Nuclear Fuel Cycle Options and Sustainability Graham Fairhall Chief Science and Technology Officer Overview • Background and Nuclear Fuel Cycles • UK nuclear options and initial programmes • The future • Summary Growth of Nuclear – WNA Outlook • >80% increased capacity in countries with existing nuclear power • Increased closed fuel cycle but some nations well advanced with open fuel cycle and disposal (Finland / Sweden) Open versus closed fuel cycles Open fuel cycle Closed fuel cycle Uranium resources Current Uranium requirements ~ 66,000 te / yr Making our Uranium last longer • Mining leaner reserves • Squeezing out more U-235 from “tails” via further enrichment • Advanced thermal reactor designs to increase efficiency • Reprocessing – increases uranium utilisation and enables MOX usage • Fast breeder reactors – utilise U-238 • Thorium – more abundant than uranium Thorium history • In the 1950s through to the 1980s, there were thorium research programmes for: • Pressurised water reactors (PWR) • Shippingport breeder core • Germany-Brazil collaboration • High temperature gas reactors (HTR) • DRAGON (UK), Fort St Vrain (USA), Peach Bottom (USA), AVR (Germany) • Molten salt reactors (MSR) • Molten Salt Reactor Experiment (USA) • The common driver for all these plants was to decouple nuclear expansion from uranium availability • Increased focus on Thorium e.g. India Thorium fuel cycles Options for a thermal reactor: • Once-through fuel cycle with Th-232 as alternative fertile material to U-238 with U-235 or Pu-239 driver • U-233 fissioned in-situ without reprocessing/recycle • Modest reduction in uranium demand and sustainability • Recycle strategy with reprocessing/recycle of U-233 • Much improved sustainability analogous to U/Pu breeding cycle Options for a fast reactor: • MSFR and other Gen IV concepts A Thorium Fuel Cycle needs Uranium or Plutonium to initiate a fission reaction Minor Actinides (Transuranic elements) • A small fraction of heavy elements are produced in the reactor through neutron captures in plutonium: • • • Americium (Am) Curium (Cm) Neptunium (Np) • Whilst a small fraction of waste these nuclides are very significant radiologically: • Very radiotoxic + very long half lives • At present minor actinides are disposed of along with spent fuel (no reprocessing) or along with the fission products (after reprocessing). Benefit of removal of Pu and minor actinides from HLW MA + FP Plutonium recycling Uranium ore (mine) P&T of MA FP Time (years) Pu + MA + FP Spent fuel direct disposal IAEA classification of nuclear energy scenario sustainability • Level 1. Safe, secure, economical and publicly acceptable nuclear power with security of supply • Level 2. Safe disposal of all nuclear wastes in a complete once-through fuel cycle with thermal reactors and with retrievable spent nuclear fuel disposal. • Level 3. Initiate recycling of used nuclear fuel to reduce wastes – includes once-through breed and burn option • Level 4. Guarantee nuclear fuel resources for at least the next 1000 years via complete recycle of used fuel with breeding of fissile material • Level 5. Reduce radiotoxicity of all wastes below natural uranium level -closed fuel cycle recycling all actinides and only disposing fission products Wide UK experience with different systems 1950 1960 1970 Sodium-cooled fast reactors DFR Gas-cooled reactors Magnox HTR PFR Water-cooled reactors SGHWR AGR 1980 1990 Present Sizewell B PWR The Energy White Paper 2003 – “Creating a Low Carbon Economy” •2003 Energy Policy focus on renewable energy & energy efficiency •2006 Reconsideration over nuclear •2007 Nuclear Energy re-instated Need for nuclear R&D UK R&D Background • UK long history of nuclear energy • R&D has underpinned nuclear development • Significant R&D programmes ongoing within National Laboratories and industry • Over 30 Universities in UK undertake nuclear research • Nuclear is a key part of the energy strategy for the future Magnox Reactor Advanced Gas Reactor (AGR) PWR - Sizewell ‘B’ UK Fuel Cycle R&D • 60 years of UK R&D programmes • Conceptual flowsheets to pilot rigs to plant operational support • Fuels development experience UO2, MOX, metallic, carbide with full PIE capability • Advanced fuel cycle options developed The 2050 Calculator 80% reduction in CO2 levels from 1990 levels are legally binding Carbon Plan scenarios Higher renewables; more energy efficiency Higher CCS; more bioenergy Higher nuclear; less energy efficiency Scenarios for UK deployment DECC Energy 2050 •Legally binding 80% emission reduction by 2050 •Low carbon generation for: •Electricity •All transportation •Domestic and Industrial Heat, Light & Power •Electricity grid grows from ~85 GWe to ~300GWe •Generation sources ~ 33% renewables, CCS and nuclear UK New Nuclear – First wave? • EPR (EDF Energy) 2 units Hinkley point 2 units Sizewell • ABWR (GE-Hitachi) 2-3 units Wylfa 2-3 units Oldbury Hunterston Chapelcross Hartlepool Sellafield Heysham Wylfa Sizewell • AP1000 (NuGeneration) 2-3 units near Sellafield Bradwell Oldbury Hinkley Point Total ~ 16GWe commitment Early National Nuclear R&D Programme Meet requirements to: • Establish a strategic nuclear R&D programme to address pathways to 2050 scenarios • Underpin gaps within existing energy scenarios • Shape requirements for a long term programme. • Need to maintain key R&D skill base areas in the short term where no other funding • Leverage international R&D and UK Research Council programmes 21 Fuel cycle scenario modelling • Fuel cycle simulation computer programs are used to assess the impacts that different fuel cycle scenarios may have on: • • • • • • • Uranium ore requirements, Ability to start a sustainable fast reactor fleet, Time at which feed of natural uranium is no longer required Packing density and inventory of a geological repository The practicalities of handling fresh nuclear fuel, Processing of spent nuclear fuel Requirements for high level waste immobilisation technologies NNL's ORION code has been used to assess the impacts of the alternative pathways Generating capacity - transition from LWRs to fast reactors - Scenario (a) • 75 GWe target installed capacity • FRs introduced at same rate as LWRs retire • LWRs fuelled on mixture of UO2 and MOX Generating capacity - transition from LWRs to fast reactors - Scenario (b) • 75 GWe target installed capacity • FRs introduced at same rate as LWRs retire • LWRs fuelled only with UO2 Heat loading on a geological repository Retirement of SFR fleet when all fuel elements sent to repository intact • Blue curve - two successive 75 GWe LWR fleets • Red curve - a 75 GWe PWR fleet followed by a 75 GWe SFR fleet Advanced Fuel TRLs 4 3 Berylliadoped SiC-doped / Spark Plasma Sintering High Gadoliniadoped Light Water Reactor (LWR) High Pu content HTR Inert matrix Fuel (IMF) Dispersion Fuel Molten Salt Reactor (MSR) QUADRISO Concept Molten salts Minor Actinide (MA) containing LWR Very High Temperature Reactor (VHTR) Chromiadoped 2 1 Carbide Dual Cooled Fuel (DCF) Thoriumcontaining 5 Heavy Water Reactor (HWR) once through cycle Nitride HTR Coated Particle Annular pellets in nonVVERs High Temperature Reactor (HTR) Prismatic / Pebble Bed Sodium ExWeapons Fast Reactor Pu Niobiadoped Advanced Metal 6 Chromia & Aluminadoped Advanced MOX 9 7 National Lab Standard Fuel 10 8 University Standard UO2 and MOX Advanced UO2 Industry TRL Thorium recycle U3Si U3Si2 Zirconium hydridebased Approximate Increasing Fuel Design Ambition • The maturity of fuel cycle technologies has been established to provide basis for re-engagement with the international community Recycle Objectives Raise the technical maturity of aqueous and non-aqueous recycling technologies. Scope • Experimental testing of NNL’s modified version of the GANEX process. • Compare performance against the “Costripping” process developed under the EU ACSEPT project. • Assessment of non-aqueous processing technologies. • HLW and ILW processing technology for fast reactor recycle. Reactors Scope • Consider range of Gen-IV systems. • Conduct work in International Gen-IV programme areas; •Materials, Analytical Methods •Safety, System Integration •Fuel, Fuel Cycle • Review the basis for the selection of the priority systems for the UK • Investigate the potential for SMRs to offer benefits to the UK. 28 Generic Feasibility Assessment (GFA) • Generic Feasibility Assessment –seeks to answer the question “What are the attributes of a nuclear energy system which would justify investment in its future development with view to deployment in the UK?” • In the UK context, safety environmental and proliferation/security are all covered by well-developed regulatory regimes –reactor system deployment is not about “how safe, secure, and environmentally benign” a system is – but how much time and effort must be expended to allow the system to conform with regulation. • This leads to a process with five High Level Discriminators Key questions 1. How much time and effort will be required to achieve regulatory approvals to deploy this reactor system? 2. Is it likely that the reactor system is capable of being economically competitive with the reference (once-through LWR) system? 3. Is there a credible path between state R&D investment now and private reactor system deployment then? 4. If this system was deployed . . . . . ? (covers fuel supply, waste disposal and reactor/fuel cycle siting issues) 5. Can the system meet market demands This gives a process which can be represented as . . . Process Could it meet market demands? 5. Challenges for meeting market demands High Level Discriminators and Strategic Attributes High Level Discriminator 1 Regulatory Challenges and Timescales 2 Competitiveness 3 Viable Deployment 4 Development Route and Timescale 5 Meets Market Requirements Metrics Strategic Attribute a. Safety Licenseability b. Environmental Authorisation c. PRPP Acceptability a. Economic Competitiveness a. Fuel Security b. Waste Storage and Disposal c. Siting a. Access to International Programmes 1 2 3 4 5 6 7 8 10 1 4 9 2 6 3 0 b. Time and cost to Deployment 9 3 10 11 12 0 1 2 c. Enable UK Supply Chain a. Flexibility b. Process Heat Strategic Attributes Versus Once-through LWR Reference System Pro and cons of Thorium fuel cycle Cons Pros • Thorium more abundant than uranium & combined with a breeding cycle is potentially a major energy resource • Low inventories of transuranics and low radiotoxicity after 500 years’ cooling • Almost zero inventory of weapons usable plutonium • ThO2 potentially more stable matrix for geological disposal than UO2 • Th-232 needs to be converted to U-233 using neutrons from another source • The THOREX process demonstrated at small scale will require R&D to develop it to commercial readiness • U-233 recycle is complicated by presence of ppm quantities of U-232 • U-233 is weapons useable material with a low fissile mass and low spontaneous neutron source Need work to compare systems on like for like basis UK Nuclear Industry Strategy Ambitious Strategy Long-term partnership between Government, industry and research community. Building a Future: Innovation and R&D 1. Fission-related research programme whose scale is consistent with the UK’s nuclear aspirations (fuel, reactors, fuel cycles …). 2. World-leading facilities supporting national and international R&D 3. International research programmes with UK as a partner. “The beginning of a new approach and a new commitment. The Government will contribute funding for research and development, innovation, skills.” Nuclear Facilities EU Projects & NNL (Framework 7) The Future • UK Government has clear intent nuclear energy key part of energy mix in 2050. May involve a significant expansion of nuclear power to as much as 75 GWe beyond 2050. A significant national R&D programme would be required to underpin future energy decisions. • Requirement for R&D to underpin gaps associated with higher energy scenarios • Opportunity for the UK to collaborate and be key part of international programmes • Programme priorities being developed by Nuclear Innovation and Research Advisory Board (NIRAB) for consideration by Government 38 UK Nuclear R&D Roadmap Pathways Advanced Systems National R&D Programme • Focussed on high level of nuclear deployment • Closed fuel cycle bounding case Reactors • Strategic assessments covering fuel, reactors and overall system • Initial work to prioritise options • Future collaborations important Fuel SF / WM Strategic assessment IAEA classification of nuclear energy scenario sustainability • Level 1. Safe, secure, economical and publicly acceptable nuclear power with security of supply • Level 2. Safe disposal of all nuclear wastes in a complete once-through fuel cycle with thermal reactors and with retrievable spent nuclear fuel disposal. • Level 3. Initiate recycling of used nuclear fuel to reduce wastes – includes once-through breed and burn option • Level 4. Guarantee nuclear fuel resources for at least the next 1000 years via complete recycle of used fuel with breeding of fissile material • Level 5. Reduce radiotoxicity of all wastes below natural uranium level -closed fuel cycle recycling all actinides and only disposing fission products IAEA classification of nuclear energy scenario sustainability • Level 1. Safe, secure, economical and publicly acceptable nuclear power with security of supply • Level 2. Safe disposal of all nuclear wastes in a complete once-through fuel cycle with thermal reactors and with retrievable spent nuclear fuel disposal. • Level 3. Initiate recycling of used nuclear fuel to reduce wastes – includes once-through breed and burn option • Level 4. Guarantee nuclear fuel resources for at least the next 1000 years via complete recycle of used fuel with breeding of fissile material • Level 5. Reduce radiotoxicity of all wastes below natural uranium level -closed fuel cycle recycling all actinides and only disposing fission products What will influences fuel cycle options? • Balance of number of parameters including: Economics Proliferation • Economics • • • • • • • Proliferation Technology viability and readiness level Fuel supply Use of nuclear energy Spent fuel storage Geological disposal – heat loading, size of repository Sustainability – resource utilisation Fuel Cycle Assessment resources sustainability •Worldwide growth of nuclear will impact on UK •Higher levels of nuclear energy closed cycle more favourable Summary • UK has a long history of nuclear and associated R&D • Nuclear a key part of energy mix in the future – significant deployment may be required • UK Nuclear Industry Strategy has range of scenarios which include closed and open fuel cycles • Initial UK National R&D programmes covering strategic assessments, fuel technology, reprocessing and reactors • Development of case for future programmes ongoing Acknowledgements
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