Economics of Spent Nuclear Fuel Management An International Overview

Transcription

1 Economics of Spent Nuclear Fuel Management An International Overview Hans Forsström Senior Adviser, SKB International AB CEG Workshop, Aronsborg, Sweden, 7 October 2011

2 Spent fuel - a resource or waste? One definition of waste Waste is a resource at the wrong place and the wrong time Spent nuclear fuel (power reactor) % uranium (enrichment %) 1 % plutonium (60 70 % fissilie) 3 4 % fission products and minor actinides

3 Nuclear Fuel Cycle Natural Uranium Disposal

4 Management of spent nuclear fuel - options 1. Direct disposal the fuel is stored for at least 40 years and then disposed in a geologic repository 2. Recycling the fuel is reprocessed, U och Pu recycled as fuel in LWR or fast reactors high active and long lived waste disposed in a geologic repository 3. Wait and see delay the decision Interim storage an important component. Probably for several decades. Proven technology

5 Reprocessing of spent nuclear fuel Spent fuel Chemical and mechanical treatment U Pu Waste HLW ILW

6 Spent fuel management steps Direct disposal Buffer storage Interim storage Encapsulation Deep geological disposal Some transport steps Exists Not yet implemented Reprocessing and recycling Buffer storage Reprocessing MOX and REPU recycling (Spent MOX management?) Interim storage of HLW and ILW (Encapsulation?) Deep geological disposal Many transport steps

7 Geological repositories Geological disposal will be needed irrespective of strategy chosen International agreement on the availability of technical solutions and the capacity to show that they are safe (IAEA, NEA) No repository for spent fuel or high active waste yet built Most countries with NPPs have a programme for repositories. Same principles applied in all programmes (passive safety, several barriers) even if different geological media Positive developments in Finland, France and Sweden. Delays or changed plans in many other countries Swedish application filed March 2011

8 SKB s method for disposal of spent nuclear fuel - KBS-3 Fuel pellet of uranium dioxide Spent nuclear fuel Copper canister with cast-iron insert Cladding tube BWR fuel assemblies Bedrock Bentonite clay Primary safety function: Total containment Secondary safety function: Retardation Final repository for spent nuclear fuel

9 Objectives of reprocessing Improved use of the uranium natural resource by recycling of uranium and plutonium as new fuel (especially in fast reactors, about 60 times more energy) Reduce the long term toxicity and the heat of the waste. Could simplify the repository. A geological repository, however, still needed Remove material that will require safeguards of the repository (but increases the amount of sensitive material moving around) Manage fuel that otherwise is not stable, e.g. Magnox fuel, metal fuel Economy

10 Relative toxicity of spent fuel

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12 Views on reprocessing have changed over time -1970s Reprocessing and recycling in fast reactors 80 90s Many countries changed strategy to direct disposal Reasons: reduced plans for nuclear power, cheap uranium, problems with fast reactor developments, environmental issues around reprocessing, proliferation concerns s Renewed interest in reprocessing and fast reactors Reasons: renewed interest in nuclear power (economy, energy independence and environmental issues) concerns about uranium resources, sustainability of nuclear power, waste discussions... 10s??? Depends on future developments of nuclear power and fast reactors, and political decisions

13 Spent fuel management strategies (today) Reprocessing France, Netherlands, Japan (?), India, China, Russia, UK(?) Direct disposal Sweden, Finland, Germany, Spain, Canada, USA(?), Korea(?) Wait and see store. Hope for international solutions Most countries A geological repository will be needed irrespective of strategy chosen Wise strategy for the world: Develop both options (reprocessing and fast reactors, and disposal) in parallel.

14 Problems for development of fast reactors Technical issues Costs Reliability Cheap uranium Political resistance Good experience with reactors of generation 2 and 3 (> reactor years) Availability of fast reactors at the time of replacement of present reactors

15 Spent fuel as a resource for fast reactors Fast reactors need LWR plutonium (and depleted uranium) for the first few cycles For later cycles self-generated plutonium and depleted uranium will be used No substantial fast reactor deployment before 2050 More than tonnes spent LWR fuel by 2050, containing much more plutonium than what is needed to start fast reactors Reprocessing of some fuel needed to start fast reactors. How much depends on rate of introduction of FR A plan for disposal of spent fuel is also needed, unless economical to recycle as MOX in LWRs

16 Economy of the back-end Back-end costs are difficult to estimate due to new types of facilities and long time schedules Uncertainties in cost comparisons: Costs of reprocessing/recycling, encapsulation and disposal Costs of uranium Value of plutonium (LWR/fast reactors) Long term economic development Inflation and interest rates Economy depends strongly on national policy and availability of facilities

17 Example: Swedish cost estimates Direct disposal Assumptions: Interim storage, encapsulation and disposal of ton U. Generation Disposal Cost level of Cost components: Transports 600 M (50 k /ton U) Interim storage 2400 M (200 k /ton U) Encapsulation 1600 M (130 k /ton U) Disposal 3400 M (280 k /ton U) R&D 1400 M (120 k /ton U) Total cost: 9400 M for ton U or 780 k /ton U Corresponds to less than 0.1 Eurocent/kWh

18 Cost comparisons recycling direct disposal Some studies The Economics of the Nuclear Fuel Cycle, OECD/NEA, 1994 Economic Forecast Study of the Nuclear Power Option, Charpin study, France, 2000 The Economics of Reprocessing vs. Direct Disposal of Spent Nuclear Fuel, Harvard University, USA, 2003 Economic Assessment of Used Nuclear Fuel Management in the United States, The Boston Consulting Group, USA, 2006 The Future of the Nuclear Fuel Cycle, MIT, USA, 2011 IAEA TM on Costs of Spent Fuel Management Options, March 2011 NEA Expert Group on the back end costs to be convened October 2011

19 Conclusions of cost comparisons All comparisons are made for direct disposal vs recycling as MOX-fuel in LWRs. Studies on fast reactor use are premature All studies show direct disposal as the lowest cost option (40 80 % of closed cycle) Results are strongly dependent on uranium price, reprocessing costs and management of spent MOX fuel, as well as on interest rates Example: A reprocessing cost of 1000 US$/kgU requires a uranium cost of 370 US$/kgU (today ~125) for break even (Bunn, 2005) The back-end costs are a small part of the total electricity generating costs for nuclear power (< 5 %) Economics might not be decisive for choice of spent fuel management

20 Conclusions Back end costs are large, but a small part of electricity costs Both options, reprocessing/recycling plus disposal and direct disposal, are technically feasible and being developed The choice of spent fuel management option will depend on: National policy and energy strategy Belief in fast reactor development Belief in uranium availability and price Availability of national facilities Economy The choice differs between countries and has changed over time (E.g. Germany and the US)

21 Conclusions (continued) Fast reactors will be needed if nuclear shall remain a long term energy option will require plutonium from LWR fuel No substantial fast reactor deployment expected before 2050 Recycling as MOX in LWRs is not economical (unless sunk costs) and the reduction in uranium use is limited (about 25 %) Surplus of spent fuel can be expected. Some fuel will need disposal. How much depends on fast reactor development rate Important to develop in the world both direct disposal and recycling in fast reactors Important to ensure that funding is available whatever option is chosen