Transcript FusionPresU3A26Nov08..

Dr Ian Falconer
School of Physics, University of Sydney
Some of the slides shown in this presentation were provided by:
Dr Joe Khachan, University of Sydney
Professor John O’Connor, University of Newcastle
I gratefully acknowledge their permission to use these slides
Fusion:
our energy future
FUSION
• The energy that drives the stars
• Can it also be harnessed on earth to
provide the energy our society needs?
Why fusion?
And what IS fusion?
•
The world has real energy problems
(And fusion energy MUST be a big part of the solution)
•
•
What is fusion?
How do we harness fusion energy?
The world is running out of (cheap) energy i.e. fossil fuels
and CO2 from fossil fuels
is a greenhouse gas
For these reasons, we URGENTLY need a
energy source to replace fossil fuels
(and it must be “portable” - like petrol –
so it can be used in cars and trucks)
The world has real energy problems
•
•
We are fast running out of oil (and natural gas)
Burning of fossil fuels generates carbon dioxide (CO2)
For every tonne of oil or coal used for generating energy,
around THREE tonnes of CO2 are generated
•
Per capita energy consumption increases as
nations become wealthier
Think about India and China
The case for fusion energy : standard of living
Growth of Australia’s Primary energy consumption and GDP
The case for fusion energy : standard of living
The case for fusion energy : standard of living
How long will it last?
Oil
~50-100 years
Natural gas
~60-100 years
Nuclear fission energy (U235 burners)
50 to ~100 years
Nuclear fission energy (breeder reactors)
Thousands of years
Solar, wind, tidal energy
Fusion energy
Renewable
Millenia
Fusion energy MUST be part of the solution
•
We have only limited oil and natural gas resources
Not only do these fuels generate CO2, but are a valuable
feedstock for the chemical industry
•
•
•
The combustion of coal must necessarily generate
the greenhouse gas CO2
Nuclear energy is another limited resource, and waste
disposal and proliferation are problematic – at least
politically
The “renewables” are intermittent resources, which
require extensive – and expensive - energy storage
capacity if the are to provide energy “on tap”
What is fusion?
Fusion energy powers the Sun
What is fusion?
•
The release of the energy stored in the nuclei of “heavy
hydrogen” atoms - deuterium and tritium
Hydrogen: nucleus consists of 1 proton
Deuterium: nucleus consists of 1 proton and 1 neutron
Tritium: nucleus consists of 1 proton and 2 neutrons
Chemically these isotopes are the same, but the deuterium and
tritium store considerable energy in their nuclei – this is the energy
that holds the nuclei together
The Most Promising Fusion Reaction
D-D Fusion Reaction
Proton
Neutron
Where do the fuels come from?
Deuterium is present in all “natural” hydrogen.
There is 1 atom of deuterium for every 6,000
atoms of hydrogen. Water is thus an abundant
source of deuterium
Tritium also occurs naturally, but in a fusion
reactor will be created by bombarding a blanket of
lithium surrounding the core of the reactor
Lithium is also abundant in nature: Australia has
60% of the world’s proven lithium reserves
“Breeding” tritium
Lithium + neutron → Tritium + Helium + ENERGY
Liquid lithium will be used as a coolant in fusion reactors.
It will absorb the energy of the neutrons, and at the same
time “breed” tritium and produce more energy
How do we harness fusion energy?
How do we harness fusion energy?
•
•
•
•
Bang a deuterium nucleus and a tritium nucleus
HARD together so they “fuse”
A mixture of deuterium and tritium gases must be heated
to a very high temperature if the nuclei are to “fuse”
– about 100 million degrees! Under these conditions
all the atoms are ionized and form a PLASMA
These high temperatures can only be achieved if the
gases are contained in a “bottle” constructed from a
really strong magnetic field
And a high density of colliding nuclei is required
if we are to get more fusion energy from the reactor
than we put into it
Magnetic Confinement
Toroidal field produces
greater confinement
Tokamak confinement
Inside a TOKAMAK
Tokamak Operating
Progress in magnetically confined fusion
• “Breakeven” regime :
ITER
Q = Pout /Pin ~1
Eg. Joint European
Tokamak : 1983 1997 : Q=0.7, 16.1MW fusion
• “Burning” regime : plasma
dominantly self-heated by fusion
born alpha’s
• “Ignition” regime, fully self-sustained : Power Plant.
ITER – “the way”
International Thermonuclear Experimental Reactor
An international project to produce a prototype fusion reactor
ITER partners
•
European Union
•
Japan
•
China
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Russian Federation
•
USA
•
Korea
•
India
•
(and possibly Brazil – and Canada, Mexico and Kazakhstan)
The ITER project
• Fusion power = 500MW
• Power Gain > 10
• Temperature ~ 80 million C
•Consortium of 7 nations
Cadarache,
France
Construction cost $10 billion, 10 year operation $6 billion
Fiscally, world’s largest science experiment
ITER
Person
ITER – the next generation tokamak
Design completed – construction has just commenced
Aims of the ITER project
• Produce and study inductively-driven, burning plasma at
Q =Pout/Pin  10 (400-500 MW) for an “extended” time, ~
400 s
• Produce and study burning plasma with non-inductive
drive Q  5
• Integrate essential fusion reactor technologies:
superconducting magnets, high heat flux components,
remote handling
• Test reactor components: eg tritium breeding module
concepts (neutron power load > 0.5 MW m-2, fluence >
0.3 MW year m-2).
Fusion is part of our Energy Future
But
….. When?
2016
First plasma
2020
First DT “burn”
2021
Q = 10
2024
Construction of DEMO to commence
2033
Operation of DEMO to commence
2045
Construction of power plant to commence
2055? Power plants operates!!!
NOW
ASSEMBLY STARTS
FIRST PLASMA
Beyond ITER…
2005
2010
2015
2020
2025
2030
2035
2040
2045
2050
today’s experiments
ITER
materials testing facility (IFMIF)
demonstration power-plant (DEMO)
commercial power-plants
R &D on alternative concepts and advanced materials
Source: Accelerated development of fusion power. I. Cook et al. 2005
Comparison to CPU transistors
The pros and cons of fusion energy
PRO
•
“Unlimited” fuel supply
•
Little waste produced
CON
•
Relatively expensive (High construction and
maintenance costs)
•
Structure highly radioactive – for a short time
0.001 $ / kWhr
The case for fusion energy : fusion economics
internal costs: costs of
constructing, fuelling,
operating, and disposing of
power stations
external costs: “estimated”
impact costs to the
environment, public and
worker health,
Prospects for fusion electricity, I. Cook et al. Fus. Eng. & Des. 63-34, pp25-33, 2002
Fusion: a safe, relatively inexpensive source of
energy for which we have an inexhaustible
supply of fuel
ITER is – undoubtedly – “the way”
Why isn’t Australia
– pioneers in the field of fusion physics involved in the ITER project??
THE END
LHC: the Large Hadron Collider
7 TeV = 7,000,000,000,000 eV