The DTT project Il progetto DTT Raffaele Albanese

The DTT project – Il progetto DTT Raffaele Albanese* and the DTT executive board (R. Albanese, F. Crisanti, P. Martin, A. Pizzuto) on behalf of the DTT team * Consorzio CREATE / Univ. Napoli Federico II ILO Industrial Opportunities Days, Napoli, 6 June 2019 1

OUTLINE • • • Introduction Why DTT? What is DTT? DTT layout DTT components DTT management 2

Introduction: Fusion vs fission E = m c 2 Advantages of fusion: • Abundance of fuel • Small amount of fuel needed for reactor conditions • No pollution • No greenhouse effect • No direct nuclear waste • No risk of severe accidents 3

Introduction: Fusion on Earth Ignition condition: n • T • τ ≥ 5× 1021 m-3 s Ke. V In the 90 s the JET Tokamak achieved: n • T • τ = 0. 9× 1021 m-3 s Ke. V Q= Pfus/Pin=(16 MW/25 MW)=0. 6 Gravitational Inertial confinement At the very high (100 million °C) temperatures needed for fusion the gas is fully ionized and is a very good conductor: plasma (4 th state of the matter). Magnetic confineme nt 4

Why DTT? DTT aims • JET: In the 90’s the JET tokamak achieved 16 MW of nuclear fusion power from D-T reactions, with 25 MW of input power, i. e. , with a fusion gain Q>0. 6. • ITER: To improve Q, the current strategy aims to increase magnetic field, plasma current and machine dimensions. This is the mission of ITER, an international tokamak conceived in the 80’s under construction at Cadarache, France. The first plasma is expected in 2025. In the next decades ITER should produce Pfus=500 MW from Pin=50 MW with Q 10. • DTT: The DTT is a facility conceived to develop and test controllable power exhaust solutions in an integrated environment and DEMO relevant conditions. • DEMO: According to the EU Fusion Roadmap, DEMO is expected to be the first fusion plant to provide electricity to the grid in the second half of this century. 5

Why DTT? Fusion Roadmap 6

Why DTT? EU Fusion Roadmap & DTT added value The European fusion community identified eight important missions on the path towards fusion electricity: 1) Plasma regime of operation 2) Heat-exhaust system 3) Neutron resistant materials …. divertor plates www. euro-fusion. org/fileadmin/user_upload/EUROfusion/Documents/2018_Top. Level_Roadmap. pdf • DTT is a new device, where the modern technologies can be adopted and further developed; the presently operating tokamaks were designed about 40 years ago • By 2025 most of the plasma experiments built in the ‘ 80 will likely shut down and the experimental plasma physics activities are carried out on a few machines • DTT construction will keep industry linked to fusion field • DTT would be the ideal training device to grow the new ITER & DEMO generations 7

Why DTT? EU Fusion Roadmap & DTT added value • Plasma facing components to cope with very large power fluxes – 10 -20 MWm-2 achieved • Geometry + plasma physics Innovative materials (Liquid Metal PFCs) • Remove plasma energy before it reaches PFCs radiation Strike point sweeping (courtesy of JET) 8

What is DTT? DTT = Divertor Tokamak Test facility is: • • • An Italian fully superconducting tokamak project Under final design To be built in ENEA Frascati Research Centre Within the European roadmap to the realization of fusion energy To study the power exhaust problem in: o an integrated environment o DEMO relevant conditions 9

What is DTT? History k” o o b e b n o e re u l B “ 30 th SOFT 2015 ” k o 2017 2018 “G 2019 Jul 15 DTT Project Proposal (“Blue Book”) Jul 17 European workshop on DTT roles and objectives -> Eurofusion PEX-AHG Dec 17 Call for interest open to all Italian Regions to host DTT Apr–Sep 18 Appeal to the supreme court by some regions against the results of the call Apr–Aug 18 Cost revision committee on the “Blue Book” design Jul 18 First Design review meeting to address the recommendations from the Eurofusion PEX-AHG Oct 18 DTT management organization set-up Apr 19 DTT Interim Design Report (“Green Book”) https: //www. dtt-project. enea. it/downloads/DTT_IDR_2019_WEB. pdf 10

What is DTT? Parameters + technology DTT ITER DEMO R (m) a (m) A Ip (MA) B (T) Heating Ptot (MW) Psep /R (MW/m) Pulse length (s) 2. 14 0. 65 3. 3 5. 5 6 45 15 95 6. 2 2 3. 1 15 5. 3 120 14 400 9. 1 2. 93 3. 1 19. 6 5. 7 460 17 7600 Flexibility and DEMO relevant technologies 11

DTT layout: Site & torus hall 9 sites were proposed from all over Italy “Casale Monferrato” (TO) “Ferrania” (SV) “La Spezia” (SP) “Porto Marghera” (VE) “CR ENEA Brasimone” (BO) “Cittadella Della Ricerca” (BR) “CR ENEA Frascati” (RM) “Capitolo San Matteo” (SA) “Manoppello” (PE) 12

DTT layout: DTT machine at a glance Item TF CS PF VV Cryostat NBI Total 45 126 153 302 80 ~ 1000 Mass [ton] 270 ~11 m 13

DTT layout: Neutronics o Neutron yield is significant for a DD device (1. 5 x 1017 n/s from DD and 1. 5 x 1015 n/s DT) o Radiation & loads to be taken into account for the design of DTT components o Neutron induced radioactivity calls for remote handling o Tokamak building walls at least 220 cm to comply with limits for professional workers (300 Sv/yr) outside the building and for public (10 Sv/yr) at about 40 m distance from the building 14

DTT components: Magnet system 18 Toroidal Field coils Nb 3 Sn Cable-In-Conduit Conductors 5 Double-Pancakes (3 regular + 2 side) 6 Central Solenoid module coils Nb 3 Sn Cable-In-Conduit Conductors 6 independent modules 6 Poloidal Field coils 4 Nb. Ti Cable-In-Conduit Conductors 2 Nb 3 Sn Cable-In-Conduit Conductors 6 independent modules Design based on proven and reliable technologies 15

DTT components: Vacuum vessel Shell Thickness (inboard) 15 mm Shell Thickness (outboard) 15 mm Ports Thickness 25 mm Ribs thickness 10 mm Volume VV 75 m 3 Material Weight of main vessel body Operating Temperature of the VV (max) Baking temperature of the VV (max) AISI 316 -L(N) ~ 2. 2 m 36900 kg 60 °C ~4 m 110 °C 16

DTT components: In-vessel components Design requirements compatibility: liquid lithium divertor (closed cycle) remote handling system In-vessel magnetic diagnostics In-vessel control coils DEMO Materials electromagnetic loads FW inboard module: 2 modules per VV sector for RH limitations FW outboard: plane modules plus a top part per VV sector for RH limitations and loads EUROfusion decision on the first divertor planned in 2023 flexibility needed to incorporate it inside the DTT vessel 17

DTT components: Flexibility required 18

DTT components: Constraints 9. 1 T 19

DTT components: Heating system DTT ITER DEMO Psep /R (MW/m) 15 14 17 20

DTT components: Power supply system The power supply system has to feed 6 superconducting modules of the central solenoid, 6 poloidal field superconducting coils, 18 toroidal field superconducting coils designed for a current up to 45 k. A, the in-vessel coils for plasma fast control and vertical stabilization, the ELM/RWM coils, the negative neutral beam injectors, the electron and ion cyclotron additional heating systems, and, finally, the auxiliary systems and services. 21

DTT components: Cryostat Top Lid Major diameter at equatorial section Maximum height including ~11 m basement SA-240 Structural Material Main Cylinder ~11. 2 m 304 LN Operational pressure (Vacuum) 10 -3 Pa Design temperature of cryostat wall 293 K Thickness of the Cryostat walls 30 mm Thickness of the external ribs 25 mm Estimated Mass of CV main cylinder ~66 tons Basement Estimated Mass of CV top lid ~16 tons Estimated Mass of CV basement ~220 tons 22

DTT management: Organizational chart 23

DTT management: Investments 24

DTT management: Main procurements and services 1. Superconducting Magnets: 4. Heating system: Strands: Nb 3 Sn and Nb. Ti * Cables Magnets (coils+casings) Externalstructure Ion Cyclotron Electron Cyclotron Neutral Beam Injector 5. Cryocooler 2. Vessel/In-Vessel: Vacuum Chamber First Wall Divertor 3. Power Supplies: CS, PF, TF & protection systems Additional heating Auxiliaries Distribution systems 6. Control & data acquisition 7. Remote maintenance 8. Buildings 9. Assembly * Call for nomination + prequalification + call for tender phases concluded: evaluation ongoing 25

DTT management: Type of companies, services, contracts • Most procurements will be oriented to the SMEs • In a few cases the bidders should have high financial capacity • Services are expected to be required mainly during the assembly and operation phases • Due to the tight schedule, call for tender specs will be based on well assessed design and proven technology • Framework contracts and open procurements are deemed too risky for a timely construction within budget • Procurements will be typically based on Call for Nomination, Pre-qualification, Call for Tender or Negotiated Procedure limited to pre-qualified candidates 26

DTT management: Timeline Design completion Tender phase Manufacturing 27

DTT management: Next steps • • • Apr 2018: Frascati selected as DTT site • Fall 2019 : Establishment of DTT Consortium, Award of SC strand contract, TF coil tender, Loan activated by EIB after licensing • • 2022 -2023: Decision on divertor configuration (PEX) July 2018: 1 st Design Review Meeting of major components End 2018: Launched first call for tender procedure (for SC strands) End 2018: Recruitment of ENEA personnel started Mar 2019: 2 nd Design Review Meeting Apr 2019 : DTT Interim Design Report 2022 -2025: Assembly and commissioning End 2025: First experimental plasma: 3 T, 2 MA 2025 : Operations 28

DTT management: Further information For further information: www. dtt-project. enea. it fsn@enea. it 29