ML092321080

MELLLA Plus Implementation

ML092321080
Person / Time
Site:	Brunswick
Issue date:	08/20/2009
From:	Farideh Saba Plant Licensing Branch II
To:	Progress Energy Co
References
Download: ML092321080 (20)

Text

Brunswick Units 1 and 2 MELLLA+ Iltti I mp l emen t a ti onAugust192009 August 19 , 2009 Eric Geyer Bill Murray John Siphers Agenda Introduction and objectivesMELLLA+ benefits for Brunswick (BSEP)Fuel and plant licensing analysis strategyThermalhydraulicstabilitysolution Thermal hydraulic stability solutionATWS analysis and mitigationFueldesign Fuel design ScheduleQuestions and answers 2

Introduction and objectives MELLLA+ overview1100120.0BrunswickMELLLA+ with Representative EO-III NTSP Channel Exclusion Region ScramAPRM STP Scram NTSP80090.0100.0110.0APRM STP Rod Block NTSPEO-III ChannelExclusion 60.070.0 80.0% PowerMELLL LineEO-III ChannelExclusion and NC Line Scram MELLLA+ LineSPT AL Line30.040.0 50.0Scram AvoidanceRegion(Immediate Exit)ScramBSP Region0.010.0 20.0 00 77154231308385462539616693770847924Mlbs/hrCoreFlowOPRM Enabled Region 3 0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4Mlbs/hr Core Flow0 10 20 30 40 50 60 70 80 90 100 110 120  % Core Flow Introduction and objectivesBSEP MELLLA+ licensing progress to dateNov 2002: BSEP MELLLA+ LAR submittedSignificant NRC review completed; BSEP RAI responses:May 2003Moisture carryover FACJun2003,Oct2003Vesselfluence Jun 2003, Oct 2003 Vessel fluenceJul 2003SLO APRM STP scramSep 2003ATWS responseN2003HfiiN ov 2003 H uman factors, operator tra i n i ngApr 2004, Mar 2005Irradiated stress corrosion crackingAug2005:MELLLA

+LARwithdrawn Aug 2005: MELLLA LAR withdrawnIntent to resubmit at late r date "as soon as practical"Pending resolution of concerns with supporting generic LTRs 4

Introduction and objectivesProgress toward LAR readinessBSEP fuel supplier change approvedJl2007 ANP2638AREVAEPUthdlibilitJ u l 2007: ANP-2638 AREVA EPU me th o d s app li ca bilit yMar 2008:BSEP ATRIUM-10 reloadSupportinggenericLTRsapproved Supporting generic LTRs approvedSep 2007:NEDC-33006 GEH generic MELLLA+ for GE14Jan 2008:NEDC-33173 GEH methods for GE14M2008 ANP10262AREVAEOIIISbiliM ay 2008: ANP-10262 AREVA EO-III S ta bili ty ObjectivesProvidecomplete,efficientLARthatleveragespastwork Provide complete, efficient LAR that leverages past workReduce challenges to reactivity management and fuel integrityMaintain and improve safety marginsImprove reactivity management 5

MELLLA+ benefits for BSEPReactivity can be controlled with flow or control rodsMELLLA+ expands flow window from 5.5% to 19.5%MELLLA requires ~75% more rod movement than MELLLA+Ctldthll C on t ro l ro d movemen t c h a ll enges:Reactivity management (2007 INPO Area For Improvement)Fuelintegrity(2008INPORecommendation)Fuel integrity (2008 INPO Recommendation)MELLLA+ improves reactivity management and fuel integrityCostsavingsdonotsupportMELLLA+implementation Cost savings do not support MELLLA+ implementationAnalyses do not support significant fuel utilization improvementReduced pumppowerprovidesonlysmall generation increaseReduced pump power provides only small generation increase 6 MELLLA+ benefits for BSEP 8%10%(Percent)4%6%ntrol Rod Desnity 0%

2%Co n 105%e d)95%100%w (Percent Rat e 85%90%05101520Core Flo 7Cycle Exposure (GWd/MtU)MELLLAMELLLA Plus MELLLA+ benefits for BSEPParameterMELLLA C ycle Av g / C ycleLimitin g MELLLA+C ycle Av g / C y cle Limitin gygy gygygCore flow101.5% / 99.0%93.1% / 86.0%Core max radialpeak1.35 / 1.461.33 / 1.38CPRmargin119%/68%89%/53%CPR margin 11.9% / 6.8%8.9% / 5.3%Core avg void46.4% / 50.4%47.9% / 52.2%

Core max exitvoid84.3% / 87.7%85.4% / 87.9%LHGR margin19.3% / 10.1%17.9%/ 11.1%MAPRATmargin23.7% / 13.4%22.9% / 16.7%

Inlet subcooling21.6Btu/lb/NA23.9Btu/lb/NA Inlet subcooling 21.6 Btu/lb / NA 23.9 Btu/lb / NA*Radial peaking and excess CPR margin exchanged for reduced flow

• Core performance margins maintained 8

Fuel and plant licensing analysis strategyGeneric GEH M+ LTR process (NEDC-33006PA) will address:NonfuelimpactsNon-fuel impactsLong term ATWS and ATWS instability for GE14 fuelAREVA methodologies and analyses will address:Fuel, core design, COLR fuel limitsATWS overpressureGE14 ATWS analysis applicability to AREVA fuelMethods applicability to MELLLA+Progress Energy will address:IntegrationofGEHandAREVAanalyses Integration of GEH and AREVA analysesAPRM and Enhanced Option III set pointsRisk evaluation, EPG/SAGs, operator trainingPlantmodificationstomitigateATWSPlant modifications to mitigate ATWS Stability scram activation 9

Fuel and plant licensing analysis strategy Preliminary Technical Specification changesTLO APRM flow biased STP scram line (3.3.1.1.2b)Scrammargin:expansionforM+region;reductionforEO

-IIIstabilitysolutionScram margin: expansion for M+ region; reduction for EO III stability solutionCorresponding changes in fl ow biased rod blockExisting AL-AV-NTSP set-point margins maintainedDefineMELLLA+regionaddEO

-IIItoCOLRmethods(565) Define MELLLA+ region , add EO-III to COLR methods (5.6.5)New equipment OOS LCO actions (various TS's)SRVOOS (if required), SLO and OPRM inoperableEitMELLLAiithi12hfdilldditiE x it MELLLA+ reg i on w ithi n 12 h ours f or di sa ll owe d con diti on OPRM inoperableImplement manual BSP regions in COLR (no change)Exit MELLLA+ region within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />; OPRM OOS or reduced FWT (new)APRM scram natural circ line protection above BSP scram region (new protection)1 SLCS pump OOSExit MELLLA+ region within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (new)Shutdown in 7 days (no change) 10 Thermal hydraulic stability solution Enhanced Option III TLO APRM Scram 110 120MELLLA+ APRM SPT Scram ReductionEnhancedOptionIIIChannelExclusion 80 90 100 110 (%)EnhancedOption III Channel ExclusionStability Protection Trip (SPT) Reduction 50 60 70 ated NTSP Power 20 30 40Estim a 0 100102030405060708090100110120Drive Flow (%)

11EO-III APRM STP ScramEO-III APRM STP RB Thermal hydraulic stability solution Power flow map1100120.0BrunswickMELLLA+ with Representative EO-III NTSP Channel Exclusion Region ScramAPRM STP Scram NTSP80090.0100.0110.0APRM STP Rod Block NTSPEO-III ChannelExclusion 60.070.0 80.0% PowerMELLL LineEO-III ChannelExclusion and NC Line Scram MELLLA+ LineSPT AL Line30.040.0 50.0Scram AvoidanceRegion(Immediate Exit)ScramBSP Region0.010.0 20.0 00 77154231308385462539616693770847924Mlbs/hrCoreFlowOPRM Enabled Region 12 0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4Mlbs/hr Core Flow0 10 20 30 40 50 60 70 80 90 100 110 120  % Core Flow ATWS analysis and mitigationLong term responseBSEP EPU increased SLCS B10 enrichment to 47 w/oATWSrulecompliancebasisremainstwopumpsbutATWS rule compliance basis remains two pumps , butSingle pump meets ATWS rule boron injection rate requirementEPU risk assessment and current PSA model credit pump redundancyLong term ATWS MELLLA+ margin improvement will be demonstrated with GE14 ODYN analysesMELLLA+ rod line intercepts NC line post 2RPT ~20% higher in powerFaster B10 injection reduces heat load (HSBW injected faster)BSEP can increase SLCS B10 enrichment by up to a factor of 2Potential to offset MELLLA+ heat load increase clearly sufficientNo loss of margin with MELLLA+; no increase in risk with single SLCS pumpAREVAfuelapplicabilitytobedispositionedsimilartoBSEPAREVA AREVA fuel applicability to be dispositioned similar to BSEP AREVA fuel transition 13 ATWS analysis and mitigation Post depressurizationNEDC-33006P Generic M+ LTR and SER: Best estimate TRACGorequivalentanalysisofpostdepressurizationATWS TRACG or equivalent analysis of post depressurization ATWS required if HSBW not injected before HCTL reachedBSEP has potential to inject HSBW before HCTLIncrease SLCS B10 enrichment (x2)Credit both SLCS pumps (x2)NewTSLCOactiontoexitMELLLA

+if1SLCSpumpOOS New TS LCO action to exit MELLLA if 1 SLCS pump OOSApplicability of GE14 analysis to AREVA fuel will be dispositionedSubstantial physical safety improvementSimplifies analysis Simplifies NRC reviewNRC feedback critical 14 ATWS analysis and mitigationOverpressure and instabilityATWS instabilityShltdtthiifS ame approac h as l ong t erm; d emons t ra t e c h ange i n marg i n f or GE14 core with increased B10 injection rateB10 injection rate increase expected to provide some mitigation even with shorter event timing than long term containment heatingApplicability to AREVA fuel to be addressed by dispositionNRC feedback criticalATWS overpressure mitigationMG set replacement with adjustable speed drive improves 2RPT coastdownrate coastdown rateSRVOOS support for MELLLA+ to be evaluatedCycle specific AREVA overpressure analysis 15 Fuel design ATRIUM-10XM (A10XM)MELLLA+ LAR to be based on A10XM if timing and reviews supportA10XMrequiresaddingtwoCOLRmethodologiestoTS A10XM requires adding two COLR methodologies to TSACE CPR correlation and RODEX4 fuel rod TM methodologyLAR will demonstrate SER complianceGenerically approved; no sample problemA10XM LAR separate from MELLLA+Separate submittal preceding MELLLA+A10XM approval (both Units) preceding MELLLA+ approvalMELLLA+ LAR sample problem and cycle applicationB2C20reloadanalysisreportsampleproblem;firstUnit2A10XMreloadB2C20 reload analysis report sample problem; first Unit 2 A10XM reloadB1C19 reload analysis report cycle specific application; first Unit1 A10XM reload and MELLLA+

16 Fuel design ATRIUM-10XM fuel cycle operationParameterMELLLA+ A10 C ycle Av g / C ycleLimitin g MELLLA+ A10XM C ycle Av g / C y cle Limitin gygy gygygCore flow93.1% / 86.0%91.4% / 85.7%Core max radialpeak1.33 / 1.381.39 / 1.47CPRmargin89%/53%148%/50%CPR margin 8.9% / 5.3%14.8% / 5.0%Core avg void47.9% / 52.2%47.7% / 52.9%

Core max exitvoid85.4% / 87.9%87.5% / 90.0%LHGR margin17.9%/ 11.1%13.7%/ 7.3%MAPRATmargin22.9% / 16.7%22.9% / 16.4%

Inlet subcooling23.9Btu/lb/NA24.2Btu/lb/NA Inlet subcooling 23.9 Btu/lb / NA 24.2 Btu/lb / NA*Improved CPR margin supports radial peaking increase and reduced flow

• Core performance margins maintained 17 ScheduleA10XM LAR; ACE and RODEX (both Units)Spring 2010MELLLA+LARsubmittal(bothUnits)Fall2010 MELLLA+ LAR submittal (both Units)Fall 2010B2C20 sample problem with A10XMATRIUM-10XM approval (both Units)Spring 2011First ATRIUM-10XM reload (B2C20)Spring 2011B1C19 cycle specific applicationFall 2011First MELLLA+ c y cle with A10XM yMELLLA+ approval (both Units)Spring 2012NRCfdbkitil NRC f ee db ac k cr iti ca l 18 SummaryReduce challenges to reactivity managementRdhlltflitit R e d uce c h a ll enges t o f ue l i n t egr it yMaintain and improve safety marginsEfficientLARapproach Efficient LAR approachLeverage past workAddress fuel design 19 BSEP Units 1 and 2 MELLLA+ ImplementationQti?Q ues ti ons?20