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ACCESSIOP„ NBR:9304290160 DOC.DATE: 93/04/20 NOTARIZED: YESFACIAL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C

50-251 Turkey Point Plant, Unit 4, Florida Power and Light CAUTH.NAME AUTHOR AFFILIATION

PLUNKETT,T.F. Florida Power 6 Light Co.RECIP.NAME RECIPIENT AFFILIATION

Document Control Branch (Document Control Desk)

SUBJECT: Application for amends'o Licenses DPR-31 6 DPR-41,modifyingTS Table 2.2-1, "Reactor Trip Sys Instrumentation TripSetpoints" to remove lead/lag compensator term on measureddelta T from overtemp delta T a overpower delta T.

DISTRIBUTION CODE: AOOZD COPIES RECEIVED:LTR I ENCL I SIZE: 1 WgTITLE: OR Submittal: General DistributionNOTES:

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P.O. Box 029100, Miami, FL, 33102-9100

APR 8 0 1S93

L-93-08110 CFR 50.90

U. S. Nuclear Regulatory CommissionAttn: Document Contzol DeskWashington, D. C. 20555

Gentlemen:

Re: Turkey Point'nits 3 and 4Docket Nos. 50-250 and 50-251Proposed License Amendments—Removal of Lead/Lag Compensator Term on measured aT inOvertem erature wT and Over ower ~T Reactor Tzi Functions

In accordance with 10 CFR 50 '0, Florida Power and Light Company (FPL)requests that Appendix A of Facility Operating Licenses DPR-31 andDPR-41 be amended to modify Turkey Point Units 3 and 4 TechnicalSpecifications Table 2.2-1, Reactor Trip System Instrumentation TripSetpoints. The purpose of these amendments is to revise TechnicalSpecification Table 2.2-1, Reactor Trip System Instrumentation TripSetpoints, to remove the lead/lag compensator term on measured aT fromthe overtemperature ~T and overpower ~T zeactor trip functions. Thisis accomplished by setting the time constants, 9, and 9„ to zeroseconds.

FPL has determined that the proposed license amendments do not involvea significant hazard pursuant to 10 CFR 50.92. A description of theamendments request is provided in Attachment 1. The no significanthazards determination in support of the proposed TechnicalSpecification change is provided in Attachment 2 ~ Attachment 3provides the proposed revised Technical Specification changes.

In accordance with 10 CFR 50 '1 (b)(1), a copy of these proposedlicense amendments are being forwarded to the State Designee for theState of Florida.

The proposed amendments have been reviewed by the Turkey Point PlantNuclear Safety Committee and the FPL Company Nuclear Review Board.

Should there be any questions on this request, please contact us.

Very truly yours,

T. F. PlunkettVice PresidentTurkey Point Nuclear Plant

TFP/RJT/rt

Attachments

cc: Stewart D. Ebneter,, Regional Administrator, 'Region II, USNRCR. C. Butcher, Senior Resident Inspector, USNRC, Turkey PointMr. W. A. Pasetti, Florida Department of Health andRehabilitative Services

9304290160 930420,,a,„PDR ADOCK 05000250, ",,y

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STATE OF FLORIDA

COUNTY OF DADE

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T. F. Plunkett being first duly sworn, deposes and says:

That. he is Vice President Turke Point Nuclear Plant, of Florida Powerand Light Company, the Licensee herein;

That he has executed the foregoing document; that the statementsmade in this document are true and correct to the best of hisknowledge, information and belief, and that he is authorized toexecute the document on behalf of said Licensee.

T; F. P lunkett

Subscribed and sworn to before me thisday of fE + , 1993.

Name of Notary Public (Type or Print)

NOTARY PUBLIC, inDade, State of Fl

My Commissionexp''

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I+r ',": MY COMMISSION S CC 22378 I

qi EXPQES: SoptNRNf 2T, 1996

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Commission No.

T. F. Plunkett is personally known to me.

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ATTACHMENT 1

DESCRIPTION OF AMENDMENTS REQUEST

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L-93-081Attachment 1Page 1 of 5

DESCRIPTION OF AMENDMENTS RE UEST

IntroductionTo reduce the potential foz a spurious turbine runback or reactortrip, Florida Power and Light Company (FPL) proposes a change to theTechnical Specifications reactor trip functions. The proposed changeis requested to alleviate the effects of existing temperatureoscillations which became significant when the primary reactor coolantsystem Resistance Temperature Devices (RTDs) were relocated from thebypass lines to the main loops at Turkey Point. FPL has concluded thatthis proposed change will not compromise the health and safety of thepublic. The basis of FPL's conclusion is discussed below.

The proposed amendments revise the Turkey Point Units 3 6 4 TechnicalSpecifications Table 2.2-1, Reactor Trip System InstrumentationSetpoints, to remove the lead/lag compensator term on the measuredreactor coolant system (RCS) loop temperature difference (aT) from theoveztemperature aT and overpower ~T reactor trip functions. This isaccomplished by changing the time constants, 0, and 0„ from 8 and 3seconds respectively, to zero seconds each.

Issue

After experiencing several spurious overtemperatuze ~T turbine runbackalarms on the Unit 3 Eagle-21 system, FPL determined that the cause ofthese alarms was the oscillations of the Loop B reactor coolant systemhot leg temperature. These temperature oscillations reached 2-3 'Fpeak to peak amplitude at a fzequency between .067 Hz and 1 Hz.

These oscillations have been experienced at other Westinghouse plantsthat have eliminated the RTD bypass loops and are attributed tophenomena resulting from such factors as power level, core loading,fuel burnup, hot channel factors (Fq, F,„), and coze exit flowcharacteristics. Current evidence supported by the Nuclear SteamSupply System vendor, Westinghouse, suggests that the amplitudes ofthese oscillations decrease with coze burnup. Westinghouse presenteda summary of the hot leg streaming issue to the NRC staff on September17, 1991.

Based upon industry information provided by Westinghouse, and a reviewof Turkey Point's plant data, FPL concluded that the elimination ofthe lead/lag compensator term on measured ~T from the overtemperatuzeaT and overpower wT reactor trip functions would reduce the potentialfor a spurious turbine runback or reactor trip signal.Current Requirements

Turkey Point Units 3 and 4 Technical Specification 2.2, LIMITINGSAFETY SYSTEM SETTINGS, specifies the REACTOR TRIP SYSTEMINSTRUMENTATION TRIP SETPOINTS for Overtemperature ~T (NOTE 1) andOverpower sT (NOTE 3). Both the Overtemperature aT and the OverpoweraT reactor trip functions include a term on the left hand-side of theexpression, referred to as the lead/lag compensator term on measuredaT. This term is expressed as follows:

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L-93-081Attachment 1Page 2 of 5

Lead/Lag Compensator term 1 + GS1 + O,S

where 9, - 8 seconds,0, 3 seconds, andS Laplace transform operator, sec

'hesevalues were chosen based on Westinghouse experience and aretypical foz a lead/lag compensator function. The basis for thelead/lag compensatoz term on measured aT in both the overtemperaturezT and overpower aT reactor trip functions is discussed below.

Discussion

Overtem erature aT Reactor Tri Function:

The overtemperature aT reactor trip function is defined in NOTE 1 ofTurkey Point Technical Specifications Table 2.2-1. This reactor tripfunction provides core protection to prevent Departure from NucleateBoiling (DNB) for all combinations of pressure, power, coolanttemperature, and axial power distribution, provided the transient isslow with respect to piping transit delays from the core to thetemperature detectors and pressure is within the range between thePressurizer High and Low Pressure trips. The setpoint isautomatically varied with: (1) coolant temperature to correct fortemperature induced changes in density and heat capacity of water, andincludes dynamic compensation for piping delays from the core to the.loop temperature detectors, (2) pressurizer pressure, and (3) axialpower distribution.The measured aT is multiplied by the lead/lag compensator termdiscussed above, and the product is compared to the continuouslycalculated oveztemperature aT setpoint. If the product exceeds thecalculated setpoint in 2 out of 3 channels, a reactor trip signal isgenerated.

Over ower aT Reactor Tri Function:

The overpower aT reactor trip function is defined in NOTE 3 of TurkeyPoint Technical Specifications Table 2.2-1. This reactor tripfunction is designed specifically to ensure operation within the fuelcenterline temperature design basis. This is accomplished bycontrolling the gross core thermal power within a prescribed limit(118 percent of nominal full power). This provides assurance of fuelintegrity (i.e., no fuel pellet melting and less than 1% claddingstrain) under all creditable overpower conditions, limits the requiredrange for overtemperatuze aT trip, and provides a backup to the HighNeutron Flux trip. The setpoint is automatically varied with: (1)coolant temperature to correct for temperature induced changes indensity and heat capacity of water, and (2) rate of change oftemperature for dynamic compensation of piping delays from the core tothe loop temperature detectors to ensure that the allowable heatgeneration rate (kw/ft) is not exceeded.

The measured aT is multiplied by the lead/lag compensator, and theproduct is compared to the continuously calculated overpower aTsetpoint. If the product exceeds the calculated setpoint in 2 out, of3 channels, a reactor trip signal is generated.

L-93-081Attachment 1Page 3 of 5

Lead La Com ensator Term on measured aT in the Overtem erature wT andOver ower ~T Reactor Tri Functions:

The function of the lead/lag compensator term is to amplify changes inmeasured aT for comparison to the overtemperature nT and overpower ~Treactor trip functions. The lead/lag compensator term on measured aTis used at some plants in instances where a faster response to achange in measured aT is required earlier to satisfy the plant'ssafety analyses.

The lead/lag compensator on measured ~T was added to FPL' TurkeyPoint Units 3 and 4 Technical Specifications in Amendments 140 and135. The Technical Specification change was due to the RTD BypassElimination project and the installation of the Eagle-21 digitalprotection system. The Eagle-21 digital protection system givesTurkey Point the capability to have a lead/lag compensator term on themeasured aT signal and is used as input to the overtemperature sT andoverpower aT reactor trip functions. The predecessor to Eagle-21, theWestinghouse Hagan 7100 analog protection system as installed atTurkey Point, did not have a lead/lag compensator term on measured aT.FPL verified that the lead/lag compensator term on measured ~T for theoveztempezatuze ~T and overpower ~T reactor trip functions are notrequired or assumed foz accident mitigation in any of the safetyanalyses that comprise the Turkey Point licensing basis.

Other plants of Turkey Point's vintage currently do not have thelead/lag compensator term on measured aT in the overtemperature aT andoverpower aT reactor trip functions.

Licensin Basis:

During the reload design process, the overtemperature ~T and overpower~T reactor trip setpoints are reverified each cycle based on thereload core and reactor coolant system parameters.

FPL performed a review of the Turkey Point licensing basis accidentanalyses to determine the analyses in which either oveztemperature aTor overpower aT reactor trips were used as the primary method forsystem protection. This review included the following accidentanalyses:

Dropped Rod Cluster Control Assembly (RCCA) with and withoutTurbine Runback,RCCA Bank Withdrawal at Power,Feedwater Enthalpy Reduction,Boron Dilution Analysis for Density Compensation Correction,Steamline Break for Continued Feedwater Addition fromStandby Feedwater Pumps,Loss of Flow,Locked Rotor,Rod Ejection,Loss of Load, andStartup of an Inactive Loop.

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L-93-081Attachment 1Page 4 of 5

The overtempezature aT reactor trip is used as the primary protectionfor three Updated Final Safety Analysis Report (UFSAR) Chapter 14accident scenarios:

Rod Withdrawal at Power (UFSAR Chapter 14.1.2),Dropped Rod at Power (UFSAR Chapter 14.1.3), andBoron Dilution Mode 1 (UFSAR Chapter 14.1.5) .

The overpower aT reactor trip is not used as the primary protectionfor any UFSAR Chapter 14 accident scenario; however it is assumed inthe overpower.kw/ft analysis performed by Westinghouse for each fuelcycle.This review verified that the lead/lag compensator term on measured aTfor the overtemperature ~T and overpower ~T reactor trip functions arenot required or assumed for accident mitigation in any of the safetyanalyses that comprise the Turkey Point licensing basis. The proposedamendments will not change the trip setpoints for the overpower aT andovertemperature ~T reactor trip functions.

Proposed Technical Specification Changes

FPL proposes to change the values in the Overtempezature ~Treactor trip function in Technical Specification Table 2.2-1,REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS, NOTE l.Specifically, the proposed change involves changing the timeconstants 9, and 9„ from 8 and 3 seconds respectively, to 0seconds each.

Justification:The lead/lag compensator term on measured ~T in theovertemperature aT reactor trip function serves to amplify achange in measured aT. By setting the time constants 9, and 9,equal to zero, this amplifier term (lead/lag compensator term) isremoved while still maintaining the ability to trip prior toexceeding the Departure from Nucleate Boiling Ratio (DNBR) limit.FPL's safety analyses for UFSAR Chapter 14 events do not requirethe lead/lag compensator term on measured ~T in theoveztempezature aT reactor trip function.

Within the results of the UFSAR Chapter 14 safety analyses, FPLcan change the lead/lag compensator term on measured aT as longas the reactor is tripped prior to zeaching the DNBR and fuelcenterline temperature limits. Changing the time constants 9, and9, to 0 seconds, provides a gain of unity and thus ensures thereactor will trip on a valid input signal, while reducing thepotential for a turbine runback or reactor trip on a spurious(invalid) input signal.

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L-93-081Attachment 1Page 5 of 5

2. FPL proposes to change the values in the Overpower aT reactortrip function in Technical Specification Table 2.2-1, REACTORTRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS, NOTE 3.

Specifically, the proposed change involves changing the timeconstants 9, and 9„ values from 8 and 3 seconds respectively, to0 seconds each.

Justification:The lead/lag compensator term on measured aT in the overpower ~Treactor trip function serves to amplify a change in measured aT.By setting the time constants 9, and 9, equal to zero, thisamplifier term (lead/lag compensator term) is removed while stillmaintaining the ability to trip prior to exceeding the fuelcenterline temperature limit. Turkey Point's safety analyses forUFSAR Chapter 14 events does not require the lead/lag compensatorterm on measured aT in the overpower u,T reactor trip function.Within the results of the UFSAR Chapter 14 safety analyses, FPLcan change the lead/lag compensator term on measured ~T as longas the reactor is tripped prior to exceeding the DNBR and fuelcenterline temperature limits. Changing the time constants 9, and9, to 0 seconds, provides a gain of unity and thus ensures thereactor will trip on a valid input signal, while reducing thepotential for a turbine runback or reactor trip on a spurious(invalid) input signal.

FPL has confirmed that the lead/lag compensatoz tezm on the measured~T in the overtemperature ~T and overpower ~T reactor trip functionsare not required oz assumed as a basis for the Turkey Point UFSARsafety analyses. As a result, this proposed amendment does not eithercreate the possibility of a new or different kind of accident from anyaccident previously evaluated, or impact the margin of safety as

'alculatedin the licensing basis analyses. FPL proposes to removethe lead/lag compensatoz term on measured aT from the overtemperatureaT and overpower aT'eactor trip functions by setting the timeconstants 9, and 9, to zero seconds each, from 8 and 3 seconds,respectively.

ATTACHMENT 2

DETERMINATION OF NO SZGNIFZCANT HAZARDS CONSIDERATION

L-93-081Attachment 2Page 1 of 2

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION

Description of Proposed License Amendments

Turkey Point Units 3 and 4 Technical Specification Table 2.2-1,Reactor Trip System Instrumentation Trip Setpoints, specifies theovertemperature ~T and overpower ~T reactor trip functions. Both theovertemperature aT and overpower ~T reactor trip functions includeterms on the left hand-side of the expression, referred to as thelead/lag compensatoz term on measured ~T. The lead/lag compensatorterm is expressed as (1 + 9, times S) divided by (1 + 9, times S) where9, and 9, are time constants (seconds) and S is the Laplace transformoperator (seconds ') . Currently in Turkey Point's Units 3 and 4Technical Specifications, the time constants 9, and 9, are set to 8 and3 seconds, respectively.Florida Power and Light Company (FPL) proposes to revise the lead/lagcompensator term on the measured ~T in the overtemperature aT andoverpower aT reactor trip functions by setting the time constants, 9,and 9„ equal to zero seconds.

IntroductionThe NRC has provided standards foz determining whether a significanthazards consideration exists (10 CFR 50.92(c)) . A proposed amendmentto an operating license for a facility involves no significant hazardsconsideration, if operation of the facility in accordance with theproposed amendment would not (1) involve a significant increase in theprobability or consequences of an accident previously evaluated; oz(2) create the possibility of a new or different kind of accident fromany accident previously evaluated; or (3) involve a significantreduction in a margin of safety. Each standard is discussed below forthe proposed license amendments.

Discussion

(l) Operation of the facility in accordance with the proposedamendment would not involve a significant increase in theprobability or consequences of an accident previously evaluated.

The amendment will not increase the probability oz consequencesof an accident previously evaluated since the lead/lagcompensator term on measured aT in the oveztemperature aT andoverpower aT reactor trip functions are not required or assumedfor accident mitigation in any of the UFSAR safety analyses thatcomprise the Turkey Point licensing basis. In addition, thereactor protection system will continue to perform its intendeddesign function of ensuring that the core and reactor coolantsystem do not exceed their safety limits during normal operationor design basis anticipated operational occurrences.

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L-93-081Attachment 2Page 2 of 2

(2) Operation of the facility in accordance with the proposedamendment would not create the possibility of a new or differentkind of accident from any accident previously evaluated.

The overtemperature aT reactor trip function is used as theprimary protection for three UFSAR Chapter 14 accident scenarios:Rod Withdrawal at Power (UFSAR Chapter 14.1.2), Dropped Rod atPower (UFSAR Chapter 14.1.3), and Boron Dilution Mode 1 (UFSARChapter 14.1.5). The overpower sT reactor trip function is notused as the primary protection for any UFSAR Chapter 14 accidentscenario; however it is assumed in the overpower kw/ft analysisperformed by Westinghouse for each fuel zeload. The lead/lagcompensator term on measured aT in the overtemperature ~T andoverpower ~T reactor trip functions are not required or assumedfor accident mitigation in any of the UFSAR safety analyses thatcomprise the Turkey Point licensing basis.

The proposed amendments will not create the possibility of a newoz different kind of accident from any accident previouslyanalyzed, since the operating modes, plant configuration andsafety analysis assumptions will not be changed from thosepreviously analyzed in the UFSAR.

(3) Operation of the facility in accordance with the proposedamendment would not involve a significant reduction in a marginof safety.The margin of safety for the proposed-amendment is defined in thelicensing basis safety analysis. The oveztemperature ~T reactortrip function is used as the primary protection for three UFSARChapter 14 accident scenarios: Rod Withdrawal at Power (UFSARChapter 14.1.2), Dropped Rod at Power (UFSAR Chapter 14.1.3), andBoron Dilution Mode 1 (UFSAR Chapter 14.1.5). The overpower aTreactor trip is not used as the primary protection for any UFSARChapter 14 accident scenario; however it is assumed in theoverpower kw/ft analysis performed by Westinghouse for each fuelreload. The lead/lag compensator term on measured ~T for theovertemperature aT and overpower ~T reactor trip functions arenot required or assumed for accident mitigation in any of thesafety analyses that comprise the Turkey Point licensing basis.

The proposed amendments will not reduce the margin. of safetysince the plant operating and safety limits, the inputassumptions to the safety analyses and the plant response totransients as analyzed in the Turkey Points Units 3 & 4 licensingbasis will not be changed from those previously analyzed in theUFSAR.

Based on the above, FPL has determined that the amendment request doesnot (1) involve a significant increase in the probability orconsequences of an accident previously evaluated, (2) create thepossibility of a new or different kind of accident fzom any accidentpreviously evaluated, or (3) involve a significant reduction in amargin of safety; and therefore the proposed changes do not involve asignificant hazards consideration as defined in 10 CFR 50.92.