the pebble bed modular reactor (pbmr) project
DESCRIPTION
The Pebble Bed Modular Reactor (PBMR) Project. The Technology. - PowerPoint PPT PresentationTRANSCRIPT
The Pebble Bed ModularReactor (PBMR) Project
The PBMR is a small-scale, helium-cooled, graphite-moderated, temperature reactor (HTR). Although it is not the only gas-cooled HTR currently being developed in the world, the South African project is internationally regarded as the leader in the power generation field.
The Technology
PBMR (Pty) Ltd intends to:Build a demonstration module at Koeberg near Cape Town
Build an associated fuel plant at Pelindaba near Pretoria
Commercialize and market 165MWe modules for the local and export markets
Transform PBMR (Pty) Ltd into a world-class company
The Project
South African Government (DPE)
Eskom
Industrial Development Corporation (IDC)
British Nuclear Fuels (BNFL)
Negotiating with other potential investors
Current investors
Growth in SA Electricity DemandCompound annual demand growth of 3.4% per year since 1992 (2004 peak 34,210MW compared to 22,640 in 1992)
National Energy Regulator’s Integrated Resource Plan shows:
Projected growth of ~2.8%/annum to 2022New build capacity of over 20,000MW required by 2022Growth at 4% would require ~40,000MW
Eskom predicts growth in demand of 1200 MW p/a over next 20 years
[PMG note: graphics not included, please email [email protected]]
The expansion of generating capacity in South Africa should include a diversity of energy sources, including coal, hydro, nuclear, wind, solar, wave, tidal etc.
To meet energy development challenges, South Africa needs to optimally use all energy sources available and vigorously pursue energy efficient programmes
[PMG note: graphics not included, please email [email protected]]
Diversity of energy sources
World electricity marketWorld capacity in January 2002 was 3,465GW (~100 x Eskom)
World average growth of 3% per annum since 1980 (equates to 600 PBMRs per year)
MIT forecasts world demand to triple by 2050
Current world spending is about $100bn per year on new power stations
Fossil fuel costs have risen dramatically
Environmental pressure is increasing
[PMG note: graphics not included, please email [email protected]]
Thirty nuclear plants are being built today in 12 countries around the world
Green guru James Lovelock and Greenpeace co-founder Patrick Moore calls for “massive expansion” of nuclear to combat global warming (May 2004)
George Bush signs energy bill and describes nuclear as one of the nation’s most important sources of energy (Aug 2005)
US Energy Secretary Samuel Bodman predicts nuclear will “thrive as a future emission-free energy source” (April 2005)
Tony Blair proposes new generation of nuclear plants to combat climate change (July 2004)
Resurgence of nuclear energy
China plans to build 27x1000MW nuclear reactors over the next 15 years
India plans a ten-fold nuclear power increase
France to replace its 58 nuclear reactors with EPR units from 2020, at the rate of about one 1600 MWe unit per year.
IAEA predicts at least 60 new reactors will become operational within 15 years
Resurgence of nuclear energy
"How are we going to satisfy the extraordinary need for energy in really rapidly developing countries? I don't think solar and wind are going to do it. We are going to have to find a way to harness all energy supplies that includes civilian nuclear power."
Condoleezza Rice, US Secretary of State, Sept 2005
Views on nuclear
“The long-term future of power reactors belongs to very high temperature reactors such as the PBMR.” Nuls Diaz, Chairman of the US Nuclear Regulatory Commission, July 2004
“I feel we made a mistake in halting the HTR programme.” Klaus Töpfer, Germany’s former Minister of Nuclear Power and Environment. Davos, January 2003
“The PBMR technology could revolutionize how atomic energy is generated over the next several decades. It is one of he near-term technologies that could change the energy market.” Prof. Andrew Kadak, Massachusetts Institute of Technology, January 2002
“Little old South Africa is kicking our butt with its development of the PBMR. This should be a wake-up call for the US.” Syd Ball, senior researcher at Oak Ridge National Laboratory, 11 June 2004.
Views on PBMR
Why PBMR could be the first successful commercialGeneration IV reactor
Non-CO2 emitting option in climate change debate
Inherent safety reducing regulation burden
Small unit flexibility with short construction periods
Accepted as very low nuclear proliferation risk
Close enough to commercial deployment to achieve “first to market” dominance
Eskom build program of at least 20 000 MW over the next 15 years
PBMR uniquely positioned
Can be placed near point of demand
Small safety zone
On-line refuelling
Load-following characteristics
Process heat applications
Well suited for desalination purposes
Synergy with hydrogen economy
Salient features
Ability to site on coast, away from coal fields
RSA based “turnkey” supplier allows localisation of manufacture on sub-contractors
Locally controlled technology limiting foreign exchange exposure
About 56 000 local jobs created during full commercial phase
R23 billion net positive impact on Balance of Payments
Advantages to South Africa
Pre-application letter submitted to Nuclear Regulatory Commission (February 2004)
Official kick-off meeting with NRC staff (November 2004)
Formal Design Certification application scheduled for submission to NRC (2007)
US NRC final design approval estimated (2011)
US licensing programme
Why is PBMR safe and environmentally friendly
Simple design base
If fault occurs, system shuts itself
The transfer medium (helium) is chemically inert
Coated particle provides excellent containment for the fission product activity
No need for safety grade backup systems
No need for off-site emergency plans
License application for small safety zone
Inherent safety proven during public tests
Safety Features
Reactor Safety Fundamentals
Main safety objective is to preserve the integrity of the fuel under all postulated events
To reach this objective it is therefore necessary to ensure that the fuel does not heat up or is degraded by some other means to a point where the activity retention capability is lost
Reactor Safety Fundamentals
The ultimate fuel temperature and the fuel element structural characteristics determine the activity retention capability during operation and following an event.
Three factors determine the ultimate fuel temperature during operation and following an event:
- Production of heat in the core
- Removal of heat from the core
- The heat capacity of the core
Reactor Design PRESSURIZED WATER REACTOR (PWR)
The water which flows through the reactor core is isolated from the turbine. The water which passes over the reactor core to act as moderator and coolant does not flow to the turbine. The primary loop water produces steam in the secondary loop which drives the turbine. Fuel leak in the core would not pass any radioactive contaminants to the turbine and condenser. The PWR can operate at higher pressure and temperature, about 160 atmospheres and about 315 °C.
The water which flows through the reactor core is isolated from the turbine. The water which passes over the reactor core to act as moderator and coolant does not flow to the turbine. The primary loop water produces steam in the secondary loop which drives the turbine. Fuel leak in the core would not pass any radioactive contaminants to the turbine and condenser. The PWR can operate at higher pressure and temperature, about 160 atmospheres and about 315 °C.
Fuel Rods filled with pellets are grouped into fuel
[PMG note: graphics not included, please email [email protected]]
ECCS Denotes Emergency Core Cooling System
Decay Heat Comparison
Time (h) PBMR PWR
0.0 27 200
0.25 8 60
0.50 7 50
0.75 6 45
1.00 5.5 41
2.00 4.5 34
Decay power in megawatt after subcriticality
3000 MWt PWR
400 MWt PBMR
Decay heat in the fuel due to the energy released
from the decay of the fission products in the fuel
Decay heat is a function of the reactor thermal power
PBMR Passive Decay Heat Removal
Centre Reflector Pebble Bed Side Reflector Core Barrel RPV RCCS Citadel
RadiationConduction
Conduction
Conduction
Convection
Radiation
Convection
Conduction
Radiation
Convection
Conduction
Convection
Radiation
Convection
Conduction
Radiation
PBMR Passive Decay Heat Removal
900930960990
102010501080111011401170120012301260129013201350138014101440147015001530156015901620
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
Time (hrs)
Tem
pera
ture
(C)
Maximum Fuel Temp Average Fuel Temp
0.0
1.5
7.3
8.0
9.4
10.910.4
12.012.5
11.6
9.5
6.9
0.00.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
<500 500-600 600-700 700-800 800-900 900-1000 1000-1100
1100-1200
1200-1300
1300-1400
1400-1500
1500-1600
>1600
Temperature Interval (C)%
of fue
l sph
eres
Fuel Temperature History and Distribution
Safety Comparison Loss of coolant event PBMR vs LWR
Initial heat-up will render reactor sub-critical in both cases.
PBMR LWR
Coolant Single phase Two-phase
Heat production Low High
Heat removal Passive (natural) Active (engineered)
Heat capacity High Low
Heat-up rate Slow High
Fuel characteristics Ceramic Metallic
• For HTR no core melt possible• For LWR core behaviour dependent on engineered systems however a Chernobyl type accident is not possible in both cases
Fuel fabrication at Necsa
One Pebble (11.5MWh) can:
* power 115 000x100W light bulbs for 1 hour
* power one 60W light bulbs, burning 12 hours per day, for 43 years
The SA Government proposes 50kWh free to each household. One pebble can supply this 'free‘ power for 230 households for one month … or for 1 household for 19 years.
Power of the Pebble
Power conversion unit
Spent fuel handling
PBMR spent fuel to be kept on site
A 165 MWe module will generate 32 tons of spent fuel pebbles per year, about one ton of which is uranium
Fuel balls are “pre-packaged” for final disposal purposes
Draft nuclear waste management policy issued for public comment in 2003
[PMG note: graphics not included, please email [email protected]]
Multi-module concept
PBMR’s breaks first ground
22 November 2004: Sod-turning ceremony for 43m high helium test facility at Pelindaba
Helium blower, valves, heaters, coolers, recuperator and other components to be tested at pressures up to 95 bar and 1200 degrees C
[PMG note: graphics not included, please email [email protected]]
• EIA to be reopened (public meetings to start tomorrow (9 November) in Cape Town
• Construction to start in 2007 (subject to positive conclusion of regulatory processes)
• Demonstration module and fuel plant to be completed by 2011
• First commercial modules to be completed by 2013
What happens next?