Nuclear group

2. 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?"

3. 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

4. Enrico Fermi
Physicist who studied
nuclear physics
Discovered that firing
these free neutrons at
elements caused them
to become radioactive
and emmit β-particles

5. 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.

6. 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.

7. 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.

8. 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

9. 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.

10. 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.

11. “A mechanism by which a heavy nucleus absorbing a neutron
might become unstable and split into two lighter nuclei.”
Source: Energy Systems & Sustainability

12. 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

13. Chain Reaction
Initiation  2 or more
neutrons  neutrons
escape/initiate more
fission.
High Concentration of
U-235 required to
maintain chain reaction
Animation of Fission & Chain ReactionSource: ThinkQuest ‘98

14. Critical Mass- The amount of material of a given shape
and volume to maintain a chain reaction
Source: Energy systems & sustainability

15. Products of Fission
2 new radioactive nuclei
2 or 3 free neutrons
Heat / Gamma Radiation
ENERGY
Source: Nuclear Fission and Nuclear Fusion

16. 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

17. 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

18. 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)

19. 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
Nuclear Fusion Animation
Source: Joint European Torus (JET)

20. Source: FusEdWeb: Fusion Energy Educational Web Site

21. 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/

22. 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

23. 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/

24. Yield of Fission vs. Fusion
Source: General Atomics

25. Nuclear Fuel Cycle

26. Reactor Core

27. Moderators
Slows the neutrons in order to maintain chain
reaction

28. 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

29. Pressurized Water Reactor

30. Boiling Water Reactor

31. 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

32. 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

33. Spent Fuel
2 Distinct Processes:
Direct Disposal
Reprocessing

34. 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

35. Abundant
Reliable
Relatively safe
Little pollution
Radiation

36. Meltdowns – lack of coolant in the core
Waste Disposal- high and low level
Radiation- weak carcinogen

37. 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?

38. Radioactivity
Waste heat
Sulfur Dioxide
Air quality

39. 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.

40. 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.

41. 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.

42. 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

43. 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.

44. Safety Factor
Fuel Immediate fatalities 1970-92 Who? Deaths per TWy* electricity
Coal 6400 workers 342
Natural gas 1200 workers & public 85
Hydro 4000 public 883
Nuclear 31 workers 8

45. References
 “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 2-13-05.
 “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


46. References