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Transcript of Nuclear Fusion….. - WordPress.com · Nuclear Fusion….. Icarus flies too close to a fusion...
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Nuclear Fusion…..
Icarus flies too close to a fusion reactor.
Fall of Ikarus, Pieter Bruegel, Musées
Royaux des Boaux-Artes, Brussels
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
A talk by Robin Stafford Allen FIMechE
Monday 2nd September 2019
For Camberley and District U3A Members.
Fusion Power –
within our grasp?
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Fusion --within our grasp?
• Purpose and outcomes.
– Explain the basics of Plasma and Fusion Physics.
– Introduce the JET, MAST and ITER machines.
– Explain some of the terminology and technology.
– But first – WHY?
Present annual consumption / person
0.7 TCE
12.5 TCE6 TCE
1.4 TCE
mbh
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Fossil FuelsAll-world conventional oil production will peak in 5-15 years
And then there is
Global Warming …
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Fossil FuelsAll-world conventional oil production will peak in 5-15 years
And then there is
Global Warming …
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Summary
• We need base-load energy for the future– Fossil fuels reserves (oil and gas) are running low
– Global Warming means• Fossil Fuel with total carbon capture.
• Fission.
• Fusion (magnetic or laser).
• A technology yet to be found.
• “Renewables” are not the answer, they are a diversion.
• And now to Physics…..
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Structure of the average atom.
The number of protons define the element
Hydrogen has ONE proton
Helium has 2 protons
Lithium has 3 protons
Beryllium has 4 protons
……………..
Carbon has 6 protons
……………..
Iron has 26 protons
……………..
Uranium has 92 protons
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Isotopes.
• The same element can have other forms.
• Hydrogen (1) has a proton and no neutron.
– Usually called simply Hydrogen; Sometime termed “protium”
• Hydrogen (2) has 1 proton and 1 neutron.
– Usually called “Deuterium”
• Hydrogen (3) has 1 proton and 2 neutrons.
– Usually called “Tritium”.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Fusion Process Introduction
• Fusion
A fusion reaction occurs when two
light nuclei (ions) approach each
other so closely that they fuse.
Methods being investigated include:
– Magnetic Confinement fusion
(Tokamak’s)
– and Inertial Confinement fusion
(Lasers).
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Fusion Process Introduction
•Lawson’s CriterionUsable Fusion is feasible if Lawson
criterion is exceeded
“Plasma density”,
“Plasma temperature” and
“Confinement Time” are all sufficient at
the same time).
Typical numbers required are:
•Plasma density ~0.000001
atmospheres (million times less than
atmosphere),
•Plasma temperature 150 million
degrees C (million times room
temperature)
•Confinement time ~5-10s.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
A PLASMA
A ”soup” of ions, and electrons,
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
D + T Fusion
D + T a (3.5 MeV) + n (14.1 MeV)
Ash Plasma
heating
Energy
production
1 gram of D and T reacted is equivalent to burning 10,000,000 grams of coal or gas.
On a gallon of D and T a car would go 300,000,000 miles theoretically.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Mass deficit
E=Dmc2
In the process of fusion, 0.4% of the mass of the nuclei is lost and released as energy.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Plasma, Magnetic Confinement and
Interaction with the Wall
Motion of ions and electrons without magnetic field
With magnetic field
Motion in all directions
Particle contact with
the wall
Ordered particles
motion
Reduced (minimised)
contact with the wall
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Bend it around into a Torus
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Ohmic Heating.
• The first of three forms of
“Additional Heating”
• The transformer effect.
• This is used to drive a huge
current through the plasma.
• Used in the early stages of
heating the plasma.
• Not much use once the
temperature is up to
50 million °C as the plasma is
too good a conductor by then.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
RF Heating (Radio Frequency)
• Cyclotron frequency
– Charged particles in a magnetic field have a natural frequency of
gyration in the plane perpendicular to the field - the cyclotron
frequency. For electrons in a tokamak, the cyclotron frequency is
typically a few tens of GHz, and for ions, a few tens of MHz.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Neutral Beam Heating
• A beam of VERY
energetic fast particles.
• Ions, can be accelerated
but cannot penetrate to
magnetic field without
being recombined with
electrons to make
electrically neutral
particles.
– Analogy is a blow-lamp!
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
A pulse on JET
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Disruptions
• Disruption
– Sudden loss of the plasma – it “goes out” with, usually a bang!
• Disruption information
– During a disruption forces of over 600 tonnes have been recorded. It is an audible bang!
– Vessel movements up to 8 or 9mm have been seen. (JET weighs 2,800 tons, and is now restrained on hydraulic dampers) .
– Anecdotally, there is a seismic station north of Oxford which can detect the vibrations from a JET disruption. Apparently the spectrum is different from the spectrum of an earthquake.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
A pulse on JET
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Flywheel Generators
Progress on JET
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Can we improve the tokamak?
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Mega
Amp
Spherical
Tokamak
MAST
Spherical Tokamak
MAST
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
MAST-UPGRADE
Spherical Tokamak
MAST
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
The Next Step - ITER
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
ITER
Construction costs €20 Billion in 15 years
Construction in Cadarache - France
Construction began in 2007/8
Operation in 2025
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
ITER Machine 2018
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
ITER site in 2018
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Transporter• A dummy load of 360
concrete blocks will
be loaded onto the
special self propelled
platform (88 axles,
352 wheels) to travel
the whole length of
the itinerary..
• Its weight and dims. –
800 tons, 40 metres
long, 9 metres wide,
11 metres high –
mimic the most
exceptional ITER
load.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
A Fusion Powerplant
Lithium blanket captures
energetic neutrons from the
fusion process and serves
two purposes.
Boils water in a heat
exchanger to produce
steam to drive a generator.
The Lithium and neutron
react to produce Tritium, one
of the primary fuels in the
fusion process.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Hydrogen from Fusion?
• High temperature catalytic thermo-chemical cracking of water
• Heat (800C or more) + 2H2O 2H2 + O2
• Only real candidate technologies are solar thermal, electric, or nuclear power. Fusion is safer, cleaner than fission.
HTR-10
Source: Solar Developments
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
So what’s holding us back?
• Money – limited funding.
– The big experiments are being done in sequence
JET → ITER → DEMOResults in the “30-year-rule”!
– D-T experiments: 1997, 2020, and 2025?
• Technical Limitation.
– Materials, and materials research.– The high-energy neutrons generally damage materials and
can only realistically be studied within fusion machines.
“Nuclear fusion…would
provide an inexhaustible
supply of energy without
pollution or global warming.”
(Professor Stephen Hawking)
“We know how to do fusion
as physicists, how it works.
It is an engineering solution
that is within our grasp.”
(Professor Brian Cox)
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
ITER News.
• Fusion - the neglected alternative
"In the current energy policy debate the longer-term prospects for a sustainable energy supply have been lost from view. Especially the potential of nuclear fusion are hardly perceived in the public debate", writes Dennis Wesselbaum, the author of an article recently published by the renown Institute for World Economy based in Kiel, Germany. In his conclusion, the Macro-Economist writes: "Our society can not afford not to invest into this technology."
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Advantages of Fusion …
• Fusion has little or no environmental impact – No greenhouse
gasses.
• Fusion will not produce any ‘long-lived’ radioactive waste.
• There is no risk of critical safety events e.g. ‘meltdown’.
• The fuels are abundant. Lithium in the earth’s crust, and…
Deuterium is freely available in …. Water.
CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority
Advantages of Fusion …
Fusion has little or no environmental impact – No greenhouse gasses.
Fusion should not produce any ‘long-lived’ radioactive waste.
There is no risk of critical safety events e.g. ‘meltdown’.
The fuels are abundant. Lithium in the earth’s crust, and
Deuterium is freely available in …. Water.
Any Questions?