1. 1 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Outlook on Gen IV Nuclear Systems and related Materials R&D Challenges - Goals for innovative reactor systems - Requirements for structural materials: generic and specific - Synergies, crosscutting R&D areas and modelling - Significance of international collaboration Frank Carré and Pascal Yvon CEA – Nuclear Energy Division franck.carre@cea.fr

2. 2 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Sustainable Nuclear Energy Technology Platform (SNE-TP) SNE-TP Objectives & Organization Kick-off meeting : September 21, 2007

3. 3 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 New goals for sustainable nuclear energy New goals for sustainable nuclear energy Continuous progress: Economically competitive Safe and reliable Members of the Generation IV International Forum USA Argentina Brazil Canada France Japan South Africa UnitedKingdom South Korea Switzerland EU EU Systems marketable from 2040 onwards True potential for new Applications: Applications: Hydrogen, Syn-fuel, Desalinated water, Process heat Internationally shared R&D Break-throughs: Natural resources conservation Waste minimisation Proliferation resistance Generation IV Nuclear SystemsChina Russia A closed fuel cycle

4. 4 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Generation IV Forum: selection of six nuclear systems Sodium Fast Reactor Lead Fast Reactor Molten Salt Reactor Gas Fast Reactor Supercritical Water-cooled Reactor Very High Temperature Reactor (12-20y) R&D (~1 B) before a 1 st prototype or techno demo

5. 5 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Fast Reactors & recycling for Sustainable Nuclear Power RT U dep FP U Pu MA RT U dep MA U Pu FP RT U dep FP MA U Pu Homogeneous Recycling Heterogeneous Recycling U & Pu Recycling Natural resources conservation Waste minimisation Proliferation resistance (intl standards) Type of nuclear materials Detection, technical difficulty, cost, time… Strategies for a flexible management of actinides in Gen IV fast neutron systems. Implementation depending on international standards and national optimization criteria (economics & waste).

6. 6 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Technical challenges & Leading physical phenomena 60-year lifetime Fast neutron damage (fuel and core materials) Effect of irradiation on microstructure, phase instability, precipitation Swelling growth, hardening, embrittlement Effect on tensile properties (yield strength, UTS, elongation…) Irradiation creep and creep rupture properties Hydrogen and helium embrittlement High temperature resistance (SFR > 550°C, V/HTR > 850-950°C) Effect on tensile properties (yield strength, UTS, elongation…) High temperature embrittlement Effect on creep rupture properties Creep fatigue interaction Fracture toughness Corrosion resistance (primary coolant, power conversion, H 2 production) Corrosion and stress-corrosion cracking (IGSCC, IASCC, hydrogen cracking & chemical compatibility…) Requirements for materials in future nuclear systems (1/2)

7. 7 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Additional requirements Material availability and cost Fabricability, joining technology In service inspection Non destructive examination techniques Safety approach and licensing Codes and design methods R&D effort needed to establish or complement mechanical design rules and standards Decommissioning and waste management Requirements for materials in future nuclear systems (2/2)

8. 8 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Structural materials for Innovative Reactor Systems SFRGFRLFRVHTRSCWRMSRFusion Coolant T (°C) Liquid Na few bars He, 70 bars 480-850 Lead alloys 550-800 He, 70 bars 600-1000 Water 280-550 24 MPa Molten salt 500-720 He, 80 b 300- 480 Pb- 17Li 480- 700 Core Structures Wrapper F/M steels Cladding AFMA F/M ODS Fuel & core structures SiCf-SiC composite Target, Window Cladding F/M steels ODS Core Graphite Control rods C/C SiC/SiC Cladding & core structures Ni based Alloys & F/M steels Core structure Graphite Hastelloy First wall Blanket F/M steels ODS SiC f -SiC Temp. °C 390-700600-1200350-480600-1600350-620700-800500-625 Dose Cladding 200 dpa 60/90 dpa Cladding ~100 dpa ADS/Target ~100 dpa 7/25 dpa ~ 100 dpa + 10 ppmHe/dpa + 45 ppmH/dpa Other components IHX or turbine Ni alloys IHX or turbine Ni alloys

9. 9 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 A new generation of sodium cooled Fast Reactors Reduced investment cost Simplified design, system innovations (Pool/Loop design, ISIR – SC CO 2 PCS) Towards more passive safety features + Better manag t of severe accidents Integral recycling of actinides Remote fabrication of TRU fuel SFR Steering Committee U.S.A. Japan France South Korea Euratom countries 2009: Feasibility – 2015: Performance 2020+ : Demo SFR (FR, US, JP…) Sodium Fast Reactor (SFR) 2007 + Russia China

10. 10 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 SFR Primary system New 9-12%Cr F/M steel vs Advanced Austenitic Good physical and thermal properties, dilatation, low cost Better creep resistance (T91, T92 (Fe-9Cr-xW-V-N…)) Compactness, mass reduction of components DBTT but Improved toughness Weldability (%Cr dependent) Good compatibility with sodium impurities (C, O, N) (Demonstrated in Phénix 2 ry system & Steam generator + 150 000 h Irradiation experiments of T91 & ODS (SuperNova)) Compact component and system designs (piping, IHX…) Potential margin for temperature increase (< 600°C) (especially if using a gas turbine power conversion system) Allowable departure from the negligible creep regime? New materials for sodium fast reactors (1/2)

11. 11 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 J.L. Séran, A. Alamo, A. Maillard, H. Touron, J.C. Brachet, P. Dubuisson, O. Rabouille J. Nucl. Mater. 212-215 (1994) 588-593. Great stability of fracture properties 9% Cr Martensitic steels Sodium Fast Reactor structural materials: F/M Steels

12. 12 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Advanced fuel cladding 316 Ti 15-15 Ti F/M ODS Reduced swelling with neutron fluence EM10 & 15-15 Ti 100 dpa @ 400-700°C T92/HC & ODS 200 dpa @ 480 – 750/800°C Weldability & joining techniques Good compatibility with sodium impurities (C, O, N) Increased fuel burnup 200 GWd/t & 200 dpa Increased safety with low sodium content in the core & low sodium void effect Better prevention of severe accidents New materials for sodium fast reactors (2/2) Research in progress on hardening of F/M steels with micro/nano structures (dispersion / precipitates) 2nd generation ODS F/M steels with carbo/nitride precipitates

13. 13 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Sodium Fast Reactor cladding material Swelling of advanced austenitic steels and ferrito-martensitic steels used as fuel cladding in Phenix

14. 14 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Safety enhancement of Fast Reactor core Low reactivity sodium void effect high BU core Large diameter fuel pin with thin spacer wire ODS cladding for low swelling (Experiments in Phenix (Supernova, Matrix1&2) + in Joyo) COEXCOCA MOX fuel fabrica- tion from co-precipita- ted UPu solution from the COEX process To be first tested in Phenix (Copix expt) Various recycling modes of minor actinides in Fast Reactors: Homogeneous (~2% MA): GACID Heterogeneous in blanket (10-20% MA): Curios, Amboine2-Joyo expts

15. 15 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 A novel type of Gas-cooled Fast Reactor: an alternative to the Sodium Fast Reactor, and a sustainable version of the VHTR Robust heat resisting fuel (<1600°C) 1200 MWe – T He ~ 850 °C - Cogeneration of electricity, H 2, synfuel, process heat Safe management of cooling accidents Potential for integral recycling of Actinides GFR Steering Committee Japan Switzerland France Euratom countries Generation IV Gas Fast Reactor (GFR) 2012 : Feasibility ~2020 : ETDR (EU ?) 2020: Performance 2030+: GFR Prototype GCFR 5-6 EU PCRD System Arrangement GFR signed Nov. 30 Nov.,2006 Project Arrangements Fuel & Design-Safety-Integration in 2007 U.S.A.

16. 16 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Gas Fast Reactor fuel designs 0 2550 75100 %vol. of actinides compound in the volume dedicated to fuel High density compartmented platelet Advanced particles HTRs Cladded pellets

17. 17 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Candidate ceramics materials for the GFR fuel Ceramics for Gas Fast Reactor Usual low toughness of ceramics Composite CERMET TiC (HIP) 10 µm trans-granulaire inter-granulaire Mixed CER & MET matrices Fibre strenthened Multi-layer materials Interfaces Manufacturing and testing monolithic and composite ceramics (C/C, SiC/SiC) Characterization and optimization Objectives: Increase ceramics ductility and toughness Investigation and modelling of phenomena Matrix & concept in Phénix

18. 18 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 43.0mm 5.0mm Wall thickness: 1.0mm Goal: 3m (length) x 10mm (inner diameter) x 1mm (wall thickness) 2D SiC/SiC by NITE Process for GFR Fuel Pin or Plate Fuel Pin Fuel Plate Nite Process Kyoto University

19. 19 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 A few specific R&D areas on ceramics for GFR fuels Possible applications as matrix or interphase in SiC/SiCf composite… Nano-laminate structureTi 3 SiC 2 Ti, C, Si MAX Phases Special properties Damage tolerant Low density, machinable High thermal and electrical conductivities Methods used to obtain large- scale bulk Ti 3 SiC 2 CVD, Arc melting, HIP, HP, SHS High energy ball milling & reactive sintering to obtain bulk Ti 3 SiC 2 with very fine grain Synthesis of TiC from nano-powder HIP without grain growth Stable under irradiation (electrons & ions)

20. 20 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 A nuclear system dedicated to the production of high temperature process heat for the industry and hydrogen 600 MWth - T He >1000 °C Thermal neutrons Block or pebble core concept Passive safety features I-S Cycle or HT Electrolysis for H 2 VHTR Steering Committee U.S.A. Japan Switzerland France South Korea South Africa Euratom Generation IV Very High Temperature Reactor (V/HTR) 2009: Feasibility – 2015: Performance ~ 2020: PBMR, NGNP & Other Near Term Projects 2007 + China

21. 21 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 VHTR vs PWR pressure vessel manufacturing techniques PWR Vessel VHTR Vessel Normal/off-normal service temperatures and vessel size dominate materials requirements Up to <450/550°C at 5-9 MPa Up to 1 x 10 19 n/cm 2 fluence Very large vessel sizes require scale- up of ring forging & on-site joining technologies Irradiation resistance to be demonstrated for licensing 9Cr1Mo alloy for pressure vessel of gas cooled reactors

22. 22 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 VHTR core material: Graphite & Composites Graphite (PCEA (UCAR), NBG 17 (SGL)…) Characterization: chemical, structural, thermal & mechanical properties (20-1000°C), corrosion tests (air; water, O 2, CO 2 …) Irradiation tests (T ~1050°C, 1-6 dpa G) Optimization for waste minimization ( 14 C) Technical file for codification of design standards C/C & SiCf/SiC composites Manufacturing: 2D & 3D woven fibres (C,Hi-Nicalon S), interphases, CVI or pitch densification, anti-oxidation coating (Si, B)…) Characterization: chemical, structural, thermal & mechanical properties (20-1000°C), corrosion (air,water, O 2, CO 2 ), irradiation tests Technical file for codification of design standards 500 mm 60 mm 100 mm

23. 23 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Three IHX technologies identified: Plate-machined Heat Exchanger (Fig. 1) Plate-Fin Heat Exchanger (Fig. 2) Tubular concept Key issues to be addressed: Materials development - Haynes 230 - Inconel 617 - Ni-ODS Intermediate Heat Exchanger design - Compactness - High thermomechanical resistance - High thermal efficiency (95%) - Low pressure drop, no leakage Properties required at 850°C - 950°C - Tensile, long term creep (Fig. 3), fatigue,creep-fatigue - Corrosion resistance - Fabrication and joining techniques VHTR Intermediate Heat Exchanger Creep strength: Haynes 230 and Inconel 617 FIG. 1 FIG. 2 FIG. 3

24. 24 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Generation IV Systems related R&D Needs VHTRSFR GFRSCWRLFRMSR Metals Mechanics, Corrosion F/M steels ODS Ni-alloys F/M steels ODS Austenitic Steels F/M steels ODS Ni-Alloys Clad & structures Ni-alloys Radiolysis Hastelloys Ceramics & Composites Graphite C/C, SiC f /SiC SiC, TiC Ceramics Component mock-ups IHX & HX, RPV (9 Cr) Control rods HX, SGIHX & HX RPV & DHR IHX & HX Pump 1ry system Technology He test benches & Loops MW ISIRHe test benches & Loops MW Heat transfer SCW Loops Water chemistry Corrosion Purity control MSalt Techno Loops Mechanical Design Rules HT Design Codification ASME RCCM-R HT Design Codification Structural materials & Components

25. 25 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Typical Tokamak Configuration T-Breeding Blanket: Dual Coolant Lithium Lead Design and technology of T- breeding blanket

26. 26 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Materials science and new materials are key for optimizing 2 nd & 3 rd generation LWRs as well as to meet 4 th nuclear systems objectives : > 2040: Fast reactors with a closed fuel cycle (SFR, GFR, LFR) ~2025-30: High temperature reactors (V/HTR) for process heat (H 2 …) More prospective nuclear systems (SCWR, MSR) Incremental progress and breakthroughs are sought on a wide span of structural materials for fuel claddings, core structures, reactor cooling systems & components (RPV, IHX, SG…), power conversion systems (electricity, H 2 …): Metals: Austenitic steels, 9-12Cr F/M steels, ODS, Ni-alloys… Ceramics & composites: Graphite, C/C, SiC f/ SiC & (TiC, ZrC, Ti 3 SiC 2 …) Fabrication, characterization, manufacturing, ND examination Mechanical design codification: ASME, RCCM-R + extensions / harmonization needed for fast neutrons, high temperature, lifetime… Synergies between materials for 4 th generation nuclear systems as well as with materials for Fusion (1st wall & blanket) Ni-alloys, 9-12%Cr F/M steels, ODS, Ceramics (SiC…) Innovative Reactor Systems & Requirements for Structural Materials Summary (1/2)

27. 27 Nuclear Energy Division Materials for Generation IV Nuclear Reactors Cargese, Sept. 24 – Oct. 6, 2007 Increased role of Materials science (analytical research and modelling) for a more predictive R&D towards aimed materials properties Metals Ceramics Fuels International cooperation to increase and share R&D work and achieve breakthroughs for 21st century nuclear power systems Federate national programs into a consistent international roadmap Enhancing R&D and technology demonstrations (Gen IV, EU FP7…) Databases of materials properties Multi-scale modelling of materials & fuels Synergies between Fission and Fusion materials Progressing towards harmonized international standards Mechanical design rules and standards, Codification Safety, non-proliferation, physical protection… Innovative Reactor Systems & Requirements for Structural Materials Summary (2/2)