EU DEMO Conceptual Design Work Status

Transcription

1 EU DEMO Conceptual Design Work Status Gianfranco Federici Power Plant Physics and Technology

2 Outline Background Organisation of design and R&D activities Definition of plant requirements See talk M. Shannon given by C. Waldon Lesson learned from GEN-IV DEMO Stakeholder meetings Concept design approach Physics basis and design drivers Preliminary design choices under evaluation DEMO Design and physics integration challenges Key interdependencies and trade-off studies Results of selected studies no results of R&D reported in this talk Conclusions G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 2

3 Background Outstanding Technical Challenges with Gaps beyond ITER For any further fusion step, safety, breeding, power exhaust, RH, component lifetime and plant availability, are important design driver and CANNOT be compromised Tritium breeding blanket - most important/novel parts of DEMO - TBR >1 marginally achievable but with thin PFCs/few penetrations - Feasibility concerns/ performance uncertainties with all concepts - Selection now is premature L. Boccaccini (KIT)/ Y. Poitevin (F4E) Remote Maintenance - Strong impact on IVC design - Significant differences with ITER RM approach for blanket - RH schemes affects plant design and layout - Large size Hot Cell required - Service Joining Technology R&D is needed. M. Mittwollen (KIT) Exhaust - Peak heat fluxes near technological limits (5-10 MW/m2) - ITER solution may be marginal for DEMO - Advanced divertor solutions may be needed but integration is very challenging - Also exploring DN as a serious option R. Albanese (CREATE), H. Reimerdes (CRPP), C. Linsmeier (FZJ), I. Mazul (Efremov) Structural and HHF Materials - Embrittlement of EUROFER and Cu-alloys at low temp. and loss of mechanical strength at ~ high temp. are important design issues. H. Tanigawa (JAEA) - Development needs of design rules for structural materials J. Aktaa (KIT) - Progressive blanket operation strategy (1st blanket 20 dpa; 2nd blanket 50 dpa). - Technical down selection of options for DT n-sources has been made in Europe S. O hira (JAEA) G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 3

4 Background EU Fusion Roadmap to Fusion Electricity An ambitious roadmap implemented by a Consortium of Fusion Labs (EUROfusion) Distribution of resources based on priorities and on the quality of deliverables. Support to facilities based on the joint exploitation. Focus around 8 Missions Plasma Operation Heat Exhaust Neutron resistant Materials Tritium-self sufficiency Safety Integrated DEMO Design Competitive Cost of Electricity Stellarator IPH DEMO IPH Emphasis on: Central role of ITER See talk M. Gasparotto assu ptio i oad ap ITE co es i operatio i early 2020 s DEMO as a single step to commercial fusion power plants DEMO construction starting early in the 2030s G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 4

5 Organisation of Design and R&D Activities DEMO Stakeholder Group Bureau General Assembly (GA ) STAC PPPT Expert Group Programme Management Unit IPH/JET PPPT Breeding Blanket PMU & PMI Activities Project coord. and control Physics & Design Integration Programme Manager Magnets Divertor Admin H&CD Systems Communications Tritium Fuelling & Vacuum PHTS & BoP Contain Structures Safety Materials Remote Maintenance Diagnostics and Control A project-oriented structure set-up Distributed Project Teams aiming at the design and R&D of components Project Control and Design Integration Unit Each WP has a Project Board G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 5

6 Organisation of Design and R&D Activities G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 6

7 Concept Design Approach Conceptual Design Pre-Conceptual Design Phase Preparatory Phase Time Plan and Scope Documents Scope EFDA PPPT EUROFusion PPPT EUROFusion PPPT Identify DEMO pre-requisites Identify main design and technical challenges (physics/ technology) Preliminary assessment technical solutions Prioritization of R&D to be included in the Roadmap Engage DEMO Stakeholders and define DEMO HLRs Study machine configurations and key parameters. Optimisation / trade-off studies SE approach to solve design integration issues Resolve Plant System Architecture with variants Address key technology R&D needs (mainly PoP, fabrication feasibility, performance tests) Develop and qualify materials and fill database gaps Select design options from leading technologies Select coolants Select divertor layout concept Finalise Plant System Architecture / down-select variants in: BoP, BB, H&CD e.t.c. Safety Analysis report EU Roadmap to fusion electricity Work-Plan , AWPs List of Grant deliverables Scope, Schedule and Resourcenew loaded Projects Project Management Plans PRDs, SRDs, OCD, PBS, Interface Process Trade-Off studies States & Modes Diagrams Functional Flow Block Diagrams (FFBD) Design Description Docs 3D CAD model of Plant Cost Analysis new Preliminary Safety Analysis Report Plant RAMI Report Prel. Manufacturing Plans Preliminary Assembly & Maintenance Plan Programme Management Plan (for EDA phase) G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 7

8 Concept Design Approach Basic Process Flow for Conceptual Design Work In 2014 a traceable design process with SE approach was started to explore available design/ operation space for DEMO to understand implications on technology requirements Main challenges Integration of design drivers across different projects. Design dealing with uncertainties (physics and technology) High degree of system integration/ complexity/ system Interdependencies Trade-off studies/ sensitivity studies with multi-criteria optimisations, including engineering assessments. Typical example is the selection of coolants. Technical issues include: thermal power conversion efficiency; breeder tritium extraction; pumping power requirements; T permeation/ coolant T purification & control; power handling requirements; chemical reactivity, coolant leakage; inner blanket thickness (n-shielding and streaming); design integration and feasibility of BoP. achievable tritium breeding ratio; G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 8

9 Concept Design Approach DEMO physics basis / uncertainties G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 9

10 Concept Design Approach DEMO physics basis / uncertainties Pel tburn G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 10

11 Concept Design Approach Main size drivers: Divertor and H-mode Objective: Protect divertor and operate in H-mode Power transported by electrons and ions across separatrix: Psep=Pα+Padd-Prad,core Physics/ Material limit condition for divertor Psep/ 20MW/m Boundary condition to access and operate in H-mode with good confinement: Psep flh PLH Results of PROCESS Analysis: For low Psep/PLH major radius is determined by the divertor protection constraint (Psep/R) From a certain Psep/PLH onwards this in combination with Psep/R is driving the major radius Main problem: Extreme uncertainty on PLH is passed on to the major radius G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 11

12 Concept Design Approach Preliminary DEMO design features 2000 MWth~500 Mwe Pulses > 2 hrs SN water cooled divertor PFC armour: W LTSC magnets Nb3Sn (grading) Bmax conductor ~12 T (depends on A) RAFM (EUROFER) as blanket structure VV made of AISI 316 Blanket vertical RH / divertor cassettes Lifetime: starter blanket: 20 dpa (200 appm He); 2nd blanket 50 dpa; divertor: 5 dpa (Cu) Open Choices: Operating scenario Breeding blanket design concept selection Primary Blanket Coolant/ BoP Protection strategy first wall (e.g., limiters) Advanced divertor configurations Number of coils G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 12

13 Concept Design Approach Sensitivity study: Aspect Ratio ITER DEMO1 (A=2.6) DEMO (A=3.1) DEMO Courtesy R. Kemp (CCFE) ITER DEMO1 DEMO1 DEMO2 (2015) (2015) (2015) A=2.6 A= Volume (m3) Pfus (MW) tburn (hrs) ss IP (MW) BT (T) βn,total βα/βth 8% 14% 14% 17% βf/βth 12% 16% 16% 25% Te0 (kev) ne0 (1020 m-3) Prad,core (MW) % 66% 67% 81% s 133 Prad,core/Pheat PCD (MW) Z (m) A (m2) R (m) G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 13

14 DEMO design and physics integration challenges Investigate impact of increasing plasma elongation, k, constrained by vertical stability, through optimising for example PF coils layouts and current distributions (see next slide). Investigate divertor configurations with a lower X-point height and larger flux expansion as they may provide a more favourable compromise between pumping and power exhaust for DEMO than the vertical target divertor chosen for ITER. Improve power handling capabilities near the upper secondary null point in a SN DEMO and assess impact of design and maintainability of the solutions proposed. Explore a Double Null (DN) Configuration: higher plasma performance with improved vertical position control, and an accompanying reduced machine size. The impact on blanket vertical RH should be investigated together with impact on T- breeding. Investigate divertor strike point sweeping, including technology issues such as thermal fatigue of the HHFCs, AC losses of the adjacent PF coils, etc. Investigate magnetic field ripple: trade-off between RH access, coil size, and NBI access. Estimate dwell time and evaluate impact of trade-offs on CS, BoP, pumping, etc. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 14

15 Design and physics integration challenges Optimisation of baseline divertor configuration Plasma VS is an important design driver. A variation of Beta or li (e.g., due to loss of NBI, RF, or impurity influx) or loss of H-mode would lead to a V moment that in the case of an asymmetric configuration (SN) would challenge control requirements. Options 1) SN deep divertor (ITER) 2) Shallow SN divertor 3) Shallow DN divertor Advantages Compatible with BB vertical RH Compatible with BB vert. RH improved T breeding higher plasma performance with improved vertical position control Shortcomings Elongation constrained by VS Marginal T breeding Limited power handling near upper secondary null Elong. constrained by VS Problems of heat loads near upper secondary null? T breeding to be assessed compatibility with BB vertical maintenance scheme questionable. Requires study. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 15

16 Design and physics integration challenges Results of Selected Studies Sensitivity to plasma elongation Optimisation of the Upper Null Divertor Geometry optimisation studies Neutronic / TBR sensitivity analysis divertor size Strike point sweeping parametric scan (not shown here) G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 16

17 Design and physics integration challenges 10 22,5 9, ,5 d = 0.5, q95 = 3.0 8,5 d = 0.75, q95 = Ip (MA) R0 (m) Increasing k,d (~20%) has large impact on machine layout Single null baseline ,5 1,6 1,8 2 Elongation (k) 2,2 1, d = 0.5, q95 = d = 0.75, q95 = Single null baseline 1 0 1,6 1,8 2 Elongation (k) 2,2 f_bs 5 Bt (T) d = 0.75, q95 = ,5 Single null baseline 7,5 d = 0.5, q95 = ,8 2 Elongation (k) 2,2 0,5 0,45 0,4 0,35 0,3 0,25 0,2 0,15 0,1 0,05 0 d = 0.5, q95 = 3.0 d = 0.75, q95 = 3.0 Single null baseline 1,6 1,8 2 Elongation (k) 2,2 G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 17

18 Design and physics integration challenges Results of selected analysis: Optimisation of upper null Upper null position optimization x x upper null isoflux upper null plasma boundary FW-isoflux upper null Upper null closer Upper null farther to plasma from plasma x x x intersection Inward-outward upper null position movement, while preserving plasma shape Intersection of upper-null isoflux curve with first wall larger with null outward: less peaked heat loads expected (TBC) 0 = 0 Portion intersecting upper FW Ongoing evaluation of q portion incident on upper wall Courtesy R. Ambrosino (CREATE)) G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 18

19 Results of selected studies Optimisation of divertor geometry I estigatio o shallo divertor: Comparison previous (red) & new (dashed blue) geometry with increased B.B. area (dashed green) Investigation on moving strikepoint closer to x-point: Wetted area increases linearly with flux expansion fexp,t Connection length Toroidal incidence angle Exlcude divertor dome as the necessity is not obvious > Effect of the dome will be investigated with SOLPS. Divertor area decreased and breeding area increased in favour of meeting the DEMO However: Higher flux fexp,t also reduces the grazing angles g between unique tritium breeding requirement. the field lines and the target plate, which cannot be arbitrarily small G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 19

20 Results of selected studies TBR sensitivity analysis Neutron wall load: Potential Tritium breeding contributions: Total TBR: P. Pereslavtsev, U. Fischer (KIT) Significant improvement of TBR due to reduction of divertor size. DN configuration with two small divertors seems possible regarding TBR. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 20

21 Conclusions The demonstration of electricity production ~2050 in a DEMO Fusion Power Plant is a priority for the EU fusion program ITER is the key facility in this strategy and the DEMO design/r&d will benefit largely from the experience gained with ITER construction See talk M. Gasparotto There are outstanding gaps requiring a vigorous integrated design and technology R&D (e.g., breeding blanket, divertor, Remote Handling, materials) DEMO reactor design suffers from high degree of system integration/ complexity/ system Interdependencies. Trade-off studies/ sensitivity studies with multi-criteria optimisations, including engineering assessments In 2014 a traceable design process with SE approach was started to explore DEMO design/ operation space to understand implications on technology requirements Main difficulty with designing is dealing with uncertainty. One of the greatest difficulties is the definition of a sufficiently flexible design / analysis framework and approach to start a coherent iterative design process and technology development in the projects. We are also keeping some flexibility in exploring options in parallel. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 21

22 Highlights of Achievements WPBB: 4 designs studied: HCPB. HCLL, WCLL, DCLL. Key technology R&D work in progress. WPBOP: modelling work is underway for systems using water and He as coolant. Feasibility issues are being identified and proposals for solutions examined. WPDIV: several target candidate concepts developed and fabrication trials performed. Design integration of several divertor layout configurations are analysed. WPHCD: systems studies are exploring options for NBs, EC and IC Heating. System efficiencies and feasible launch positions for these technologies are investigated. WPMAG Basic coil layouts defined. Samples of optimised design of LTSCs with improved performance were manufactured and will be tested in HTSC samples fabricated /tested. WPMAT: two 80 kg batches of low temp. optimised EUROFER material were produced, + nine 80 kg of high temp optimised material. 23 lab-scale batches ( g each) of ODS steel were produced. Development of Codes and Design Criteria has been started. WPRM: consolidate the requirements for RH systems. Blanket extraction and installation processes have been developed. WPSAE: S&E philosophies and approaches have been prepared, together with the high-level principles, requirements. Initial safety studies are in progress. WPTFV: define system block diagrams and requirements for Tritium, Fuelling and Vacuum systems. Direct Pumping concept further developed. WPDC/ WPENS: Being implemented. Definition of activities and establish working teams. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 22

23 Acknowledgements The PPPT PMU Team: M. Shannon, C. Morlock, R. Wenninger, F. Maviglia, C. Bachmann, M. Coleman, B. Meszaros, T. Franke, S. Ciattaglia, E. Diegele, F. Cismondi, H. Hurzlmeyer. PPPT Project leaders: L. Boccaccini (KIT), M. Rieth (KIT), C. Day (KIT), W. Biel (FZJ), J-H. You (IPP), N. Taylor (CCFE), T. Loving (CCFE), L. Zani (CEA), A. Ibarra (CIEMAT), M.Q. Tran (CRPP), M. Grattarola (ENEA). PPPT Work Programme Collaborators on this talk (in particular): R. Kemp (CCFE), G. Giruzzi (CEA), M. Gilbert (CCFE), U. Fischer (KIT), P. Pereslavtsev (KIT), R. Albanese (ENEA/Create), R. Ambrosino (ENEA/Create) PPPT Expert Group: H. Zohm, W. Morris, B. Saoutic, C. Waldon, P. Sonato, T. Mull, K. Hesch, S. Chiocchio, P. Barabaschi. G. Federici & PPPT Team 3rd IAEA DEMO Progr. Workshop HEFEI 11-14/05/2015 Page 23