Electricity Production by Fuel
9%
Coal
Hydroelectric
Power
Other
23%
56%
Nuclear
3%
9%
U.S. Department of Energy, Annual Energy Review 1999
Natural Gass
Fig 1: Nuclear Reactors in the World
Source : AIEA
By the end of 2002:
30 countries
441 reactors
16% of electricity production
7% of primary energy
4
Radioactivity
• Types
• Alpha particles consist of 2 protons and 2 neutrons,
and therefore are positively charged
• Beta particles are negatively charged (electrons)
• Gamma rays have no mass or charge, but are a form
of electromagnetic radiation (similar to X-rays)
• Sources of natural radiation
•
•
•
•
•
Soil
Rocks
Air
Water
Cosmic rays
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Radioactivity
• Radioactivity: Nuclear changes in which
unstable (radioactive) isotopes emit particles &
energy
• Radioactive decay continues until the the original
isotope is changed into a stable isotope that is not
radioactive
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Relative Doses
from Radiation
Sources
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
Effects of Radiation
• Genetic damages: from mutations
that alter genes
• Genetic defects can become
apparent in the next generation
• Somatic damages: to tissue, such as
burns, miscarriages & cancers
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Half-Life
The time needed for one-half of the nuclei in a
radioisotope to decay and emit their radiation to
form a different isotope
Uranium 235
Plutonium 239
Half-time
710 million yrs
24,000 yrs
emitted
alpha, gamma
alpha, gamma
During operation, nuclear power plants
produce radioactive wastes, including some
that remain dangerous for tens of thousands
of years
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Destructive power:
[1] Small towns have been leveled by floods and landslides.
[2] The same size town could be leveled by 1,000 tons of
chemical explosives.
[3] Hiroshima (quarter of a million people) was
destroyed by releasing the energy in 40 kg of Uranium
We know the least about the strong nuclear force.



1945
first large scale use
atomic bombs were used
by the US to knock
Japan out of WWII

since then attention has
been given to the peaceful
uses of atomic energy

In a conventional nuclear
power plant
a
controlled nuclear fission chain
reaction
 heats water
 produce high-pressure steam
 that turns turbines
 generates electricity.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
 approximately
20,000 times as
much heat and energy is
released from uranium fuels
as from an equivalent amount
of coal
 when
a sufficient amount of
fissionable material is brought
together, a chain reaction
occurs splitting atoms and
releasing a tremendous
amount of heat
Nuclear Fission
Controlled Fission
Chain Reaction
neutrons split the
nuclei of atoms such
as Uranium or
Plutonium
release energy (heat)
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Fusion and Fission are governed by the nuclear strong force.
Fusion: two nuclei stick together (or fuse) to form a
new, larger nucleus
Two separate
nuclei
One new nucleus
Fission: When a single nucleus splits to form two smaller
nuclei.
Large nucleus
Two smaller nuclei
Controlled Nuclear Fission
Reaction
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
Under
appropriate
operating
conditions, the
neutrons given
off by fission
reactions can
"breed" more
fuel, from
otherwise nonfissionable
isotopes, than
they consume
www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
 Fusion
is combining together
 the atoms are fused together
rather than split apart
 possibilities for nuclear fusion
are much greater than those
for nuclear fission
Imagine putting a hydrogen nucleus together instead of
pulling it apart. We normally write this in a special way:
n + p
neutron
n
proton
+
2
H
1
Hydrogen
nucleus
p
This reads: a neutron and a proton fuse together to form a
hydrogen nucleus.
n + p
n
+
More energy
2
H
1
p
Less energy
Where did the excess energy from the left-hand-side go?
There must be energy released in this process!! It comes in
the form of Radiant and Thermal energy
Nuclear
(fusion) Energy
Thermal + Radiant Energy
 fusion
reactors would be
fueled by deuterium, an
isotope of hydrogen
 available in almost unlimited
supply in sea water
Problems:
 process is so difficult to
control that it is questionable
whether commercial
adaptation will ever be
economically feasible
 fusion
requires extreme
pressure and temperatures (as
high as 100 million degrees)
 such heat was achieved by the
Hydrogen bomb by first
setting off a fission explosion
Concerns about the safety, cost,
and liability have slowed the
growth of the nuclear power
industry
 Accidents at Chernobyl and
Three Mile Island showed that a
partial or complete meltdown is
possible

Chernobyl
• April 26, 1986, reactor explosion (Ukraine) flung
radioactive debris into atmosphere
• Health ministry reported 3,576 deaths
• Green Peace estimates32,000 deaths;
• About 400,000 people were forced to leave their
homes
• ~160,000 sq km (62,00 sq mi) contaminated
• > Half million people exposed to dangerous levels of
radioactivity
• Cost of incident > $358 billion
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Three Mile Island
• March 29, 1979, a reactor near Harrisburg, PA lost
coolant water because of mechanical and human
errors and suffered a partial meltdown
• 50,000 people evacuated & another 50,000 fled area
• Unknown amounts of radioactive materials released
• Partial cleanup & damages cost $1.2 billion
• Released radiation increased cancer rates.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
 evacuation
of preschool
children and pregnant
women within five miles of
the plant
Photos from :
The Yucca Mountain Project:
http://www.ymp.gov
/
Radioactive Waste
1. Low-level radiation (Gives of low amount of
radiation)
• Sources: nuclear power plants, hospitals &
universities
• 1940 – 1970 most was dumped into the ocean
• Today deposit into landfills
2. High-level radiation (Gives of large amount of
radiation)
• Fuel rods from nuclear power plants
• Half-time of Plutonium 239 is 24000 years
• No agreement about a safe method of storage
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Radioactive Waste
1. Bury it deep underground.
• Problems: i.e. earthquake, groundwater…
2. Shoot it into space or into the sun.
• Problems: costs, accident would affect large area.
3. Bury it under the Antarctic ice sheet.
• Problems: long-term stability of ice is not known,
global warming
4. Most likely plan for the US
• Bury it into Yucca Mountain in desert of Nevada
• Cost of over $ 50 billion
• 160 miles from Las Vegas
• Transportation across the country via train & truck
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Yucca Mountain
www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
 “The
odds of an American
dying from a nuclear power
accident are 300 million to
one.”
Electricity
Electricity
& H2
Long-Term Nuclear Energy Depends on
an Advanced Nuclear Fuel Cycle
Multiple
Nuclear
Reactors
Reactor
Fuel
Fabrication
Interim
Storage
Recycle
Reprocessing
Recycling TRU
In Adv. Reactor
Enrichment
Conversion
Uranium
Extraction
Fissile
Resources
Encapsulation
High
Level
Waste
Fissile Waste
235U/233U/239Pu
Intermediate/Low
Level Waste
Waste
Disposal
Spent
Fuel
The Nuclear Fuel Cycle
including
High level vs. low level
Nuclear Waste