Nuclear PowerIndustrial Applications, Natural Occurrences and Military Uses

By Jordan Brown, Gynter Kotrri,

Kevin RupasingheVinay Jayachandiran

•Nuclear Reactions – Good

•Nuclear Reactions – BadSomali Pirates

Taliban

North Korea

Al-Qaeda

China

•Electricity

• Steam turns turbine attached to shaft

• Coils of copper rotate inside magnets

• Alternating electrical current generated

•Atom

•Electron – Orbit (e-)•-1 charge, very small

•Proton – Nucleus (p+)•+1 charge, 1 amu

•Neutron – Nucleus (n0)•0 charge, just over 1 amu•Essentially one e- and one p+

•4 Fundamental Forces

Function/Effect Relative

Strength

Range

Gravitational Attractive force between matter

1 Infinite

Electromagnetic Like charges repel, opposites attract

1036 Infinite

Weak Nuclear Involved in nuclear decay 1029 10-18

Strong Nuclear Holds the nucleus of an atom together

2 x 1037 10-15

•Types of Radiation•Alpha Radiation

•Helium nuclei

•Beta Radiation•Electrons

•Gamma Radiation•Electromagnetic

•Fission•Large nuclei become unstable and break apart•Decay into smaller elements and emit radiation

• Alpha, Beta and Gamma Radiation• Neutrons break off, split into protons and electrons

•Happens slowly in nature •Scientists can shoot neutrons at Uranium nuclei to start a reaction

•Mass is lost during fission and converted into energy

•Chain Reaction•Each reaction releases 3 neutrons•These neutrons may hit other nuclei, causing a chain reaction

•In nature, the fissile material is not dense enough for a chain reaction

•Scientists can calculate a “critical mass” at which the chain reaction is sustained

•The equation below can be used to determine critical mass

Where k is neutron multiplication factorf is the number of neutrons released in the reactionl is the number of neutrons lost from the system

Fission Reactors

• Radioactive materials have to be disposed off• Eventually over time these materials will loose

their radioactivity• Half Life

• Iodine 8 days

• Krypton 10 years

• Uranium 238 – 4.47 billion years

• Radiation causes deletions and mutations in DNA

• Have to be disposed of really safely

• Waste is stabilized before being disposed off

• Remove water

• Usually stored underground

•Nuclear Waste

• 26 April 1986• Power Surge ruptured reactor

• Sent radioactive material into air • Many locations had to be evacuated

• Three Mile Island• Relief Valve failed• Many radioactive gases were released into air

• Chernobyl

•Nuclear Disasters

•Atomic Bomb

•E = mc2

• Einstein stated that mass and energy are interchangeable

• In nuclear reactions, mass is lost and converted into energy

• This change in mass yields vast amounts of energy

• When U-235 decays, 0.7% of its mass is converted into energy

• Assume 1 mole reacts:

0.007 (235g) = 1.645g = 0.001645kgE = (0.001645 kg)(300,000,000 m/s)2 = 148.05 x 1012 = 148 terajoules

•Nuclear Fusion•Used to describe the process whereby two nuclei “fuse” to form heavier nuclei

•The fusion of two nuclei with lower masses than iron

•Generally releases energy while the fusion of nuclei heavier than iron absorbs energy

•Naturally occurs in stars

•Fusion Bombs

•Hydrogen Isotopes•H-1 (protium)

•1 proton, no neutrons

•H-2 (deuterium)•1 proton, 1 neutron

•H-3 (tritium)•1 proton, 2 neutrons

• 15 million Kelvin and really high pressure• 2 protons fuse to make a deuteron• 1 proton and a deuteron make Helium 3• 2 Helium 3 fuse and make Beryllium 6• Beryllium 6 is unstable and breaks apart

into 2 protons and Helium 4• Helium 4 has less energy than its reactants, so

it releases energy• Also less mass, E=Δmc2

• 600 million tons of Hydrogen converted to helium/second

•Fusion on SunProton-Proton

•Fusion on Sun4 x 1026 Watts of Energy a day.

• Have to overcome the electromagnetic force of protons

• Requires 100 million Kelvin (6 times temperature of Sun’s core)

• At this temperature atoms lose electrons and become plasma

• Lots of pressure needed

• To maintain pressure we need gas to be in container

• No container can survive at 100 million Kelvin

• Invisible Magnetic Container

• Plasma is magnetic

• Proton-Proton Fusion•Fusion on Earth

Magnetic Container

100 million Kelvin

DEUTERIUM - DEUTERIUM FUSION

• Needs less heat than proton-proton fusion

• 100s of millions of degrees• Still needs to be highly dense• Unrealistic

• Works at lower temperatures and Pressure

• Scientists think these are realistic conditions

• 6Li + n 4He + T• Produce tritium

DEUTERIUM – TRITIUM FUSION

•Alternative FusionMore Efficient

• Run a current through plasma, creates magnetic force around plasma

• Run current through tube and make a donut shaped tube

• Contractile rings to stop plasma from moving

• Create Spiral magnetic coils to avoid diffusion

• Tokamak•Fusion Reactors

• Scientists think this could be the next step

• High intensity lasers fired at a pellet containing deuterium and tritium atoms

• Pellet explodes and reaction forces crushes the atoms together to create fusion

• Nova• Lawrence Livermore National

Laboratory in California

• The New Way Forward•Laser Fusion Reactors

•Implications of Nuclear Fusion•Harnessing nuclear fusion on Earth could produce unlimited, clean energy for millions of years

•This could lead to:• 1) Cheap and affordable energy• 2) The deceleration of global warming• 3) The total transformation of the global economy

•Output energy has been less than the amount of input energy

•Stars – Nature’s Nuclear Reactors•The energy of the stars also comes from nuclear fusion processes

•Big Bang created hydrogen and helium•fusion created all other elements

Thank You for Listening!