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Nuclear Power . Locations of Nuclear Power plants in the US. Locations of Nuclear Power plants in the World. Do Nuclear Power plants Pollute?. No they don’t. This is Steam being released. . Nuclear Power Plant Operation. Uranium ore. Nuclear Reactor Fuel. Uranium ore is refined then
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Nuclear Reactor Fuel Uranium ore is refined then formed into pellets.
Nuclear Reactor Fuel These Pellets are then put into Fuel rods which are Assembled Into packs of Fuel Rod Assemblies
Parts Of an Atom • What is a nucleus composed of? • Protons • Neutrons • Electrons
Protons Protons have a positive charge and are located in the nucleus of the atom.
Neutrons Neutrons are located in the nucleus and have no charge
Electrons • Electron are found on • The outside of the atom. • An electrically balanced • atom will have the same • number of electrons • and protons
Review of Atoms • Mass Number – protons (p+) and neutrons (n0) • Atomic Number – Protons (p+) Neutral Atoms = P and E If you change the atomic number it is a new element • Number of Neutrons = Mass – Atomic #
Isotopes • Atom with same protons but different neutrons. Most have only one stable form. • Best Example is Hydrogen
What is Nuclear Decay? Nuclear decay nucleus gives off matter and energy. Result: New element Strong Force = Holds together P and N. Larger nucleus has a weaker force.
Radioactive • A nucleus with too many or too few neutrons compared to protons is considered radioactive.
Ionizing Radiation • Ionizing radiation is produced by unstable atoms. Unstable atoms differ from stable atoms because they have an excess of energy or mass or both. • Unstable atoms are said to be radioactive. In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation.
4 types of ionizing Radiation • Alpha Helium Nucleus • Beta Electron • Gamma EM Radiation These are other products that can be produced along with the new element
Ionizing Radiation alpha particle beta particle Radioactive Atom Neutron X-ray gamma ray
Alpha radiation • Nucleus of a helium atom • Symbolically represented: • Chemically written: 4He • Least Destructive Radiation • Can be stopped by a sheet of thick paper 2
Alpha Particles Alpha Particles: 2 neutrons and 2 protons They travel short distances, have large mass Only a hazard when inhaled
Beta radiation • Composed of One Electron • Symbolically represented: • Chemically written: e- or 1e • More Destructive than Alpha Radiation • Stopped by a sheet of aluminum 0
Gamma radiation • High energy Electro-Magnetic Waves • Has no mass or charge • Symbolically represented: • Most Destructive Radiation (Most penetrating) • Very difficult to stop • Reduced by thick lead or concrete
Half Life • Period of time it takes for a substance to decrease its mass by 1/2
Nuclear Half-Life Equation • Ni* (1/2)nt1/2 = Nf • Ni – Initial amount of radioactive material • nt1/2 -# of half-lives • Nf– Final amount of radioactive material To get nt1/2, you must divide time given in problem by the half-life.
Nuclear halflife examples • Polonium210 • Half Life: 138 days • Alpha decay • Strontium90 • Half Life: 28.5 years • Beta decay • Cobalt60 • Half Life: 5.27 years • Gamma decay
Alpha Decay Example • Polonium210 • Half Life: 138 days • Alpha decay If you have 48kg of Polonium 210, How much will be left after 138 days? Ans: 24 kg How much will be left after 276 days? (2 half lives) Ans: 12 kg How much will be left after 414 days? (3 half lives) Ans: 6 kg
Beta Decay Example • Strontium90 • Half Life: 28.5 years • Beta decay If you have 30kg of Strontium 90, How much will be left after 28.5 years? Ans: 15 kg How much will be left after 57 years? (2 half lives) Ans: 7.5 kg How much will be left after 85.5 years? (3 half lives) Ans: 3.75 kg
Gamma Decay Example • Cobalt60 • Half Life: 5.27 years • Gamma decay If you have 1 kg of Cobolt 60, How much will be left after 5.27 years? Ans: 0.5 kg How much will be left after 10.54 years? (2 half lives) Ans: 0.25 kg How much will be left after 15.81 years? (3 half lives) Ans: 0.125 kg
Nuclear Reactions • Decaying nucleus releases particles or energy. • Creates new atoms or elements • A Released mass = released energy. E = mc2 Some are used in medicines
Nuclear Fission • Splitting a nucleus = two smaller nuclei (smaller mass) = Big energy ex) Atomic Bombs and Nuclear Reactors Chain Reaction = Ongoing fission Ex) box of mouse traps, once one hits it causes the others to snap Critical Mass = Amount of material need to keep a constant rate in our chain reaction
Nuclear Fusion • Joining of two nuclei, smaller mass= Larger nucleus with larger mass • Must have a very high rate of speed to overcome the natural tendency to repel. • Ex) Sun and Stars