ML13007A373
| ML13007A373 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 01/08/2013 |
| From: | Duke Energy Carolinas |
| To: | Office of Nuclear Reactor Regulation |
| Gratton C NRR/DORRL/LPL2-2 301-415-1055 | |
| References | |
| Download: ML13007A373 (22) | |
Text
B i k U it 1
d 2 Brunswick Units 1 and 2 MELLLA+ Implementation p
Pre-Application Meeting Pre-Application Meeting January 08, 2013
Brunswick Units 1 and 2 MELLLA+ Implementation Duke Participants John Siphers R
Th Roger Thomas Jeff Boaz Bill Murray Charles Stroupe (Presenter) 2
Agenda Introduction and Objectives MELLLA+ benefits for Brunswick (BSEP)
Approach to fuel and plant licensing analysis strategy Approach to thermal hydraulic stability solution Approach to thermal hydraulic stability solution Approach to ATWS analysis Other MELLLA+ impacts Other MELLLA impacts Schedule Questions and answers 3
Objectives Identify benefits of MELLLA+ for Brunswick (BSEP)
Looking for feedback on specific aspects of MELLLA+
implementation that are unique to BSEP Use of two vendors and mixed vendor methodology Use of two vendors and mixed vendor methodology Use of AREVAs approved Enhanced Option III (EO-III) methodology for stability Sample problem for LAR will be mixed core (A10XM & A10)
No change to existing Containment Accident Pressure (CAP) credit No impact on Annulus Pressurization (AP) Loads Project schedule 4
Introduction and Objectives MELLLA+ overview 120.0 Brunswick MELLLA+ Power Flow Map 90.0 100.0 110.0 60.0 70.0 80.0
% Power MELLLA Line MELLLA+ Line 30.0 40.0 50.0 0.0 10.0 20.0 0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4 Mlbs/hr Core Flow 5
0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4 Mlbs/hr Core Flow 0 10 20 30 40 50 60 70 80 90 100 110 120 % Core Flow
MELLLA+ benefits for BSEP MELLLA+ will increase the full-power flow window Current MELLLA flow window is 5 5%; MELLLA+ will extend the flow Current MELLLA flow window is 5.5%; MELLLA+ will extend the flow window to 19.5%
MELLLA+ reduces the number of down powers and rod improvements required to manage reactivity Operation at MELLLA+ conditions requires ~70% fewer power maneuvers to facilitate rod improvements than at MELLLA minimizing required rod improvements minimizing required rod improvements MELLLA+ provides the opportunity to increase the Standby Liquid Control (SLC) system capability by increasing the B-10 enrichment 6
MELLLA+ benefits for BSEP 8%
10%
y (Percent) 4%
6%
trol Rod Density 0%
2%
Con 105%
d) 95%
100%
w (Percent Rated 85%
90%
0 5
10 15 20 Core Flow 7
Cycle Exposure (GWd/MtU)
MELLLA MELLLA+
MELLLA+ benefits for BSEP Core performance margins maintained MELLLA+ will have minimal impact on core parameters No loss of thermal limit margins (MFLCPR, MAPRAT, LHGR)
MELLLA MELLLA+
Core max radial peak 1.38 average 1 46 max 1.39 average 1 47 max peak 1.46 max 1.47 max Core average void 49.1% average 51.8% max 47.7% average 52.9% max Core max exit 84 9% average 87 5% average Core max exit void 84.9% average 87% max 87.5% average 90% max Average inlet subcooling 20.9 Btu/lb 24.2 Btu/lb 8
subcooling
Fuel and plant licensing analysis strategy GEH generic M+ LTR process (NEDC-33006P-A) with GEH methodologies and analysis will address:
methodologies and analysis will address:
Non-fuel impacts Long term ATWS and ATWS instability explicitly modeling A10XM fuel AREVA th d l i
d l
ill dd AREVA methodologies and analyses will address:
Fuel, core design, COLR fuel limits ATWS overpressure (COTRANSA2)
Methods applicability to MELLLA+ (Report submitted as part of LAR)
Duke Energy will address:
Integration of GEH and AREVA analyses g
y APRM and Enhanced Option III setpoints and implementation Risk evaluation, procedure updates, operator training Plant changes to mitigate ATWS (SLC B-10 enrichment increase)
Plant changes to mitigate ATWS (SLC B 10 enrichment increase)
Stability scram activation Application of existing plant specific EPU analysis 9
Fuel and plant licensing analysis strategy MELLLA+ LAR to be based on current A10XM fuel type GEH will analyze long term ATWS and ATWS I by explicitly modeling an GEH will analyze long term ATWS and ATWS-I by explicitly modeling an A10XM equilibrium core designed by AREVA MELLLA+ LAR sample problem and cycle application B1C19 reload analysis report sample problem to be used in LAR; core B1C19 reload analysis report sample problem to be used in LAR; core comprised of 1 batch of A10XM with remainder A10 B1C21 reload analysis report cycle specific application; first Unit 1 MELLLA+ cycle with full core A10XM MELLLA+ cycle with full core A10XM B2C22 reload analysis report cycle specific application; first Unit 2 MELLLA+ cycle (implement mid-cycle with full core A10XM)
The LAR will have proprietary information from both vendors The LAR will have proprietary information from both vendors appropriately marked to protect each vendors proprietary information 10
Fuel and plant licensing analysis strategy Preliminary Technical Specification changes
TLO APRM flow biased STP scram line Scram margin: expansion for M+ region; reduction for EO-III stability solution Corresponding changes in flow biased rod block Existing AL-AV-NTSP set-point margins maintained Protect EO-III Channel Instability Exclusion Region (CIER) region y
g
(
)
g
Define MELLLA+ region, add EO-III to COLR methods
New equipment OOS actions FWHOOS SLO and OPRM inoperable not allowed in MELLLA+
FWHOOS, SLO and OPRM inoperable not allowed in MELLLA Exit MELLLA+ region within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> for inoperable condition
OPRM inoperable Implement manual BSP regions in COLR (no change)
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)
Automatic scram stability protection above BSP scram region (new protection) protection)
SLC B-10 enrichment increase 11
Thermal hydraulic stability solution Implement approved AREVA Enhanced Option III (EO-III)
EO-III Algorithm same as Option III with additional channel instability protection EO III h Ch l E l
i SPT AL Li th t ill b EO-III has a Channel Exclusion SPT AL Line that will be protected via:
Setdown of flow biased APRM SCRAM NTSP Setdown of flow biased APRM SCRAM NTSP Setdown of flow biased APRM Rod Block NTSP Provides an automatic scram to protect the CIER after a Provides an automatic scram to protect the CIER after a 2RPT trip from MELLLA+ conditions Implemented via existing BSEP PRNM hardware Implemented via existing BSEP PRNM hardware 12
Thermal hydraulic stability solution Power flow map 120.0 Brunswick EO-III MELLLA+ Power Flow Map Flow Biased APRM STP Scram 90.0 100.0 110.0 Flow Biased APRM STP Rod Block NTSP EO III Ch l I t bilit 60.0 70.0 80.0
% Power MELLLA Line EO-III CIER and NC Line 2RPT Scram Above BSP Scram Region MELLLA+ Line EO-III Channel Instability Exclusion Region AL 30.0 40.0 50.0 BSP Immediate Exit Region OPRM Enabled Region Wd=60%
BSP Scram Region 0.0 10.0 20.0 0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4 Mlbs/hr Core Flow 13 0.0 7.7 15.4 23.1 30.8 38.5 46.2 53.9 61.6 69.3 77.0 84.7 92.4 Mlbs/hr Core Flow 0 10 20 30 40 50 60 70 80 90 100 110 120 % Core Flow
ATWS analysis and mitigation Long term response BSEP EPU increased SLC B-10 enrichment to 47 atom percent TS require two pumps in service but TS require two pumps in service, but Single pump meets ATWS rule boron injection rate requirement Long term ATWS MELLLA+ margin improvement will be d
t t d ith A10XM ifi ODYN l
demonstrated with A10XM specific ODYN analyses MELLLA+ rod line intercepts NC line post 2RPT ~20% higher in power SLC B-10 enrichment increase to 92 atom percent (~2x increase)
SLC enrichment should offset MELLLA+ heat load increase No anticipated loss of margin with MELLLA+
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ATWS analysis and mitigation Post depressurization NEDC-33006P-A Generic MELLLA+ LTR and SER: Best estimate TRACG or equivalent analysis of post estimate TRACG or equivalent analysis of post depressurization ATWS required if HSBW not injected before shutdown/HCTL is reached BSEP h t
ti l t i j t HSBW b f h td
/HCTL BSEP has potential to inject HSBW before shutdown/HCTL Increase SLC B-10 enrichment (47 to 92 atom percent)
TRACG analysis will be performed if needed explicitly modeling y
p p
y g
A10XM fuel 15
ATWS analysis and mitigation Overpressure and instability ATWS instability GEH ill li itl l
th A10XM f l f ATWS I GEH will explicitly analyze the A10XM fuel for ATWS-I ATWS overpressure mitigation Existing AREVA methodology will provide analysis of record Existing AREVA methodology will provide analysis of record SRVOOS is supported for MELLLA+ (no change)
Analysis will apply 95/95 SRV upper setpoint tolerance Different than the TS requirement Based on plant performance No deviation from MELLLA+ LTR 16
MELLLA+ Impact Containment Accident Pressure (CAP)
Brunswick MELLLA+LAR will not request any new or additional CAP credit relative to the current approved EPU licensing basis as described i
Brunswick MELLLA+ implementation will have no adverse impact on CAP margin
No impact on LOCA CAP (NEDC-33006P-A NRC SER Section 4.2.6)
BNP takes no CAP credit for short term LOCA with some credit for long term LOCA
No impact on Appendix R CAP (NEDC-33006P-A NRC SER Section 4.2.6)
No impact on SBO CAP (NEDC-33006P-A NRC SER Section 4.2.6)
Expected improved ATWS CAP margin due to SLC B-10 enrichment upgrade
New results will be compared to existing to show bounded p
g
No requirement that additional uncertainty be applied to ECCS NPSH calculations i.e,. 21% uncertainty in SECY-11-0014 will not be used 17
MELLLA+ Impact Annulus Pressurization (AP) Loads Impact BSEP has a Mark I containment Current Licensing Basis:
BSEP analyzed two breaks: feedwater and recirc suction line Recirc guards were installed to mitigate limiting recirc suction line Recirc guards were installed to mitigate limiting recirc suction line break MELLLA+ does not impact AP loads Existing licensing basis will be maintained Existing licensing basis will be maintained 18
Project schedule MELLLA+ LAR submittal (both Units)
Summer 2014 B1C19 sample problem with A10XM B1C19 sample problem with A10XM B1C21 cycle specific application results to NRC Fall 2015 First planned MELLLA+ cycle First planned MELLLA+ cycle MELLLA+ requested approval (both Units)
Spring 2016 MELLLA+ implementation BNP1 - During B1C21 refueling outage Spring 2016 BNP2 - Online implementation during B2C22 Summer 2016 19
Objectives Looking for feedback for unique BSEP specific aspects of MELLLA+ implementation MELLLA implementation Use of two vendors and mixed vendor methodology Use of AREVAs approved Enhanced Option III (EO-III) methodology for stability methodology for stability Sample problem for LAR will be mixed core (A10XM & A10)
No change to existing Containment Accident Pressure (CAP) g g
(
)
credit No impact on Annulus Pressurization (AP) Loads Project schedule Project schedule Plan on sharing results of ongoing analyses during an interim update (Summer 2013) 20
BSEP Units 1 and 2 MELLLA+ Implementation Q
ti
?
Questions?
21
Selected Acronyms AL - Analytical Limit AP - Annulus Pressurization HSBW - Hot Shutdown Boron Weight MELLLA - Maximum Extended Load Line Limit Analysis APRM - Average Power Range Monitor ATWS - Anticipated Transient Without Scram AV - Allowed Value BSP - Backup Stability Protection Analysis NC - Natural Circulation NPSH - Net Positive Suction Head NTSP - Nominal Trip Setpoint BSP Backup Stability Protection CAP - Containment Accident Pressure CIER - Channel Instability Exclusion Region ECCS - Emergency Core Cooling System PRNM - Power Range Neutron Monitor SBO - Station Black Out SLC - Standby Liquid Control S O S
O EO-III - Enhanced Option III EPU - Extended Power Uprate FWHOOS - Feedwater Heater Out Of Service FWT Feed ater Temperat re SLO - Single Loop Operation SPT - Stability Protection Trip STP - Simulated Thermal Power TLO - Two Loop Operation FWT - Feedwater Temperature HCTL - Heat Capacity Temperature Limit TLO Two Loop Operation 2RPT - Two Recirculation Pump Trip 22