(4)hourlimit.IfthevalvecannotberestoredtoOPERABLE, theplantwouldbeplacedinHOTSTANDBYinthenext6hoursandCOLDSHUTDOWNwithinthefollowing twenty-four (24)hours.II.DISCUSSION ANDANALYSISTheMPIVsarerequiredtobeOPERABLEtoensurethatfeedwater flowtotheaffectedsteamgenerator isterminated intheeventofamainsteamline break(MSLB).Ifmainfeedwater flowisnotterminated, twoeffectsmayresult:(1)thepost-trip returntopowermaybegreate'rwithresultant higherfuelfailureand,(2)thesteamreleasetothecontainment mayexceedcontainment designpressureifthebreakisinsidecontainment.
Additionally, theMFIVsfunctiontoensurethatauxiliary feedwater (AFW)canbedelivered totheintactsteamgenerator intheeventofamainfeedlinebreak(MPLB).BackflowoftheAFWtotheMainFeedwater Systemfollowing afeedlinebreakcouldresultinalossofcondensate inventory andthepotential fornotbeingabletofeedtheintactsteamgenerator.
TheclosureofasingleMPIVineachfeedline, asrequiredbythesafetyanalysis, providesisolation ofmainfeedwater andavailability ofAFWfollowing asteamline orfeedlinebreak.ThesecondMPIVensuresthatasinglefailurewhichprecludes closureofonevalvewillnotprecludemainfeedwater isolation orAFWavailability.
Theproposedchangeisacceptable forthefollowing reasons:(A)UndercurrentTechnical Specifications, operation withaninoperable, yC~1 ATTACHMENT 2Page2of3openMFIVisallowedforfourhours.IntheeventofaDesignBasisEvent(DBE)duringthisperiod,failuretoterminate feedflowwouldrequirethat:1)thesecondMFIVinthesamelineasthefirstvalvemustalsofailopen,2)amainsteamline(orfeedline)breakmustoccurandtheaffectedsteamgenerator (orfeedline)mustbetheonefedbythelinewhichhastwofailedMFIVs,and3)thisseriesofeventsmustoccurduringtheactiontime(4.hours)identified intheLCO.Thelikelihood ofthissequenceofeventsoccurring isverylow.Inordertogainperspective onthesignificance oftheproposedchange,from4to72hours,1)anestimated MFIVfailopenfrequency perNUREG2728(lE-3perdemand)canbecombinedwith2)anestimateofthefrequency ofMSLBasgivenintheZionPRA(9.4E-04) toprovideaconservative estimateofthefailuretoterminate flowgivenaMSLBeventoccursduringoperation withoneMFIVinoperable, open.ReviewofNPRDSdataforJanuary,1985toMay,1987revealedoneLERwrittenontheMFIVs.Therefore, anassumption ofenteringanLCOonceperyearisconservative.
Usingthedescribed rationale providesaconservative estimatewhichcanhelpillustrate therelativesignificance ofachangefroma4hourtoa72houractiontime.(MFIVfailsopen)x(MSLB)x(LCOActionTime)=frequency offailuretoterminate flowduringMSLB(1E-03/d) x(9.4E-4/Rx yr)x(4hr)(1/8760yr/hr)=4.3E-10/d (1E-03/d) x(9'E-4/Rxyr)x(72hr)(1/8760yr/hr=7.7E-09/d Therangesof.0000000077 and.00000000043 aresuchlowoccurrence eventsthatforpractical purposesthedifference betweenthetwo(7.3E-09) isnotsignificant.
Asimilarargumentandlowfrequency ofoccurrence canbedemonstrated forthefeedlinebreakscenario.
B)IfanMFIVbecomesinoperable andisopen,thepresentTechnical Specification Section3/4.7.1.6 allowsoperations tocontinueforonlyfour(4)hourspriortoproceeding toHOTSTANDBY.AsstatedinNUREG1024,TechSpecallowable outagetimesforinoperable equipment havebeenestablished onthebasisofengineering judgmentconsidering theuseofstandardintervals (e.g.1hour,4hours,72hours,etc.).Itisalsostatedthat ATTACHMENT 2Page3of3outagetimesthataretooshortcanresultinunnecessary planttrips,transients andfatiguecycling.Theproposed72hourallowable outagetimeforaninoperable, openMFIVisconsistent withthestandardtimeintervalselectedforothersafeguards systems.Forexample,withaninoperable Emergency CoreCoolingSystem(ECCS)subsystem, Section3/4.5.2allowsoperations tocontinuefor72hourswhiletheredundant subsystem isrestoredtoOPERABLE.
Similarsituations existwiththeContainment SpraySystems(Section3/4.6.2)Containment FanCoolers(Section3/4.6.2.3),
IntakeCoolingSystem(Section3/4.7.4)andComponent CoolingWaterSystem(Section3/4'.3).Ineachcase,theabovesystemshaveredundant subsystems andtheACTIONtimeineachTechSpecallowsoperations tocontinueforupto72hourswhileaninoperable subsystem isrestoredtoOPERABLE.
Also,theMFIVsfunctionasaportionoftheflowboundaryoftheAFWandtheproposedchangeisconsistent withtheAFWTechSpecACTIONTIME(Section3/4.7.1.2) givenasingleinoperable component inredundant trains.Thus,anextension oftheMFIVACTIONTIMETO72hoursprovidesthesametimetorepairaninoperable subsystem asothersafeguards systems.
ATTACHMENT 3DETERMINATION OFNOSIGNIFICANT HAZARDSCONSIDERATION Thestandards usedtoarriveatadetermination thatarequestforamendment involvesnosignificant hazardsconsideration areincludedintheCommission's regulations, IOCFR50.92,whichstatesthatnosignificant hazardsconsiderations areinvolvediftheoperation ofthefacilityinaccordance withtheproposedamendment wouldnot(I)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated; or(2)createthepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated; or(3)involveasignificant reduction inamarginofsafety.Eachstandardisdiscussed asfollows:(I)Operation ofthefacilityinaccordance withtheproposedamendment wouldnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.
Theproposed72hourACTIONstatement withaninoperable MainFeedwater Isolation Valve(MFIV)isconsistent withothersafeguards equipment outagetimes.Thelikelihood ofafeedlineorsteamline breakwithaconcurrent failureofthesecondvalveinthesamefeedlineisremoteduringtheoutagetime.Thus,theproposed72hourallowable outagetimewillnotsignificantly increasetheprobability orconsequences ofanaccidentpreviously evaluated.
(2)Useofthemodifiedspecification wouldnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.
Thischangewillnotcreatethepossibility ofanewordifferent kindofaccidentfromanypreviously analyzedbecauseitdoesnotintroduce anewmodeofnormaloremergency plantoperation.
Inadditiontheproposedchangedoesnotinvolveaphysicalmodification totheplant.(3)Useofthemodifiedspecification wouldnotinvolveasignificant reduction inamarginofsafety.BecausefailureofthesecondMFIVinthesamefeedlinewithasimultaneous feedlineorsteamline breakduringtheseventy-two (72)hourallowableoutagetimeisunlikely, thischangedoesnotinvolveasignificant reduction inamarginofsafety.Basedontheabove,wehavedetermined thattheamendment requestdoesnot(I)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated, (2)createtheprobability ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated, or(3)involveasignificant reduction inamarginofsafety;andtherefore doesnotinvolveasignificant hazardsconsideration.
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Revision as of 16:47, 29 June 2018

Proposed Tech Spec 3.7.1.6,changing Action Statement to Allow 72 H to Restore Inoperable,Open Main Feedwater Isolation Valve to Operable Status
ML17221A565
Person / Time
Site: Saint Lucie NextEra Energy icon.png
Issue date: 12/22/1987
From:
FLORIDA POWER & LIGHT CO.
To:
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ML17221A564 List:
References
NUDOCS 8712300081
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Text

ATTACHMENT lMarked-up Technical Specification Pages3/47-I0B3/47-3(withinsert)87i2300081 871222iDa.~DOCK-O500OZ89-

--IDI9EJW4/0I7/2 I4II tPLANTSYSTEMSMAINFEEDWATER LINEISOLATION VALVESLIMITINGCONDITION FOROPERATION 3.7.1.6Eachmainfeedwater lineisolation valveshallbeOPERABLE.

APPLICABILITY:

MODES.1,2,3,and4.ACTION:MODE1Withonemainfeedwater lineisolation lveinoperable butopen,POWEROPERATION maycontinuep'rovided heinoperable valveisrestoredtoOPERABLEstatuswithinhours;otherwise, beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing 24hours.MODES2,3-Withonemainfeedwater lineisolation valveinoperable, and4subseqent operation inMODE2,3,or4mayproceedprovided:

a.Theisolation valveismaintained closed.b.The'p>ovisionsofSpecification 3.0.4arenotapplicable.

Otherwise, beinatleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOWNwithinthefollowing 24hours.SURVEILLANCE REUIREMENTS 4.7.1.6Eachmainfeedwater lineisolation valveshallbedemonstrated OPERABLEby:a.Part-stroke exercising thevalveatleastonceper92days,a'ndb.Verifying fullclosurewithin5.15secondsonanyclosureactuation signalwhileinHOTSTANDBYwithTavg>515'Fduringeachreactor"shutdowne'xceptthatverification offullclosurewithin5.15secondsneednotbedetermined moreoftenthanonceper92days.ST.LUGIE-UNIT23/47-10Amendment No.B

.PLANTSYSTEMSBASES3/4.7.1.4.ACTIVITYThelimitations onsecondary systemspecificactivityensurethattheresultant offsiteradiation dosewillbelimitedtoasmallfractionof10CFRPart100limitsintheeventofasteamlinerupture.Thisdosealsoincludestheeffectsofacoincident 1.0gpmprimaryto.secondary tubeleakinthesteamgenerator oftheaffectedsteamlineandaconcurrent lossofoffsiteelectrical power.Thesevaluesareconsistent withtheassumptions usedinthesafetyanalyses'/4.7.1.5 MAINSTEAMLINEISOLATION VALVESTheOPERABILITY ofthemainsteamlineisolation valvesensuresthatnomorethanonesteamgenerator willblowdownintheeventofasteamlinerupture.Thisrestriction isrequiredto(1)minimizethepositivereactivity effectsoftheReactorCoolantSystemcooldownassociated withtheblowdown, and(2)limitthepressurerisewithincontainment intheeventthesteamlineruptureoccurswithincontainment.

TheOPERABILITY ofthemainsteamisolation valveswithintheclosuretimesoftheSurveillance Requirements isconsistent withtheassumptions usedinthesafetyanalyses.

3/4.7.1e6MAINFEEDWATER LINEISOLATION VALVESThemainfeedwater lineisolation valvesarerequiredtobeOPERABLEtoensurethat(1)feedwater isterminated totheaffectedsteamgenerator following asteamlinebreakand(2)auxiliary feedwater isdelivered totheintactsteamgenerator following afeedwater linebreak.Iffeedwater isnotterminated toasteamgenerator withabrokenmainsteamline,twoseriouseffectsmayresult:(1)thepost-trip returntopowerduetoplantcooldownwillbegreaterwithresultant higherfuelfailureand(2)thesteamreleasedtocontainment willexceedthedesign.utoreovaofthminfeecckvalfromthelantdesgnanditreplaentwitsecondinfeedwaerline'tionaltheistngothertantheinfeedwelineotionalvesoreventckflowoWfolwinafednebrak.hismayre1ina1ofconensinntoryathepeialrotbeingletofethestamgeror.Theconcernisthefailureofonemainfeedwater lineisolation valvetoclosewiththeothermainfeedwater lineisolation valveinthatlinebeinginoperable (i.e.,stuckopen).Itisthusdesiredtoprecludeoperation forextendedperiodswithamainfeedwater lineisolation va'.veknowntobestuckinthe'openposition.

~X~Scnf+gs~n,k+I83/47"3 INSERT8'1Tworedundant mainfeedwater isolation valves(MFIV's)areprovidedineachmainfeedlinetoassurefeedwater isolation intheeventofasteamlinebreakwithasinglefailure.Also,redundant MFIV'sassurethatbackflowinthefeedlines isprevented following afeedlinebreak.INSERTP2Atimelimitof72hoursonoperations withaninoperable mainfeedwater isolation valveprovidesassurance thatoperations willnotcontinueforanextendedperiodwithafailed,openMFIV.

ATTACHMENT 2SAFETYEVALUATION I.INTRODUCTION TheexistingACTIONstatement fortheSt.LucieUnit2Technical Specifications Section3/4.7.1.6, MainFeedwater Isolation Valves(MFIV)allowsoperations tocontinuefour(4)hourswithaninoperable, openMFIV.ThisACTIONstatement doesnotprovideadequatetimetoanalyzeanMFIVproblemandeffectrepairs.Asaresult,thereexiststhepotential forunnecessary plantshutdowns.

ThisproposedchangetotheTechnical Specifications willmodifytheSection3/4.7.1.6 ACTIONStatement foraninoperable, openMFIVtoallowoperations tocontinueforupto72hoursinsteadofthepresentfour(4)hourlimit.IfthevalvecannotberestoredtoOPERABLE, theplantwouldbeplacedinHOTSTANDBYinthenext6hoursandCOLDSHUTDOWNwithinthefollowing twenty-four (24)hours.II.DISCUSSION ANDANALYSISTheMPIVsarerequiredtobeOPERABLEtoensurethatfeedwater flowtotheaffectedsteamgenerator isterminated intheeventofamainsteamline break(MSLB).Ifmainfeedwater flowisnotterminated, twoeffectsmayresult:(1)thepost-trip returntopowermaybegreate'rwithresultant higherfuelfailureand,(2)thesteamreleasetothecontainment mayexceedcontainment designpressureifthebreakisinsidecontainment.

Additionally, theMFIVsfunctiontoensurethatauxiliary feedwater (AFW)canbedelivered totheintactsteamgenerator intheeventofamainfeedlinebreak(MPLB).BackflowoftheAFWtotheMainFeedwater Systemfollowing afeedlinebreakcouldresultinalossofcondensate inventory andthepotential fornotbeingabletofeedtheintactsteamgenerator.

TheclosureofasingleMPIVineachfeedline, asrequiredbythesafetyanalysis, providesisolation ofmainfeedwater andavailability ofAFWfollowing asteamline orfeedlinebreak.ThesecondMPIVensuresthatasinglefailurewhichprecludes closureofonevalvewillnotprecludemainfeedwater isolation orAFWavailability.

Theproposedchangeisacceptable forthefollowing reasons:(A)UndercurrentTechnical Specifications, operation withaninoperable, yC~1 ATTACHMENT 2Page2of3openMFIVisallowedforfourhours.IntheeventofaDesignBasisEvent(DBE)duringthisperiod,failuretoterminate feedflowwouldrequirethat:1)thesecondMFIVinthesamelineasthefirstvalvemustalsofailopen,2)amainsteamline(orfeedline)breakmustoccurandtheaffectedsteamgenerator (orfeedline)mustbetheonefedbythelinewhichhastwofailedMFIVs,and3)thisseriesofeventsmustoccurduringtheactiontime(4.hours)identified intheLCO.Thelikelihood ofthissequenceofeventsoccurring isverylow.Inordertogainperspective onthesignificance oftheproposedchange,from4to72hours,1)anestimated MFIVfailopenfrequency perNUREG2728(lE-3perdemand)canbecombinedwith2)anestimateofthefrequency ofMSLBasgivenintheZionPRA(9.4E-04) toprovideaconservative estimateofthefailuretoterminate flowgivenaMSLBeventoccursduringoperation withoneMFIVinoperable, open.ReviewofNPRDSdataforJanuary,1985toMay,1987revealedoneLERwrittenontheMFIVs.Therefore, anassumption ofenteringanLCOonceperyearisconservative.

Usingthedescribed rationale providesaconservative estimatewhichcanhelpillustrate therelativesignificance ofachangefroma4hourtoa72houractiontime.(MFIVfailsopen)x(MSLB)x(LCOActionTime)=frequency offailuretoterminate flowduringMSLB(1E-03/d) x(9.4E-4/Rx yr)x(4hr)(1/8760yr/hr)=4.3E-10/d (1E-03/d) x(9'E-4/Rxyr)x(72hr)(1/8760yr/hr=7.7E-09/d Therangesof.0000000077 and.00000000043 aresuchlowoccurrence eventsthatforpractical purposesthedifference betweenthetwo(7.3E-09) isnotsignificant.

Asimilarargumentandlowfrequency ofoccurrence canbedemonstrated forthefeedlinebreakscenario.

B)IfanMFIVbecomesinoperable andisopen,thepresentTechnical Specification Section3/4.7.1.6 allowsoperations tocontinueforonlyfour(4)hourspriortoproceeding toHOTSTANDBY.AsstatedinNUREG1024,TechSpecallowable outagetimesforinoperable equipment havebeenestablished onthebasisofengineering judgmentconsidering theuseofstandardintervals (e.g.1hour,4hours,72hours,etc.).Itisalsostatedthat ATTACHMENT 2Page3of3outagetimesthataretooshortcanresultinunnecessary planttrips,transients andfatiguecycling.Theproposed72hourallowable outagetimeforaninoperable, openMFIVisconsistent withthestandardtimeintervalselectedforothersafeguards systems.Forexample,withaninoperable Emergency CoreCoolingSystem(ECCS)subsystem, Section3/4.5.2allowsoperations tocontinuefor72hourswhiletheredundant subsystem isrestoredtoOPERABLE.

Similarsituations existwiththeContainment SpraySystems(Section3/4.6.2)Containment FanCoolers(Section3/4.6.2.3),

IntakeCoolingSystem(Section3/4.7.4)andComponent CoolingWaterSystem(Section3/4'.3).Ineachcase,theabovesystemshaveredundant subsystems andtheACTIONtimeineachTechSpecallowsoperations tocontinueforupto72hourswhileaninoperable subsystem isrestoredtoOPERABLE.

Also,theMFIVsfunctionasaportionoftheflowboundaryoftheAFWandtheproposedchangeisconsistent withtheAFWTechSpecACTIONTIME(Section3/4.7.1.2) givenasingleinoperable component inredundant trains.Thus,anextension oftheMFIVACTIONTIMETO72hoursprovidesthesametimetorepairaninoperable subsystem asothersafeguards systems.

ATTACHMENT 3DETERMINATION OFNOSIGNIFICANT HAZARDSCONSIDERATION Thestandards usedtoarriveatadetermination thatarequestforamendment involvesnosignificant hazardsconsideration areincludedintheCommission's regulations, IOCFR50.92,whichstatesthatnosignificant hazardsconsiderations areinvolvediftheoperation ofthefacilityinaccordance withtheproposedamendment wouldnot(I)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated; or(2)createthepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated; or(3)involveasignificant reduction inamarginofsafety.Eachstandardisdiscussed asfollows:(I)Operation ofthefacilityinaccordance withtheproposedamendment wouldnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.

Theproposed72hourACTIONstatement withaninoperable MainFeedwater Isolation Valve(MFIV)isconsistent withothersafeguards equipment outagetimes.Thelikelihood ofafeedlineorsteamline breakwithaconcurrent failureofthesecondvalveinthesamefeedlineisremoteduringtheoutagetime.Thus,theproposed72hourallowable outagetimewillnotsignificantly increasetheprobability orconsequences ofanaccidentpreviously evaluated.

(2)Useofthemodifiedspecification wouldnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.

Thischangewillnotcreatethepossibility ofanewordifferent kindofaccidentfromanypreviously analyzedbecauseitdoesnotintroduce anewmodeofnormaloremergency plantoperation.

Inadditiontheproposedchangedoesnotinvolveaphysicalmodification totheplant.(3)Useofthemodifiedspecification wouldnotinvolveasignificant reduction inamarginofsafety.BecausefailureofthesecondMFIVinthesamefeedlinewithasimultaneous feedlineorsteamline breakduringtheseventy-two (72)hourallowableoutagetimeisunlikely, thischangedoesnotinvolveasignificant reduction inamarginofsafety.Basedontheabove,wehavedetermined thattheamendment requestdoesnot(I)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated, (2)createtheprobability ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated, or(3)involveasignificant reduction inamarginofsafety;andtherefore doesnotinvolveasignificant hazardsconsideration.

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