Supplementary_Notes_files/nuclear waste 1

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Nuclear Energy and
Nuclear Waste
The Good, The Bad, and the Ugly…
What is Nuclear Energy?
• Nuclear energy is the energy that exists within the
nucleus of an atom.
• There are 2 types of Nuclear Energy:
•Nuclear fission is the splitting
of a large nucleus, releasing
HUGE amounts of energy.
•Nuclear fusion is the
combining of smaller nuclei to
form heavier nuclei, releasing
HUGE amounts of energy.
How is Nuclear Fission Energy produced?
If a Nuclear Reaction is not
controlled…
Nuclear Energy must be harnessed if
used to make energy.
• Nuclear reactions in a
nuclear power plant occur
at a controlled,
manageable pace and
release energy slowly.
• Heat is generated and used
to boil water, creating
steam. The steam turns
turbines which rotate
electric generators,
creating electricity.
• Steam is released from the
cooling towers.
•
(click on picture for more info)
How does a Nuclear Power Plant Work?
How much energy is produced?
• Nuclear power is an
extremely rich energy
source.
• One gram of Uranium235 delivers as much
energy as 3.5 metric
tons of coal!!!
• One in every 5 houses
in the U.S. is supplied
with nuclear energy.
Where are Nuclear Power Plants located?
Pros for Nuclear Power
• Rich energy source.
• 1 gram of Uranium-235 delivers as much
energy as 3.5 metric tons of coal.
• Reactors run for years without refueling or being
shut down and need little maintenance.
• No air pollution!
Cons about Nuclear Power
• Produces Radioactive Waste
• There is no permanent longterm disposal site for
commercial nuclear waste.
• There is a relatively short
supply of 235U (only enough left
for 100~200 years)
• Nuclear Power Plants are
expensive to build.
• Minor maintenance problems
can be very expensive to fix.
• Safety concerns!!!
Potential for Disaster!
• Chernobyl meltdown
in the former Soviet
Union.
– Hundreds died from
radiation exposure.
– Thousands contracted
cancers from high
levels of radiation
exposure.
A Close Call at Home!!!
• The most serious nuclear
accident in the U.S.
occurred in 1979 at
Three Mile Island
nuclear power plant in
Pennsylvania.
• A small amount of
radioactive gas escaped
the containment
structure.
Nuclear Waste
• Plutonium, cesium, strontium, and other “ium” elements created in a nuclear reactor emit
dangerous radiation that can literally knock
electrons off the atoms of our cells, disrupting
or destroying cell function or even causing
cells to mutate into cancer cells.
• Radioactive elements emit radiation because
they are unstable; they’d rather be something
else.
• They achieve this by going to pieces; emitting
particles and waves billions of times per
second. This process is called a half-life.
What is a Half-Life?
• Every radioactive element has
a half-life
• Half-life is the time it takes
for half of its atoms to decay.
• Half-lives range from a
fraction of a second to billions
of years – 4.5 billion for
uranium 238.
• The longer the half-life, the
less intense the radiation.
• After 10 half-lives, an element
is usually harmless
Types of Waste
•High-Level Waste
•The most dangerous radioactive
waste
•Spent fuel comes from nuclear
reactors (52,000 tons)
• liquid and solid waste from
plutonium production (91 million
gallons).
•About 70 percent of the
available storage space is now
filled with used fuel assemblies at
Turkey Point.
Types of Waste
Transuranic Waste
– Includes clothing,
tools, and other
materials
contaminated with
plutonium,
neptunium, and other
man-made elements
heavier than
uranium. (11.3
million cubic feet)
Types of Waste
• Low and Mixed Low-Level Waste
– Includes radioactive and hazardous wastes from hospitals,
research institutions, and decommissioned power plants (472
million cubic feet)
– Turkey Point produced annually on average about 2,500 cubic
feet of low-level waste. This amount of waste could be contained
within an area about the size of a 30'x30' room.
Types of Waste
Uranium Mill Tailings
•Residues left from the
extraction of uranium
ore (265 million tons).
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