Next and Last Generation of Nuclear Power Plants
Paul HowarthExec Director, Dalton Nuclear Institute
IMechE Branch Meeting
Jan 2009
Order of Service
• Introduction to status of advanced systems
• The 3 contending designs
– EPR
– AP1000
– ESBWR
• Way Forward
Energy Released from FissionU235 + n → fission + 2 or 3 n + 200 MeV
~ kinetic energy of fission products~ gamma rays~ kinetic energy of the neutrons~ energy from fission products~ gamma rays from fission products~ anti-neutrinos from fission products
165 MeV7 MeV6 MeV7 MeV6 MeV9 MeV
200 MeV
Energy release is equivalent to 80 million kJ/g 235U !! Or 4 million x energy in chocolate
Or 2 million x energy in Natural Gas.
Nuclear is alive and well around the World
• Provides 16% of world’s electricity• 440 nuclear reactors operating worldwide• More than 11,000 reactor-years of operating experience• 10+ new plants connected since 2004• 27 new plants under construction• In Europe:
–Some new build taking place and other countries are revising energy policy
• China has placed an order with Westinghouse for new AP1000s
• Middle East, Far East, South American and Australasian counties
Issues Surrounding Nuclear
Low Carbon Technology
Security of supply
Safety
Base load Generation
Economics
Waste Management
17%
2%
25%
13%2%
41%
Capital
Decommissioning
Operations andMaintenanceFuel
Spent Fuel Management
Financing
Modern nuclear plant costs are understood and are competitive
Typical costs are in range £30-40/MWhAll costs are accounted for …..
Building to time and cost
89 90 020100999897969594939291 03
Yonggwang 3
Yonggwang 4
Ulchin3
Ulchin 4
Yonggwang 5
Yonggwang 6
Planned schedule
Actual
Net Capacity Factors
50.0
60.0
70.0
80.0
90.0
100.0
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
US worldSource: WANO and Nuclear Energy Institute
Expectations for load-factors are high!
Load Factors for new “proto-type” plants
Average Load Factor Over Last Decade of Operation
93
82
8
37
2724
62 63
55
14
0
10
20
30
40
50
60
70
80
90
100
Emsland worldcommercial
reactors
Super-phenix
Phenix DounreayFR
PFRDounreay
WindscaleAGR
WinfrithSGHWR
Julich AVR Fort St VrainHTR
Ave
rage
Loa
d Fa
ctor
(%)
Current Nuclear Options
Reactor Design Type Country of Origin Lead Developer
ABWR BWR US Japan GE, Toshiba, Hitachi
CANDU-6 PHWR Canada AECL VVER-91/99 PWR Russia Atomstroyexport
AHWR PHWR India Nuclear Power Corporation of India
APR-1400 PWR Korea, US Kepco
APWR PWR Japan Westinghouse &
Mitsubishi
EPR PWR France, Germany Framatome ANP
AP1000 PWR US Westinghouse SWR BWR France, Germany Framatome-ANP
ESBWR BWR US GE ACR PHWR Canada AECL
• Technology– based on existing N4 and Konvoi reactors
in France and Germany– under construction in Finland, French demonstrator
ordered
• Safety Features
– Increased Safety Margins– Greater volumes to reduce transients – enhanced protection against
aircraft impact and earthquakes
• Construction– Currently being built in Finland and France
The European Pressurised-water Reactor Design
EPR characteristics
Thermal power 4300 MW Electrical power 1600 MW Efficiency 36% No of primary loops 4 No of fuel assemblies 241 Burnup 60 GWd/t Seismic level 0.25 g Service life 60 years
Higher steam efficiency comes from higher steam pressures. Through increased heat exchange surface on steam generators.
Operating Temp 300oC
Pressure 155 Bar
EPR SimplificationsCOMPARISON OF EPR EQUIPMENT WITH A TYPICAL 4-LOOP
UNIT
EXIS
TIN
G P
LAN
T
EXIS
TIN
G P
LAN
T
EXIS
TIN
G P
LAN
T
EXIS
TIN
G P
LAN
T
EPR
EPR
EPR
EPR
0%
20%
40%
60%
80%
100%
120%
VALVES PUMPS TANKS HX's
COMPONENT TYPES
NO
RM
ALI
SED
NU
MB
ER P
ER M
We 47% fewer
valves16% fewer
pumps50% fewer
tanks47% fewer heat
exchangers
Source: Areva
EPR Reactivity Control
• Enriched boron concentrations to control slow reactivity changes
• Gadolinium neutron absorbers in form of burnable fuel rods for power distribution
• Rod Cluster Control Assemblies (RCCAs) for rapid reactivity changes
• Load following through a combination of RCCA movement and boron concentration
• Larger steam generator volume -> increases secondary side water and steam volume
– Smoother transients in normal operation reducing unscheduled reactor trips
– Dry-out time increased to 30 minutes, sufficient time to recover feedwater supply, or initiate other measures
• Increased RPV volume – additional margin to core dewatering in event of LOCA – more time available to counteract situation
• Increased pressuriser volume 25% over N4 – smoothes response to operational transients
Increasing margins to improve fault tolerance and hence safety
EPR Core Damage Frequency
Predicted Core Damage Frequency for EPR improved by a factor of around 10 compared to N4 and Konvoi
Results for Olkiluoto, Finland• Transients 45%• Loss of coolant accidents 24%• Loss of off-site power supply 5%• Fires 2%• Floods 2%• External events 16%• Low power and shutdown 6%• Total 1.8x10-6/year
Manufacture of the Olkiluoto RPV (upper part)
Casting Forging Machining
Non-destructive testing
Machining
AP1000 - overview
• 1150 MWe development of the AP600
• Minimal change to AP600 2-loop design:
– 4.27m core
– larger SGs + pressuriser
– uprated turbo-generator
– larger containment building
• US utilities have selected AP1000 & progressing combined license and construction and operation
• Westinghouse successful in Chinacontract for 4 new reactors
AP1000 Characteristics
Thermal power 3415 MWElectrical power Around 1100 MWEfficiency 32%No of primary loops 2No of fuel assemblies 157Burnup 60 GWd/ tSeismic level 0.30 gService life 60 years
Source: Westinghouse
Operating Temp 312oC
Pressure 155 bar
AP1000 is Assembled with Proven Components
Components Experience
Fuel (14 ft. 17x17 ZIRLO) South Texas
Reactor Internals Doel 4, Tihange 3
Reactor Vessel Doel 4, Tihange 3
Steam Generators Arkansas, Waterford
Pressuriser South Texas
Reactor Coolant Pump Other industrial applications
Containment Kori 1, 2 & Krsko & Angra
Passive safety systems: extensively tested during US licensing
AP1000 Safety / Shut Down Systems
• Reactor Shutdown Systems (control rods and chemical poisoning)
• Passive core cooling systems (PXS)
• Containment Isolation
• Passive Containment Cooling System (PCS)
Passive Core Cooling System
• Automatic Depressurisation System to allow low pressure injection of water
• Injection and coolant makeup from:1. Core Make-up tanks (CMT) – High pressure injection boronated water2. Accumulators – Medium Pressure larger volumes3. In-containment Refueling Water Storage tank (IRWST) – low pressure gravity
feed
• Passive Residual Heat Removal (protection against transients)– PRHR Heat Exchanger (sitting in the IRWST)– IRWST as heat sink absorbs decay heat for 2 hours
AP1000 simplifications
50% Fewer Valves
35% Fewer Pumps
80% Less Pipe*
80% Fewer Heating,
Ventilating & Cooling Units
45% Less Seismic Building Volume
70% Less Cable
Assuring vessel integrity• Ring forged construction• No welds in active core region• No longitudinal welds• Top mounted in-core instrumentation – no bottom penetrations
Assuring safety injection to cover the core• RPV depressurisation and gravity fed water feed
Very high structural integrity of reactor pressure vessel such that failure is not considered credible.
Vessel designed to ensure water delivered to cover the core after a circuit break
Core Damage Frequency
1 x 10-4 5 x 10-5 1 x 10-5 4 x 10-7
Core Damage Frequency per Year
U. S. NRCRequirements
CurrentPlants
UtilityRequirements
AP1000Results
ESBWR characteristics
1,132Fuel Assemblies
287oCOperating Temp
71 BarPressure
60 yearsService Life
50 GWd/tBurn-up
34.7%Efficiency
1,550 MWElectrical power
4,500 MWThermal power
0
2000
4000
6000
8000
10000
12000
1400020
03
2005
2007
2009
2011
2013
2015
2017
2019
2021
2023
2025
2027
2029
2031
2033
2035
MWe
Existing stations Potential AGR life extension New Build
Possible Future Nuclear Capacity in the UK
UK Current Situation
• RWE Npower has secured grid connection capacity of 3600 MWeat Wylfa, in Wales, to accommodate three new nuclear power reactors.
• British Energy, now under EdF, also has grid connection agreements for Wylfa as well as for its two major announced projects at Sizewell and Hinkley Point,
• German utility EOn has 1600 MWe grid connection agreed for Oldbury.
• Total grid connection capacity for new UK nuclear plants is now 18.4 GWe
Pebble-Bed Modular Reactor (PBMR)
• Small (~400 MWt) modular pebble bed HTR– helium cooled, graphite moderated– direct cycle gas turbine – no secondary steam circuit– high outlet temperature: 900°C
good thermal efficiency (~ 42%)flexibility for alternative applications
– high fuel average burnup(~ 80 GWd/tU initially, higher later)
– very high degree of inherent safety• Design based on ABB-THTR • Direct cycle technology introduced by PBMR
PBMR fuel design
Fuel Sphere
Half Section
Coated Particle
Fuel
Dia. 60mm
Dia. 0,92mm
Dia.0,5mm
5mm Graphite layer
Coated particles imbeddedin Graphite Matrix
Pyrolytic Carbon Silicon Carbite Barrier Coating Inner Pyrolytic Carbon Porous Carbon Buffer
40/1000mm
35/1000mm
40/1000mm
95/1000mm
Uranium Dioxide
PBMR Main Power System
Reactor Unit
Recuperators
CompressorsTurbine
Inter cooler Pre cooler
Gearbox
Generator
Generation IV Systems
• Very-High-Temperature Reactor (VHTR)
• Gas-Cooled Fast Reactor (GFR)
• Sodium-Cooled Fast Reactor (SFR)
• Lead-Cooled Fast Reactor (LFR)
• Supercritical Water-Cooled Reactor (SCWR)
• Molten Salt Reactor (MSR)
Sodium Cooled Fast Reactor
• Outlet temp of 550oC
• Options are– Intermediate size (150 to500MWe)
supported by fuel cycle based upon non-aqueous reprocessing at-reactor
– Med to Large size (500 to 1500MWe) supported by fuel cycle based upon aqueous reprocessing at central location
• Designed mainly for electricity production