Natural uranium contains about 0.7% uranium-235

1
(No Transcript)
2
(No Transcript)
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
Notes

• Natural uranium contains about 0.7 uranium-235
• To make nuclear fuel from natural uranium, it has
  to be enriched.
• Uranium-235 is added to natural uranium to raise
  the concentration to 3.
• Enriched uranium can then be used in a nuclear
  reactor.
• The first nuclear bomb was made of 60 kg of pure
  uranium-235. this is called the critical mass. It
  is big enough to cause a chain reaction in an
  instant. The chain reaction in a nuclear power
  station cannot grow in such an explosive way
  because
• - the uranium is put into fuel rods with a mass
  of 5kg much less than the critical mass.
• - it is only about 3 uranium-235.

7
(No Transcript)
8
Nuclear reactor is an assembly of fissionable
material (uranium-235 or plutonium-239) designed
to produce a sustained and controllable chain
reaction for the generation of electric power.
The essential components of a nuclear reactor
are 1. The core, metal rods containing enough
fissionable material to maintain a chain reaction
at the necessary power level (as much as 50 t of
uranium may be required). 2. A source of neutrons
to initiate the reaction (such as a mixture of
polonium and beryllium) 3. A moderator to reduce
the energy of fast neutrons for more efficient
fission (material such as graphite, beryllium,
heavy water, and light water are used) 4. A
coolant to remove the fission-generated heat
(water, sodium, helium, and nitrogen may be
used) 5. A control system such as rods of boron
or cadmium that have high capture cross sections
(to absorb neutrons) 6. Adequate shielding,
remote-control equipment, and appropriate
instrumentation are essential for personnel
safety and efficient operation.
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
Walt Disney's classic 1956 indoctrination tool
that nearly every American of a certain age
remembers reading in school (in between duck and
cover drills, of course). One of the first
examples of commercial "synergy," this book was a
tie-in to the film of the same name as well as an
exhibit at Disneyland's Tomorrowland. All three
projects sought to present the cheerful,
non-destructive side of the atom in entertaining
and, in hindsight, absurdly naive ways.
                                                  
CONELRAD is currently developing a new feature
entitled "Kold War for Kids" in which "Our Friend
the Atom" figures prominently. We encourage our
readers to submit their cultural and educational
recollections of growing up during this era. We'd
particularly like to hear from those of you who
remember the ways in which the Cold War was
explained to you by parents, teachers, and,
especially, Madison Avenue.
15
(No Transcript)
16
Energy from the Nucleus

• By 1905, Albert Einstein had developed his
  famous mass-energy equation
• E mc2
• E Energy
• m mass
• c speed of light

17
Energy from the Nucleus

• When protons and neutrons combine to form a
  nucleus, a small amount of mass is converted into
  energy. This is known as binding energy.

18
Binding Energy
19
The Building of the Bomb

• Nuclear Fission Fission occurs when larger
  nuclei split into small nuclei.

20
Nuclear Chain Reaction

• Fission of one nucleus produces neutrons that
  can cause the fission of other nuclei, thus
  setting off a chain reaction.

21
Manhattan Project

• The Manhattan Project was launched by President
  Roosevelt in 1939. It consisted of 4 separate
  research teams attempting to
• a. Sustain the nuclear fission reaction.
• b. Enrich uranium.
• c. Make fissionable plutonium-239.
• d. Construct a fission atomic bomb.

22
Manhattan Project

• Replicas of Little Boy (dropped on Hiroshima)
  and Fat Man (dropped on Nagasaki).

23
Manhattan Project

• Mushroom cloud over Nagasaki from the detonation
  of Fat Man, August 9, 1945.

24
Nuclear Power Plants

• Civilian nuclear power plants use less enriched
  uranium (2.5-3.5 uranium-235 rather than 90 for
  weapons-grade).
• The nuclear chain reaction is controlled for the
  slow release of heat energy. The heat is used to
  make steam, which turns a turbine to produce
  electricity.