Workings of aWorkings of aNuclear ReactorNuclear Reactor

Reactor BasicsReactor Basics

PWRPWR

BWRBWR

Key Reactor Power Key Reactor Power TermsTerms

• Availability – Fraction of time over a Availability – Fraction of time over a reporting period that the plant is reporting period that the plant is operationaloperational– If a reactor is down for maintenance 1 If a reactor is down for maintenance 1

week and refueling 2 weeks every year, week and refueling 2 weeks every year, the availability factor of the reactor the availability factor of the reactor would bewould be(365-3 * 7) / 365 = 0.94(365-3 * 7) / 365 = 0.94

Key Reactor Power Key Reactor Power TermsTerms• Capacity – Fraction of total electric Capacity – Fraction of total electric

power that could be producedpower that could be produced– If reactor with a maximum thermal power If reactor with a maximum thermal power

rating of 1000 MWt only operates at 900 rating of 1000 MWt only operates at 900 MWt, the capacity factor would be 0.90MWt, the capacity factor would be 0.90

• Efficiency – Electrical energy output per Efficiency – Electrical energy output per thermal energy output of the reactorthermal energy output of the reactorEff=W/QEff=W/QR R (MWe/MWt)(MWe/MWt)

TermTermVisualizationVisualization

Piecing Together a Piecing Together a ReactorReactor1.1. FuelFuel

2.2. ModeratorModerator

3.3. Control RodsControl Rods

4.4. CoolantCoolant

5.5. Steam GeneratorSteam Generator

6.6. Turbine/GeneratorTurbine/Generator

7.7. PumpsPumps

8.8. Heat ExchangerHeat Exchanger

Basic Reactor ModelBasic Reactor Model2.

Mod

erat

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1. F

uel

3. C

ontr

ol r

od

5. S

team

gen

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4. Coolant

6.

8.

7.

Nuclear Power in the United Nuclear Power in the United StatesStates

• ~20% Nuclear Energy~20% Nuclear Energy

• 103 Nuclear Reactors103 Nuclear Reactors– 31 States31 States– 34 BWRs34 BWRs– 69 PWRs69 PWRs

• Largest PlantLargest Plant– Palo VerdePalo Verde– 3825 MWe/3 reactors3825 MWe/3 reactors– 1212thth Largest in World Largest in World

http://www.nei.org

Nuclear Power in the United Nuclear Power in the United StatesStates

• ManufacturersManufacturers– General ElectricGeneral Electric

• www.ge.comwww.ge.com

– WestinghouseWestinghouse• www.westinghouse.cowww.westinghouse.co

mm

– AREVA NPAREVA NP• www.framatome-anp.cwww.framatome-anp.c

omom

– ABB Combustion Eng.ABB Combustion Eng.• www.abb.comwww.abb.com

http://www.chemsoc.org

World Nuclear PowerWorld Nuclear Power

• 443 Nuclear 443 Nuclear Reactors in 30 Reactors in 30 Countries in Countries in Operation, Operation, January 2006January 2006

• Provided ~16% Provided ~16% World Production World Production of Energy in 2003of Energy in 2003

• 24 Nuclear Power 24 Nuclear Power Plants under Plants under ConstructionConstruction

http://www.insc.anl.gov

Reactor GenerationsReactor Generations

• Gen IGen I– Prototypes in 50’s & Prototypes in 50’s &

60’s60’s• Gen IIGen II

– 70’s & 80’s70’s & 80’s– Today’s Operational Today’s Operational

ReactorsReactors– BWR, PWR, CANDU, …BWR, PWR, CANDU, …

• Gen IIIGen III– ABWR, APWRABWR, APWR– Approved 90’sApproved 90’s– Some Built around the Some Built around the

WorldWorld

• Gen III+Gen III+– Current Advanced Current Advanced

Designs in the Approval Designs in the Approval ProcessProcess

– Pebble Bed ReactorPebble Bed Reactor• Gen IVGen IV

– Deploy in 2030Deploy in 2030– EconomicalEconomical– SafeSafe– Minimize WasteMinimize Waste– Reduce ProliferationReduce Proliferation

Reactor GenerationsReactor Generations

http://www.whitehouse.gov/

Pressurized Water Reactor Pressurized Water Reactor (PWR)(PWR)

• Pressure VesselPressure Vessel• Light WaterLight Water• 3.2% U-235 Fuel3.2% U-235 Fuel• 2-4 Loops => Steam2-4 Loops => Steam• UOUO22 Pellets in Zircaloy Pellets in Zircaloy• 17 x 17 array17 x 17 array• 12 foot long bundle12 foot long bundle• ~32% Efficiency~32% Efficiency• External Pipe CorrosionExternal Pipe Corrosion• Lower Capital CostLower Capital Cost

• AP600 WestinghouseAP600 Westinghouse• 600 MWe600 MWe• Passive Safety Cooling Passive Safety Cooling

SystemsSystems• Prefabricated and Prefabricated and

Assembled On-SiteAssembled On-Site• Simple Plant Design = Simple Plant Design =

Reduced Volume and Reduced Volume and CostCost

• 3-year3-yearConstructionConstruction

Basic Diagram of a PWRBasic Diagram of a PWR

http://www.nrc.gov/

A PWR in PracticeA PWR in Practice

http://www.nukeworker.com/

VVER – Russian PWR (Water-VVER – Russian PWR (Water-Cooled, Water-Moderated, Energy Cooled, Water-Moderated, Energy Reactor)Reactor)

http://www.nucleartourist.com/

Other LWR ReactorsOther LWR Reactors

• Republic of KoreaRepublic of Korea– Optimized Power Reactor, OPR-1000Optimized Power Reactor, OPR-1000– Advanced Power Reactor, APR-1400Advanced Power Reactor, APR-1400– System-integrated Modular Advanced Reactor, System-integrated Modular Advanced Reactor,

SMART (330 MWt)SMART (330 MWt)

• GermanyGermany– KONVOI, 1300 MWKONVOI, 1300 MW

• FranceFrance– N4, 1450 MWN4, 1450 MW

AREVA NP – EPR (European AREVA NP – EPR (European Pressurized-Water Reactor)Pressurized-Water Reactor)

• 1600 MWe1600 MWe• 36 – 37% Efficiency36 – 37% Efficiency• Mixed Oxide (MOX) Mixed Oxide (MOX)

FuelFuel• 60 – yr Service Life60 – yr Service Life• 3 – 4 yr 3 – 4 yr

ConstructionConstruction• Multiple Barriers Multiple Barriers

and Simple Safety and Simple Safety SystemsSystems

http://www.framatome-anp.com

/

Westinghouse – AP1000 Westinghouse – AP1000 ReactorReactor

• 1117 – 1154 MWe1117 – 1154 MWe

• Improved AP600 DesignImproved AP600 Design– Same Basic DesignSame Basic Design– Same Inherent SafetySame Inherent Safety– Optimized Power OutputOptimized Power Output– Reduced Energy CostsReduced Energy Costs

• 2 Steam Generators2 Steam Generators

• 3 year Construction3 year Construction

• Final Design Approval in Final Design Approval in December 2005!December 2005!

http://www.ap1000.westinghousenuclear.com/

AP1000 – Less PiecesAP1000 – Less Pieces

Nuclear News, November 2004

Boiling Water Reactor Boiling Water Reactor (BWR)(BWR)

• Direct BoilingDirect Boiling

• 10% Coolant = Steam10% Coolant = Steam

• Similar Fuel to PWRSimilar Fuel to PWR

• Lower Power Density Lower Power Density than PWRthan PWR

• Corrosion Product Corrosion Product Activated in CoreActivated in Core

• Higher Radiation FieldHigher Radiation Field

• GE – ABWRGE – ABWR

• 1350 MWe1350 MWe(3926 MWt)(3926 MWt)

• UOUO22 Fuel Fuel

• 60 – yr Service Life60 – yr Service Life

• Internalized Safety Internalized Safety and Recirculation and Recirculation SystemsSystems

Basic Diagram of a BWRBasic Diagram of a BWR

http://www.nrc.gov/

A BWR in PracticeA BWR in Practice

http://www.energy-northwest.com

ABWR (Advanced Boiling ABWR (Advanced Boiling Water Reactor)Water Reactor)

• 1350 MWe1350 MWe

• 77% more compact 77% more compact than BWR designthan BWR design

• 39 month construction 39 month construction periodperiod

TOSHIBA, Kashiwazaki-Kariwa Unit 6, Japan

GE

ABWR – Less PiecesABWR – Less Pieces

ABWR-IIABWR-II• Early 1990s - TEPCO, 5 Early 1990s - TEPCO, 5

other utilities, GE, other utilities, GE, Hitachi and Toshiba Hitachi and Toshiba began developmentbegan development

• 1700 MWe1700 MWe• GoalsGoals

– 30% capital cost 30% capital cost reductionreduction

– reduced construction reduced construction time time

– 20% power generation 20% power generation cost reduction cost reduction

– increased safety increased safety – increased flexibility for increased flexibility for

future fuel cyclesfuture fuel cycles

• Commercialize – latter Commercialize – latter 2010s2010s

PRCS PCCS

S/P

D/W

PHRS

S/P

D/W

PHRS

GE – ESBWR (Economic GE – ESBWR (Economic Simplified Boiling Water Simplified Boiling Water Reactor)Reactor)• 1550 MWe (4500 MWt)1550 MWe (4500 MWt)

• Passive Condenser Passive Condenser Systems for Heat TransferSystems for Heat Transfer

• Standard Seismic DesignStandard Seismic Design

• Improved EconomicsImproved Economics

• Shorter Construction TimeShorter Construction Time

• Reduced Plant Staff and Reduced Plant Staff and Operator RequirementsOperator Requirements

Raised Suppression Pool

Decay Heat Heat Exchangers Above Drywell

All Pipes/ Valves Inside Containment

High Elevation Gravity Drain Pools

Raised Suppression Pool

Decay Heat Heat Exchangers Above Drywell

All Pipes/ Valves Inside Containment

High Elevation Gravity Drain Pools

ESBWRESBWR