[attachment=11722]
Workings of a Nuclear Reactor
• Reactor Basics
• PWR
• BWR
Key Reactor Power Terms
• Availability – Fraction of time over a reporting period that the plant is operational
– If a reactor is down for maintenance 1 week and refueling 2 weeks every year, the availability factor of the reactor would be
(365-3 * 7) / 365 = 0.94
Key Reactor Power Terms
• Capacity – Fraction of total electric power that could be produced
– If reactor with a maximum thermal power rating of 1000 MWt only operates at 900 MWt, the capacity factor would be 0.90
• Efficiency – Electrical energy output per thermal energy output of the reactor
Eff=W/QR (MWe/MWt)
Term Visualization
Piecing Together a Reactor
1. Fuel
2. Moderator
3. Control Rods
4. Coolant
5. Steam Generator
6. Turbine/Generator
7. Pumps
8. Heat Exchanger
Basic Reactor Model
• Nuclear Power in the United States
• ~20% Nuclear Energy
• 103 Nuclear Reactors
– 31 States
– 34 BWRs
– 69 PWRs
• Largest Plant
– Palo Verde
– 3825 MWe/3 reactors
– 12th Largest in World
Nuclear Power in the United States
• Manufacturers
– General Electric
• ge.com
– Westinghouse
• westinghouse.com
– AREVA NP
• framatome-anp.com
– ABB Combustion Eng.
• abb.com
• World Nuclear Power
• 443 Nuclear Reactors in 30 Countries in Operation, January 2006
• Provided ~16% World Production of Energy in 2003
• 24 Nuclear Power Plants under Construction
• Reactor Generations
• Gen I
– Prototypes in 50’s & 60’s
• Gen II
– 70’s & 80’s
– Today’s Operational Reactors
– BWR, PWR, CANDU, …
• Gen III
– ABWR, APWR
– Approved 90’s
– Some Built around the World
• Gen III+
– Current Advanced Designs in the Approval Process
– Pebble Bed Reactor
• Gen IV
– Deploy in 2030
– Economical
– Safe
– Minimize Waste
– Reduce Proliferation
• Reactor Generations
• Pressurized Water Reactor (PWR)
• Pressure Vessel
• Light Water
• 3.2% U-235 Fuel
• 2-4 Loops => Steam
• UO2 Pellets in Zircaloy
• 17 x 17 array
• 12 foot long bundle
• ~32% Efficiency
• External Pipe Corrosion
• Lower Capital Cost
• AP600 Westinghouse
• 600 MWe
• Passive Safety Cooling Systems
• Prefabricated and Assembled On-Site
• Simple Plant Design = Reduced Volume and Cost
• 3-year
Construction
• Basic Diagram of a PWR
• A PWR in Practice
• VVER – Russian PWR (Water-Cooled, Water-Moderated, Energy Reactor)
• Other LWR Reactors
• Republic of Korea
– Optimized Power Reactor, OPR-1000
– Advanced Power Reactor, APR-1400
– System-integrated Modular Advanced Reactor, SMART (330 MWt)
• Germany
– KONVOI, 1300 MW
• France
– N4, 1450 MW
• AREVA NP – EPR (European Pressurized-Water Reactor)
• 1600 MWe
• 36 – 37% Efficiency
• Mixed Oxide (MOX) Fuel
• 60 – yr Service Life
• 3 – 4 yr Construction
• Multiple Barriers and Simple Safety Systems
• Westinghouse – AP1000 Reactor
• 1117 – 1154 MWe
• Improved AP600 Design
– Same Basic Design
– Same Inherent Safety
– Optimized Power Output
– Reduced Energy Costs
• 2 Steam Generators
• 3 year Construction
• Final Design Approval in December 2005!
• AP1000 – Less Pieces
• Boiling Water Reactor (BWR)
• Direct Boiling
• 10% Coolant = Steam
• Similar Fuel to PWR
• Lower Power Density than PWR
• Corrosion Product Activated in Core
Higher Radiation Field
• GE – ABWR
• 1350 MWe
(3926 MWt)
• UO2 Fuel
• 60 – yr Service Life
• Internalized Safety and Recirculation Systems
Basic Diagram of a BWR
• A BWR in Practice
• ABWR (Advanced Boiling Water Reactor)
• 1350 MWe
• 77% more compact than BWR design
• 39 month construction period
• ABWR – Less Pieces
• ABWR-II
• Early 1990s - TEPCO, 5 other utilities, GE, Hitachi and Toshiba began development
• 1700 MWe
• Goals
– 30% capital cost reduction
– reduced construction time
– 20% power generation cost reduction
– increased safety
– increased flexibility for future fuel cycles
• Commercialize – latter 2010s