Hydrogen and Nuclear H2NET Summer 2005 Meeting

Transcription

1 ydrogen and Nuclear 2NET Summer 2005 Meeting 24 th June 2005 Dr PJA owarth ead of Group Science Strategy

2 ydrogen Economy Supply Chain Energy Source ydrogen Production Distribution & Storage End Usage Scope of Nuclear Technology Interest

3 Why nuclear? Nuclear offers: a near-zero emissions option demonstrated and established technology base load generation technology long-term stability of generation cost applications for both electricity & high temperature heat generation Nuclear is not the sole answer its another component of part of a diversified and balanced energy policy

4 Powering the ydrogen Economy ELECTRICITY SUPPLY FOSSIL FUELS NUCLEAR / RENEWABLE ELECTRICITY & YDROGEN YDROGEN SUPPLY? ELECTRICITY SUPPLY? Meeting the demands of the hydrogen economy, as well as growth in conventional electricity generation, in 2030 could be equivalent to doubling today s electricity supply TODAY 2030+

5 2 Production via Nuclear Electrolysis No technology barriers exist For reactor systems with high outlet temp ( o C) this could replace some of demands on electrical energy requirements with thermal energy. This would improve the efficiency and reduce production cost Steam Reforming Process Requirements on natural gas can be significantly reduced by using nuclear heat Thermochemical Cycles Production of hydrogen without generation of CO2 Potential for long term low stable cost

6 eat applications & temperatures

7 Thermo-chemical Cycle Technology

8 Thermo-chemical Cycles Replaces thermal decomposition of water (requiring > 2500ºC) with several partial reactions Requires high temp heat source (nuclear or solar furnace) Thermal Step 2 SO 4 -> SO O + ½O 2 Electrochemical Step SO O -> 2 SO 4 + 2

9 Westinghouse Sulphur Cycle - istory Initial development by Westinghouse with DoE support from 1976 to 1983 Development of electrolyser & 2 SO 4 decomposition reactor Integrated laboratory demonstration in 1978 produced 120 L/hr 2 Renewed work to re-assess efficiency (<50%) and economics (~$2/kg)

10 igh Temperature e-cooled Reactors

11 igh-temperature Gas-cooled Reactors Based on e cooled, graphite moderated core igh outlet temperature > 800 o C ave advantages of inherent safety igh efficiency with direct turbine Small / modular reactors to cope with grid & deployment issues Proven technology historically developed in Europe (Dragon, AVR, TR, TR- Modul) and US (Fort St Vrain)

12 igh Temperature Reactor Technology Significant international interest in TR Technology: Pebble Bed Modular Reactor (PBMR) in South Africa TR-10 and TR-PM in China TTR in Japan NGNP in US at Idaho Significant interest in S. Korea General Atomics development with GT-MR France actively pursuing R&D with major development plans Above countries are also exploring thermo-chemical cycle developments

13 Why South African Interest in TR Technology? Significant coal reserves but located many miles from population centres. TR Technology offers: Small / modular reactors to cope with grid & deployment issues Provides security of supply Low electricity production cost Simplified technology Meets climate change objectives Gabon Luanda Brazzaville Congo Windhoek T Kinshasa Angola Namibia Dem Rep of the Congo Botswana Zambia Lusaka Gaborone Pretoria Johannesburg South Africa T T ET ET P Lesotho Rwanda Burundi arare Zimbabwe ET ETET ET ET ET ET ET ET ET Lilongwe T Malawi Maputo Mbabane Swaziland T Nairobi Tanzania Kenya Mozambique P T ET Dar es Salaam ydro station Pumped storage scheme Thermal Station Eskom thermal station Cape Town N P

14 Pebble-Bed Modular Reactor (PBMR) Small (~400 MWt) modular pebble bed TR Direct cycle gas turbine No secondary steam circuit igh outlet temperature: 900 C good thermal efficiency (~ 42%) flexibility for alternative applications igh fuel average burnup (~ 80 GWd/tU initially, higher later) Very high degree of inherent safety

15 PBMR Layout igh Pressure Compressor Recuperator Low Pressure Compressor Power Turbine Reactor Gearbox Generator Pre-Cooler Inter-Cooler Core Conditioning System Core Barrel Conditioning System Maintenance Isolation/Shutdown Valve Location of Intermediate eat Exchanger for 2 Process eat Removal

16 PBMR fuel design 5mm Graphite layer Coated particles imbedded in Graphite Matrix Dia. 60mm Fuel Sphere Pyrolytic Carbon 40/1000mm Silicon Carbite Barrier Coating Inner Pyrolytic Carbon 40/1000mm Porous Carbon Buffer 95/1000mm 35/1000mm alf Section Dia. 0,92mm Coated Particle Dia.0,5mm Uranium Dioxide Fuel

17 Loss of Coolant Event MW PBMR Ref. Core: Temperature Distribution during a DLOFC Temp ( C) Time (h)

18 Coupling TRs and Westinghouse 2 Process allows separation of plant components Nuclear Reactor elium 2SO4 Decomposition Electricity Electrolyser ydrogen SO2, 20, O2 2SO4

19 Future Developments

20 Future advanced reactor systems Systems development too expensive for one nation Pool resources and knowledge Develop systems to meet international objectives Skills retention Excite next generation scientists and engineers Demonstrate a united global position on future nuclear technology

21 Very igh Temp Gas-Cooled Reactors A 600 MWth VTR dedicated to 2 can yield over 2 million m 3 /day.

22 A gas-cooled reactor technology path Natural development for gas cooled systems ETDR GFR R&D fuel materials & fabrication materials for high fluence fuel cycle technology safety systems Gas-cooled Fast Reactor NGNP / VTR R&D fuel materials & fabrication high temperature materials hydrogen production technology graphite technology VTR PBMR Idaho NGNP

23 BNFL/Westinghouse Experience Significant historical capability in: Fuel Manufacture Gas-cooled reactor technology Graphite technology Active involvement in the PBMR South African project Provides links between BNFL/W & Sheffield University, University of South Carolina and Savannah River National Laboratory Development of TR Nuclear physics and fuel performance capability Involvement in international collaborative activities such as US DoE s Generation IV programme

24 Required Governmental Support Recognise benefits of nuclear and its role in hydrogen economy Fund a wider range of R&D activities supporting nuclear hydrogen production Propose long term integrated vision for all technologies required for hydrogen with appropriate roadmaps