Homer: "Where are we going, sir?"
Burns: "To create a new and better world."
Homer: "If it's on the way, could you drop me off at my house?"
History of Nuclear Power



James Chadwick first identified free neutrons
in 1932.
These neutrons were relatively heavy and
able to plough through electrons surrounding
the nucleus of other atoms
Neutrons are electrically neutral and are not
deflected by positive nuclear charge
Enrico Fermi


Physicist who studied
nuclear physics
Discovered that firing
these free neutrons at
elements caused them
to become radioactive
and emmit β-particles
Discovery of Nuclear Fission


1939 –Lise Meitner and Otto Frisch proposed
that the splitting of a heavy nucleus by way of
absorbing a neutron, caused the atom to
become unstable and split into two lighter
nuclei.
This process was called Nuclear Fission and
they observed that this reaction released a
great deal of energy.
Nuclear Fission


Fermi later discovered that
the fission reaction might
release free neutrons which
could cause further fission
reactions
A chain reaction could occur
releasing a great deal of
energy in a short time, a
nuclear explosion.
Enrichment


Niels Bohr was the first to establish that the
U-235 isotope readily underwent fission, but
the U-235 isotope is “diluted” in natural
uranium by 140 atoms of U-238
Enrichment was a way to increase the
proportion of U-235 and aid in the chain
reaction.
Manhattan Project


1941- President Roosevelt
put resources into the
development of the “atomic
bomb”
This lead to further studies
of nuclear fission and the
discovery of the first
controlled chain reaction.
achieved by Fermi and a
group of scientists at the
University of Chicago
Small Steps Toward Power
Production



December 20, 1951 – experimental reactor produced
enough power to light four 150 watt light bulbs
July 17, 1955 - Argonne Lab designed first reactor to
provide power for an entire town (Arco, Idaho).
1957 - The Atomic Energy Commission sponsored a
60 megawatt breeder reactor plant in Shippingport,
PA.
First Commercial Power Plant



1959 – Dresden Unit
One was built at a cost
of $18 million in Morris,
Illinois.
200 MW Duel Cycle
Boiling Water Reactor
Designed and operated
by General Electric until
1979 when it was shut
down.
Nuclear Fission
“A mechanism by which a
heavy nucleus absorbing a
neutron might become
unstable and split into two
lighter nuclei.”
Source: Energy Systems & Sustainability
Inducing Fission

Absorption of a free Neutron
–

free protons / other nuclei can also induce fission
Easiest in Heavy elements
fission in elements heavier than Fe  Output E
– fission in elements lighter than Fe  Input E
–

Abundance / Easy of Fission:
–
Uranium heaviest naturally occurring element
– Plutonium undergoes spontaneous fission
Source: How Stuff Works
Chain Reaction

Initiation  2 or more
neutrons  neutrons
escape/initiate more
fission.

High Concentration of
U-235 required to
maintain chain reaction
Source: ThinkQuest ‘98
Animation of Fission & Chain Reaction

Critical Mass- The amount of material of a
given shape and volume to maintain a chain
reaction
Source: Energy systems & sustainability
Products of Fission




2 new radioactive nuclei
2 or 3 free neutrons
Heat / Gamma Radiation
ENERGY
Source: Nuclear Fission and Nuclear Fusion
Where does the Energy come from?

Sum of Mass of products < Original Mass

“Missing” Mass (~0.1% of Original Mass) has been
converted to energy

E=Δmc^2

U235 + n → fission + 2 or 3 n + 200 MeV
Source: Think Quest
E=Δmc^2

A very small amount of matter is
equivalent to a vast amount of energy.

For example, 1 kg (2.2 lb) of matter
converted completely into energy would
be equivalent to the energy released by
exploding 22 megatons of TNT.
Source: Nuclear Fission and Nuclear Fusion
Nuclear Fusion

“the comming together of two lighter nuclei
to form one heavier one

Process that powers the stars
Original source of almost all of
earths energy

Source: Joint European Torus (JET)
How Fusion works

Most suitable reaction involves:
– Deuterium (D)
– Tritium (T)
(Isotopes of Hydrogen)


Temperatures of >10 million
deg. C
Plasma: State in which electrons
have been removed from atomic
nuclei
Source: Joint European Torus (JET)
Nuclear Fusion Animation
Means of Initiating Fusion:
Source: FusEdWeb: Fusion Energy Educational Web Site
Fusion by Magnetic Confinement



PLASMA is so high in energy it
requires Magnetic Fields to
contain it.
Magnetic fields trap superheated
fusion fuel in center of loop.
Immense temperatures/pressures
Source: FusEdWeb: Fusion Energy Educational Web Site
http://fusedweb.pppl.gov/
Why does Fusion yield Energy?



Mass of Products is
less than mass of
reactants.
E=mc^2
mass converted to
kinetic energy
Source: FusEdWeb: Fusion Energy Educational Web Site
Where does Tritium & Deuterium Come from?

Tritium:
–
Bombarding Lithium with
a Neutron

Deuterium:
–
–
Plentiful in ordinary
water.
1/6500 hydrogen atoms
in water is Deuterium
1 gallon of water
conceivably has the
energy content of 300
gallons of gasoline
Source: General Atomics
http://fusedweb.pppl.gov/
Yield of Fission vs. Fusion
Source: General Atomics
Nuclear Fuel Cycle
Reactor Core
Moderators

Slows the neutrons in order to maintain
chain reaction
Light Water Moderator

Ordinary Water

light-water reactors require slightly enriched
(up to 20% U-235) uranium fuel to sustain
the fission reaction.

4/5 of today’s reactors are light water
Reactor Types: Boiling and Pressurized
Water

Pressurized Water Reactor
Boiling Water Reactor
Heavy Water Moderator

Hydrogen-2 or Deuterium (D20)

Uses Natural Uranium as oppose to Enriched
uranium
isolating the small amount of D2O present in
natural water requires considerable amounts
of electricity.
Reactor Types: CANDU and Steam Generating
Heavy Water Reactor


Graphite Moderator




Most Easily Available Effective Moderator
Derived from Carbon(graphite)
Heavier than the Deuteron but neutron
absorption low
Reactor Types: Advance Gas Cooled
Reactor
Spent Fuel

2 Distinct Processes:

Direct Disposal

Reprocessing
Consumption







Nuclear power provides
about 6% of the worlds
primary energy.
439 Total Reactors in 31
different countries.
103 in the US
59 in France
53 in Japan
Three countries receive
more than half of their
electricity from nuclear:
France, Lithuania, Belgium.
US gets 20% of electricity
from nuclear
Pros
Abundant
Reliable
Relatively
safe
Little pollution
Radiation
Cons
– lack of coolant in the core
Waste Disposal- high and low level
Radiation- weak carcinogen
Meltdowns
Radioactivity: Pro and Con





Did you know that some of the foods we eat have
been treated by exposure to radiation?
Have you ever wondered how we know the age of
dinosaur bones?
Have you ever known anyone who was treated for
cancer with radiation therapy?
Have you ever wondered how a nuclear submarine
is powered?
Have you ever had an x-ray to look for a broken
bone?
Environmental Effects
Radioactivity
Waste
heat
Sulfur Dioxide
Air quality
Nuclear Efficiency
Nuclear
power plants need to be re-fueled only
once every year, while coal power plants require a
trainload of coal per day.
The energy that can be obtained from one pound
of uranium is equal to the amount of energy in
approximately million pounds of coal.
Benefits of Nuclear Energy



Nuclear power is the only energy producing
technology which takes full responsibility for all its
wastes and fully costs this in the the product.
The amount of radioactive wastes are very small
relative to wastes produced by fossil fuels .
Spent nuclear fuel may be treated as a resource.
Uranium Resources
Known Recoverable Resources* of Uranium
tonnes U
percentage of world
Australia
863,000
28%
Kazakhstan
472,000
15%
Canada
437,000
14%
South Africa
298,000
10%
Namibia
235,000
8%
Brazil
197,000
6%
Russian Fed.
131,000
4%
USA
104,000
3%
Uzbekistan
103,000
3%
World total ,107,000
* Reasonably Assured Resources plus Estimated Additional Resources - category 1, to US$ 80/kg U, 1/1/01, from OECD NEA & IAEA, Uranium 2001: Resources,
Production and Demand.
Brazil, Kazakhstan and Russian figures above are 75% of totals.
Uranium Availability
Known recoverable resources
of Uranium (1999 data)
Country
Tonnes
% World total
Australia
889,000
27
Kazakhstan
558,000
17
Canada
511,000
15
South Africa
354,000
11
Namibia
256,000
8
Brazil
232,000
7
Russian Federation
157,000
5
US
125,000
4
Uzbekistan
125,000
4
World total
3,340,000
At current usage --> 48 yrs
Greenhouse Gas Emissions

Worldwide emissions of CO2 from burning fossil fuels
total about 25 billion tonnes per year. About 38% of this
is from coal and about 43% from oil. If uranium is used
in a nuclear power reactor, these emissions do not
occur.
Safety Factor
Fuel
Coal
Natural gas
Hydro
Nuclear
Immediate fatalities 1970-92
6400
1200
4000
31
Who?
workers
Deaths per TWy* electricity
342
workers & public
public
workers
85
883
8
References
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“Basic Nuclear Fission.” ThinkQuest. Accessed from: http://library.thinkquest.org/17940/texts/fission/ fission.html?tqskip1=1. on
2-13-05.
General Atomics. FusEdWeb: Fusion Energy Educational Web Site. accessed from: http://fusedweb.pppl.gov/. on 2-13-05.
Godfrey Boyle, Bob Everett, Janet Ramage. Energy Systems and Sustainability. Oxfoord University Press 1998.
How Stuff Works. “How Nuclear Power Works.” Accessed from: http://people.howstuffworks.com/nuclear-power2.htm. on 213-05.
“Nuclear Fission and Nuclear Fusion.” Accessed from:http://chemed.chem.purdue.edu/genchem/
topicreview/bp/ch23/fission.html. on 2-13-05.
http://www.chem.duke.edu/~jds/cruise_chem/nuclear/pros.html
http://starfire.ne.uiuc.edu/~ne201/1996/kopke/problems.html
http://members.tripod.com/funk_phenomenon/nuclear/procon.htm
http://www.world-nuclear.org/info/inf69.htm
http://nuclearhistory.tripod.com/history.html
www.chemcases.com