Nuclear technology options

Transcription

1 Nuclear technology options M.Salvatores Senior Scientific Advisor CEA, Nuclear Energy Division (France) and Idaho National Laboratory (USA) ATSE National Symposium 2013 Nuclear Energy for Australia? Thursday-Friday July 2013 Powerhouse Museum, Sydney

2 Outline Introduction: needs, objectives and issues Reactor options for development Strategies and perspectives: (1) The case of Europe Strategies and perspectives: (2) USA and the case for SMRs Strategies and perspectives : (3) More upbeat strategies. Fuel cycle and the role of FR Strategies and perspectives : (4) Advanced fuel cycles- the potential role of P&T from full FR deployment to phase-out Conclusions

3 Introduction: needs, objectives and issues The deployment of nuclear energy depends on a complex interplay of factors: Energy demand growth forecast; Natural resources: availability and conservation Waste management policy Infrastructures: new needs Emergency planning awareness, Human resources (education and training long term planning) Society requirements towards acceptability Etc. The analysis of these aspects help, in general, policy makers to define a medium and a long term national strategy for the energy mix From the technical point of view, if industry has a major role in the selection of candidate reactors, waste management and, in general, crucial fuel cycle issues imply a long term perspective that needs a holistic approach (typically a government task with the support of national research institutions)

4 Reactor options for development While countries representing more than 50% of the world's population are committed to building nuclear power plants, strategies and motivations in different countries have resulted in different industrial offers and projects: a) Gen-II/III reactors: large size LWRs and medium size reactors (LWR and HWR), b) Small Modular Reactors (SMR) c) Gen-IV Fast reactors Some revival of interest for HTRs (for specific applications) and some more exotic projects (e.g. Accelerator Driven Systems)

5 A typical large size GEN-III PWR: the EPR, 1600 MWe EPR Olkiluoto EPR: European Pressurized Reactor Flamanville-3 Double-wall containment with ventilation and filtration system EPR Core melt spreading area Containment heat removal system Inner refueling water storage tank Four-train redundancy for main safeguard Le projet systems EPR Construction of the second EPR unit at the Taishan (China) nuclear power plant has reached a major milestone with the dome of the reactor building being lowered into place

6 Some examples of Medium Size Reactors Gidropress AES MWe PWR: while Rosatom is currently constructing eight AES-2006 units in Russia, it also has orders to build 19 such reactors outside of Russia The Canadian Heavy water reactor AECL's ACR-1000 The Areva Atmea-1 reactor 1100 MWe PWR which combines technologies from Areva and MHI. Turkey stands to be possibly the first country to use the Atmea1. Four units could be deployed at Sinop in the early 2020s. The Westinghouse AP-1000 PWR: Concrete has been poured the first of two AP1000 units at the VC Summer plant in South Carolina. The milestone marks the official start of construction of the USA's first new reactor in 30 years. Remarkable deployment in China.

7 Strategies and perspectives: (1) The case of Europe In the EU, the SNETP (Sustainable Nuclear Energy Technology Platform), agreed by member countries, is structured around three main pillars: NUGENIA, to develop R&D supporting safe, reliable, and competitive GEN-II (present) and GEN- III nuclear systems. The Nuclear Cogeneration Industrial Initiative (NC2I) for the low-carbon cogeneration of process heat and electricity based on nuclear energy. The European Sustainable Nuclear Industrial Initiative (ESNII) promotes advanced Fast Reactors with the objective of resource preservation and minimization of the burden of radioactive waste.

8 At the national level in European Union, new projects, ongoing and foreseen (some examples): France and Finland: EPR under construction United Kingdom: has implemented a very thorough assessment process for new reactor designs and their siting. The first of some 19 GWe of newgeneration plants could be on line about The government consider the possibility to have 16 GWe of new nuclear capacity on line by o Decision is expected on the reactor type: EPR ABWR: a Gen-III reactor design, 1600 MWe, offered in slightly different versions by GE Hitachi, Hitachi-GE and Toshiba (four ABWR units are already in operation in Japan, and the design is also licensed in the USA and in Taiwan, where two are under construction). Some potential newcomers e.g. Poland However: Phase-out in Germany. Similar decisions in Belgium and Switzerland

9 Sustainability and waste management are a major issue in Europe. The ESNII initiative foresees the construction of fast reactors for multiple missions: Pu management, resources optimization, waste management (to reduce burden on geological disposal) In France

10 Strategies and perspectives: (2) USA and the case for SMRs At less than 300 MWe in capacity, SMRs are much smaller than typical nuclear reactors and are considered an ideal choice for (remote) areas which can't support a larger reactor. Moreover, the US-DoE notes that an SMR's compact scalable design offers a host of potential safety, construction and economic benefits. Reduced financial risk for entry into nuclear power generation Better fit to electrical grid infrastructure in many places Factory manufacturing: easier to ship components, domestic supply chain Potentially adaptable to non-electricity applications Potential safety advantages (passive safety designs) Scalable incremental capacity addition Most electrical generation plants are < 500MWe Reduced land and water usage (increased site options) Adapt Gen-III+ and Gen-IV technology

11 Some examples of SMR The mpower is a B&W 180 MWe integral pressurized water reactor concept with potential benefits in terms of plant safety, security and economics. It will be fully bunkered in an underground containment building. A consortium of mpower B&W and Tennessee Valley Authority (TVA) was selected to receive DoE funding ($79 million allocated for the first year) to commercially demonstrate the mpower SMR by The Russian SVBR-100 is a multi-function small modular fast reactor cooled by lead-bismuth eutectic. The unit is an integral design: steam generators and reactor core both sit in the same pool at temperatures in the range C. The SVBR concept has already run on seven Alfa-class submarines According to AKME-Engineering, the pilot unit is scheduled to begin operating in 2017 and commercial production of the reactor would begin in 2019.

12 Some examples of SMR The Westinghouse SMR is a 225 MWe integrated PWR in which all primary components are located inside the reactor pressure vessel. It is designed to be completely fabricated in the factory and is scaled to be shippable by rail, with passive safety systems and components drawing on the full-sized AP1000 reactor design. Westinghouse and China's State Nuclear Power Technology Corporation (SNPTC) will work together to develop a small modular reactor design licensable in both the USA and China. In France, Areva and the DCNR (the French Navy construction firm) are ready to go for the Flex Blue program, i.e. underwater SMRs based on French nuclear submarine technology, which are easy to handle and protected from storms and tsunamis.

13 Strategies and perspectives : (3) More upbeat strategies. (U) Fuel cycle and role of FR A significant increase in nuclear energy demand is predicted in the next decades: e.g. by 2034 power demand in China will have grown by more than the current demand of Japan and the USA put together. Consequently some important issues about uranium resources and availability of infrastructures are likely to result, within a frame of enhanced safety requirements and waste minimization. The deployment of fast reactors with high breeding performance is a rather mature option to address these issues. However, the increase of both fuel fabrication and of reprocessing capacities will be very significant and a large increase in capacity of these facilities will be required in fast growing regions. More in general, future fuel cycles characteristics, feasibility and acceptability will be crucial for any development of nuclear energy.

14 Open cycle: spent fuel sent to the waste, limited use of resources. Pu build-up in the spent fuel can become a liability: 1GWe UOX-PWR produces 0.25 t Pu/y, then a 10GWe fleet operating for 40y produces ~100t Pu Moreover radiotoxicity and decay heat in the storage/repository have impact on the design and licensing Potential long term impact on resources availability Close fuel cycle: spent fuel reprocessing and FR deployment (or, more generally, deployment of Partitioning and Transmutation, P&T, technologies) can offer a flexible option: Breed new fuel (Conversion Ratio, i.e. ratio of Transuranics TRU production/tru destruction, CR>1 or Total Breeding Gain TBG>>0) Burn (TRU or Minor Actinides, MA), i.e. CR<1 (or TBG<<0). Breed (e.g. Pu) and burn (MA) CR~1: Self-sustaining cycles. Fuel cycle options Wide coolant and fuel type choice according to the objective, e.g. short Doubling Time DT i.e. the time required for a breeder reactor to produce enough material to fuel a second reactor: Na cooling and dense (e.g. metal) fuels Wide range of MA content and different Pu vectors or TRU compositions can be handled, according to the objective.

15 Examples of FR (besides Superphenix and Phenix): ongoing constructions, success stories (more or less) Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, India: construction initiated in October 2004 The Russian sodium-cooled fast reactor BN-800: construction initiated in July 2006 China Experimental Fast Reactor (CEFR), first grid connection on 21 July 2011 The Japanese loop-type sodiumcooled fast reactor Monju. Will it restart? The Russian sodium-cooled fast reactor BN-600 In operation since 1980

16 An example of fuel cycle issues: U resources availability To investigate development scenarios and their impact, one can make use of a «homogeneous» world representation or of a regional («heterogeneous») representation, dividing the world in regions such as: As for nuclear energy growth, current hypotheses (e.g. IPCC, IIASA) indicate a potential worldwide increase from ~3000TWhe in 2010 to ~24,000 TWhe in 2200

17 The figure below shows the variation of natural uranium consumption rate with time for three fuel cycle options: (1) PWRs open fuel cycle and (2) the PWRs transition to FRs in all world regions. (3) the PWRs transition to FR in all regions except ALM where the nuclear energy needs would be met only by PWRs operating in an open cycle: ( ) Fuel Cycle option 1: only PWRs with open cycle; ( ) option 2: ASIA and ALM (breeders) + OECD90 and REF (isogenerators) ( ) option 3: ASIA (breeders) + OECD90 + REF (isogenerator) + ALM (only PWRs).

18 Strategies and perspectives : (4)Advanced fuel cycles- the potential role of P&T from full FR deployment to phase-out Scenario a): Sustainable development of nuclear energy for electricity production and waste minimization (full FR deployment) Homogenous TRU recycling in a critical fast reactor. The fuels are standard mixed oxide or dense fuels (metal, nitride, carbide), with MA content of a few percent.

19 Scenario b): Reduction (elimination) of TRU inventory as unloaded from LWRs (e.g. In case of phase-out) - Decontamination factor - Secondary waste - Criticality FP, Losses at reprocessing Pu+MA Reprocessing Repository Multi-recycling Dedicated Transmuter FFH, ADS, FR FP, Losses at reprocessing UOX, MOX PWR Reprocessing - Decontamination factor - Secondary waste - Criticality ADS with conversion ratio CR=0 or critical burner FR with CR ~ 0.5 or less, can be envisaged Fuel Fabrication Last Transmuter - Neutron Source - Decay Heat - Process control (Am Volatility, MA miscibility, etc.) Pu+MA U

20 Regional scenarios can be also envisaged to assess the possibility of combining, from a technical point of view, diverging nuclear policy approaches and common interests for the management of the SNF in a geographical region (example: EU). Approach A: Group of countries in a stagnant or phase-out scenario for nuclear energy with the objective to optimize the management of SNF (i.e. all TRU) Shared facilities Approach B: Group of countries with a continuation of nuclear energy utilization and the objective to optimize the use of resources (Pu) for the future deployment of Gen- IV reactors and optimize waste management (i.e. MA)

21 There are potential benefits of P&T for all these fuel cycles: Reduction of the potential source of radiotoxicity in a deep geological storage ( intrusion scenario impact mitigation) Reduction of the heat load and high level waste volume: larger amount of wastes can be stored in the same repository If TRU are not separated (e.g. in the homogeneous recycling in a Fast Neutron Reactor), improved proliferation resistance could be expected Comments: Converging results of impact studies in the USA, in Japan and in Europe A comparative analysis has been completed within the OECD-NEA Discussions on these benefits still going on with Industry and Geological Disposal Community

22 Potential benefits of P&T for these fuel cycles P&T P&T MA and FP A. Porracchia, CEA-France

23 Conclusions The next forty-fifty years will be dominated by the deployment of a substantial number of standard (Gen-II and/or Gen-III) LWR (HWR), large or medium size plants: available resources do allow it. They will operate for 60 years. SMRs, if deployed, will probably answer to «niche» needs (?); potential interest for Australia? Fuel cycle will be a growing and most challenging issue: Timely strategic decision should be envisaged: often decisions about the fuel cycle when implemented are difficult to revert Waste management: early assessments for public acceptance and policy decisions. Pu build-up issue to be accounted for Potential tensions on U resources later in time. Thorium alternative for the very long term? Need to show that nuclear choice is not «irreversible» and potential future changes in the energy mix can be managed Regional issues might have an increased relevance In this context, in parallel with Gen-III power plant deployment, it could be useful to plan FR R&D, possibly in an international context (Gen-IV, bilateral?), as early as possible.

24 Back-up: the Th cycle

25 Advantages of Th fuel cycle

26 Disadvantages of Th fuel cycle

27 Possible implementations of Th fuel cycle A possible option: Th-MSR (fuel fabrication is avoided, on-line reprocessing etc). However, several technological challenges (materials, safety strategy etc). A long term alternative? Due to rather inferior neutron economy of the Th cycle, the sub-critical, source driven systems option has been often discussed (Energy Amplifier etc) PuO2/ThO2 fuel in a PWR: a possible fuel for PWR MOX fuel disposition (good stability of final waste form). Alternative to burner FR (?). Also a critical burner FR with similar fuel has been investigated. Economic interest not yet demonstrated and can depend on context Most studies were driven by the radiotoxicity issue: besides long/short term benefits analysis, radiotoxicity is no more considered a priority metric for waste management options comparison Proliferation resistance could be an issue