Nuclear Energy

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Nuclear Energy

• Recently presented in class

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Nuclear Power

• Nuclear fission is what we are talking about.
  Currently it supplies 8 of our total energy.
• It involves the splitting of U235 atoms into
  cesium and strontium atoms.
• The heat from this fission reaction can be
  converted to steam pressure that can be used to
  heat and drive big turbines to make electricity
  and power ships through our oceans.
• Like fossil fuels, nuclear energy is
  non-renewable, but it is an alternative to fossil
  fuels.
• Its a chain reaction!!!

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A Chain Reaction?
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A Chain Reaction

• Controlled in a nuclear reactor

• Uncontrolled in an atomic bomb.

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The Fission Reaction and its Uses

• Uses include making electricity..check this out

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We use nuclear power to generate 16 of the
worlds electricity
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How about a closer look around the world
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Other uses of nuclear fission include

• Propelling military vessels like nuclear subs,
  aircraft carriers, and others.
• Providing electricity to space probes and one day
  propelling space craft.
• Propelling air craft and more and more privately
  owned vehicles.
• Providing electrical power in medical
  science.like in pace makers, and bionic limbs.

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• Now lets see
• how it works!

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KABOOM!!! Uncontrolled Chain Reaction
Ended World War II
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Heres a look at the basic process!
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Nuclear Reactor Core at full power
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Heres how a typical boiler reactor makes
electricity.
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The North Anna Plant, Lake Anna, VA
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Surry Power Plant, James River, across from the
Jamestown settlement
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• Now that we know what it is
• and how it works
• Lets think about what makes
• nuclear power
• good or bad
• as a choice for the future?

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The advantages are

• It is based a working technology and it has been
  used for over 50 years to meet our needs.
• It does not pollute the air like fossil fuels.
• It will last much longer into the future than
  fossil fuels.
• It can be used for transportation, heating, and
  to make electricity.
• The United States has access to a lot of Uranium
  fuel.

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The disadvantages are

• The danger of exposure to radiation is great if
  an accident occurs or if radioactive waste leaks
  into our environment.
• Because of risks and insurance it is currently
  cheaper to build a new fossil fuel power plant
  than it is to build a new nuclear power plant.
• High and medium level nuclear waste is already
  filling present storage sites and presents a
  large threat for safe storage for thousands of
  years.
• Lets look closer at the radiation risks and
  storage problems.

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WARNING!WARNING!
Radiation exposure can come from an accident at a
nuclear power plant, an explosion of a
conventional or unconventional nuclear bomb, or
from contamination of your environment from a
radioactive substance like nuclear waste. What
can exposure do to you?
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Not feeling so good?

• Radiation sickness may be fairly mild and
  transitory, consisting of weakness, loss of
  appetite, vomiting, and diarrhea.
• Since even in a mild dose of radiation the
  blood-forming tissue is destroyed to some extent,
  there is a reduction in the supply of blood cells
  and platelets. This increases the tendency to
  bleed and reduces the body's defense against
  infection.
• After a massive dose of radiation the reaction
  may be so severe that death quickly ensues. This
  is usually due to severe anemia or hemorrhage, to
  infection, or to dehydration.
• Extremely high doses damage the tissues of the
  brain, and death usually follows within 48 hr, as
  was demonstrated at Chernobyl.
• There is no treatment for radiation sickness,
  although it is sometimes possible for persons to
  survive otherwise lethal doses of radiation if
  bone marrow transplants are performed.

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Radiation Causes Cancer?

• Potassium iodide is to protect against thyroid
  cancer from radiation exposure, but the drug
  should ideally be taken four hours prior to the
  exposure.
• Exposure to radiation can cause genetic mutation
  the progeny of those subjected to excessive
  radiation tend to show deleterious genetic
  changes.
• The genetic damage from the atomic bombs dropped
  on Japan is still evident and such damage will
  continue to surface in people directly affected
  by the nuclear disaster at Chernobyl.

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Nuclear Waste is another problem!

• Spent fuel is hot and very radioactive.
• It has to be cooled and stored where any leaking
  can be closely monitored.
• There are currently 136,000 metric tons of spent
  fuel stored in the US and only 5000 are stored in
  proper facilities, the other 131,000 metric tons
  are being stored at the reactor sites and will
  eventually need to be transported.
• Other wastes can be safely buried or dropped into
  the ocean.

• Store for how long? About 10 half-lives
• A half-life is the time it takes for half of the
  radioactive material to decay to a stable safe
  material.
• If the half-life was 10 years, it would take 100
  years before the material was considered safe for
  the environment.
• Check out these half-lives
• Although its half-life is 29 years, a quantity of
  Sr90 (Strontium) is not considered safe for 290
  years.
• 239Pu (plutonium) is also radioactive, and has a
  half-life of approximately 24,000 years
• How long would it take for that to become safe?

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Heres a picture of full storage on-site
In 1994, Minnesota's largest utility, then known
as Northern States Power, went to the state
Legislature with a controversial request. The
cooling pool where NSP stored spent nuclear fuel
inside its Prairie Island plant was nearly full.
The company wanted to store additional waste
outside, in steel casks. After months of bitter
debate, lawmakers granted permission for 17
casks. Nine years later, the casks are full and
the company ---now Xcel Energy -- is back at the
Capitol asking for more.
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• Well
• Now that you are informed
• How many of you would vote to build
• another nuclear reactor in Virginia?