Topics
1. Elements of Nuclear Physics
2. History of Nuclear Physics; beginning of nuclear
energetics
3. Detecting nuclear radiations, radiation detectors
4. A nuclear power plant
5. Types of nuclear reactors based on usage of the
reactors
6. Generations of nuclear power plants
7. Nuclear reactors in Hungary
8. Mini or small nuclear power plants
9. Reactor safety, radiation safety
10. Nuclear accidents, abnormal operations
11. Nuclear power plants and environmental protection
12. Fusion, fusion devices, fusion power plants
13. Natural nuclear reactors or nuclear reactors in nature
Lecture #9.
Part I.
Nuclear fusion
as a possible new energy
source for the future
Outline
•
Energy consumption on the Earth
•
•
Energy sources (today and „tomorrow”)
Fusion, „a friendly energy source” →
(plasma physics)
•
Magnetic confinement fusion
•
Laser fusion
Lecture #9.
Energy consumption on the Earth
• Energy consumption is
growing up on the Earth in
the XXth century
• Consumption increases by
25% by 2020
• Reasons:
In order to cover the energy demand
of the population new energy sources
are needed.
Lecture #9.
o Energy consumption in
developing contries is
growing up.
o Population growth
o Industrialization grows up
Energy sources
Energy sources - today:
• 3 droups can be defined:
o Fossil sources (dominant) –
Energy from the sun conserved
during millions of years
o Nuclear sources – energy from
nucleus
o Renewable energy sources –
energy sources generated by the
sunshine and weather on the
Earth.
gas
oil
nuclear
water
biomass
coal
Other renewables
„Energy sources for tomorrow”
o Fusion reaction as an ideal
energy source?
o ? Anything more?
Lecture #9.
Today, energy supply for the human
population is based on fossil sources.
Fossil sources
•
Coal: used in power plants. Coil
might be enough fore more than
200 years. (source: USA)
•
Oil: primary source for traffic and
vehicles. Sources are enough for
30-40 years. (USA)
•
Gas: Main energy sources for
heating. Gas might be enough for
60-70 years only. (USA)
Use of fossil energy sources will be
decreasing in the short and far future.
Reasons: environment safety+ decreasing
quantities of sources.
Lecture #9.
Nuclear sources
•
•
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•
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Nuclear power plants use isotop of
uranium 235.
Nuclear fission is the leading process in
nuclear power plants. Fission of nucleus
generates energy for the environment.
This energy can be used for energy
generation.
Isotop uranium 235 might be enough for
about 100 years.
In special reactors uranium 238 is also
used for energy production
Very hard safety instructions must valid
at nuclear power generation
Nuclear power generation is cheap and
environment-safe.
Nuclear waste must be storaged safely.
Transmutation = Conversion of nuclear
waste
Lecture #9.
Renewable sources
Solar energy:
• Energy from the sun as sunshine.
• Only a small amount of energy of
the sun energy can be used for
energy production. Lots of energy
goes to the „waste”. But
• Produced energy is about 100times more then the population
needed.
o
o
a.) solar panels
b.) solar collectors
Energy from the wind:
• Highly developing energy sources.
• Only several coutries can count
with.
• Germany: 3%, Denmark 14%
Distribution of solar and wind energy is
inhomogenious in time and in space.
Lecture #9.
Renewable sources
Water power supplies:
•
•
•
•
It is a highly used energy source of
the Earth
Energy originated from water can
cover less than 25% of energy
needs of the population of the
Earth.
12% of the usable water sources is
already used for energy generation
High reserves are in the developing
countries.
Lecture #9.
Renewable energy sources
Biomass:
•
Energy from the plants, but it is also
originating from the Sun.
•
It is highly developing source in
Hungary.
•
Two kinds of sources:
o
Industrial crops for vehicles (colza,
sunflower)
o
Burning of plant materials in power plants
(wood, reed)
Lecture #9.
Renewable energy sources
•
Wave energy:
Constantaneous move of water of
seas and oceans can generate
energy for the humans.
•
Tide energy:
Gravity between Moon and Earth
causes tide on the Earth. It has well
defined cycles.
•
Geotermical energy:
Constant energy from the deep
Earth.
Lecture #9.
Renewable energy sources
• Summary:
Renewable energy sources may play deterministic role in the
energy production in the future.
• Importances of these sources grows up continuously
• Renewable energy sources (alone) can not solve energy
problems of the human population.
Lecture #9.
An ideal energy source
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Environment friendly
Safe
Energy production on small footstep (area)
High quantity of energy can be produced
Pruducing continously
Cheap
Enough for very long time
All known energy sources are not ideal energy sources.
Lecture #9.
Nuclear fusion
•
In the nuclear power plant nuclear
fission is the basic process, what
produces energy.
•
There is an other process in the
nuclear physics, which is opposite
process of the fission. This opposite
process can also be used for energy
production. (Theoretically)
•
Nucleus stays from protons (red balls)
and neutrons (white balls).
•
If two small size and not heavy, but
light weight nucleus collides to each
other energy can be produced. This
energy is emitted out by the nucleus.
•
Emitted energy can be used for
energy production.
Lecture #9.
Energy balance of the fusion
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Energy product originated from the
fusion has lower energy but the net
energy of initial products.
•
Energy balance: usable energy is
the energy difference
•
Mass-defect transfers to energy.
•
𝐸 = 𝑚 ∙ 𝑐 2 - mass-energy
equivalence formula
Energy
Definition:
In nuclear physics, nuclear fusion is a nuclear reaction in which two
or more atomic nuclei collide at a very high speed and join to form a
new type of atomic nucleus. During this process, mass is not conserved
because some of the mass of the fusing nuclei is converted to
photons (energy).
Lecture #9.
Nuclear fusion is the friendly energy
source
• Deuterium-tritium fusion reaction
D + T  4He(3.52 MeV) + n(14.1 MeV)
(1eV = 1,610 -19 J)
Lecture #9.
Fusion – Energy source of
the stars
Lecture #9.
•
Fusion is the nuclear interaction,
which produces energy of the stars
(our only one star is the Sun.)
•
In the stars hidrogen burns to
helium, but other fusion reactions
can also be appeared.
•
It is easy to produce nuclear fusion
in the Sun. The huge gravity force
keeps the nucleus close together.
•
Fusion reactors have been, is being
worked in the universe since long
time or will be working in the
universe for long time period.
•
Let`s bring the sun to the Earth!
Can we make nuclear fusion here
on the Earth?
Theoretically yes! People can build such a device which runs nuclear
fusion inside. But, it is a hard work!
• 3 important conditions needed to make nuclear fusion on the
Earth:
Conditions
1. Very high temperature
Density must be huge
2. Enough time to keep the
material together
3. Big enough density
Time must be long enough
to keep the materials together
for the interaction – long enough
interaction time
Temperature must be
kept on very high range
Lecture #9.
Fuel of fusion–
deuterium and tritium
The easiest possible
nuclear fusion reaction
on the Earth is the
deuterium – tritium
fusion reaction
Lecture #9.
How much initial material do we
need?
•
•
10 millions of tons coal would be enough to produce energy in Hungary for one
year
Using nuclear fusion power plant 150 kg deuterium and 230 kg tritium would be
enough.
Lecture #9.
Where can we find deuterium?
•
Every 6000th of water molecula
is deuterium in the water of
seas and oceans.
•
Need technology to get every
deuterium from the water
•
Technology does exist! We do
not need to develop just use it!
•
Deuterium is enough for millions
of years on the Earth.
Deuterium can be found in the waters!
Deuterium is enough for millions of years.
Lecture #9.
Where can we found tritium?
• Tritium is radioactive
material.
• Its half-life-time is 12 years. It
is a short time period.
• Tritium does not existon the
Earth.
• How can we generate it?
Lithium
Tritium can be generated from
lithium using fast neutrons.
Lithium is enough!
Lecture #9.
• Fast neutron + Lithium 
Tritium
• We must find lithium only
• Earth has lithium for millions
of years!
Schematics of a theoretical fusion
power plant
Helium
chambers
deuterium
Tritium
container
turbine
Generating
electricity
Fusion is safe
•
•
Lecture #9.
Less than 1 gramm of fusion
material is placed into the power
plant
This small amount of quantity is not
dangerous for any real and natural
life.
Energy production using
fusion is safe
Fusion power plants are safe!
Lecture #9.
•
Hard conditions for fusion
•
Fusion reactors can be stopped
easily in any problems
•
Human population must not be
moved out
Fusion is environment safe
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Joint European Experiment –
JET, England
Lecture #9.
There is no CO2 exhaust.
There is no any pollutant.
There is no radioactive waste
Tritium is radioactive, but tritium
can not go out from the fusion
reactor.
Huge energy – small footprint
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Huge power generation -- GW
Fuels are everywhere – fusion power plants can be designed everywere
Ground power plants.
Small area, small footprint.
Friendly prices.
Fusion power plant is usable as ground power plant.
Lecture #9.
An ideal energy source
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•
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Environment friendly
Safe
Energy production on small footstep (area)
High quantity of energy can be produced
Pruducing continously
Cheap
Enough for very long time
Fusion might be ideal energy source!
Lecture #9.