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+

I Implementation l t ti August 19 19, 2009 Eric Geyer Bill Murray John Siphers

Agenda Introduction and objectives MELLLA+ benefits for Brunswick (BSEP)

Fuel and plant licensing analysis strategy Thermal hydraulic stability solution ATWS analysis and mitigation Fuel design Schedule Questions and answers 2

Introduction and objectives MELLLA+ overview Brunswick MELLLA+ with Representative EO-III NTSP Channel Exclusion Region Scram 120.0 APRM STP Scram NTSP 110 0 110.0 APRM STP Rod Block NTSP 100.0 90.0 EO-III Channel Exclusion 80 0 80.0 SPT AL Line 70.0 EO-III Channel Exclusion MELLLA+ Line

% Pow er and NC Line Scram 60.0 MELLL Line 50.0 Scram Avoidance Region 40.0 (Immediate Exit)

Scram 30.0 BSP Region 20.0 OPRM Enabled Region 10.0 0.0 00 0.0 77 7.7 15 4 15.4 23 1 23.1 30 8 30.8 38 5 38.5 46 2 46.2 53 9 53.9 61 6 61.6 69 3 69.3 77 0 77.0 84 7 84.7 92 4 92.4 Mlbs/hr Core Flow 0 10 20 30 40 50 60 70 80 90 100 110 120  % Core Flow 3

Introduction and objectives BSEP MELLLA+ licensing progress to date Nov 2002: BSEP MELLLA+ LAR submitted Significant NRC review completed; BSEP RAI responses:

May 2003 Moisture carryover FAC Jun 2003, Oct 2003 Vessel fluence Jul 2003 SLO APRM STP scram Sep 2003 ATWS response N 2003 Nov H Human ffactors, operator training i i Apr 2004, Mar 2005 Irradiated stress corrosion cracking Aug 2005: MELLLA+

MELLLA LAR withdrawn Intent to resubmit at later date as soon as practical Pending resolution of concerns with supporting generic LTRs 4

Introduction and objectives Progress toward LAR readiness BSEP fuel supplier change approved Jul J l 2007 2007: ANP 2638 AREVA EPU methods ANP-2638 th d applicability li bilit Mar 2008: BSEP ATRIUM-10 reload Supporting generic LTRs approved Sep 2007: NEDC-33006 GEH generic MELLLA+ for GE14 Jan 2008: NEDC-33173 GEH methods for GE14 May M 2008:

2008 ANP 10262 AREVA EO ANP-10262 EO-III III S Stability bili Objectives Provide complete, efficient LAR that leverages past work Reduce challenges to reactivity management and fuel integrity Maintain and improve safety margins Improve reactivity management 5

MELLLA+ benefits for BSEP Reactivity can be controlled with flow or control rods MELLLA+ expands flow window from 5.5% to 19.5%

MELLLA requires ~75% more rod movement than MELLLA+

C t l rod Control d movementt challenges:

h ll Reactivity management (2007 INPO Area For Improvement)

Fuel integrity (2008 INPO Recommendation)

MELLLA+ improves reactivity management and fuel integrity Cost savings do not support MELLLA+ implementation Analyses do not support significant fuel utilization improvement Reduced pump power provides only small generation increase 6

MELLLA+ benefits for BSEP 10%

Con ntrol Rod Desnity (Percent) 8%

6%

4%

2%

0%

105%

Core Flow (Percent Rate ed) 100%

95%

90%

85%

0 5 10 15 20 Cycle Exposure (GWd/MtU)

MELLLA MELLLA Plus 7

MELLLA+ benefits for BSEP Parameter MELLLA MELLLA+

Cycle y Avg g / Cycle y Limiting g Cycle y Avg g / Cycle y Limiting g

Core flow 101.5% / 99.0% 93.1% / 86.0%

Core max radial peak 1.35 / 1.46 1.33 / 1.38 CPR margin 11 9% / 6 11.9% 6.8%

8% 8 9% / 5.3%

8.9% 5 3%

Core avg void 46.4% / 50.4% 47.9% / 52.2%

Core max exit void 84.3% / 87.7% 85.4% / 87.9%

LHGR margin 19.3% / 10.1% 17.9% / 11.1%

MAPRAT margin 23.7% / 13.4% 22.9% / 16.7%

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 strategy Generic GEH M+ LTR process (NEDC-33006PA) will address:

Non-fuel Non fuel impacts Long term ATWS and ATWS instability for GE14 fuel AREVA methodologies and analyses will address:

Fuel, core design, COLR fuel limits ATWS overpressure GE14 ATWS analysis applicability to AREVA fuel Methods applicability to MELLLA+

Progress Energy will address:

Integration of GEH and AREVA analyses APRM and Enhanced Option III set points Risk evaluation, EPG/SAGs, operator training Plant modifications to mitigate ATWS Stability scram activation 9

Fuel and plant licensing analysis strategy Preliminary Technical Specification changes TLO APRM flow biased STP scram line (3.3.1.1.2b)

Scram margin: expansion for M+ region; reduction for EO-III EO III stability solution Corresponding changes in flow biased rod block Existing AL-AV-NTSP set-point margins maintained Define MELLLA+ region , add EO-III to COLR methods (5.6.5) (5 6 5)

New equipment OOS LCO actions (various TSs)

SRVOOS (if required), SLO and OPRM inoperable Exit E it MELLLA MELLLA+ region i within ithi 12 hhours ffor di disallowed ll d condition diti OPRM inoperable Implement 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 OOS Exit 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 MELLLA+ APRM SPT Scram Reduction 120 110 Enhanced Option III Channel Exclusion Stability Protection Trip (SPT) Reduction 100 90 Estimaated NTSP Power (%)

80 70 60 50 40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 110 120 Drive Flow (%)

EO-III APRM STP Scram EO-III APRM STP RB 11

Thermal hydraulic stability solution Power flow map Brunswick MELLLA+ with Representative EO-III NTSP Channel Exclusion Region Scram 120.0 APRM STP Scram NTSP 110 0 110.0 APRM STP Rod Block NTSP 100.0 90.0 EO-III Channel Exclusion 80 0 80.0 SPT AL Line 70.0 EO-III Channel Exclusion MELLLA+ Line

% Pow er and NC Line Scram 60.0 MELLL Line 50.0 Scram Avoidance Region 40.0 (Immediate Exit)

Scram 30.0 BSP Region 20.0 OPRM Enabled Region 10.0 0.0 00 0.0 77 7.7 15 4 15.4 23 1 23.1 30 8 30.8 38 5 38.5 46 2 46.2 53 9 53.9 61 6 61.6 69 3 69.3 77 0 77.0 84 7 84.7 92 4 92.4 Mlbs/hr Core Flow 0 10 20 30 40 50 60 70 80 90 100 110 120  % Core Flow 12

ATWS analysis and mitigation Long term response BSEP EPU increased SLCS B10 enrichment to 47 w/o ATWS rule compliance basis remains two pumps pumps, but Single pump meets ATWS rule boron injection rate requirement EPU risk assessment and current PSA model credit pump redundancy Long term ATWS MELLLA+ margin improvement will be demonstrated with GE14 ODYN analyses MELLLA+ rod line intercepts NC line post 2RPT ~20% higher in power Faster B10 injection reduces heat load (HSBW injected faster)

BSEP can increase SLCS B10 enrichment by up to a factor of 2 Potential to offset MELLLA+ heat load increase clearly sufficient No loss of margin with MELLLA+; no increase in risk with single SLCS pump AREVA fuel applicability to be dispositioned similar to BSEP AREVA fuel transition 13

ATWS analysis and mitigation Post depressurization NEDC-33006P Generic M+ LTR and SER: Best estimate TRACG or equivalent analysis of post depressurization ATWS required if HSBW not injected before HCTL reached BSEP has potential to inject HSBW before HCTL Increase SLCS B10 enrichment (x2)

Credit both SLCS pumps (x2)

New TS LCO action to exit MELLLA+

MELLLA if 1 SLCS pump OOS Applicability of GE14 analysis to AREVA fuel will be dispositioned Substantial physical safety improvement Simplifies analysis Simplifies NRC review NRC feedback critical 14

ATWS analysis and mitigation Overpressure and instability ATWS instability S

Same approach h as llong tterm; d demonstrate t t change h iin margin i ffor GE14 core with increased B10 injection rate B10 injection rate increase expected to provide some mitigation even with shorter event timing than long term containment heating Applicability to AREVA fuel to be addressed by disposition NRC feedback critical ATWS overpressure mitigation MG set replacement with adjustable speed drive improves 2RPT coastdown rate SRVOOS support for MELLLA+ to be evaluated Cycle specific AREVA overpressure analysis 15

Fuel design ATRIUM-10XM (A10XM)

MELLLA+ LAR to be based on A10XM if timing and reviews support A10XM requires adding two COLR methodologies to TS ACE CPR correlation and RODEX4 fuel rod TM methodology LAR will demonstrate SER compliance Generically approved; no sample problem A10XM LAR separate from MELLLA+

Separate submittal preceding MELLLA+

A10XM approval (both Units) preceding MELLLA+ approval MELLLA+ LAR sample problem and cycle application B2C20 reload analysis report sample problem; first Unit 2 A10XM reload B1C19 reload analysis report cycle specific application; first Unit1 A10XM reload and MELLLA+

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Fuel design ATRIUM-10XM fuel cycle operation Parameter MELLLA+ A10 MELLLA+ A10XM Cycle y Avg g / Cycle y Limiting g Cycle y Avg g / Cycle y Limiting g

Core flow 93.1% / 86.0% 91.4% / 85.7%

Core max radial peak 1.33 / 1.38 1.39 / 1.47 CPR margin 8 9% / 5.3%

8.9% 5 3% 14 8% / 5 14.8% 5.0%

0%

Core avg void 47.9% / 52.2% 47.7% / 52.9%

Core max exit void 85.4% / 87.9% 87.5% / 90.0%

LHGR margin 17.9% / 11.1% 13.7% / 7.3%

MAPRAT margin 22.9% / 16.7% 22.9% / 16.4%

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

Schedule A10XM LAR; ACE and RODEX (both Units) Spring 2010 MELLLA+ LAR submittal (both Units) Fall 2010 B2C20 sample problem with A10XM ATRIUM-10XM approval (both Units) Spring 2011 First ATRIUM-10XM reload (B2C20) Spring 2011 B1C19 cycle specific application Fall 2011 First MELLLA+ cycle y with A10XM MELLLA+ approval (both Units) Spring 2012 NRC feedback f db k critical iti l 18

Summary Reduce challenges to reactivity management R d Reduce challenges h ll tto ffuell iintegrity t it Maintain and improve safety margins Efficient LAR approach Leverage past work Address fuel design 19

BSEP Units 1 and 2 MELLLA+ Implementation Q

Questions?

ti  ?

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