1 G. Federici, DPG, Berlin 12 - March 2012 Fusion Energy Achievements and Challenges Fusion Energy Achievements and Challenges Gianfranco Federici Head of EFDA PPPT Department March 26, 2012 Deutsche Physikalische Gesellschaft e.V. Berlin, Germany

2 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

3 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

4 G. Federici, DPG, Berlin 12 - March 2012 Pros Abundant fuel (D + Li) No greenhouse gases Safe – no chain reaction, ~1 sec worth of fuel in device at any one time Minimal “afterheat”, no nuclear meltdown Residual radioactivity small; products immobile and short-lived Minimal proliferation risks No seasonal, diurnal or regional variation Cons We don’t know how to do it yet (it is a really hard problem) Capital costs will be high, unit size large Fusion energy can also be used to H, and for desalination Incentives for Developing Fusion

5 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

6 G. Federici, DPG, Berlin 12 - March 2012 The Next Frontier  ITER ITER, to be built and operated as an international project, will push research efforts into this new regime of burning plasma science Understanding the behavior of burning plasmas is a necessary step towards the demonstration of fusion as a source of energy. Q=10 “Burning” plasma = dominantly self-heated by fusion products (e.g., alpha particles) from thermonuclear reactions in the plasma. D + T → n + α MeV

7 G. Federici, DPG, Berlin 12 - March September 2011 December 2011 Polidal Field Coil Building (257m x 49m x 18m h)

8 G. Federici, DPG, Berlin 12 - March 2012 February 2012 Complete deployment of sismic pads More fotos and video on: //

9 G. Federici, DPG, Berlin 12 - March 2012 JET and ASDEX-Up Mitigation of ITER operation risks Top Risks Disruption mitigation has limited effectiveness H-mode power threshold at high end of uncertainty range ELM mitigation schemes has limited effectiveness Vertical stability control limited by excessive noise (or failure of in-vessel coils) Lack of reliable high power heating during non- active phase of programme Acceptable “divertor” performance with W. High levels of T retention require more frequent T removal procedures than foreseen Incompatibility of core plasma requirements for Q=10 with radiative divertor operation Inability to achieve densities near Greenwald value required for Q=10 Source: Lorne Horton (EFDA-Culham)

10 G. Federici, DPG, Berlin 12 - March JT-60SA Explore advanced modes of operation JT-60SA JT-60U ~4m ~2.5m EAST (A=4.25,1 MA) 1.7m 1.1m SST-1 (A=5.5, 0.22 MA) 3.0m JT-60SA(A≥2.5,Ip=5.5 MA) 6.2m ITER (A=3.1,15 MA) KSTAR (A=3.6, 2 MA) 1.8m JT60-U: Copper Coils (1600 T), Ip=4MA, Vp=80m 3 JT60-SA: SC Coils (400 T), Ip=5.5MA, Vp=135m 3 Source: P. Barabaschi, F4E

11 G. Federici, DPG, Berlin 12 - March 2012 Wendelstein 7-X During first campaign: 8MW ECRH and 7 MW NBI Diagnostics set probably sufficient to conduct the initial program Test divertor unit to study operation limits and divertor physics W7-X: Assembly according to plan W7-X: Major Milestones No delays expected: finished mid 2014 Completion: Steady state divertor Increase in heating power, ICRH Diagnostic completion

12 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

13 G. Federici, DPG, Berlin 12 - March 2012 Roadmap(s) to Fusion Energy Different countries face different energy needs and these drive different strategies for fusion development. The greater the perceived urgency for fusion energy the greater the willingness to take larger steps and larger risks. All ITER parties have a target to demonstrate fusion-driven electricity production by ~2050. The roadmaps of China and India, that foresee the largest increase in energy demand in the next decades, are the most ambitious, in terms of both goals and timescale for next steps. –China is considering the construction of a further DT machine. Engineering Design Phase is expected in 2014 and first plasma in In Eu the Roadmap is being revisited. The plan is to launch a vigorous coordinated effort to prepare for a fusion Demonstration Reactor to be built by the beginning of 2030 (EFDA PPPT Dept. is the very first step in this direction).

14 G. Federici, DPG, Berlin 12 - March 2012 Define Next-Step (after ITER) Today, there is still a divergence of opinions on how to bridge the gap between ITER and the first FPP. EU (and JA): DEMO and IFMIF; US: CTF or a Pilot Plant and no dedicated materials test facility. R. Goldston (IAEA TM, June 2011) However, there are some common outstanding issues common to any next major facility after ITER, whether a CTF, a Pilot Plant, a DEMO, or else: – Power exhaust handling (divertor) – Reference plasma scenario  CD requirements, – Coolant for in-vessel components  breeding blanket concept – Maintenance scheme  plant architecture – Structural and PFC materials Only some of these issues can be solved in ITER.

15 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

16 G. Federici, DPG, Berlin 12 - March 2012 DEMO Technical Challenges with potentially large gaps beyond ITER ITER objectives and design are well established; - not yet the case for DEMO. TECHNOLOGY – PFC and Blanket technology including T self-sufficiency – H&CD Systems – Efficiency and Reliability – Reliability of Core Components & RH for high machine availability – Qualification of resilient structural materials – Safety and licensing PHYSICS – Operating scenario: Long pulse/ Steady- state/ High-Beta – High density operation – Power exhaust and divertor R&D strategy – Abnormal events avoidance/ mitigation – Plasma diagnostics and control

17 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges – Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

18 G. Federici, DPG, Berlin 12 - March 2012 Power density fusion reactors much smaller than fission reactors But peak-to-average heat flux at coolant surfaces much higher PWRBWRHTGRLMFBRFusion 3 MW/m 2 Equivalent core diameter (m) Core length (m) Aver. core power density (MW/m 3 ) Peak-to average heat flux at coolant interface Source table: Abdou (UCLA) Power Exhaust and Divertors Very High Heat Fluxes

19 G. Federici, DPG, Berlin 12 - March 2012 Divertor Techhnology 2000 cycles at 15 MW/m 2 on W. More recently 300 cycles at 20 MW/m 2 (ITER requirements) pulses at 0.5 MJ/m 2 to simulate ELM-like loads –Longitudinal macro-cracks appeared in all monoblocks. –some melting of W at monoblock edges But no degradation of their power handling capability Water-cooling ITER Technology, W and Cu-Cr-Zr 20 MW/m 2 possible 15 MW/m 2 reliable add neutrons < 10 MW/m 2 Source: Riccardi (F4E), Visca (ENEA) >1000 cycles at 10 MW/m 2.  Recently cycles at 12 MW/m 2  Thimble is still the most critical component.  Influence of irradiation is unknown Design integration and reliability still to be addressed He-cooling ITER Technology, W and Cu-Cr-Zr 12 MW/m 2 possible 10 MW/m 2 reliable add neutrons ~5 MW/m 2 - Helium-cooled modular divertor (HEMJ) Norajitra, KIT Source: Norajitra (KIT)

20 G. Federici, DPG, Berlin 12 - March 2012 Advanced Divertors magnetic shaping created by using only 2-3 existing magnetic coils. the peak heat load is reduced, because it flares the SOL at the divertor surface. Limited impact expected on the high performance and confinement. has been studied and achieved in TCV and more recently NSTX “Snowflake divertor” V. Soukhanovskii (LLNL) ‘Super-X’ is one concept where magnetic geometry could handle extremely high divertor loads SOL taken to large major radius natural flux expansion; SOL passes through low PF region connection length is increased further spread of power – volume to enable power radiation before striking target. Issue – in-vessel coil shielding

21 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust – Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

22 G. Federici, DPG, Berlin 12 - March 2012 Tritium Supply and Breeding Large consumption of tritium during fusion –55.8 kg/yr per 1000 MW of fusion power Production and cost –CANDU reactors: 27 kg over 40 years, $30M/kg currently –Other fission reactors: 2-3 kg/yr $84-130M/kg Tritium breeding for self-sufficiency –World supply of tritium is sufficient for 20 years of ITER operation (will need ~17.5 kg, leaving ~5 kg) – Verified tritium breeding technology, to be tested on ITER, will be required for DEMO and reactors. We focus on the D-T cycle (easiest): – D + T → n + α MeV Tritium does not exist in nature! o Decay half-life is 12.3 years o T must be generated inside the blanket The only possibility to breed tritium is through neutron interactio ns with Li that must be used in some forms

23 G. Federici, DPG, Berlin 12 - March 2012 Source L. Boccaccini (KIT) Helium at 8MPa Li cer. Be. CPS: Coolant Purification Sys. TES: Tritium Extraction System HCPB HCLL Principles of HCPB blanket concept: breeding and T extraction (shown as example) There are other alternative Blanket Design Concepts During ITER Research Programme, TBMs will be installed in ITER to investigate breeding. ITER has three ports for blanket testing and 2 TBMs can be installed in each port. Breeding Blankets

24 G. Federici, DPG, Berlin 12 - March 2012 Internal Components Reliability/ Maintainability Large Port Concept Vertical Port Concept MMS Concept Reliability represents a challenge to fusion, particularly for the core components. RH strongly impacts machine availability (MTTR, MTBF) and affects in depth the design of many components/interfaces. It is needed from the design outset. Proposed design solutions must be fully remotely maintainable. Significant amount of time consuming demonstration and R&D often requiring design iteration and changes before we start to build.

25 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) – Radiation resistant structural materials Summary

26 G. Federici, DPG, Berlin 12 - March 2012 Fusion Structural Materials Fusion reactors need high-temperature, radiation resistant materials In DEMO demanding operational requirements that are beyond today’s experience (including ITER and fission reactors), e.g., elevated operating temp., long periods of operation, higher irradiation damage and He accumulation, high reliability and availability, etc. In Fe for 1 MW/m 2 and 1 FPY – 10 dpa – 100 appm He – 450 appm H – He/dpa ~ 10 appm/dpa RAFM: currently EUROFER 9%Cr [1W 0.14Ta 0.2V] steels (reference for DEMO)

27 G. Federici, DPG, Berlin 12 - March 2012 The IFMIF Facility will allow qualifying materials under fusion spectrum EVEDA Phase in progress (as part of the BA with Japan Reduced-cost/ reduced performance options are being explored In DEMO for 1 MW/m 2 and 1 FPY – 10 dpa (in Fe) – 100 appm He – 450 appm H – He/dpa ~ 10 appm/dpa Lack-of irradiation facilities with adequate n-spectrum (14 MeV + He) Beam Spot (20x5cm 2 ) High Flux Low Flux Medium Flux Liquid Li Jet Deuteron Beam Deuteron beams: – 2 x 125 mA – E d = 40 MeV Neutron production: –  1.1  s -1 Test volumes: – high flux: 0.5 L > 20 dpa/fpy – medium flux: 6 L > 1 dpa/fpy, – low flux: ~8 L dpa/fpy Accelerator driven Li(d,n) source 2 x 125mA 40MeV deuteron beams Liquid Li target (~15m/s) subject to 10MW 1GW/m 2 Full range of PIE facilities Designed to reach ~150dpa within a few years of full power operation Source: U. Fischer

28 G. Federici, DPG, Berlin 12 - March 2012Outline Incentives for developing fusion The next frontier ITER and the role of other machines Roadmap to fusion energy DEMO Main Technical Challenges –Power exhaust –Power extraction and tritium breeding (blankets) –Radiation resistant structural materials Summary

29 G. Federici, DPG, Berlin 12 - March 2012Summary Fusion has a tremendous potential ITER must be a success and it will answer open physics questions related to burning plasmas There are still several challenges to be overcome for DEMO, especially for the core components (divertor, blanket) and materials. Demonstration of fusion electricity by 2050: challenging but possible In Europe the roadmap for the exploitation of fusion is being revisited. Expected a tighter coordinated effort with clearer focus and more technology orientation W7-X will demonstrate the quality expected from stellarator optimisation If we succeed, with fusion, we handover to future generations a clean, safe, sustainable power source.

30 G. Federici, DPG, Berlin 12 - March 2012 Thanks for your attention Born , married with two children (16 and 11) Degree in Nucleal Engineering, Polytechnic of Milan 1985 Ph.D. UCLA 1989 (Fusion Eng. and Applied Plasma Physics) Post-Doc Fellowship EU Commission, Fusion NET Team, ITER Team, : Divertor and plasma interfaces EFDA Garching, : Field Coordinator Vessel/ In-Vessel F4E Barcelona, 2008 –2010: Senior Advisor to Chief Engineer F4E Garching, 2011-today: Head of EFDA Power Plant Physics and Technology Dept. Who I am!