ITER and the way towards a fusion reactor

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ITER and the way towards a fusion reactor

• M.Q.Tran
• Centre de Recherches en Physique des Plasmas
• Association Euratom- Confédération Suisse
• Ecole Polytechnique Fédérale de Lausanne

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Outline

• Introductionfusion as a sustainable energy
  source the conditions and challenges for the
  realisation of fusion energy
• ITER Missions, Physics basis, Technological
  development
• Material research
• Electricity generating power plant conceptual
  study
• The role of fusion energy in future energy
  scenarios

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Ethical aspects
Resources
Present CO2 concentration 360 ppm
Environement
Security of supply
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Environmental issue
Destructiveness of tropical hurricanes Ref.
Emanuel, Nature 436, 608 (2005)
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HDI vs Energy use
Ref. BP statistics UN Development Report 2004
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Fusion reactions
Binding Energy MeV/nucleon

• D T ---gt He4 (3.5 MeV) n (14.1 MeV)
• D D ---gt He3 n 3.2 MeV
• D D ---gt T H 4.03 MeV
• D He3 ---gt He4 H 18.3 MeV
• Li6 n ---gt T He4 4.8 MeV
• In a fusion reactor using D-T, T is regenerated
  in the reactor within the tritium breeding
  blanket through the reaction between Li and the
  fusion neutron.
• Li in the blanket is in the form of compound and
  not pure Li

Fission
Fusion
Atomic mass
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Why do we develop fusion?

• Fusion could be a sustainable energy source
• Practically inexhaustible fuel source
• No CO2 emission
• Waste
• Accident analysis
• Homi Bhaba at the 1st Geneva Atoms for Peace
  (1955)
• When that ( a method for liberating fusion
  energy in a controlled manner) happens, the
  energy problem of the world will truly have been
  solved forever for the fuel will be as plentiful
  as the heavy hydrogen in the oceans

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Fuel

• Reserve of D 1 D for 6700 of H
• (88 kg/a for a 1000 MWe power plant (PP))
• T short lived radio isotope (13 years) but
  generated from reaction Li6 n ---gt T He4
• (236 kg of Li6 / year for a 1000 MWe PP)

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The Li resources (1)

• 6Li n --gtHe ( 2.1 MeV) T (2.7 MeV)
• 7Li n --gt He n - 2.87 MeV

Ref. D. Fasel et al. SOFT 2004
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The Li resources (2)

• Li Minerals, Brines, and sea water
• As usual, difficulties to get proprietary
  information about reserve and resources
• Reserves 4-6 millions tons
• Resources 8- 21 millions tons
• Sea water 170 / billion 2 x 1011 tons.
  Extraction processes have been studied by
  Steinberg et al. ( US Govt Printing Office, 1976)
  and Yoshitaka et al. ( Separation science and
  technology 23, 179, 1988)
• Resources are practically unlimited

-Ullmanns Encyclopedi of Industrial Chemistry,
Vol. A15 - USA Geological survey
http//minerals.usgs.gov/minerals - Roskill
Information services, The economics of Li, ISBN
0862148596, http//www.roskill.co.uk
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CO2 emission

• The production of energy from fusion does not
  generate any green house gas
• Life cycle study

Fusion
Ref. Tokimatsu et al 17th IAEA FEC
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Waste (1)

• The fusion reaction DT does not yield any
  radioactive daughter product (only a n and a He
  nucleus)
• The interaction of the energetic neutron (14 MeV)
  with nuclei will produce transmutation and hence
  yield radioactive daughter products
• But these products does not have extremely long
  life

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Waste (2)
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Waste (3)

• Calculation of radioactive life time and
  recycling limit of a fusion power plant

Ref. EU Fusion Power Plant Conceptual Study
(PPCS) , EFDA
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Accident (1)

• Accident sequences were assessed during the
  design phase of ITER and during the power plant
  conceptual study.
• No evacuation of the population most severe
  conceivable accident driven by in plant energies
  lead to a dose of 18 mSv, below the threshold of
  50 mSv for evacuation

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Accident (2)

• Beneficial aspects in case of loss of coolant
  accident (LOCA) delicate balance of conditions
  for fusion reactions, fuel inventory sufficient
  only for a few minutes of burn

Temperature below melting point
Ref. PPCS study , EFDA
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Cross sections
1 keV is equivalent to 107 oK
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Conditions for a fusion reactor (1)

• Temperature in the range of 100 millions degree.
  At around 104-105 oK, matter is in the plasma
  state, i.e. an ionized gas with global charge
  neutrality and dominated by collective effects.
• The Sun is a thermonuclear reactor operating at
  about 10 millions degrees, using as fuel H
• Creation and confinement of a plasma at 100
  millions oK Confinement by magnetic field
  heating by RF waves (170 GHz, 5 GHz, and 50 MHz
  in ITER) and by injection of energetic (1 MeV)
  neutral particles
• In the Sun, confinement is insured by gravity

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Conditions for a fusion reactor (2)

• Power balance

Power loss Ploss
Pout
Electricity production hel
Power from fusion reactions PFusion
Heating power PH
The a particles produced by fusion reactions
remain in the plasma and contribute to its
heating
ntET gt 5 .1021 m-3s keV n Particle density, T
Temperature, tE Energy confinement time in the
plasma
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Tokamak plasma confinement

• The plasma in a tokamak is confined by magnetic
  fields toroidal field created by coils and
  poloidal field created by a current carried by
  the toroidal plasma

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Fusion status (1)
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Fusion status (JET) (2)
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Fusion status 50 D 50 T shots in JET (3)
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The Broader Approach

• The European Fusion Programme is energy oriented,
  aiming towards the realisation of a DEMO Reactor
• In this frame, the realisation of ITER is only
  one important element of the programme
• A more global vision of the programme (the
  Broader Approach) is developed by EU and Japan
• The Broader Approach includes a vigorous physics
  programme to advance the physics optimisation
  towards DEMO and the advance of the science and
  technology of materials for a fusion reactor

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A possible roadmap
FY
2010
2015
2020
2005
2035
2030
2025
Performance extension phase

Basic performance phase
Decomissioning
Construction
ITER program
Satelite Tokamaks And other devices
JET
NCT
Fusion technology development
Development of breeding blanket
Fusion material development (inc. IFMIF)
Confirm physics database
DEMO physics input for starting EDA
Confirm material database
DEMO
Concept exploration
CDA-like
EDA/RD
construction
power production
Coordination of DEMO physics and tech. RD
Grid connection
Decision of construction
licencing
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Outline

• Introduction
• ITER Missions, Physics basis, Technological
  development
• Material research
• Electricity generating power plant conceptual
  study
• The role of fusion energy in future energy
  scenarios

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ITER

• Academician Boris Kadomstev
• The major task has , however, been achieved - a
  physical data base for a fusion reactor has been
  created and because of this the design of fusion
  reactor -tokamaks are currently being developed.
  Among them, the most advanced one is the design
  of ITER.

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The ITER project

• ITER The only step between the present devices
  and a demonstration reactor producing electricity
  DEMO
• International project with 7 Parties EU
  (including Switzerland), China, India, Japan,
  Korea, Russia, USA
• ITER thus gathers countries representing more
  than half of the world population
• Interest to join (through a Party) Brasil,
  Australia
• The decision to build ITER at the European site
  Cadarache in France was taken in June 2005
• Signature of ITER agreements
• 21st November 2006 in Paris

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ITER
Central Solenoid Nb3Sn, 6 modules
Blanket Module 421 modules

Vacuum Vessel 9 sectors
Outer Intercoil Structure
Cryostat 24 m high x 28 m dia.
Toroidal Field Coil Nb3Sn, 18, wedged
Port Plug (IC Heating) 6 heating 3 test
blankets 2 limiters/RH rem. diagnostics
Poloidal Field Coil Nb-Ti, 6
Machine Gravity Supports
Torus Cryopump 8
Divertor 54 cassettes
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The tokamak ITER

• Major radius R 6.2m
• Minor radius a 2.0 m
• Plasma current IP 15 MA
• Elongation 1.7
• Plasma volume 837 m3
• Heating power 73 MW
• BT 5.3 T
• Neutron flux 0.57 MW/m2
• Fusion power 500-700 MW
• (thermal) during gt 400s
• Electrical power 500MW-
• required 400 MVAr

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ITER design goals (1)

• Physics
• produce a plasma dominated by a-particle heating
• produce a significant fusion power amplification
  factor (Q 10) in long-pulse operation
• aim to achieve steady-state operation of a
  tokamak (Q 5)
• retain the possibility of exploring controlled
  ignition (Q 30)
• Assessment by international community confirms
  the physics basis of ITER

Q Pfusion / PHeating
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ITER design goals (2)

• Technology
• demonstrate integrated operation of technologies
  for a fusion power plant
• test components required for a fusion power plant
• test concepts for a tritium breeding module
• demonstrate the safety characteristic of a fusion
  power plant

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ITER scenario
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Technology

• No show stopper regarding specific technology or
  the integration of the whole device
• Critical components were identified and
  industrial size mock-up developed by all
  international Parties the so called 7 Large
  Projects were successfully completed
• Specific development was undertaken by the EU
  party in all areas development of heating
  systems, of the vacuum vessel construction, of
  high heat flux components, of low temperatures
  superconducting cables, high temperatures
  superconducting current leads, tritium breeding
  concepts,remote handling, tritium pumps

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7 Large projects
CENTRAL SOLENOID MODEL COIL
VACUUM VESSEL SECTOR
Radius 3.5 m Height 2.8m Bmax13 T W 640 MJ 0.6
T/sec
Double-Wall, Tolerance 5 mm
REMOTE MAINTENANCE OF DIVERTOR CASSETTE
BLANKET MODULE
HIP Joining Tech Size 1.6 m x 0.93 m x 0.35 m
Attachment Tolerance 2 mm
TOROIDAL FIELD MODEL COIL
DIVERTOR CASSETTE
Height 4 m Width 3 m Bmax7.8 T Imax 80kA
4 t Blanket Sector Attachment Tolerance 0.25 mm
Heat Flux gt15 MW/m2, CFC/W
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Operation Schedule
Q 10500 MW400 s
FIRST PLASMA
Full field, current,and H/CD power
Short DTburn
Q 10500 MW
Full non-inductivecurrent drive
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
Commissionwith neutrons.Reference scenarios in
D. Short DT burn
Develop full DT high Q. Develop
non-inductive aimed at Q 5. Low duty.
Improve operation. High duty.
Commission machinewith plasma. Heating and CD
Expts.Reference scenarios in H.
IntegratedCommissioning
PLASMA AND PERFORMANCE
H Plasma
D Plasma
DT Plasma
Equivalent accumulated nominal burn pulses
1
750
1750
3250
5750
8750
11750
System checkout and characterisation
Performance Test
BLANKETTESTING
Electromagnetics. Hydraulics.
Neutronics. Validate
Short-term T breeding.Thermo-mechanics.
On-line tritium recovery.High grade heat
generation.
Nominal burn 400 s/500 MW / 0.77
MWm-2 on outboard surface Neutron fluence
0.12 MWam-2 for the first 10 years Tritium
consumption 4.7 kg
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Outline

• Introduction The conditions and challenges for
  the realisation of fusion energy
• ITER Missions, Physics basis, Technological
  development
• Material research
• Electricity generating power plant conceptual
  study
• The role of fusion energy in future energy
  scenarios

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Material science and technology

• Materials for fusion must be low activation and
  retain their mechanical and thermal properties
  under irradiation

Nuclear reactions
Cascades
Diffusion processes
Production of impurities (He, H)
Production of vacancies and interstitials
Formation of the final microstructure
Time s
10-6
10-13 - 10-8
10-16
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Characterisation of irradiation damage

• dpa displacement per atom

Main difficulty is the non availability of
suitable neutron sources energy 14 MeV and
high fluence
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Mechanical effects
9Cr type of steel
Hardening (H) Loss of ductility (LD) Loss of
fracture toughness Loss of creep strength
Swelling
Change in the Ductile to Brittle Transition
temperature DBTT
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Kinetic rate theory
Fracture toughness versus temperature
kRT
Bend bar with FEM mesh
Space
Finite element modelling
FEM
1 µm - 1 cm
Interaction dislocations-defects
Creep tests
Discrete dislocation dynamics
Kinetic Monte Carlo
DDD
kMC
Tensile tests
10 nm - 10 µm, µs - hours
Molecular dynamics
Nanocrystal
TEM image
10 nm - µm, ns - s
Interaction edge dislocation-void
1 nm - 1 µm, 10 ps - s
TEM image
Stacking fault tetrahedron
1-5 nm, 2 ps - s
TEM image
TEM simulated image
kRT equations
Atomic displacement cascade
MD
1-30 nm, 1-10 ps
0.1 nm - 1 m, 1 ps - years
Formation energies of point defects
Time
0.1 nm
Ab Initio
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Material for fusion reactor

• Criteria

Specific radioactivity Radioactive decay
heat Half-life radio nuclides Waste disposal
Candidate materials presently under developement
have a chemical composition based on low
activation elements Fe, Cr, V, Ti, W, Ta, Si,
C Steel of the 9Cr type such as EUROFER 97 8.9
wt. Cr, 1.1 wt. W, 0.47 wt. Mn, 0.2 wt. V,
0.14 wt. Ta, 0.11 wt. C, Fe for the balance.
Oxide (Yttria) dispersion strengthened (ODS)
steel. SiCf in SiC matrix, Va alloys
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IFMIF (1)

• International fusion material irradiation
  facility IFMIF a neutron source capable of
  simulating the fusion neutron with high flux
• IFMIF is the key infrastructure for fusion
  material science

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IFMIF (2)
High flux region(20 dpa/y) is 0.5 l --gt Small
sample test technology
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Outline

• Introduction The conditions and challenges for
  the realisation of fusion energy
• ITER Missions, Physics basis, Technological
  development
• Material research
• Electricity generating power plant conceptual
  study
• The role of fusion energy in future energy
  scenarios

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Power plant conceptual studies (PPCS) (1)

• Define the parameters of a fusion power plant,
  the underlying physics assumption, the key
  technologies
• Assess the safety and environmental impacts
• Assess the economics of the a fusion plant
• PPCS assume a tokamak reactor
• Ref. PPCS report from EFDA

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PPCS (2)
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Parameters (1)
tE HHtEH98(y,2)
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Parameters (2)
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Outline

• Introduction The conditions and challenges for
  the realisation of fusion energy
• ITER Missions, Physics basis, Technological
  development
• Material research
• Electricity generating power plant conceptual
  study
• The role of fusion energy in future energy
  scenarios

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Economics
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Economics (1)
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Fusion and the energy mix
India
EU
Pre industrial level of CO2 280 pmm Now 360
ppm
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Conclusions (1)

• Fusion progresses have been significant

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Conclusions (2)

• The decision to build ITER opened a new era for
  the achievement of fusion as an energy source
• A fusion programme must also continue to include
  physics (preparation of the exploitation of ITER,
  physics basis basis for a demonstration reactor)
  and a vigorous programme on material science and
  technology
• The training of the physicists and engineer is
  also a priority of the programme, in view of its
  long term character

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Conclusions (3)

• Academician L. Arstimovich in 1972
• It (the task of accomplishing fusion) is bound
  to be accomplished when thermonuclear energy
  becomes necessary for mankind , because there is
  no insurmontable obstacles to it
• ITER and the Broader Approach are proving the
  correctness of Artsimovitchs claim, because
• There is urgency to develop new technologies
  like fusion since otherwise the per capita
  production (and the quality of life) in the
  developing world is likely to stagnate in 20-25
  years (P.K.Kaw 1992)

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ITER Performances (1)

• Q 10 operation scenario

Q10 for 400s at 15MA (q953) PRF 7 MW, PNB 33
MW
60
ITER performances (2)
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ITER Performances (3)

• Aim to achieve steady state performances at Q 5

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Specific Environmental and Irradiation Conditions
Advanced fission reactors
fission neutrons (Core structure 3-30
dpa/year) Max. operating temperature
1600C Compatible with He
ADS demonstrator
High energy protons and neutrons (Beam window
100 dpa/year 50 appm He/dpa, 500 appm H/dpa) Max.
operating temperature 550C Compatible with
liquid Pb-Bi
Fusion reactor
14 MeV neutrons (First wall 30 dpa/year in
Fe 15 appm He/dpa and 50 appm H/dpa) Max.
operating temperature 650C Compatible with
liquid Pb-17Li
Ref. N. Baluc CRPP
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Application in other fields
Advanced fission reactors
Oxide dispersion strengthened steels Refractory
metals and alloys Intermetallic alloys C/C, SiC,
SiC/SiC ceramic composites
Accelerator Driven System demonstrator
Fusion reactor
Reduced activation ferritic/martensitic
steels Oxide dispersion strengthened steels
Reduced activation ferritic/martensitic
steels Oxide dispersion strengthened
steels Refractory metals and alloys Vanadium
alloys SiC/SiC ceramic composites
Ref. N. Baluc CRPP
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The Materials Development Strategy FM Steels

• EUROFER 9Cr WVTa Reduced Activation Ferritic
  Martensitic Steel
• (7.5 tons heat was ordered in EU in 2004)
• Target
• Composition tailored to reduce activation and
  waste.
• Breeding blanket with operational window 300-550
  C.
• Two more steps
• Optimization of mechanical properties
  (EUROFER-2).
• Development towards low activation (EUROFER-3).
  
• Use for first generation breeding blankets,
  i.e.
• The reference structural material for the DEMO
  blankets.
• Used in the ITER TBMs.

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Breeding blanket
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Breeding blanket

• Tritium breeding materials Li, Pb-Li alloy,
  Li2O, LiAlO2, Li2ZrO3, Li4SiO4, Li2TiO3 (6Li
  n--gt 4He T 4.8 MeV)
• Neutron multiplier materials Be, Pb to have a
  breeding ratio slightly larger than 1 (about 1.1)
• Coolants water, He (Gen IV cooling), liquid
  Pb-Li alloy

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Parameters (3)