ITER

1. ITER the next step
BY SUMAN SEKHAR TAKRI
IIT KHARAGPUR
17CR60R07

2. Available sources of energy and their limitation
 Fossil fuel
 Nuclear energy
 Renewable energy
DISAVANTAGES
 Fossil fuel which include Coal, petroleum and Natural gas are non-renewable sources of
energy . Their supply is limited and they will eventually run out moreover Fossil
fuels release carbon dioxide when they burn, which adds to the greenhouse effect and
increases global warming.
 Nuclear fuels are non-renewable energy resources. And if there is an accident, large
amounts of radioactive material could be released into the environment. In
addition, nuclear waste remains radioactive and is hazardous to health for thousands of
years.
 Renewable energy is difficult to generate the quantities of electricity that are as large
as those produced by traditional fossil fuel generators. Renewable energy often relies on
the weather for its source of power

3. WHAT IS ITER ?
 ITER (International nuclear fusion research and engineering) is one of the most
ambitious energy projects in the world today.
In southern France, 35 nations are collaborating to build the world's largest
tokamak, a magnetic fusion device that has been designed to prove the feasibility
of fusion as a large-scale and carbon-free source of energy based on the same
principle that powers our Sun and stars.
 The experimental campaign that will be carried out at ITER is crucial to advancing
fusion science and preparing the way for the fusion power plants of tomorrow.
 ITER will be the first fusion device to produce high amount of net energy and also
the first fusion device to maintain fusion for long periods of time. And ITER will be
the first fusion device to test the integrated technologies, materials, and physics
regimes necessary for the commercial production of fusion-based electricity.
 Thousands of engineers and scientists have contributed to the design of ITER since
the idea for an international joint experiment in fusion was first launched in 1985.
The ITER Members—China, the European Union, India, Japan, Korea, Russia and
the United States—are now engaged in a 35-year collaboration to build and
operate the ITER experimental device, and together bring fusion to the point
where a demonstration fusion reactor can be design

4. OBJECTIVE OF ITER
1) Produce 500 MW of fusion power
The world record for fusion power is held by the European tokamak JET. In 1997, JET produced 16 MW of
fusion power from a total input power of 24 MW . ITER is designed to produce a ten-fold return on energy
(Q=10), or 500 MW of fusion power from 50 MW of input power. ITER will not capture the energy it produces
as electricity, but—as first of all fusion experiments in history to produce net energy gain—it will prepare the
way for the machine that can.
2) Demonstrate the integrated operation of technologies for a fusion power plant
ITER will bridge the gap between today's smaller-scale experimental fusion devices and the demonstration
fusion power plants of the future. Scientists will be able to study plasmas under conditions similar to those
expected in a future power plant and test technologies such as heating, control, diagnostics, cryogenics and
remote maintenance.
3) Achieve a deuterium-tritium plasma in which the reaction is sustained through internal heating
Fusion research today is at the threshold of exploring a "burning plasma"—one in which the heat from the
fusion reaction is confined within the plasma efficiently enough for the reaction to be sustained for a long
duration. Scientists are confident that the plasmas in ITER will not only produce much more fusion energy,
but will remain stable for longer periods of time.
4) Test tritium breeding
One of the missions for the later stages of ITER operation is to demonstrate the feasibility of producing
tritium within the vacuum vessel. The world supply of tritium (used with deuterium to fuel the fusion
reaction) is not sufficient to cover the needs of future power plants. ITER will provide a unique opportunity
to test mockup in-vessel tritium breeding blankets in a real fusion environment.
5) Demonstrate the safety characteristics of a fusion device
ITER achieved an important landmark in fusion history when, in 2012, the ITER Organization was licensed as
a nuclear operator in France based on the rigorous and impartial examination of its safety files. One of the
primary goals of ITER operation is to demonstrate the control of the plasma and the fusion reactions with
negligible consequences to the environment.

5. Working principle
 It’s simple in principle. Take two forms (isotopes) of hydrogen, squash them together,
and you get a helium atom and a very energetic subatomic particle called a neutron.
 The product of the reaction is a fraction lighter than its atomic ingredients, and by
Einstein’s famous equation E = mc2 that tiny loss of mass results in a colossal release of
energy. Harness that release in an efficient way and the world’s energy needs are
solved.

6. TOKAMAK
The tokamak is an experimental machine designed to harness the energy of fusion. Inside a tokamak,
the energy produced through the fusion of atoms is absorbed as heat in the walls of the vessel. Just like
a conventional power plant, a fusion power plant will use this heat to produce steam and then
electricity by way of turbines and generators.
The heart of a tokamak is its doughnut-shaped vacuum chamber. Inside, under the influence of extreme
heat and pressure, gaseous hydrogen fuel becomes a plasma—the very environment in which hydrogen
atoms can be brought to fuse and yield energy. The charged particles of the plasma can be shaped and
controlled by the massive magnetic coils placed around the vessel, physicists use this important property
to confine the hot plasma away from the vessel walls. The term "tokamak" comes to us from a Russian
acronym that stands for “toroidal chamber with magnetic coils”.
.

10. VACUUM VESSEL IN TOKAMAK
 The ITER experiments will take place inside the vacuum vessel, a hermetically sealed steel
container that houses the fusion reactions and acts as a first safety containment barrier. In its
doughnut-shaped chamber, or torus, the plasma particles spiral around continuously without
touching the walls.
 Forty-four openings, or ports, in the vacuum vessel provide access for remote
handling operations, diagnostics, heating, and vacuum system.
 In a tokamak device, the larger the vacuum chamber volume, the easier it is to confine the plasma
and achieve the type of high energy regime that will produce significant fusion power.
INWALL SHEILDING
 Approximately 55 percent of the space between the double walls of the vacuum vessel will be
occupied by in-wall shielding in the form of modular blocks, weighing up to 500 kg each. Made of
borated and ferromagnetic stainless steel, the blocks will provide shielding from neutron radiation
for components situated outside of the vacuum vessel
THERMAL SHEILDING
 Two layers of thermal shielding are interposed between the vacuum vessel and the cryostat to
minimize heat loads transferred by thermal radiation and conduction from warm components to the
components and structures that operate at 4.5K.
 The thermal shield consists of stainless steel panels with a low emissivity surface (<0.05) that
are actively cooled by helium gas flowing inside of a cooling tube welded on the panel surface.
 One layer of thermal shield will be installed between the vacuum vessel and the superconducting
magnets; another will be installed between the magnets and the cryostat.

12. BLANKETS
The 440 blanket modules that completely cover the inner walls of the vacuum vessel protect the steel
structure and the superconducting toroidal field magnets from the heat and high-energy neutrons
produced by the fusion reactions. As the neutrons are slowed in the blanket, their kinetic energy is
transformed into heat energy and collected by the water coolant. In a fusion power plant, this energy
will be used for electrical power production.
Each blanket module measures 1 x 1.5 meter and weighs up to 4.6 tones. all have a detachable first
wall that directly faces the plasma and removes the plasma heat load, and a main shield block that is
designed for neutron shielding. The blanket modules also provide passageways for diagnostic viewing
systems and plasma heating systems.
FIRST WALL PANEL
The first wall panels are the detachable, front-facing elements of the blanket that are designed to
withstand the heat flux from the plasma. These highly technological components are made of beryllium
tiles bonded with a copper alloy and 316L (N) stainless steel. Due to its unique physical properties
(low plasma contamination, low fuel retention), beryllium has been chosen as the element
to cover the first wall. The rest of the blanket modules will be made of high-strength
copper and stainless steel.
SHEILD BLOCKS
The shield blocks (the heavier of the two elements, at left) provide nuclear shielding for the vacuum
vessel and coil systems as well as support for the first wall panels. Cooling water will run to and from
the shield blocks through manifolds and branch pipes to remove the high heat load expected during ITER
operation.

14. MAGNETS
Ten thousand tones of magnets, with a combined stored magnetic energy of 51
Gigajoules , will produce the magnetic fields that will initiate, confine, shape and
control the ITER plasma. Manufactured from niobium-tin (Nb3Sn) or niobium-
titanium (Nb-Ti), the magnets become superconducting when cooled with
supercritical helium in the range of 4 Kelvin (-269 °C).
Superconducting magnets are able to carry higher current and produce stronger
magnetic field than conventional counterparts. They also consume less power and are
cheaper to operate .
ITER uses high-performance, internally cooled superconductors called "cable-in-
conduit conductors," in which bundled superconducting strands—mixed with copper—
are cabled together and contained in a structural steel jacket.

15. TOROIDAL AND POLOIDAL FIELD SYSTEM
 Eighteen "D"-shaped toroidal field
magnets placed around the vacuum
vessel produce a magnetic field
whose primary function is to confine
the plasma particles. The toroidal
field coils are designed to produce a
total magnetic energy of 41
gigajoules and a maximum magnetic
field of 11.8 tesla. Weighing 310
tonnes each, and measuring 9 x 17
m, they are among the largest
components of the ITER machine.
 Six ring-shaped poloidal field coils
are situated outside of the toroidal
field magnet structure to shape the
plasma and contribute to its stability
by "pinching" it away from the
walls. The largest coil has a diameter
of 24 metres; the heaviest is 400
tonnes. The poloidal field coils are
designed to produce a total magnetic
energy of 4 gigajoules and a
maximum magnetic field of 6 tesla.

17. CRYOSTAT
 The ITER cryostat—the largest stainless steel high-vacuum pressure chamber ever
built (16,000 m³)—provides the high vacuum, ultra-cool environment for the ITER
vacuum vessel and the superconducting magnets.
 Nearly 30 metres wide and as many in height, the internal diameter of the
cryostat (28 metres) has been determined by the size of the largest components
its surrounds: the two largest poloidal field coils. Manufactured from stainless
steel, the cryostat weighs 3,850 tones. Its base section—1,250 tones—will be the
single largest load of ITER Tokamak assembly.
 The cryostat has 23 penetrations to allow access for maintenance as well as over
200 penetrations—some as large as four metres in size—that provide access for
cooling systems, magnet feeders, auxiliary heating, diagnostics, and the removal
of blanket sections and parts of the divertor.
 Large bellows situated between the cryostat and the vacuum vessel will allow for
thermal contraction and expansion in the structures during operation. The
structure will have to withstand a vacuum pressure of 1 x 10 -4 Pa; the pump
volume is designed for 8,500 m³.

19. FUELLING THE FUSION REACTOR
 Although different isotopes of light elements can be paired to achieve fusion, the
deuterium-tritium (DT) reaction has been identified as the most efficient for
fusion devices. ITER and future devices will use the hydrogen isotopes deuterium
and tritium to fuel the fusion reaction.
 Deuterium can be distilled from all forms of water. It is a widely available,
harmless, and virtually inexhaustible resource. In every cubic meter of seawater,
there are 33 milligrams of deuterium.
 Tritium is a fast-decaying radioelement of hydrogen which occurs only in trace
quantities in nature. It can be produced during the fusion reaction through contact
with lithium, however: tritium is produced, or "bred," when neutrons escaping the
plasma interact with lithium contained in the blanket wall of the tokamak.
 Lithium from proven, easily extractable land-based resources would provide a
stock sufficient to operate fusion power plants for more than 1,000 years. What's
more, lithium can be extracted from ocean water, where reserves are practically
unlimited.

20. PLASMA HEATING
One of the main requirements for achieving fusion is to heat the plasma particles to very
high temperatures. In ITER, several heating methods will work concurrently to bring the
plasma in the core of the machine to 150 million °C.
Within the tokamak, the changing magnetic fields that are used to control the plasma
produce a heating effect. The magnetic fields create a high-intensity electrical current
through induction, and as this current travels through the plasma, electrons and ions
become energized and collide. Collisions create "resistance" that results in heat, but as the
temperature of the plasma rises, this resistance decreases and therefore the heating effect
also decreases. Heat transferred through high-intensity current, known as ohmic heating, is
limited to a defined level.

21. EXTERNAL HEATING
Two families of external heating methods—neutral beam injection and high-
frequency electromagnetic waves that will complement ohmic heating to bring
the ITER plasma to temperature.
1. NUCLEAR BEAM INJECTION
Neutral beam injection consists in shooting high energy particles into the plasma. Outside of the
tokamak, charged deuterium particles are accelerated to the required energy level. These accelerated
ions then pass through an "ion beam neutralizer" where their electrical charge is removed. The high
velocity neutral particles can then be injected into the heart of the plasma where, by way of rapid
collision, they transfer their energy to the plasma particles.
2. MICROWAVE TRANSFER
In the same way that microwaves transfer heat to food in a microwave oven, the energy carried by high-
frequency waves introduced into the plasma is transferred to the charged particles, increasing the
velocity of their chaotic motion, and at the same time their temperature. Following this principle three
types of waves will be employed in ITER, each matching a frequency of plasma ions and electrons in the
interior of the ITER machine to maximize heat transfer.

22. PLASMA CONFINEMENT
 The doughnut-shaped torus of the tokamak represented a major break-through in plasma
science at the time, offering the conditions for temperature levels and plasma confinement
times that had never before been reached.
 The ITER Tokamak chamber will be twice as large as any previous tokamak, with a plasma
volume of 840 cubic meters, the plasma would occupy all of the space in the chamber (1,400
m³), however no material could withstand contact with the extreme-temperature plasma.
Scientists are able to contain or "confine" the plasma away from the walls by
exploiting its properties.
 Plasmas consist of charged particles—positive nuclei and negative electrons—that can be
shaped and confined by magnetic forces. Like iron filings in the presence of a magnet,
particles in the plasma will follow magnetic field lines. The magnetic field acts as a recipient
that is not affected by heat like an ordinary solid container.

23.  Total fusion power 500 MW
 Q = fusion power/auxiliary heating power ≥10 (inductive)
 Peak temperature 2×10⁸ K
 Plasma inductive burn time ≥ 300 s
 Plasma major radius 6.2 m
 Plasma minor radius 2.0 m
 Plasma current 15 MA
 Vertical elongation @95% flux surface/separatrix 1.70/1.85
 Triangularity @95% flux surface/separatrix 0.33/0.49
 Safety factor @95% flux surface 3.0
 Toroidal field @ 6.2 m radius 5.3 T
 Plasma volume 837 m3
 Plasma surface 678 m2
 Installed auxiliary heating/current drive power 73 MW (100 MW)

24. CONTRIBUTION TO ITER
A large diversity of professional experience 2000 staff,35 nation and 40 language
ITER currently have 636 members,
in addition to 450 contractors,
experts and consultant directly work
for ITER

26. WHEN THE EXPERIMENT WILL BEGIN?
 The ITER scientific facility is under construction now in southern France.
 On a cleared, 42-hectare site, building has been underway since 2010. The ground
support structure and the seismic foundations of the ITER Tokamak are in place
and work is underway on the Tokamak Complex—a suite of three buildings that will
house the fusion experiments. Work is also underway on auxiliary plant buildings
such as the ITER cryoplant, the radio frequency heating building, and facilities for
cooling water, power conversion, and power supply.
 As soon as access to the Tokamak Building is possible, scientists and engineers will
progressively assemble, integrate, and test the ITER fusion device. Commissioning
will ensue to verify that all systems function together and to prepare the ITER
machine for operation.
 The successful integration and assembly of over one million components (ten
million parts), built in the ITER Members' factories around the world and delivered
to the ITER site constitutes a tremendous logistics and engineering challenge. The
assembly workforce, both at ITER and in the Domestic Agencies, will reach 2,000
people at the height of assembly activities. In the ITER offices around the world,
the exact sequence of assembly events has been carefully orchestrated and
coordinated. The first large components were delivered to the ITER site in 2015.

27. ITER Timeline
 2005 Decision to site the project in France
 2006 Signature of the ITER Agreement
 2007 Formal creation of the ITER Organization
 2007-2009 Land clearing and levelling
 2010-2014 Ground support structure and seismic foundations for the Tokamak
 2012 Nuclear licensing milestone: ITER becomes a Basic Nuclear Installation under
French law
 2014-2021* Construction of the Tokamak Building (access for assembly activities in
2019)
 2010-2021* Construction of the ITER plant and auxiliary buildings for First Plasma
 2008-2021* Manufacturing of principal First Plasma components
 2015-2021* Largest components are transported along the ITER Itinerary
 2018-2025* Assembly phase I
 2024-2025* Integrated commissioning phase (commissioning by system starts several
years earlier)
 Dec 2025* First Plasma
 2035* Deuterium-Tritium Operation begins


29. THANK YOU