Nuclear Power

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Nuclear Power

• BY
• Tarek Eldin, Banu Cetin, and Jian Fan

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Outline

• Overview Tarek Eldin
• What is Nuclear Power?
• Purpose of Nuclear Power
• Comparison of existing energy sources
• Risks
• Fission Banu Cetin
• What is Fission (Technical)
• Nuclear Fission Reactors
• Nuclear Fission Waste Control
• Fussion Jian Fan
• What is Fission (Technical)
• History of Fussion
• Pros and Cons of Fussion

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Nuclear Power

• Majority of Information from
• American Nuclear Society
• http//nova.nuc.umr.edu/ans/index.html
• professional organization devoted to advancing
  science and engineering related to the atomic
  nucleus
• 13,000 scientists and engineers in the Society's
  membership are active in diverse fields of
  research, teaching, consultation, administration,
  and engineering.

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Nuclear Power

• Nuclear Power
• Power that is generated by a nuclear reaction.
• Fission
• The splitting of a heavy nucleus into two roughly
  equal parts.
• The internal energy that was holding the two
  parts together is the resulting energy.
• Fusion
• Similar to Fission--combining instead of
  splitting of nucleus
• Difference is that fusion yields energy for low
  mass elements while fission releases energy for
  high mass elements.
• The break between the two regimes falls at the
  element iron (Fe) (26 protons in its nucleus)

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Nuclear Power

• How important is it to have more energy?
• Very important!
• Anything that limits us actually limits our
  freedom.
• Energy is in no way different.
• Imagine the amount of gas becoming so limited
  that government gives individuals a monthly
  allowance.
• It limits the governments freedom and in turn
  citizens freedom.
• Do we need Nuclear power to generate electricity?
• We cant depend on oil and gas forever.
• Cleanest and least damaging to our environment.
• We avoid having to depend on other countries.

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Nuclear Power

• Cost of Nuclear Power vs Other?
• Nuclear power versus Coal
• Cost per kilowatt-Hour is slightly higher for
  Nuclear Power
• Fraction of a cent
• Nuclear power versus Oil
• Cost per kilowatt-Hour is lower for Nuclear
  Power.
• Shown to have save American consumers 70 Billion
  over the past decade.
• Savings show how expensive it is to be dependent
  on other countries and import from them.

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Nuclear Power

• So why not use nuclear power?
• Radiation
• The health effects of very high doses of
  radiation are serious.
• Somatic increased chance of cancer and life
  shortening
• Genetic affects the offspring as genes are
  altered.
• Possible Property Damage
• April 1986 accident at the Chernobyl plant in the
  Soviet Union
• Sabotage
• Insane workers
• Terrorists
• Who knows?

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Nuclear Power

• Radiation
• Radiation is everywhere and its natural.
• Microwaves, cell phones, radio, television,
  X-Rays..etc
• Natural radiation exists as in sunlight also.
• 3 types of nuclear radiation(alpha, beta, and
  gamma)
• All exist in nature.
• Average exposure is 360 millirems per person in a
  year.
• More than half our average yearly dose comes from
  Natural Radiation.
• If you live close to a power plant average dose
  is 5 millirems per person.
• Nuclear plants contain less radioactivity than
  the releases from comparable coal-fired plants

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Nuclear Power

• Property Damage
• USA
• First U.S. commercial power reactor serviceable
  in 1957
• Since then no property damage reported, or injury
  caused in USA.
• More than 100 nuclear power plants in USA today.
• Elsewhere
• Chernobyl plant in the Soviet Union
• 31 workers and firefighters died
• 2 explosions (steam and Hydrogen) was the cause
  of death

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Nuclear Power

• Chernobyl -- Cant this happen in USA
• Explosions could have been avoided
• Steam explosion. If some of cooling water
  converts to steam power is increased. This of
  course causes more steam and more power.
• Caused a rupture in the cooling system and an
  explosion.
• American designs reduce power if steam is
  generated.
• Because of steam explosion the cooling system
  failed
• Hydrogen formed and .
• Second explosion
• They had no containment structure.
• America and other countries do have a containment
  structure that experiments have shown could have
  eliminated the affects of the second explosion.

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Nuclear Power

• Sabotage
• Can it be avoided?
• Utilities follow stringent security precautions
  to protect nuclear power plants and equipment
  from malicious damage
• People working in the plants are carefully
  screened for their integrity and emotional
  stability.
• Random visitors cannot enter.
• Business visitors always accompanied by
  employees.
• But life has proven that anything is possible.

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Nuclear Power

• How do Risks Compare to Risks we face already
• Less than we face today
• airplane crashes and explosions are 100,000 times
  more likely to kill 10 people that the operation
  of 100 nuclear plants would be.
• 2,000 times more likely that 10 persons will be
  killed by an earthquake
• 60,000 times more likely that 1,000 persons will
  be killed by hurricane
• Greatest Risk we take aside from illness is
  getting into our cars.

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FISSIONby Banu Cetin
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WHAT IS FISSION?

• Fission is a nuclear process in which a heavy
  nucleus splits into two smaller nuclei.
• Starting a fission reaction is accomplished by
  bombarding fissionable nuclei with neutrons. This
  causes the nuclei to fly apart, splitting into
  two fission products and emitting two or three
  neutrons of their own
• Fission reactions can produce any combination of
  lighter nuclei.
• A great amount of energy is released.

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WHY FISSION OCCURS

• Fission occurs because of the electrostatic
  repulsion created by the large number of
  positively charged protons contained in a heavy
  nucleus.
• Two smaller nuclei have less internal
  electrostatic repulsion than one larger nucleus.
  So, once the larger nucleus can overcome the
  strong nuclear force which holds it together, it
  can FISSION.

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WHY FISSION OCCURS

• Fission can be seen as a tug-of-war between the
  strong attractive nuclear force and the repulsive
  electrostatic force. In fission reactions,
  electrostatic repulsion wins.

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THE NUCLEAR FUEL CYCLE

• The set of activities required for producing
  nuclear power, from the mining and processing of
  uranium to its use in reactors and final
  disposal, is known as the nuclear fuel cycle.
• The mining of uranium is similar to the mining of
  many other ores but miners must also be
  protected against radioactive dust and radon, a
  radioactive gas.

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NUCLEAR REACTORS

• Fissionable material is placed in the "core" of a
  reactor. The rate of the fission chain reaction
  is controlled and "moderated", and the heat
  generated is converted into electricity.
• Control and moderation refer, respectively, to
  the manipulation of both the number and velocity
  of the neutrons present in the core.
• Control rods made of boron or other neutron
  absorbing materials control the number of
  neutrons present.
• Raising and lowering the control rods in the core
  can speed up or slow down the rate of the chain
  reaction.

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NUCLEAR REACTORS

• 4 types of
• nuclear reactors.
• The majority
• -boiling water
• -pressurized water

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SAFETY of NUCLEAR POWER REACTORS

• There have been two major reactor accidents in
  the history of civil nuclear power - Three Mile
  Island and Chernobyl. One was contained and the
  other had no provision for containment.
• These are the only major accidents to have
  occurred in over 10 000 cumulative reactor-years
  of commercial operation in 32 countries.

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ENVIRONMENTAL and SAFETY CONCERNS

• Fission reactors are very complicated devices,
  capable of causing a great deal of harm both to
  humans and to the environment.
• With any nuclear reactor, there is the
  possibility of a malfunction which could cause
  the chain reaction in the core to run out of
  control, resulting in very high temperatures and
  a core "meltdown".
• Meltdowns that breach reactor containment vessels
  could potentially release huge amounts of
  radiation into the surrounding environment, as
  seen by the accident at Chernobyl in 1986.
• Following a major accident, along with the
  initial radiation exposure, the land and water
  covering a large area around an accident site
  could become contaminated, and unfit for human
  habitation for thousands of years.

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NUCLEAR WASTE STORAGE

• One of the greatest problems with nuclear energy
  is the waste produced. The waste is generally
  radioactive, and thus toxic
• Fuel Rod Storage Pool

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NUCLEAR WASTE STORAGE

• Storage Tunnels
• Dry cask Storage Containers

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ECONOMY

• Nuclear power has not fulfilled its early promise
  as a cheap, clean and unlimited source of
  electricity.
• Public concern over potential accidents,
  "acceptable" emissions of radiation, disposal of
  radioactive waste and the possibility of weapons
  proliferation have resulted in opposition to the
  construction of new power plants.
• At the present time , worldwide use of
  electricity is so inefficient that its cheaper
  to save energy through efficiency improvements
  than its to build new nuclear power plants to
  supply more electricity.

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Fusion

• Jian Fan

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What is Fusion

• Two ways to release nuclear energy splitting and
  combining

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Example of Fusion

• The energy radiated by stars, including the Sun,
  arises from such fusion reactions deep in their
  interiors.

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Fusion vs. Fission

• Difficult to maintain the nuclei repel each
  other
• Limited elements the forces of repulsion are so
  effective in keeping nuclei apart, reactions
  useful for controlled fusion seem largely limited
  to deuterium and tritium
• No radioactive products

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Basic difficult issues in Fusion

• Need very high temperature condition to heat the
  gas
• The hot gases tend to expand and escape from the
  enclosing structure. Need to confine a sufficient
  quantity of the reacting nuclei for a long enough
  time to permit the release of more energy than is
  needed to heat and confine the gas.
• Hard to obtain the capture of this energy and its
  conversion to electricity.

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History of nuclear fusion research I

• In the early 1930s Nuclear fusion was first
  achieved on earth by bombarding a target
  containing deuterium, the mass-2 isotope of
  hydrogen, with high-energy deuterons in a
  cyclotron
• Problem To accelerate the deuteron beam a great
  deal of energy is required, most of which
  appeared as heat in the target. As a result, no
  net useful energy was produced.

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History of nuclear fusion research II

• In the 1950s the first large-scale but
  uncontrolled release of fusion energy was
  demonstrated in the tests of thermonuclear
  weapons by the United States, the USSR, the
  United Kingdom, and France.
• Problem This was such a brief an uncontrolled
  release that it could not be used for the
  production of electric power.

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History of nuclear fusion research III

• In the early 1960s One device, called Tokamak,
  originally suggested in the USSR by Lgor Tamm and
  Andrey Sakharov, began to give encouraging
  results.

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History of nuclear fusion research IV

• In the early 1980s Based on the successful
  operation of small tokamaks at several
  laboratories, two large devices were built , one
  at Princeton University in the United States and
  one in the USSR.

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History of nuclear fusion research V

• In the early 1990s some progress was made. In
  1991, for the first time ever, a significant
  amount of energy-about 1.7 million watts-was
  produced from controlled nuclear fusion at the
  Joint European Torus (JET) Laboratory in England.
  In December 1993, researchers at Princeton
  University used the Tokamak Fusion Test Reactor
  to produce a controlled fusion reaction that
  output 5.6 million watts of power.
• Problem both the JET and the Tokamak Fusion Test
  Reactor consumed more energy than they produced
  during their operation.

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What is the good nuclear fusion reactor in the
future

• In any useful fusion device, the energy output
  must exceed the energy required to confine and
  heat the plasma.
• Progress in fusion research has been promising,
  but the development of practical systems for
  creating a stable fusion reaction that produces
  more power than it consumes will probably take
  decades to realize.

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Advantages of Fusion Energy

• Economy
• Provides a limitless source of fuel deuterium is
  from the ocean
• Would replace increasingly scarce fossil fuels
  and lower the cost of electricity
• would provide a relatively inexpensive
  alternative energy source for electric-power
  generation and thereby help conserve the world's
  dwindling supply of oil, natural gas, and coal
• Creates incentive to the utility industryin the
  United States, no new reactors had been ordered
  since 1978. European countries have begun or
  planned to phase out nuclear power completely

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Advantages of Fusion Energy

• Environment
• Limited possibility of a reactor accident, as the
  amount of fuel in the system is very small.
• Waste products much less radioactive and simpler
  to handle than those from fission systems
• Reduction in air pollution and strip mining than
  plants that burn fossil fuels

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Advantages of Fusion Energy

• Besides generating power, a fusion reactor might
  desalinate seawater. Approximately two-thirds of
  the world's land surface is uninhabited, with
  one-half of this area being arid. The use of both
  giant fission and fusion reactors in the
  large-scale evaporation of seawater could make
  irrigation of such areas economically feasible.

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Disadvantages of Fusion Energy

• The research is expensive
• Possible high construction and operation costs

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Ethic Questions

• The public in general looked favorably on this
  new energy source, hoping for the transition of
  nuclear power from wartime to peaceful uses.
• Reality is always against common goods While
  fusion reactor is still in research phase, Weapon
  based on thermonuclear fusion already realized.
  the hydrogen bomb, the "super bomb," is a
  thousand times more destructive than the atomic
  fission variety.

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Unknown Areas

• What are the effects of low-level radiation over
  long periods?
• How can nuclear power's waste products, which
  will remain dangerous for centuries, be
  permanently isolated from the environment?
• Is electricity from nuclear power plants less
  costly, equally costly, or more costly than
  electricity from coal-fired plants?