ML17221A568
| ML17221A568 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 12/22/1987 |
| From: | FLORIDA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML17221A567 | List: |
| References | |
| NUDOCS 8712300089 | |
| Download: ML17221A568 (23) | |
Text
ATTACHMENTIMarked-upTechnicalSpecificationPages:ST.LUCIEUNITI3/4I-6(withinsert)B3/4I-I(withinsert)ST.LUCIEUNIT23/4I-5(withinsert)B3/4I-I~87i230008987i222anOC~SeqoSSSEJW4/052/3 REACTIVITYCONTROLSYSTEMSSURVEILLANCEREUIREMENTSContinued4.1.1.4.2TheMTCshallbedetermfnedatthefollowingfrequenciesandTHERMALPOWERconditionsduringeachfuelcycle:uok.:a.Priortoinitialoperatfonabove5XoTHERMALPOWER,dele.><,fth~'f(J;b.AtanyTHERMALPOWER,within7EFPOafter4~+44y-reachingaRATEOTHERMALPOWERequilibriumboronconcentration.rc~con'cQQcF00pp~ST.LUCIEŽUNIT13/41-6AmendmentNo.
~~Ari1i INSERTFORST.LUCIEUNITIp.3/4l-6AtanyTHERMALPOWER,within7EFPDafterreachingaRATEDTHERMALPOWERequilibriumboronconcentrationof300ppm.TheMTCdeterminationofthisparagraphisnotrequirediftheresultsofSurveillanceRequirements4.I.I.4.2a.and4.l.I.4.2b.arewithinatoIeranceof+2.0pcm/Ffromcorrespondingdesignvalues.EJW4/052/4 44tt44~il'4IIIl~4'It4I4It44,It.itI,Fv>l4~':444~~~lil4I4,II4'li1'.lI,4'44t4>I~4441~I.I,4 3/4.1REACTIVITYCONTROLSYSTEMSBASES3/4.1.1BORATIONCONTROL3/4.1.1.1and3/4.1.1.2SHUTDOWNMARGINAsufficientSHUTDOWNMARGINensuresthat1)thereactorcanbemadesubcriticalfromalloperatingconditions,2)thereactivitytransientsassociatedwithpostulatedaccidentconditions.arecontrollablewithinacceptablelimits,and3)thereactorwillbemaintainedsufficientlysubcriticaltoprecludeinadvertentcriticalityintheshutdowncondition.SHUTDOWNMARGINrequirementsvarythroughoutcorelifeasafunctionoffueldepletion,RCSboronconcentrationan,dRCST.ThemostrestrictiveconditionoccursatEOL,withTaveatnooldoperatingtemperature,andisassociatedwithapostulatedsteamlinebreakaccidentandresultinguncontrolledRCScooldown.Inth6analysisofthisaccident,aminimumSHUTDOWNMARGINof3.6gak/kisrequiredtocontrolthereactivitytransient.Accordingly,theSHUTDOWNMARGINrequiredbySpecification3.1.1.1isbaseduponthislimitingconditionandiscon-sistentwithFSARaccidentanalysisassumptions.Forearlierperiodsduringthefuelcycle,thisvalueisconservative.WithTavq<200'F,thereactivitytransientresultingfromaborondilutioneventwithapartiallydrainedReactorCoolantSystemrequiresa2Xhk/kSHUTDOWNMARGINandrestrictionsonchargingpumpoperationtoprovideadequateprotection.A.2%ak/kSHUTDOWNMARGINis1.0Xak/kconservativeforMode5operationwithtotalRCSvolumepresent,howeverLCO3.1.1.2iswrittenconservativelyforsimplicity.3/4.1.1.3BORONDILUTIONANDADDITIONAminimumflowrateofatleast3000GPMprovidesadequatemixing,preventsstratificationandensuresthatreactivitychangeswillbegradualduringboronconcentrationchangesintheReactorCoolantSystem.Aflowrateofatleast3000GPMwillcirculateanequivalentReactorCoolantSystemvolumeof11,400cubicfeetinapproximately26minutes.Thereactivitychangerateassociatedwithboronconcentrationchangeswillbewithinthecapabilityforoperatorrecognitionandcontrol.,~-~v34.1.1.4MODERATORTEMPERATURECOEFFICIENTMTCAmendmentNo.21,pp~//:lB3/41-1Thelimitingva1uesassumedfor'heMTCusedintheaccidentandtransientanalyseswere+0.7x10"dk/k/'FforTHERMALPOWERlevelsI<70%ofRATEDTHERMALPOWER,+0.2x10"hk/k/'FforTHERMALPOWERTevels>70KofRATEDTHERMALand-2.8x104gk/k/'FatRATEDTHERMALPOWER.Therefore,theselimitingvaluesareincludedinthisspecification.8'~4e~eei+ied-eoncVH-;io-t-h'\hC~tp84tt.i-.+~a~A8ST.LUCIE-UNIT1 INSERTFORST.LUCIEUNITIp.B3/4I-IThelimitationsonmoderatortemperaturecoefficient(MTC)areprovidedtoensurethattheassumptionsusedintheaccidentandtransientanalysisremainvalidthrougheachfuelcycle.ThesurveillancerequirementsformeasurementoftheMTCduringeachfuelcyclecombinedwiththeTechnicalSpecificationSurveillanceRequirement4.l.l.l.2areadequatetoconfirmtheMTCvaluesincethiscoefficientchangesslowlydueprincipallytothereductioninRCSboronconcentrationassociatedwithfuelburnup.TheconfirmationthatthemeasuredMTCvalueiswithinitslimitprovidesassurancesthatthecoefficientwillbemaintainedwithinacceptablevaluesthroughouteachfuelcycle.EJW4/052/4 thIIttt~III~I9IhIhI,'
REACTIVITYCONTROLSYSTEMSMODERATORTEMPERATURECOEFFICIENTLIMITINGCONDITIONFOROPERATION3.1.1.4Themoderatortemperaturecoefficient(MTC)shallbe:a.Lesspositivethan+0.5x10delta-k/k/4Fat<70KRATEDTHERMALPOWER,b.C.Lesspositivethan+0.3x10deltak/k/'Fat>70KRATEDTHERMALPOWER,andLessnegativethan-2.7x10deltak/k/4FatRATEDTHERMALPOWER.APPLICABILITY:MODES1and2"¹ACTION:Withthemoderatortemperaturecoefficientoutsideanyoneoftheabovelimits,beinatleastHOTSTANDBYwithin6hours.SURVEILLANCF.REUIREMENTS4.l.1.4.1TheMTCshallbedeterminedtobewithinitsl.imitsbyconfirmatorymeasurements.MTCmeasuredvaluesshallbeextrapolatedand/orcompensatedtopermitdirectcomparisonwiththeabovelimits.4.1.1.4.2TheMTCshallbedeterminedatthefollowingfrequenciesandTHERMALPOWERconditionsduringeachfuelcycle:a.Priortoinitialoperationabove5XofRATEDTHERMALPOWER,aftereachfuelloading.b.C.AtanyTHERMALPOWER,within7EFPDafterreachingaRATEDTHERMALPOWERequilibriumboronconcentrationof800ppm.\~n,i-thi.n EFPB-easter-reaching'ns~g~ckithKeffgreaterthanorequalto1.0.¹SeeSpecialTestExceptions3.10.2and3.10.5.ST.LUCIE-UNIT23/41-5AmendmentNo.14 INSERTFORST.LUCIEUNIT2p.3/4I-5AtanyTHERMALPOWER,within7EFPDafterreachingaRATEDTHERMALPOWERequilibriumboronconcentrationof300ppm.TheMTCdeterminationofthisparagraphisnotrequirediftheresultsofthetestsrequiredinSurveillancerequirements4.I.I.4.2a.and4.I.I.4.2b.arewithinatoleranceof+2.0pcm/Ffromcorrespondingdesignvalues.EJW4/052/5
'$fi.cvgQt'IIlive<rl"I'31~'$P~HII's.'swsrII41044ltIr.,'a>II4e~Mex~sP~uII'~>>'-I:rs-fdL,>f"k 3/4.1REACTIVITYCONTROLSYSTEMSBASES3/4.1.1BORATIONCONTROL3/4.1.1.1and3/4.1.1.2SHUTDOWNMARGINAsufficientSHUTDOWNMARGINensuresthat1)thereactorcanbemadesubcriticalfromalloperatingconditions,2)thereactivitytransientsassociatedwithpostulatedaccidentconditionsarecontrollablewithinacceptablelimits,and3)thereactorwillbemaintainedsufficientlysubcriticaltoprecludeinadvertentcriticalityintheshutdowncondition.SHUTDOWNMARGINrequirementsvarythroughoutcorelifeasafunctionoffueldepletion,RCSboronconcentration,andRCST.Themostrestrictiveavg'onditionoccursatEOL,withTatnoloadoperatingtemperature,andisavgassociatedwithapostulatedsteamlinebreakaccident.andresultinguncon-trolledRCScooldown.Intheanalysisofthisaccident,aminimumSHUTDOWNMARGINof5.0Xdeltak/kisrequiredtocontrolthereactivitytransient.Accordingly,theSHUTDOWNMARGINrequirementisbaseduponthislimitingconditionandisconsistentwithFSARsafetyanalysis'ssumptions.Atearliertimesincorelife,theminimumSHUTDOWNMARGIN'equiredforthemostrestric"tiveconditionsislessthan5.0Xhk/k.WithTlessthanorequalto200F,avgthereactivitytransientsresultingfromanypostulatedaccidentareminimalanda3Xdelta.k/kSHUTDOWNMARGINprovides.adequateprotection.3/4.l.1.3BORONDILUTIONco~iinesc,Il.Supv4ill4~~~~)l//,(./.po4ouatnllCoke6q/n~cC-coeresent(MTC)areprovidedidentandtransientanalysisveillancerequirementsforareadequatetoconfirmtheMTCrincialltothereductionThelimitationsonmoderatortemperaturetoensurethattheassumptionsusedintheacremainvalidthrougheachfuel'ycle.Thesu'measurementoftheMTCduringeachfuelcyclevaluesincethiscoefficientchanesslowldgyueppyinRCSboronconcentrationassociatedwithfuelburnup.TheconfirmationthatthemeasuredMTCvalueiswithinitslimitprovidesassurancesthatthecoef-ficientwillbemaintainedwithinacceptablevaluesthroughouteachfuelcycle.IIAminimumflowrateofatleast3000gpmprovidesadequatemixing,preventsstratificationandensuresthatreactivitychangeswillbegradualduringboronconcentrationreductionsintheReactorCoolantSystem.Aflowrateofatleast3000gpmwillcirculateanequivalentReactorCoolantSystemvolumeof10,931cubicfeetinapproximately26minutes.Thereactivitychangerateassociatedwithboronconcentrationreductionswillthereforebewithinthecapabilityofoperatorrecognitionandon3/4.1.1.4MODERATORTEMPERATURECOEFFICIENTST.LUCIE"UNIT2B3/41-1AmendmentNo.8 P;<<'4br,~lv ATTACHHENT2Safet..EvaluationIntroductionTheproposedchangetotheSt.LucieUnits1and2TechnicalSpecificationsistomodifytherequirementtoperformaNoderatorTemperatureCoefficient(HTC)testneartheendofeachcycle.Undertheproposedchangethistestwouldnotberequirediftestsconductedatearliertimesinthecycle,designNTCcalculations,andcorereactivitycharacteristicspredictsatisfactoryNTCbehaviorwillbeobtainedfortheremainderofthecycle.ThechangemodifiesSt.LucieUnits1and2TechnicalSpecificationSurveillanceRequirement4.1.1.4.2fortheHoderatorTemperatureCoefficientandtheassociatedbases.ThevaluesoftheNTCLimitingConditionsofOperation,whichwillnotbechanged,arelistedinTechnicalSpecification3.1.1.4.TheproposedchangeisbasedontheacceptableperformanceoftheHTCdesignmethodologydemonstratedovertheoperatinghistoryofUnits1and2,onthecyclespecificverificationofHTCmethodologydemonstratedbytestsconductedearlierinthecycle,andonthesurveillanceoftheparameterswhichinfluencethereactivitybehaviorofthereactor.Inadditiontomodifyingtheend-of-cyclesurveillancerequirementsforbothunits,St.LucieUnit1SurveillanceRequirement4.1.1.4.2.bisalsomodifiedforconsistencywithCombustionEngineeringStandardTechnicalSpecifications(NUREG0212Rev.2)andSt.LucieUnit2TechnicalSpecifications.DiscussaonHTCisaffectedbymanyfactorswhichvaryfromcycletocycle.ThemostsignificantfactoraffectingNTCistheReactorCoolantSystem(RCS)boronconcentration.ThisisdiscussedintheCombustionEngineeringStandardTechnicalSpecifications(NUREG0212Rev.2)basesforHTCsurveillancecriteriawhichstates"thiscoefficientchangesslowlydueprincipallytothereductioninRCSboronconcentrationassociatedwithfuelburnup."CoolantdensityvariationscausedbytemperaturevariationsresultinchangesofthetotalmassofmoderatorandRCSboronpresentinthecore.WhenRCStemperaturerises,the thermalexpansionoftheRCScoolantdisplacesmoderatorandsolubleboronfromthecore.Thisthermalexpansionresultsintwoseparateeffects.First,whenRCStemperaturerises,thereductioninthemassofwaterinthecoreresultsinanegativereactivitychange.Thisnegativecomponentduetomoderatordisplacementisnearlyconstantthroughoutthecyclebecausethemassofwaterdisplacedforagivenriseintemperatureisconstantthroughoutthecycle.ThesecondeffectresultingfromRCSthermalexpansionisthatduringexpansionsolubleboronisdisplacedfromthecore.TheamountofborondisplacedisdirectlyproportionaltotheRCSboronconcentration(i.e.earlyincyclethelargestnumberofboronatomsaredisplaced;laterincyclemanyfeweraredisplaced).Thereductioninmassofsolubleboroninthecoreincreasesthereactivityofthecore.Theproportionalityoftheeffecttotheboronconcentrationmeansthatthepositivereactivityeffectsofthermalexpansionwoulddecreasegraduallythroughoutthecycle.ThenetresultisthatHTCisnearzeroorslightlypositiveatthebeginningofthecyclewhentheRCSboronconcentrationisthehighest,anditdecreasesalmostlinearlytolargenegativevaluesastheboronconcentrationisreducedtocompensatefortheburnupoffuelthroughoutthecycle.Whileotherfactorssuchasvariationsininitialfuelenrichment,useofburnablepoisons,andchangesinisotopicinventoryduetofueldepletionhaveasignificanteffectonHTC,themagnitudesoftheseeffectsaremuchlessthanthemagnitudeoftheeffectsduetoRCSboronandtheyhavelessvariabilityoverthecyclethandoestheeffectofRCSboron.TheseotherfactorswhichaffectHTCdirectlybychangingtheneutronfluxspectrumalsoaffectNTCindirectlybychangingthereactivityofthecore.TheRCSboronconcentrationisadjustedtocompensatefortheseotherreactivitychangesandthereforealsoaffectHTC.BecausecontinuousmeasurementofHTCisnotpossible,designcalculationsareusedtopredicttheHTCbehaviorthroughoutthereactorcycle.PeriodicHTCtestsassuretheaccuracyofthesedesigncalculations.CurrentTechnicalSpecificationSurveillanceRequirements4.1.1.4.2.athrough4.1.1.4.2.cspecifythreerequiredHTCtests.ForUnit1,HTCtestingmustbeperformed(1)duringinitialstart-upfollowingreload,(2)within7EFPDofreachingaratedthermalpowerequilibriumboronconcentrationand(3)within7EFPDofreachinganequilibriumboronconcentrationof300ppm.ForUnit2,HTCtestingmustbeperformed(l)duringinitialstart-upfollowingreload,(2)within7EFPDofreachinganequilibriumboronconcentrationof800ppmand(3)within7EFPDofreachinganequilibriumboronconcentrationof300ppm.
Qs Currently,acceptableHTCvaluesbeyondthe300ppmpointinthecycleareassuredbyanEOCdesignvaluewhichiswithinTechnicalSpecificationlimits.Theaccuracyofthedesigncalculationswillhavebeenverifiedbythreeprevioustestsinthecycle,includingthetestat300ppm.Undertheproposedchange,therequirementforanHTCtestat300ppmwouldbeeliminatedinmostinstances.Specifically,iftheresultsofthetwoHTCtestspreviouslyperformedforagivencycleareinagreementwithdesignpredictionswithinacceptancecriteria,andifthecorereactivitybalancesspecifiedinSurveillanceRequirement4.1.1.1.2demonstratethatthemeasuredvaluesoftherequiredparametershavebeenwithinlXdeltak/kofthenormalizeddesignvalues,thenthe300ppmHTCmeasurementtestmaybeomitted.Thischangewouldhavenoeffectonoperationsbeforethe300ppmRCSboronconcentrationwasreached.TheonlychangeinvolvedisthemannerinwhichTechnicalSpecificationcompliancewouldbeassuredinthetimebetweenreaching300ppmandtheendofthecycle.Ouringthisperiod,compliancewouldbeassuredbyadesignEOCHTCvaluewhichwouldbewithinTechnicalSpecificationlimits.Two,insteadofthree,successfulHTCtestswillhavebeencompletedearlierinthecycletoconfirmthevalidityofthedesignHTCcalculations.ThemethodologyusedtocalculatetheendofcycleHTCvaluewillhavebeenverifiedtwiceearlierinthecyclebyperformanceofSurveillanceRequirements4.1.1.4.2.aand4.1.1.4.2.b.Thiswilldemonstratethattheanalyticalmethodshaveadequatelymodelledthecurrentcycle.BecausethetwotestswillhavebeenconductedatsubstantiallydifferentRCSboronconcentrations(differencesupto700ppm),theabilitytomodeltheHTCvariationversusboronconcentrationwillalsohavebeendemonstrated.Ouetouncertaintiesassociatedwiththedesigncalculationsandwithmeasurements,+2pcm/oF(+2*10-5deltak/k/oF)hasbeenestablishedaSanacceptancecriteriaforthecomparisonofmeasuredanddesignvaluesbyAdvancedNuclearFuelsCorporation(ANF)(ReferenceI).CombustionEngineering(C-E)usesavalueof+3pcm/oF(Reference2).HTCcalculationsperformedbyotherfuelvendors/utilitiesusesimilarvaluesasacceptancecriteria.Because+2pcm/oFisthemorerestrictiveofthevaluesprovidedbycurrentSt.Luciefuelvendors,andbecausethisvalueisconsistentwiththeANSIStandardforReloadStartupPhysicsTestsforPressurizedWaterReactors(ANSI/ANSStandard19.6.1-1985),thisvaluehasbeenestablishedastheacceptancecriteriaspecifiedinSurveillanceRequirement4.1.1.2.cforbothunits.
Verificationofthedesignmethodologyisalsoprovidedbymonitoringthecorereactivity.Thisisaccomplishedbytrackingthesolubleboronconcentrationversuscoreexposure.BecausethesameanalyticaltoolsareusedtodevelopcorereactivityandHTCdesignpredictions,verificationoftheaccuracyofthedesignboronletdownpredictionincreasestheconfidenceinthepredictedNTCvalues.DemonstrationthatthecoredepletionisproceedinginthepredictedmanneralsosupportsthevalidityoftheassumptionsusedintheNTCcalculations.BecausevaluesofNTCarecloselyrelatedtoreactorboronconcentrationitisusefultoestimatetheimpactonNTCofdeviationsbetweenthepredictedcoreboronconcentrationandthemeasuredboronvalueatthesameexposure.Todothis,thepermissibleupperboundondeviationsbetweenthemeasuredandpredictedboronvaluesareestimated,takingintoaccountthelXdeviationcriteriafromSurveillanceRequirement4.1.1.1.2.TheresultingboronvaluesarethenmultipliedbytherateofchangeoftheHTCwithrespecttoboronconcentration.Asanexample,consideraveryconservativevalueofboronworthfor300ppm;eg.8pcm/ppm.Ifthetotal1XdeviationpermittedbySurveillanceRequirement4.1.1.1.2wereduesolelytoboronthenthemaximumpermissibledeviationbetweenmeasuredandpredictedboronvalueswouldbeabout125ppm.TypicalvaluesfortherateofchangeoftheNTCwithrespecttochangingboronconcentrationarelessthan1.5pcm/oF/100ppm(Reference1).Therefore,themaximumHTCdeviationwhichcouldresultfromthemaximumboronconcentrationdeviationallowedbySurveillanceRequirement4.1.1.1.2islessthan2pcm/oF(125ppmdeviation*1.5pcm/oF/100ppm1.9pcm/oF).NTCdeviationsofthismagnitudewouldbewithintheallowanceformeasurementuncertaintyprovidedbythedesignacceptancecriteria.OthercorereactivityparametersmonitoredunderSurveillanceRequirement4.1.1.1.2havealesssignificantimpactonNTCthanRCSboron.VariationoftheseparameterswithinlXdeltak/kwouldaffectHTCmuchlessthan2pcm/oF.InadditiontothepreviouslydiscussedHTCtestsandreactivitysurveillances,designcalculationsareverifiedbythelowpowerphysicstestingprogramandthepowerascensiontestingatthebeginningofeachcycle.Thesetestingprogramsprovideadditionalconfirmationofdesigncalculationsbyverifyingsuchitemsascriticalboronconcentration,controlrodworthsandpowerdistributions.
TheproposedchangewillalsomodifySt.LucieUnit1SurveillanceRequirement4.1.1.4.2.bsothatitwillbeconsistentwiththeCombustionEngineeringStandardTechnicalSpecificationsandwithSt.LucieUnit2TechnicalSpecifications.Underthischange,theNTCSurveillanceRequirement4.1.1.4.2.aforlowpowerphysicstestingwillremainunchanged.However,theHTCSurveillanceRequirement4.1.1.2.bwillbechangedsothatthissurveillancewillberequiredataspecificRCSsolubleboronconcentration(800ppm)ratherthanwithin7EffectiveFullPowerDaysofreachingratedthermalpowerboronconcentration.References2.St.LucieUnit1Cycle7StartupandOperationsReport,ExxonNuclearCompany,Inc.(nowAdvancedNuclearFuelsCorp.),November1985.Letter,E.L.Trapp(C-E)toJ.L.Perryman(FPL),"TransmittalofSt.LucieUnit2Cycle3StartupTestPredictionsandPhysicsDataBookInformation,"F2-CE-R-078.
Os ATTACHNENT-3DETERNINATION.OFNOSIGNIFICANTHAZARDSCONSIDERATIONThestandardsusedtoarriveatadeterminationthatarequestforamendmentinvolvesnosignificanthazardsconsiderationareincludedintheCommision'sregulations10CFR50.92,whichstatesthatnosignificanthazardsconsiderationsareinvolvediftheoperationofthefacilityinaccordancewiththeproposedamendmentwouldnot(1)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated;or(2)createthepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluatedor(3)involveasignificantreductioninamarginofsafety.Eachstandardisdiscussedasfollows:(I)Operationofthefacilityinaccordancewiththeproposedamendmentwouldnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.Undertheproposedchanges,adequateassurancesofcompliancewithcurrentHTClimitationsaremaintainedbythemodifiedsurveillanceprogram.InadditiontotheNTCtestswhichwillstillberequiredduringeachcycle,thefactorsthataffecttheHTCwillbemonitoredduringthecycleasrequiredbyTechnicalSpecificationSurveillanceRequirement4.1.1.1.2.ThisensuresthatthereactivitybehaviorofthecorehasbeenaccuratelycalculatedandthattheHTCwillremainwithinTechnicalSpecificationLimitingConditionsForOperations(LCOs).Consequencesofaccidentspreviouslyevaluatedwillnotbeincreasedbecausethischangewillnotrequirethemodificationofanyassumptionusedintheinputtothecurrentsafetyanalysis.ThecurrentsafetycalculationswillremainvalidbecausetheallowedrangeofHTCvaluesinTechnicalSpecification3.1.1.4willnotbechanged.ThechangetoSt.LucieUnitISurveillanceRequirement4.1.1.4.2.bwillchangethetimeinthecyclewhenthesecondHTCsurveillanceisrequired,sothatthisrequirementwillbeconsistentwithCombustionEngineeringStandardTechnicalSpecifications(NUAE60212Rev.2).Thiswillnotincreasetheprobabilityoforconsequencesofanyaccidentpreviouslyevaluated.
Qs (2)Useofthemodifiedspecificationwouldnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.Nonewaccidentinitiatorsarecreatedbytheincorporationofthemodifiedsurveillancerequirements.Thechangewillnotresultinanychangetothemethodofoperatingtheplant.(3)Useofthemodifiedspecificationwouldnotinvolveasignificantreductioninamarginofsafety.ThemarginofsafetywillnotbereducedasaresultofthischangebecausetherangeofallowedNTCvaluesaredefinedbyTechnicalSpecificationLCO'swhichwillnotbechanged.ThemodifiedsurveillanceprogramwillmaintaintherequirementtoperformtheEOCHTCtestintheeventthereactivitybehaviorduringthecycledoesnotperformaspredictedbydesigncalculations.ThemodifiedsurveillanceprogramwillcontinuetoprovideadequateassurancethattheNTCcharacteristicsareaspredictedbydesigncalculationsandarewithintherangeofacceptedvalues.Basedondoesnotconsequenprobabiliaccidentreductionsignificatheabove,wehavedeterminedthattheamendmentrequest(1)involveasignificantincreaseintheprobabilityorcesofanaccidentpreviouslyevaluated,(2)createthetyofanewordifferentkindofaccidentfromanypreviouslyevaluated,or(3)involveasignificantinamarginofsafety;andthereforedoesnotinvolveanthazardsconsideration.