Equipment during fabrication and service: Safety, Competitiveness, Innovation. New requirements and R&D needs for future nuclear reactors

Transcription

1 ESOPE 2007 European Symposium on Pressure Equipment Paris October Equipment during fabrication and service: Safety, Competitiveness, Innovation New requirements and R&D needs for future nuclear reactors F. Carré, C. Renault CEA, Nuclear Energy Division, France ESOPE 2007 CR Paris, October 9-11,

2 Generations of Nuclear Power Systems st generation DISMANTLING UNGG Magnox 2 nd generation REP 900 REP 1300 N4 (1450) OPERATION 3 rd generation OPTIMIZATION EPR (1600) GT-MHR, PBMR 4 th generation DESIGN and R&D Prototypes ESOPE 2007 CR Paris, October 9-11,

3 The 3 rd Generation : EPR EPR: European Pressurized Reactor A mature concept, based on experience feed-back of current PWRs Site EPR Flamanville Double enceinte de confinement avec ventilation et filtration Aire d'étalement du coeur fondu Système d'évacuation de la chaleur de l'enceinte EPR Olkiluoto Réservoir d'eau interne à l'enceinte Significant improvements in safety New requirements? RCC-M? ASME? (safety by design principle) Redondance 4 trains des principaux systèmes de sauvegarde ESOPE 2007 CR Paris, October 9-11,

4 Forum Generation IV : towards sustainable nuclear energy New requirements for sustainable nuclear energy Continuous progress: Economically competitive Safe and reliable Break-throughs: Waste minimisation Natural resources conservation Proliferation resistance Systems marketable from 2040 onwards True potential for new applications: Hydrogen, syn-fuel, desalinated water, process heat Internationally shared R&D Russia France United Kingdom Canada Members USA of the Generation IV International Brazil Forum Argentina South Africa Euratom Japan China South Korea Switzerland ESOPE 2007 CR Paris, October 9-11,

5 Generation IV Forum: selection of six nuclear systems Top-ranking and outsiders? Sodium Fast Reactor closed cycle closed cycle Lead Fast Reactor closed cycle Gas Fast Reactor open cycle Very High Temperature Reactor open/closed cycle Supercritical Water Reactor closed cycle Molten Salt Reactor The recognition of the major potential of fast neutron systems with closed cycle for breeding (fissil regeneration) and waste minimization (minor actinide burning) ESOPE 2007 CR Paris, October 9-11,

6 R&D Strategy of France for Future Nuclear Systems Approved by the Ministries of Research and Industry on March 17, 2005 Sodium Fast Reactor 1 - Development of Fast Reactors with a closed fuel cycle: Sodium Fast Reactor (SFR) Gas Fast Reactor (GFR) New processes for spent fuel treatment and recycling Gas Fast reactor 2 - Nuclear hydrogen production and high temperature process heat supply to the industry: Very High Temperature Reactor (VHTR) Water splitting processes for hydrogen, synthesis of hydrocarbon fuels, process heat 3 - Innovations for LWRs (Fuel, Systems ) Very High Temperature Reactor ESOPE 2007 CR Paris, October 9-11,

7 Two options in the fast neutron strategy The reference option (significant past experience and innovation objectives) Reduction of investment cost SFR Safety level comparable to 3 rd generation LWRs Improved operation techniques (ISIR, ) GFR An alternative track based on: Benefits from helium as a coolant Robust fuel (including severe accident conditions) Potential for high temperature applications A common concern : the potential for integral recycling of actinides Milestone 2020: prototype ( MWe) Milestone 2020: experimental reactor (ETDR, 50 MWt) ESOPE 2007 CR Paris, October 9-11,

8 Schedule of R&D on Future Nuclear Energy Systems 1st phase of studies Confirmation of technical options Selection of design features Techno R&D Preliminary & detailed design studies, SAR, & Construction La Hague plant La Hague plants Head-end 1st extraction cycle 2 nd U 2 nd Pu cycle cycle MA (U)PuO 2 Micro-pilot plant for MA fuel MA separation MA fuel fabrication with remote handling 10 s kg/yr MOX fabrication workshop Reference technologies selected in 2012 Pu 20 % 5-10 ton/yr ESOPE 2007 CR Paris, October 9-11,

9 Some stop and go in the development of reactor concepts LMFR in France Rapsodie start-up in 1967, Phenix in 1973 Superphenix final shut-down in 1998 Phenix HTR in Europe and USA THTR (Germany) and Fort St Vrain (USA) shut-down in 1989 HTTR (Japan) operated since 1998, HTR-10 (China) since 2000 Fort St Vrain MSRE MSR in USA MSRE operated from 1965 to 1969 MSBR project stopped in 1976 ESOPE 2007 CR Paris, October 9-11,

10 The need to implement additional knowledge The R&D on innovative nuclear systems should incorporate new requirements and areas, beyond traditional nuclear engineering, for example: Design of innovative components (IHX, ) New options for materials (eg ceramics, composites) to be operated at very high temperature, fast neutron spectrum, etc. Additional data on well known coolants (sodium, lead, helium) or more innovative coolants (liquid salts, supercritical fluids), including chemical compatibility New applications of nuclear energy (hydrogen production, desalination, etc.) Innovative processes for fuel recycling (MA incorporation, grouped actinides separation) ESOPE 2007 CR Paris, October 9-11,

11 Requirements for future nuclear systems (1/2) Technical challenges to materials and components 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 > 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 ) ESOPE 2007 CR Paris, October 9-11,

12 Requirements for future nuclear systems (2/2) Design, operation and safety 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 ESOPE 2007 CR Paris, October 9-11,

13 Structural materials for Innovative Reactor Systems SFR GFR LFR VHTR SCWR MSR Fusion Coolant T ( C) Liquid Na few bars He, 70 bars Lead alloys He, 70 bars Water MPa Molten salt He, 80 b Pb- 17Li 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 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 ESOPE 2007 CR Paris, October 9-11,

14 A new generation of Sodium Fast Reactors SFR PWR Competitive economics relative to Gen III LWRs Reduction of investment cost (design simplification, increased compactness) Optimization of operation in order to alleviate possible constraints associated with a metallic coolant (in-service inspection, maintenance, repair) SG-HX unit, 600MW Na/Pb-Bi/H 2 0 Φ~4m X h~11m Enhanced safety Decrease or suppression of risks of sodium/water interaction (optimisation of the Power Conversion System, for example use of fluids alternative to water: nitrogen/helium, supercritical CO 2 ) Practical exclusion of large energy release in case of severe accidents (reactivity effects, reliability of passive systems) ESOPE 2007 CR Paris, October 9-11,

15 A new generation of Sodium Fast Reactors Large pool-type concept (1500 MWe) Design optimisations core vessel diameter reduced by ~ 30% compared to EFR (17 m) 3 compact intermediate loops Simple rotating plug Decay hear removal heat exchanger Compact intermediate heat exchanger EMP Degasser Heat exchanger Loop type primary system Modular concept (500 MWe) with gas conversion system (no intermediate circuit) Transportable core vessel (~ 7 m) Nitrogen energy conversion system (2 loops), sodium/nitrogen heat exchanger Core outlet temperature > 600 C ESOPE 2007 CR Paris, October 9-11,

16 New materials for Sodium Fast Reactors Swelling of advanced austenitic steels and ferritomartensitic steels used as fuel cladding in Phenix (%) Average 316 Ti Average 15/15Ti Best lot of 15/15Ti Embrittlement limit Ferritic-martensitic (F/M) steels, ODS included dose (dpa) Advanced fuel cladding: 316 Ti Ti F/M ODS ESOPE 2007 CR Paris, October 9-11,

17 Sodium Fast Reactors: In-Service Inspection and Repair ULTRASONIC CONTROL OF CORE SUPPORT WELDINGS IN PHENIX ESOPE 2007 CR Paris, October 9-11,

18 ETDR and GFR pre-conceptual designs Robust decay heat removal strategy (passive after 24hrs) maximum fuel temperature ( C) GFR 2400 MWt, back-up pressure 10 bars time (s) Innovative fuel GFR 2400 MWt reference concept ETDR (50 MWt) ESOPE 2007 CR Paris, October 9-11,

19 GFR innovative fuel concept Axial gap: closed at beginning of life (BOL) for homogeneous thermal behaviour Radial gap: retention of fission gases and helium, closure at end of life (EOL) Composite SiC-SiC fiber Fission gases Actinide compound: UPuC or UPuN (56% vol of the fuel) Diffusion barrier Refractory metal: W, Mo, Cr, Brevet CEA ESOPE 2007 CR Paris, October 9-11,

20 GFR innovative fuel concept: fabrication 2D SiC/SiC by NITE process for GFR fuel pin or plate Goal: 3m (length) x 10mm (inner diameter) x 1mm (wall thickness) Nite Process Kyoto University Fuel Pin Fuel Plate 5.0mm 43.0mm Wall thickness: 1.0mm ESOPE 2007 CR Paris, October 9-11,

21 HTR/VHTR : Potential applications of process heat for the industry ANTARES PROJECT Primary Loop 600 MWt Rx core IHX Gas Cycle High Temp. Process Heat ~550 to 800C Potential Applications - Hydrogen-SI -Hydrogen-SMR -Coal Liquefaction Circulator S.G. Steam Cycle Gas turbine He He or N 2 /He Water/steam Med. Temp. Process Heat ~250 to 550C -Coal Gasification -Advanced Electrolytic Hydrogen -Oil Shale - Tar Sands -Biomass Condenser Generator Low Temp. Process Heat ~30 to 250C - District Heating - Desalination ANTARES concept (600 MWt, 850 C) The interest to VHTR is essentially driven by its potential for a large scope of process heat applications ESOPE 2007 CR Paris, October 9-11,

22 VHTR vs PWR pressure vessel manufacturing techniques 9Cr1Mo alloy for pressure vessel of gas cooled reactors Normal/off-normal service temperatures and vessel size dominate materials requirements Up to < 450/550 C at 5-9 MPa Up to 1 x n/cm 2 fluence Very large vessel sizes require scale-up of ring forging & on-site joining technologies VHTR vessel PWR vessel Irradiation resistance to be demonstrated for licensing ESOPE 2007 CR Paris, October 9-11,

23 R&D on high temperature gas-gas IHX and materials Different plate concepts appear as good candidate technologies Plate assembly 1000 C 350 C 300 C 10 0 Header H230 Diffusion bonding Printed Circuit Heat Exchanger (PCHE) (temperature < 550 C with inox) Thickness (µm) very intensive Inconel 617 moderate Haynes 230 Hastelloy X [log(po2)= -23,7 Pco= 50µbar] few few 6025 PM1000 Carbide less zone Internal oxidation Loose oxide Oxyde scale Alloys composition effect on corrosion behavior CORALLINE tests in impure helium with low PO 2 (950 C, 800 hr) Plate Stamped Heat Exchanger (PSHE) (temperature 850 C) ESOPE 2007 CR Paris, October 9-11,

24 Fusion : In-Vessel Components and Breeding blankets blanket manifolds shield divertor plates b c a d e h f g TF coils upper ports blanket modules central ports vacuum vessel lower ports Severe working conditions and requirements High surface heat flux 0.5 (FW) 15 MW/m 2 (div.) High neutron wall loading (FW) ~2.5 MW/m 2, ~150 dpa (Fe) Operation under void (plasma), complex torus geometry low coolant leakages High magnetic field (~7 Tesla) (high MHD effects) Moreover: Remote access in high radiation field (maintenance, inspection, repairs, diagnostics, ) (Source CEA, JF. Salavy, Nov 2006) ESOPE 2007 CR Paris, October 9-11,

25 Analysis of component integrity and design rules Some reference design rules for mechanical analysis ASME III RCC-M (AFCEN) NFEN ASME VIII RCC-MR (AFCEN) NFEN ASME B31 RCC-MX (CEA) CODAP CODETI code nucléaire code industriel récipients code industriel tuyauteries ESOPE 2007 CR Paris, October 9-11,

26 Analysis of component integrity and design rules A new edition of RCC-MR? November 2006 : AFCEN decision to issue a new edition of the RCC-MR design rules Updating of RCC-MR is underway (RCC-MR 2007) with: account for new European standards and directives (nuclear pressure equipment ESPN) specific requirements for application to ITER VV (fabrication, weldings, controls, ) some modifications for Generation IV reactors (high temperature operation) Issue of RCC-MR 4 th edition October 2007 Next edition in 2011? RCC-M : Règles de Conception et de Construction des Matériels RCC-MR : Règles de Conception et de Construction des Matériels pour les réacteurs Rapides ESOPE 2007 CR Paris, October 9-11,

27 Analysis of component integrity and design rules Specific ITER concerns regarding design rules Choice of a nuclear code (RCC, ASME III) or not (CODAP, ASME VIII)? ITER is not a pressure equipment (Vacuum Vessel, adequacy of ASME III and RCC-M? Thin structures (RCC-MR, Code Case N47), but small temperature effect on structures Some structures are submitted to irradiation (RCC-MX?) RCC-MR, developed for Sodium Cooled Fast Reactors in Europe (EFR, Phenix lifetime extension), has been selected for the design and construction of ITER Vacuum Vessel (high temperature and low pressure operation, box structure, 316 L(N) steel) EFR core support with strongback resting on the main vessel bottom ITER Vacuum Vessel box structure ESOPE 2007 CR Paris, October 9-11,