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Introduction to mPower IRUG Conference Salt Lake City, Utah July 27, 2011. Jason Williams Babcock&Wilcox. Outline. Introduction Plant layout Integral reactor design Safety concept Development testing Methods Development Conclusion. Industry Partners.
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Introduction to mPowerIRUG Conference Salt Lake City, UtahJuly 27, 2011 Jason Williams Babcock&Wilcox
Outline • Introduction • Plant layout • Integral reactor design • Safety concept • Development testing • Methods Development • Conclusion
Industry Partners Generation mPower Industry Consortium • Alliance between B&W and Bechtel • Risk sharing with 90/10 current ownership • 250+ FTE development team • Technology and project execution • Turnkey projects = cost/schedule certainty • Broad industry engagement • Investment from 15 member Consortium • 26 member Industry Advisory Council • Goal is to deploy lead plant by 2020 • Industry side of public-private partnership • Platform for industry cost/risk sharing Hoosier Energy Rural Electric Cooperative, Inc. Nebraska Electric G&T Cooperative Industry Advisory Council Includes Consortium members above plus: AEP Dayton Power & Light Duke Energy Exelon NPPD Vattenfall Bruce Power Dominion Entergy MidAmerican Progress Energy www.generationmpower.com
Goal and Value Proposition • Develop and deploy, by 2020, an SMR that offers: • Lower Capital Cost • Schedule & Cost Certainty • Competitive LCOE Pricing • Within the constraints of: • Proven: GEN III+, established NRC regulation • Safe: Robust margins, passive safety • Practical: Standard fuel, construction and O&M • Benign: Underground, small footprint
High-Level Requirements • 125 MWe Nominal Output per Module and 60-Year Plant Life • NSSS Forging Diameter Allows Readily Available Forgings and Unrestricted Rail Shipment • Passive Safety Requirements – Emergency (Diesel) Power Not Required • Minimize Primary Coolant Penetrations, Maximize Elevation of Penetrations • Large Reactor Coolant Inventory • Low Core Power Density • Standard Fuel (less than 5% U235) • Long Fuel Cycle, 4+ Year Core Life • Spent Fuel Storage on Site for Life of Plant • No Soluble Boron in Primary System for Normal Reactivity Control • Conventional/Off-the-Shelf Balance of Plant Systems and Components • Accommodate Air-Cooled Condensers as well as Water-Cooled Condensers • Flexible Grid Interface (50 Hz or 60 Hz) • Digital Instrumentation and Controls Compliant with NRC Regulations 5 © 2011 The Babcock & Wilcox Company. All rights reserved. .5
The B&W mPower Nuclear Plant • “Twin-pack” mPower plant configuration • 40 acre site footprint • Low profile architecture • Water or air cooled condenser • Enhanced security posture • Underground containment • Underground spent fuel pool • Lower overnight construction cost • Competitive levelized cost of electricity © 2010 Babcock & Wilcox Nuclear Energy, Inc. All rights reserved. Patent Pending Security-informed plant design contains O&M costs .6
Integral Reactor • Simplified – Integrated, Pressurized Water Reactor • Internal Components to Minimize Penetrations • Control Rod Drives – No rod ejection • Coolant Pumps – Not safety related • Control Rods versus Boron Shim • Load Following Capability – Up to 10%/Min • Passive Safety • No safety-related emergency diesel generators • No core uncovery during design basis accident (small break LOCA) • Performance of Critical Functions by Multiple Systems for Improved Reliability and Plant Safety • Multiple Module Plants – BOP Equipment Not Shared © 2011 The Babcock & Wilcox Company. All rights reserved.
Integral Reactor Arrangement Pressurizer Central Riser 571°F at 825 psia 50°F SuperheatedSteam 325°F Feedwater Steam Generator Tubes Steam Outlet (2) Feedwater Inlet (2) Reactor Coolant Pumps (12) 1900 psia, 609°F Core Outlet 568°F Core Inlet 25.4M lbm/hr Control Rod Drive Mechanisms (61) Core (69 Bundles) Secondary Loop Primary Loop
Design Objectives – Core and Fuel Assembly • Ensure that assemblies are mechanically designed to remain leak tight and maintain structural integrity under all possible conditions • Load enough fuel inventory to accommodate a 4 year operating cycle at a capacity factor of > 95% • Optimize fuel assembly design to maximize fuel utilization • Maintain conservative peaking factors and linear heat rate throughout the operating cycle • Ensure a shutdown margin of > 1% keff/keff under the most reactive conditions and highest worth CRA cluster stuck out • Meet a MDNBR > 1.3 for limiting thermal-hydraulic conditions and confirm via unique CHF correlation
Core Design Features • 69 fuel assemblies • < 5 wt% 235U enrichments • Two fuel assembly configurations • No soluble boron for control • Axially graded BPRs • Gd2O3 spiked rods • Control rod sequence exchanges • AIC and B4C control rods • 3% shutdown margin
Fuel Mechanical Design Features Upper End Fitting End Grid (Inconel-718) Conventional 17x17 design Fixed grid structural cage Design optimized for mPower Mid Grid (Zircaloy-4) 17 x 17 Square Array Control Rod Guide Tube (Zircaloy-4) End Grid (Inconel-718) Lower End Fitting Shortened and Simplified Conventional Fuel Assembly Design © 2010 Babcock & Wilcox Nuclear Power Generation Group, Inc. All rights reserved. © 2011 The Babcock & Wilcox Company. All rights reserved. 11
Low Core Linear Heat Rate Low Power Density Reduces Fuel and Clad Temperatures During Accidents Low Power Density Allows Lower Flow Velocities that Minimize Flow Induced Vibration Effects Large Reactor Coolant System Volume Large RCS Volume Allows More Time for Safety System Response in the Event of an Accident More Coolant Is Available During a Small Break LOCA Providing Continuous Cooling to Protect the Core Small Penetrations at High Elevation High Penetration Locations Increase the Amount of Coolant Left in the Vessel after a Small Break LOCA Small Penetrations Reduce Rate of Energy Release to Containment Resulting in Lower Containment Pressures Inherent Safety Features .12 CONFIDENTIAL AND PROPRIETARY TO B&W
Key Features of the Integral RCS RCS volume and small break sizes allow simplification of RCS safety systems * Assumes double ended break © 2011 The Babcock & Wilcox Company. All rights reserved.
ECCS Safety Functions • Removes core heat following certain anticipated operational occurrences and analyzed accidents • Reduces containment pressure and temperature following certain analyzed accidents • Provides an alternate means of reactivity control for beyond design basis accidents (i.e. ATWS) • Provides a barrier to the release of fission products to the environment
B&W mPowerContainment • Underground containment and fuel storage buildings • Metal containment vessel • Environment suitable for human occupancy during normal operation • Simultaneous refueling and NSSS equipment inspections • Leakage free • Volume sufficient to limit internal pressure for all design basis accidents © 2010 Babcock & Wilcox Nuclear Energy, Inc., All rights reserved.
Component Tests Reactor Coolant Pump CRDM Fuel Mechanical Testing CRDM/Fuel Integrated Test Fuel Critical Heat Flux Emergency High Pressure Condenser Integrated Systems Test (IST) Heat Transfer Phenomena Steam Generator Performance LOCA Response Pressurizer Performance Reactor Control Development Testing Programs Center for Advanced Engineering Research (CAER) Bedford, VA .16
Principal Computer Codes Current thinking… • RELAP5-3D • Primary T/H system transient response • Multi-dimensional hydrodynamics, reactor kinetics • Large code assessment database for PWR T/H phenomena • RELAP5-HD (simulator tool from GSE) available for supplemental T/H analysis • GOTHIC • Containment analysis • Supplemental T/H system transient response
Evaluation Methodology Development and Assessment Process (EMDAP) (RG 1.203)
Identify and Rank Phenomena • Preliminary PIRTs • SB LOCA – Ortiz, Ghan, NUREG/CR-5818 • Non LOCA – Greene, et al., ICONE 9, 2001 • Containment – OECD/NEA CSNI-1999-16 • Final PIRTs • SBLOCA – DEGB in mid-flange attached pipe • Plans • Long-term Non LOCA events (±DT, ±Vol, -Flow) • Short-term Non LOCA events (reactivity anomalies)
Specify Figures of Merit • Chapter 15 Non LOCAs • DNBR • Fuel centerline temperature • Primary and Secondary Pressure • Mass and Energy releases for Chapter 6 analysis (Steamline break only) • Chapter 15 LOCA • Liquid level, surrogate for peak clad temperature and oxidation-related measures • Mass and Energy releases for Chapter 6 analysis • Chapter 15 Reactivity initiated events • Fuel enthalpy (also feeds into source term assumptions in radiological) • Chapter 15 Radiological events • A person located at any point on the boundary of the exclusion area for any 2-hour period would not receive a dose in excess of 25 rem • A person located at any point on the outer boundary of the low population zone would not receive a dose in excess of 25 rem • Chapter 6 Containment events • Pressure
Conclusion • B&W and Bechtel have formed an alliance to design and construct the mPower SMR plant • The mPower modular reactor plant has a unique integral reactor design with passive safety system design • Design and licensing activities are well underway • A comprehensive test program is in process • A letter of intent has been signed with TVA for up to six units for deployment of the first unit by 2012