Fusion and ITER Flashcards
The ITER Members—
Seven
China, the European Union, India, Japan, Korea, Russia the United States
ITER
I
T
E
R
International
Thermonuclear
Experimental
Reactor
ITER
Additional meaning
“The Way” in Latin
Where is ITER
Saint Paul-lez-Durance, southern France.
The world record for fusion power to date?
Date
Who
Q=
MW
In 1997 the European tokamak JET produced 16 MW of fusion power from a total input power of 24 MW (Q=0.67).
Record for Longest Tokamak Runtime
Plasma containment without fusion
Date, who
With fusion
Date, who
Without fusion, in tokamaks, the longest runtime is 29 hours, set by the fusion startup Tokamak Energy on July 6, 2016.
The record with fusion is 11 ms and was set by the fusion startup Tri Alpha Energy in 2015.
JET
J
E
T
Joint European Torus
ITER
Q=
MW
ITER is designed to produce a ten-fold return on energy (Q=10)
500 MW of fusion power from 50 MW of input power.
FUSION
Three conditions for fusion in a lab?
Three conditions must be fulfilled to achieve fusion in a laboratory
- very very high temperature
- sufficient plasma particle density (to increase the likelihood that collisions do occur)
- and sufficient confinement time (to hold the plasma, which has a propensity to expand, within a defined volume).
Sun Fusion Temperature
In the Sun’s core temperatures reach 15,000,000 °C
In the sun, where does the energy come from?
what percent of the mass is released as energy?
In the fusion of two hydrogen nuclei to form helium, 0.7% of the mass is carried away in the form of kinetic energy of an alpha particle or other forms of energy, such as electromagnetic radiation.
temperature needed for fusion in a lab?
150,000,000° Celsius)
Word origin of ‘tokamak’
from Russian
to(roidál’naya)
kám(era s)
ak(siál’nym magnitnym pólem),
ie. toroidal chamber with magnetic field
What is a Plasma?
At extreme temperatures, electrons are separated from nuclei and a gas becomes a plasma—often referred to as the fourth state of matter. Fusion plasmas provide the environment in which light elements can fuse and yield energy.
Who pays how much for ITER?
Europe is responsible for the largest portion of construction costs (45.6 percent); the remainder is shared equally by China, India, Japan, Korea, Russia and the US (9.1 percent each). The Members deliver very little monetary contribution to the project: instead, nine-tenths of contributions will be delivered to the ITER Organization in the form of completed components, systems or buildings.
Two other contributors to ITER
Names
Dates
The ITER Organization has also concluded non-Member technical cooperation agreements with Australia (through the Australian Nuclear Science and Technology Organisation, ANSTO, in 2016) and Kazakhstan (through Kazakhstan’s National Nuclear Centre in 2017).
ITER non-Member technical cooperation agreements.
Define
Enables this country access to research results of ITER in exchange for construction of selected parts of ITER machine.
When is ITER’s First Plasma scheduled
ITER’s First Plasma is scheduled for December 2025.
That will be the first time the machine is powered on,
Fusion compared to
Coal
Fission
terms of sheer scale, the energy potential of the fusion reaction is superior to all other energy sources that we know on Earth. Fusing atoms together in a controlled way releases nearly four million times more energy than a chemical reaction such as the burning of coal, oil or gas and four times more than nuclear fission.
ITER
How is the energy utilised?
The helium nucleus carries an electric charge which will be subject to the magnetic fields of the tokamak and remain confined within the plasma, contributing to its continued heating.
However, approximately 80 percent of the energy produced is carried away from the plasma by the neutron which has no electrical charge and is therefore unaffected by magnetic fields.
The neutrons will be absorbed by the surrounding walls of the tokamak, where their kinetic energy will be transferred to the walls as heat.
Role of Lithium in Fusion
If the blanket modules surrounding the Tokamak contain lithium, a reaction occurs: the incoming neutron is absorbed by the lithium atom, which recombines into an atom of tritium and an atom of helium. The tritium can then be removed from the blanket and recycled into the plasma as fuel.
Blankets containing lithium are referred to as breeding blankets. Through them, tritium can be bred indefinitely. Once the fusion reaction is established in a tokamak, deuterium and lithium are the external fuels required to sustain it. Both of these fuels are readily available.
Tritium breeding
If the blanket modules contain lithium, a reaction occurs: the incoming neutron is absorbed by the lithium atom, which recombines into an atom of tritium and an atom of helium. The tritium can then be removed from the blanket and recycled into the plasma as fuel.
Blankets containing lithium are referred to as breeding blankets. Through them, tritium can be bred indefinitely. Once the fusion reaction is established in a tokamak, deuterium and lithium are the external fuels required to sustain it. Both of these fuels are readily available.
Tritium breeding
Why is it important?
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 (enough to fulfill the world’s energy needs for ~ 6 million years).
Global inventory for tritium is presently around twenty kilos, which ITER will draw upon during its operational phase. The concept of “breeding” tritium within the fusion reaction is an important one for the future needs of a large-scale fusion power plant.
DEUTERIUM
Origin of Deuterium
Percent of Hydrogen as Deuterium
Deuterium is destroyed in the interiors of stars faster than it is produced. Other natural processes are thought to produce only an insignificant amount of deuterium. Nearly all deuterium found in nature was produced in the Big Bang 13.8 billion years ago, as the basic or primordial ratio of hydrogen-1 to deuterium (about 26 atoms of deuterium per million hydrogen atoms) has its origin from that time.
ITER Timeline
Past Milestones
- Decision to site the project in France
- Signature of the ITER Agreement
- Formal creation of the ITER Organization
2007-2009. Land clearing and levelling. (3 Yrs)
2010-2014. Ground support structure and seismic foundations for the Tokamak (5 Yrs)
ITER Timeline
Manufacturing, Construction and Assembly Phases
2008-2021 Manufacturing of principal First Plasma components
2010-2021 Construction of the ITER plant and auxiliary buildings for First Plasma
2014-2021 Construction of the Tokamak Building
2015-2021 Largest components are transported along the ITER Itinerary
2019-2024 Access to Tokamak Building for assembly activities
ITER TIMELINE
Overview of the most significant dates
The ITER facility is expected to finish its construction phase in 2019.
It will start commissioning the reactor that same year and initiate plasma experiments in 2020.
is not expected to begin full deuterium-tritium fusion until 2027.
ITER
Heating Methods
Internal heating
Name
How does it occur?
Maximum temperatures reached
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 paradoxically as the temperature of the plasma rises, this resistance—and therefore the heating effect—decreases. Heat transferred through high-intensity current, known as ohmic heating, is limited to a defined level (40-50 million degrees). In order to obtain still higher temperatures and reach the threshold where fusion can occur, heating methods must be applied from outside of the tokamak.
ITER
Heating Methods
External heating
First Method
What exactly is used
Two families of external heating methods—neutral beam injection and high-frequency electromagnetic waves—will complement ohmic heating to bring the ITER plasma to temperature.
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.
Millions of watts of heating power can be delivered to the plasma using this technique, bringing its temperature closer to the level where fusion can occur. (~100 million degrees?)
ITER
Heating Methods
External heating
Second Method
What exactly is used
A third source of heat—high frequency electromagnetic waves—is planned into the design of the ITER Tokamak to boost temperatures to the required 150 million °C.
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.
ITER
First three heating methods
Summary
OHMIC HEATING
Inside the magnetic containment, collisions are equivalent to ‘resistance’ and like electrons in a wire, increase the temperature. Up to a max of 40-50 million degrees where the temperature itself limits the resistance.
NEUTRAL BEAM INJECTION
Deuterium ions are accelerated by magnetic fields to high velocity then stripped of their charge (adding electrons?) and fired into the plasma. Heat to ~100M° ?
HIGH-FREQUENCY WAVES
Three frequencies of electromagnetic waves are fired into the plasma, like a microwave oven. Tuned to Deuterium, Tritium, and electrons? Combined heating reaches 150M° and Fusion occurs.
ITER
Ultimate Fusion Heating method
What is it
What % self sustain is needed?
Ultimately, researchers hope to achieve a “burning plasma”—one in which the energy of the helium nuclei produced by the fusion reaction is enough to maintain the temperature of the plasma. The external heating methods can then be strongly reduced or switched off altogether. A burning plasma in which at least 50 percent of the energy to drive the fusion reaction is generated internally is an essential step to reaching the goal of fusion power generation.
ITER VOLUME
Plasma volume
Vacuum Chamber volume
The ITER Tokamak chamber will be twice as large as any previous tokamak, with a plasma volume of 840 cubic metres. Left to itself, 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.
FUSION HISTORY
First Controlled Release Fusion Power
Date
Who
JET, which is collectively used by more than 40 European laboratories, achieved the world’s first controlled release of fusion power in 1991.
FUSION RECORDS
Highest Triple Product
Define
The Japanese JT-60 achieved the highest value of fusion triple product—density, temperature, confinement time—of any device to date.
FUSION RECORDS
Hottest Temperatures
US fusion installations have reached temperatures of several hundred million degrees Celsius.
FUSION
Progress made vs progress needed
Fusion research has increased key fusion plasma performance parameters by a factor of 10,000 over 50 years; research is now less than a factor of 10 away from producing the core of a fusion power plant.
Why is ITER not striving alone in its quest?
Fusion machines all over the world have re-oriented their scientific programs or modified their technical characteristics to act either partially or totally in support of ITER operation.
Name some areas of fusion research ongoing
These machines are conducting R&D on advanced modes of plasma operation, plasma-wall interactions, materials testing, and optimum power extraction methods, contributing to the success of ITER and the design of the next-phase device.
ITER Timeline
Operational Phase
2024-2025 Integrated commissioning phase (commissioning by system starts several years earlier)
- First Plasma
- Deuterium-Tritium Operation begins
What modifications have already been made to the ITER machine based on advancements in fusion science?
the addition of vertical stability
and Edge Localization Mode (ELM) coils, were incorporated into the 2010 Baseline
Australia’s Role in ITER?
Role
Our Party
Date
non-Member technical cooperation agreement
through the Australian Nuclear Science and Technology Organisation, ANSTO, in 2016
Fusion Equation
What goes in
What comes out
Fusion of deuterium with tritium
creating helium-4, freeing a neutron,
and releasing 17.59 MeV as kinetic energy of the products while a corresponding amount of mass disappears, in agreement with kinetic E = Δmc2, where Δm is the decrease in the total rest mass of particles.
Why do some elements fuse and others fission?
Light nuclei (or nuclei smaller than iron and nickel) are sufficiently small and proton-poor allowing the nuclear force to overcome repulsion. This is because the nucleus is sufficiently small that all nucleons feel the short-range attractive force at least as strongly as they feel the infinite-range Coulomb repulsion. Building up nuclei from lighter nuclei by fusion releases the extra energy from the net attraction of particles. For larger nuclei, however, no energy is released, since the nuclear force is short-range and cannot continue to act across longer atomic length scales. Thus, energy is not released with the fusion of such nuclei; instead, energy is required as input for such processes.
What is the cutoff Fusion -> Fission ?
Iron / Nickel
FUSION
Explain binding energy
Explain the repulsive energy
What is the interplay
In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons). The difference in mass between the reactants and products is manifested as the release of large amounts of energy. This difference in mass arises due to the difference in atomic “binding energy” between the atomic nuclei before and after the reaction.
The release of energy with the fusion of light elements is due to the interplay of two opposing forces: the nuclear force, which combines together protons and neutrons, and the Coulomb force, which causes protons to repel each other. Protons are positively charged and repel each other by the Coulomb force, but they can nonetheless stick together, demonstrating the existence of another, short-range, force referred to as nuclear attraction.[2] Light nuclei (or nuclei smaller than iron and nickel) are sufficiently small and proton-poor allowing the nuclear force to overcome repulsion. This is because the nucleus is sufficiently small that all nucleons feel the short-range attractive force at least as strongly as they feel the infinite-range Coulomb repulsion. Building up nuclei from lighter nuclei by fusion releases the extra energy from the net attraction of particles. For larger nuclei, however, no energy is released, since the nuclear force is short-range and cannot continue to act across longer atomic length scales. Thus, energy is not released with the fusion of such nuclei; instead, energy is required as input for such processes.
FUSION
What changes as nuclei approach?
It takes considerable energy to force nuclei to fuse, even those of the lightest element, hydrogen. When accelerated to high enough speeds, nuclei can overcome this electrostatic repulsion and brought close enough such that the attractive nuclear force is greater than the repulsive Coulomb force. The strong force grows rapidly once the nuclei are close enough, and the fusing nucleons can essentially “fall” into each other and result is fusion and net energy produced. The fusion of lighter nuclei, which creates a heavier nucleus and often a free neutron or proton, generally releases more energy than it takes to force the nuclei together; this is an exothermic process that can produce self-sustaining reactions.
FUSION HISTORY
1991 Milestone
In 1991 (1st yr Con) the Preliminary Tritium Experiment at the Joint European Torus in England achieved the world’s first controlled release of fusion power.
FUSION HISTORY
1997 Milestone
In 1997, JET produced a peak of 16.1MW of fusion power (65% of heat to plasma[130]), with fusion power of over 10MW sustained for over 0.5 sec.
Fusion Equation
How is the energy released?
The helium-4 nucleus gains 3.5 MeV as kinetic energy
The freed neutron, gains 14.1 MeV as kinetic energy
Fusion Equation
The easiest nuclear reaction, at the lowest energy, is:
2/1D + 3/1T → 4/2He (3.5 MeV) + 1/0n (14.1 MeV)
This reaction is common in research, industrial and military applications, usually as a convenient source of neutrons.
Tritium
Half life
Quantities and Values
Tritium is a natural isotope of hydrogen, but because it has a short half-life of 12.32 years, it is hard to find, store, produce, and is expensive. Trace amounts are formed by the interaction of the atmosphere with cosmic rays.
About 1 kilogram would be the total amount of tritium needed in a typical power station.
At the turn of the millennium, commercial demand for tritium is 400 grams per year and the cost is approximately US$30,000 per gram. 20kg total collected and stored on earth.
Deuterium
Deuterium is a naturally occurring isotope of hydrogen and is commonly available.
Separation of Hydrogen Isotopes
The large mass ratio of the hydrogen isotopes makes their separation easy compared to the difficult uranium enrichment process.
Lithium Breeding Reactions
L6
L7
FUSION
Lithium Equations
reactions:
1/0n + 6/3Li → 3/1T + 4/2He
The reaction with 6Li is exothermic, providing a small energy gain for the reactor.
1/0n + 7/3Li → 3/1T + 4/2He + 1/0n
The reaction with 7Li is endothermic but does not consume the neutron. At least some neutron multiplication reactions are required to replace the neutrons lost to absorption by other elements. Leading candidate neutron multiplication materials are beryllium and lead however the 7Li reaction above also helps to keep the neutron population high. Natural lithium is mainly 7Li however this has a low tritium production cross section compared to 6Li so most reactor designs use breeder blankets with enriched 6Li.
FUSION FUTURE
DEMO
Baseline Goals
MW
Q=
compared to current power stations.
MW = 2000-4000 (on a continuous basis)
Q = 25
Roughly equivalent to current power stations.
DEMO (DEMOnstration Power Station) is a proposed nuclear fusion power station that is intended to build upon the ITER experimental nuclear fusion reactor. The objectives of DEMO are usually understood to lie somewhere between those of ITER and a “first of a kind” commercial station. While there is no clear international consensus on exact parameters or scope, the following parameters are often used as a baseline for design studies: DEMO should produce at least 2 gigawatts of fusion power on a continuous basis, and it should produce 25 times as much power as required for breakeven. DEMO’s design of 2 to 4 gigawatts of thermal output will be on the scale of a modern electric power station.
FUSION FUTURE
DEMO Timeline
Decision
Construction
Operation
Electricity Production
Engineering design complete, and decision to build, in 2030
Construction from 2030 to 2045
Operation from 2045
Electricity generation demonstration 2050
[In 2012 European Fusion Development Agreement (EFDA) presented a roadmap to fusion power with a plan showing the dependencies of DEMO activities on ITER and IFMIF.
Conceptual design to be complete in 2020]
FUSION FUTURE
PROTO
Define
Date
PROTO is a proposed nuclear fusion reactor to be implemented not before 2050, a successor to the ITER and DEMO projects. It is part of the European Commission long-term strategy for research of fusion energy. PROTO would act as a prototype power station, taking in any technology refinements from earlier projects, and demonstrating electricity generation on a commercial basis. It may or may not be a second part of DEMO/PROTO experiment
It is estimated that subsequent commercial fusion reactors could be built for about a quarter of the cost of DEMO.
FUSION FUTURE
DEMO vs ITER
Size and plasma difference
To achieve its goals, DEMO must have linear dimensions about 15% larger than ITER, and a plasma density about 30% greater than ITER.
As a prototype commercial fusion reactor, DEMO could make fusion energy available by 2044.
ITER LOCATION
Cadarache is the largest technological research and development center for energy in Europe including CEA research activities and ITER.
CEA Cadarache is one of the 10 research centers of the French Commission of Atomic and Alternative Energies.
Established in the French département Bouches-du-Rhône, close to the village Saint Paul-lez-Durance, CEA Cadarache, created in 1959, is located about 40 kilometers from Aix-en-Provence, approximately 60 kilometres (37 mi) north-east of the city of Marseille
Cadarache
People
Other notables
It employs over 5,000 people, and approximately 700 students and foreign collaborators carry out research in the facility’s laboratories. ITER, the experimental nuclear fusion tokamak, is currently under construction at Cadarache and is expected to create his first plasma by 2025.
Other nuclear installations at Cadarache include the Tore Supra tokamak – a predecessor to ITER – and the Jules Horowitz Reactor, a 100-megawatt MTR which is planned to begin operation in 2021.
MTR
Definition
Example
A materials test reactor (MTR) is a high power research nuclear reactor.
The Jules Horowitz Reactor is a 100-megawatt MTR which is planned to begin operation in 2021, located in Cadarache where ITER is.
TRITIUM
Commercial uses
tritium gas-filled, thin glass vials with inner surfaces coated with a phosphor. In the tube, the tritium gives off a steady stream of electrons due to beta decay. These particles excite the phosphor, causing it to emit a low, steady glow. Such a tube is known as a “gaseous tritium light source” (GTLS), or beta light (since the tritium undergoes beta decay).
wide use in applications such as emergency exit signs, illumination of wristwatches, and portable yet very reliable sources of low intensity light which won’t degrade human night vision or easily alert others to your presence. Gun sights for night use and small lights (which need to be more reliable than battery powered lights yet not interfere with night vision or be bright enough to easily give away your location) used mostly by military personnel.
ng. Radium was used to make self-luminous paint from the early years of the 20th century until approximately 1970. Promethium briefly replaced radium as a radiation source. Tritium is the only radiation source used in radioluminescent light sources today.
The average such GTLS has a useful life of 10–20 years.[citation needed] As the tritium component of the lighting is often more expensive than the rest of the watch itself, manufacturers try to use as little as possible.[citation needed] Being an unstable isotope with a half-life of 12.32 years, the rate of beta emissions decreases by half in that period. Additionally, phosphor degradation will cause the brightness of a tritium tube to drop by more than half in that period. The more tritium that is initially placed in the tube, the brighter it is to begin with, and the longer its useful life. Tritium exit signs usually come in three brightness levels guaranteed for 10-, 15-, or 20-year useful life expectancies.[1] The difference between the signs is how much tritium the manufacturer installs.
Also 4g per Warhead
