Overview of the Present Progresses and Activities on the Chinese Fusion Engineering Test Reactor Y.X. Wan 1,4, J. Li 1, Y. Liu 2, X.L. Wang 3, and CFETR Team 1) Institute of Plasma Physics, CAS, Hefei, China 2) Southwest Institute of Physics, Chengdu, China 3) Chinese Academy of Physics Engineering, Mianyang, China 4) University of Science and Technology of China, Hefei, China 26th IAEA Fusion Energy Conference, Kyoto, Japan 17–22 October 2016 Outline (OV/3-4)  Introduction • CN MCF Roadmap • Mission of CFETR  Progresses and activities of CFETR • Previous concept design • New design version • Phase I • Phase II  Key R&D activities  Summary CN MCF Roadmap (Page 3) Timeline: 2015 to 2060 - J-TEXT: Disruption mitigation, basic plasma - HL-2M: Advanced divertor, high power H&CD, diagnostics - EAST: Advance PFC, steady-state advanced operation - ITER: • Phase I: Q=10, 400 s, 500 MW, Hybrid burning plasma • Phase II: Q=5, 3000 s, 350 MW, steady-state burning plasma - CFETR: • Phase I: Q=1-5, steady state, TBR>1, >200MW, <10 dpa • Phase II: DEMO validation, Q>10, CW, 1 GW, >50 dpa - PFPP: 1 GW, Power Plant Validation Mission: Bridge gaps between ITER and DEMO, realization of fusion energy application in China • A good complementarities with ITER • Rely on the existing ITER physical (k~1.8, q>3, H~1) and technical (SC magnets, diagnostic, H&CD) bases • Demonstration of the burning plasma with Pf = 200MW~1000MW • Demonstration Long pulse or steady-state operation of burning with duty cycle ≥ 0.3 ~ 0.5 • Demonstration of full cycle of T self-sustained with TBR over 1.0 • Exploring options for DEMO blanket & divertor with an easy changeable core by RH • Exploring the technical solution for licensing DEMO • With power plant potential step-by-step approach. The advanced design and 3D simulation platform has been set up - Design and management servers <-> Terminals of the design cloud <-> Virtual reality system - CFETR VPM tree -> CFETR main machine integration - Subsystem models: Remote handling, Cryostat, Divertor, Blanket, Magnet, Vacuum Vessel Advanced features of the design platform: - Collaboration design platform & Remote collaboration: Advanced data compression technology; Complete data sharing; Remote design on any terminal on the internet - Centralized management: Centralized data storage; High correlation and traceability; Safe and data tolerant - 3D stereo review: Frequent 3D stereo review; No need of physical mockups; Inaccessible positions in reality become examinable First Design version of CFETR (2011.11-2015.8) Phase I: • Ip = 7-10 MA • Bto = 4.5-5.0 T • R0 = 5.7 m • a = 1.6 m • k = 1.8～2.0 • q95 ≥ 3 • βN ～ 2-3 • Pfusion : 200MW Phase II: • Possible upgrade to R~5.9m, a~2.0 m, Bt= 4.8 T, Ip~15MA • Pfusion : 1000MW Key parameter investigation (180VS) Parameters across Operation modes A, B, C, D, E, ITER-SS, and Upgrade: - Mode D (Baseline candidate): Ip=8 MA, Paux=65~70 MW, q95=4.9, W=171 MJ, PFus=187~210 MW, Qpl=2.7~3.2, Ti0=20.6~21 keV, Nel=0.65 10^20/m^3, nGR=0.65, βN=2, βT=2%, fbs=50%, τ98Y2=1.37 s, PN/A=0.33~0.37 MW/m^2, ICD=4.0 MA, H98=1.2, Tburning=SS. (Bt=4.5T; R=5.7 m; a=1.6 m; k=1.8~2.0) - Upgrade Mode: Ip=15 MA, Paux=65 MW, q95=3.9, W=540 MJ, PFus=1000 MW, Qpl=15, Ti0=25 keV, Nel=1 10^20/m^3, nGR=0.85, βN=2.7, βT=4.2%, fbs=47%, τ98Y2=1.88 s, PN/A=1.38 MW/m^2, ICD=3.0 MA, H98=1.2, Tburning=1200 s. (Bt=4.8T; R=5.9 m; a=2.0 m) The first design version has been summarized in published monograph: 'Fusion Engineering Test Reactor Main Machine Design' (聚变工程实验堆装置主机设计). Key issues for CFETR mission: 1. Obtained Burning Plasma for fusion power: - 1. Larger device (Bt, Ro, a, K) - 2. Standard H mode - 3. Advanced operation scenario 2. Steady-state operation for fusion energy: - 4. Increasing flux to sustain longer Ip - 5. CW Ext H&CD (NB, EC, LH, IC) - 6. Higher fb - 7. Higher energetic α heating - 8. Divertor physics and tech. 3. Breeding Tritium for T self-sustained: - 9. T-breeding by blanket - 10. T-plant: extract & reprocessing - 11. Materials - 12. RH (Remote Handling) - 13. Licensing New design version (2015.8-2016.8): Easy transfer from Phase I to Phase II The key points changed: • Larger size: R = 6.7m, a = 1.95m • Higher BT: 5.0 - 7.0 T • Advanced CS magnet: ≥ 480 VS • Lower Ip: 6 - 12MA • 12 TF coils for easy RH, H&CD • More reliable Plasma targets • Higher confidence for STE goals CFETR Physics design: • 0D system code + 1.5D integrated modeling (OMFIT, EFT, ONETWO, GATO, TGYRO/TGLF, NEO, ELITE) • Off-axis NBI + ECCD, LHCD are major H&CD tools together with bootstrap current for SSO (Steady-State Operation) • Using 800 kV NBI (1.1MA/10MW) + 190GHz ECCD for phase I operation. More effective current drive – HFS LHCD + Top ECCD: - Low Field Side (LFS): f=4.6GHz, P=30MW, N//=1.8 -> ILH = 1.43 MA; Combined LFS LHCD + LFS ECCD gives ΔI = 0.34 MA, ICD = 2.49 MA. - High Field Side (HFS): f=4.6GHz, P=30MW, N//=1.8 -> ILH = 1.83 MA; Combined HFS LHCD + TOP ECCD gives ΔI = 0.3 MA, ICD = 4.0 MA. Two New Fully Non-Inductive CFETR Scenarios with Larger Size Have Been Evaluated (Computed with self-consistent core-pedestal-equilibrium model under OMFIT by GA-CFETR team): Key parameters comparing Previous (5.7m/1.6m), Phase I (6.6m/1.8m), 0D Phase I, Phase II (6.6m/1.8m), and 0D Phase II: - Phase I: R0/a = 6.60/1.80 m, NBI Input Power = 13, 22.8 MW, EC Power = 20 MW (230 GHz), QFUS = 3.0, PFUS = 169 MW, BT/Ip = 6.0 T / 7.6 MA, Bootstrap fraction fbs = 64%, Central Tio, Teo = 18.8, 25.3 keV, βN = 1.89, H98y2 = 1.32, Diverter heat loading = 10.4 MW/m. - Phase II: R0/a = 6.60/1.80 m, NBI Input Power = 20.0, 14.3 MW, EC Power = 20 MW (230 GHz), QFUS = 14.9, PFUS = 811.0 MW, BT/Ip = 6.0 T / 10.0 MA, Bootstrap fraction fbs = 84%, Central Tio, Teo = 25.6, 33.5 keV, βN = 3.15, H98y2 = 1.34, Diverter heat loading = 25.8 MW/m. New Larger CFETR Reduces Heating and Current Drive Requirements, and Lower Divertor and Wall Power Loading • Fully non-inductive CFETR scenarios have been developed with a self-consistent core-pedestal-equilibrium model • New larger CFETR reduces heating and current drive requirements, lower divertor heat flux and neutron wall loading, higher bootstrap current fraction and H98y2 at similar βN • Higher βN ~ 3.2 Phase II configuration requires a close conducting wall for n = 1,2 ideal stability but for Phase I dont need the conducting wall 12 TF Coil design (High Performance Nb3Sn): Dimensions: Height 13370 mm, Width 9183 mm Parameters for TF Magnet: - Strand: High Jc (3000 A/mm^2) Nb3Sn, Φ1.0mm strand - No. of SC strand: Coil 1 = 1350, Coil 2 = 270 - Turns: Coil 1 = 66, Coil 2 = 154 - Operating current for Bt = 7.5T: 64.3 kA - Bmax in coil: Coil 1 = 14.3 T, Coil 2 = 11.4 T - Max Force: 643 MPa Advanced plasma equilibrium shape: - Snowflake divertor configurations for Ip=11 MA and Ip=14 MA - Parameters for Ip=11 MA: Type=Snowflake, R=6.72 m, a=1.76 m, βp=1.59, li=1.02, βt=0.025, δu/δl=0.33/0.63, κ=1.99, q95=3.9 - Parameters for Ip=14 MA: Type=Snowflake, R=6.72 m, a=1.75 m, βp=1.1, li=0.95, βt=0.024, δu/δl=0.33/0.63, κ=1.99, q95=3.3 Helium cooled ceramic breeder (HCCB) blanket design: Material section: - Li4SiO4 as tritium breeder - Be as neutron multiplier - RAFM steel as structural material - Tungsten as armor material of the FW Main features: - Modularized breeding unit - Multi-layer back plates manifold - Coolant: 8 MPa, 300 °C inlet / 500 °C outlet Phase-I: 5 (Tor.) × 2 (Pol.) breeding unit, each has one U-shape breeder unit. TBR: 1.213 Phase-II: 6 (Tor.) × 5 (Pol.) breeding unit, each has two U-shape breeder unit. TBR: 1.15 Water cooled ceramic breeder (WCCB) blanket design: Material section: - Mixed breeder of Li2TiO3 and Be12Ti - A bit of Be to improve neutrons multiplying - RAFM steel as structural material - Tungsten as armor material of the FW Main features: - Coolant: 15.5 MPa, 285 °C inlet / 325 °C outlet - The cooling plates and the breeder zone parallel to the FW - The compact coolant enlarges the breeder zone - Purge gas is directed in the toroidal direction to reduce pressure drop Phase-I: 4 (Rad.) × 4 (Tor.) mixed breeder zones and 2 (Rad.) × 4 (Tor.) thin Be layers; TBR: 1.21 Phase-II: 8 (Rad.) × 4 (Tor.) mixed breeder zones and 2 (Rad.) × 4 (Tor.) thin Be layers; TBR: 1.1 Shielding capability for TFC: - Fast neutron (>0.1MeV) fluence in TFC conductor: Limit 1×10^19 n/cm^2, Value 3.67×10^16 n/cm^2 - Fast neutron (>0.1MeV) fluence in TFC insulator: Limit 5×10^17 n/cm^2, Value 1.10×10^17 n/cm^2 - Nuclear heating rate in TFC case: Limit 2×10^-3 W/cm^3, Value 2.19×10^-5 W/cm^3 - Nuclear heating rate in TFC conductor: Limit 1×10^-3 W/cm^3, Value 1.88×10^-5 W/cm^3 Tritium cycling systems (T-plant): 3 main loops for tritium recovery: • Inner cycling: Tritium recovery, isotopic separation from plasma exhaust gases and re-fueling to torus. • Outer cycling: Tritium extraction and measurement from the full breeding blanket. • Tritium confinement and effluent detritiation. Main parameters for tritium process flow (4500s of time span for cycling): • Inner cycling: ~357g T/shot, 2 m^3 (D2, T2)/h for TEP and SDS, >4 m^3/h for ISS. • Outer cycling: tritium extraction every two weeks to get more than 200g of pure tritium from the breeders. • Tritium confinement: 3 g/a of environmental tritium release at current stage, to be minimized to 0.6 g/a for the future. • Total startup tritium: CFETR may need around 2 kg of tritium for startup (Burnup 226g, Dynamic 107g, In-vessel retention 661g, Retention in FCS 353g, Backup 452g = Total 1799g). RH strategy of CFETR: RH strategy plays the key role for CFETR’s high efficiency and reliability maintenance. The vertical port maintenance scheme with multi-module segment blanket and divertor was preferred for in-vessel components maintenance. It will make the RH simpler and more efficient. Components include: Blanket radial remove RH, Toroidal remove RH, Assembly hall, Maintenance RH, RH system cell, Tokamak Building, Maintenance CASK, Top corridor and crane, Transfer cask system, Hot cell RH. New Design version of CFETR Dimensions: - Machine Diameter: 34 m - Machine Height: 37 m - Major Radius / Inner Profile dimensions: 6500 mm, 13420 mm to 17000 mm outer cryostat limits. R&D strategy of CFETR: Integrated system links: - Advanced Diverter - Breeding blanket - Tritium loop system and radiation protection - CS and VV mockups - First wall and blanket materials - Supporting facilities: HL-2 experiments and technology, EAST experiments and technology, CN ITER Procurement Packages (PA), Other physical research (Heating, CD, Diagnostics), and Talent/Education. Other important R&D for CFETR: • Auxiliary Heating & CD: - Off-axis NBI (0.8MeV) + ECRH (top, 190, 230GHz) - LHCD (HF, 4.6GHz) + ECRH (top, 230GHz) • Advanced Superconducting Magnet: - TF (Nb3Sn, 7.0 T); CS (Bi-2212 CICC) • Advanced Divertor (X-Divertor, >20MW/m^2) • Blanket (He gas, water cooled) • T-Plant (99.9% T recovery) • Materials (First wall, structure) • RH (Remote Handling) R&D for RF Sources: • LHW: - EAST: 2.45GHz, 200kW, CW; 4.6 GHz, 0.3MW, CW - CFETR: 4.6 GHz, 0.3-0.5MW, CW; 7.5GHz, 0.5MW, CW • EC: - EAST: 140GHz, 1MW, CW; 170GHz, 1MW, CW - CFETR: 170GHz, 1MW, CW; 230GHz, 1MW, CW - Testing: 5x8 hours testing for Klystrons; Gyrotron start commissioning @ 2016.12 CS Model Coil – Nb3Sn (baseline): Design Parameters of CFETR CS Model Coil: - Max. field: 12 T - Max. field rate: 1.5 T/s - Inner radius: 750 mm - Coil structure: Hybrid magnet (Inner: Nb3Sn coil) - Conductor type: Nb3Sn CICC - Start experiments @ 2017.12 in new ASIPP site (Huainan) CS Model Coil (1/3 size) – Bi2212 CICC (Target): • Bi2212 High temperature Superconducting Central Solenoid: - CS coils include eight Bi2212 coils. Each coil consists of 14 double pancakes. - Max flux / field: Max. 240 V·s, Max. 20 T - Conservative: enhanced Nb3Sn: 360VS, 4-6h - Ideal: 2212 CICC, 480VS, ~8h (for Ip=10MA) • Batch production for 200-m long Φ1.0mm wires: - 4.2K, 14T: Jce > 750 A/mm^2 (vs. ITER ~ 320 A/mm^2) - 4.2K, 20T: Jce > 660 A/mm^2 (vs. ITER ~ 200 A/mm^2) - High pressure sintering process is on the way, Jc-B property may be increased 3 times. New Divertor validation: • Physics: Field expansion + radiation; Reduce heat detail simulations (5y) + experimental validation (5-8y) [EAST Snowflake and CFETR-X] • Engineering: Design & manufacture of key components: - W mono-block: >20 MW/m^2 - W-Cu mono-block: >20 MW/m^2 (5-10y) • Inner + external coils optimization is underway up to 15 MA (12 MA baseline) R&D for Divertor Target: • Monoblock W/Cu: 5000 cycles at 10 MW/m^2; 300 cycles at 20 MW/m^2 • Flat tile W/Cu: 5000 cycles at 10 MW/m^2; 1000 cycles at 20 MW/m^2 • Efforts for 30 MW/m^2: 3D printing full W block (Tw=1700°C); Flat tile W/ODS-Cu (Tw=1650°C, Tcu=520°C) CFETR T-plant technologies: 1. Tritium handling technologies: Tritium purification, Hydrogen isotope separation, Tritium removal/recovery in tritiated gases (Integrated hydrogen permeation, Cryogenic Distillation) 2. Tritium Analysis and Monitoring: Tritium online detection by gas chromatograph, Radiometric analysis (Solids contained tritium desorption and collection) 3. Tritium safety techniques: Atmospheric detritiation, Water detritiation, Tritium permeation barrier (D.S. for inert gas, Metallic getter approach) 4. ITER TBM tritium systems: Tritium Extraction System (TES), Coolant purification system (CPS), Tritium measurement system (TMS) In-Pile Tritium Release and Extraction Test: • China Mianyang Research Reactor: - Maximum load: 500 g - Tritium production: 1 Ci/day - Online refueling, irradiation - Irradiation temperature: 300-750 °C - Neutron flux: ~5×10^13 n cm^-2 s^-1 • China Advanced Research Reactor: - Maximum load: 400 g - Tritium production: 1 Ci/day - Online thermal conductivity test - Irradiation temperature: 400～850 °C - Neutron flux: ~5×10^13 n cm^-2 s^-1 Materials Research Activities (Simulation, manufacture, validation): • Low Activation Martensitic (RAFM) steel: - Nominal compositions: 9Cr1.5W0.2V0.15Ta0.45Mn0.1C - 5 ton smelting with good control of main compositions - Facilities: HIP (0.8x1.8m), 400kW EM facility, 15kW laser welding (0.05mm) • Irradiation properties and TBM Fabrication: - High-dose neutron irradiation experiments (Spallation source ~20dpa, HFTE ~2dpa) - Fabrication of test blanket module (1/3 scale P91 TBM, 1/3 scale CLAM first wall) • Plasma-facing materials (W): - Scope: W alloy, W coating, W/Cu component (W/Cu, W/OFHC-Cu, W/FGM-W/Cu, W/RAFM Steel, W/graphite) - Chemical vapor deposition (CVD-W) deposition rate: 0.2-1 mm/h - High purity W and W-TiC powder metallurgy & SPS samples R&D on VV 1/8 mock-up: - Overview of CFETR VV Design (Sector height: 17.4 m) - Narrow Gap TIG (NG-TIG) system & welding samples - Laser Tracker Measurement on VV Sector - Assembly of VV Poloidal Sectors - Test bench for installation and replacement of VV components by RH CFETR 5 years Plan: • Self-consistent, reliable physical design (lead: V. Chan) • Detailed engineering design (main machine and auxiliary systems) • R & D for key technologies and systems: - (I): Blanket related to nuclear, thermal hydraulic processes - (II): Magnets, T-factories, NBI, ECRH, RH - (III): Experimental verification, diagnosis, control, divertor, cryogenic, ICRF, radiation protection, assembly, and so on. Further working Plan of CFETR: • Re-organize the design team led by Drs. J. Li, Y. Liu, and X.L. Wang • Management structure: J. Li ("CIC" Director), V. Chan (Division head of fusion plasma physics) • Promote both domestic and international collaboration broadly on design, R&D, and construction of CFETR International cooperation partners: • PPPL-CFETR team: H. Nielson, T. Bown, P. Titus, C. Kessel, A. Khodak • GA-CFETR team: L. Lao, R. Boivin, J. Candy, X. Chen, R. Prater, M. Christopher, A. Garofalo, O. Meneghini, M. Vanzeeland, P.B. Snyder, S.P. Smith, G.M. Staebler, E.J. Strait, and D. Zhao • Useful discussion and suggestions from CFETR-IAC and CFETR Physics group IAC • EU-DEMO team: CCFE (SYScode, RH), ENEA (Blanket, Divertor), Julich (Diagnostic&Control, FM materials), EPFL (H&CD) Summary: • Integrated Design and R&D of CFETR are in progress. • CFETR is moving to Phase II design of the new version with emphasis on high BT option. • There are gaps to CFETR readiness, especially for Phase II; need new solutions and technologies. • Detailed engineering design and large-scale R&D will continue in next 5 years. • It is hoped that the proposal for CFETR construction can be approved by government within next 5 years finally.