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Download Radiation Overview - American Nuclear Society
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Atomic Energy Overview Boy Scout Merit Badge 2006 American Nuclear Society Schedule 9:00-9:55 10:00-10:40 10:45-11:25 11:30-12:10 12:15-12:55 1:00-1:40 1:45-2:25 2:30-3:00 Introduction Station 1 Station 2 Lunch Station 3 Station 4 Station 5 Wrap-Up/Sign Blue Cards Blue Cards Put my name in appropriate spot Workshop Leader Address Line 1 Address Line 2 Phone Number Requirements 1a. Radiation Effects 1b. Drawing of radiation symbol 2. Definitions 3. Scientists 4a. Model of atoms 4b. Fission pictures 4c. Critical Mass 5c. Time, distance and shielding 5f. X-ray facility 5g. Cloud Chambers 6b. US nuclear reactors 7. Nuclear Careers Brief History of the Atom 500 BC Long time 1808 AD 1911 1913 1920’s Democritus (Romans Dark Dalton Rutherford Bohr Many People Atom Ages) Plum Pudding Nucleus Orbits Quantum Mechanics So What is an Atom? Atoms are made up of protons, neutrons & electrons • Protons: + charge • Neutrons: no charge • Electrons: - charge Atoms want to have no net charge • #protons = #electrons Mass of an Atom Masses • Proton: 1 amu • Neutron: 1 amu • Electron: .000549 amu So mass of atom ~ • #neutrons + #protons What is the mass of: Helium? • 2 protons, 2 neutrons, 2 electrons Oxygen • 8 protons, 8 neutrons, 8 electrons Fissile Uranium • 92 protons, 143 neutrons, 92 electrons Alpha particle • 2 protons, 2 neutrons Isotopes Isotopes are similar elements with different amounts of neutrons There are similar properties Some have very different properties Stable and unstable versions of atoms Example Sodium – 23 • 11 protons, 12 neutrons • Very plentiful, in salt that you eat (NaCl) Sodium – 24 • 11 protons, 13 neutrons • Not natural • Highly radioactive, beta decay • Used to find leaks in industrial pipes Put together models of: Hydrogen • 1 Proton, 1 electron Deuterium • 1 Proton, 1 neutron, 1 electron Tritium • 1 Proton, 2 neutrons, 1 electron What are the atomic and mass numbers of each isotope? What are the net charges? (Requirement 4a) Fission vs. Fusion Fission • • • • Makes 20% of our electricity Breaking apart of Heavy Nuclei Nuclear Reactor tour later Today! Example: N + U-235 Ba-139 + Kr-94 + 3N Fusion • • • • • Powers the Sun Hard to get on Earth Combination of Light Nuclei IEC Fusion Tour later Today! Example: H-3 + H-2 N + He-4 Tritium + Deuterium neutron + Helium Where does radiation come from? The sun Soil, water and vegetation Internal sources • Potassium-40 (bananas) • Carbon-14 (air) • Lead-210 (radon) Man-made sources • Medical sources (x-rays, radiation…) • Nuclear Power Types of Radiation Ionizing radiation • Produces ions in the material it strikes Non-ionizing radiation • Can cause damage by physically striking material Ionizing radiation Alpha particles Beta particles Photons • Gamma rays • X-rays Non-Ionizing Radiation Low energy photons • Such as light, infrared light, etc Neutrons • Neutral particle in nucleus • Like a proton but with no charge Radiation Penetration Radioactive Material What is it? • Material that releases radiation. How do we get rid of it? • When an atom decays, it may or may not be radioactive still. Eventually, it will decay to a stable atom Decay Radioactive material has a probability of decaying Overtime, this probability averages into a half life Half-life: Amount of time it takes for half of the radioactive substance to decay Biological Effects of Radiation Deterministic • responses which increase in severity with increased dose (sunburn) Stochastic • effects which have an increased probability of occurrence with increased dose, but whose severity is unchanged (skin cancer) Radiation Exposure To avoid accidental exposure, we use the radiation hazard symbol Colors • Magenta or Black • Yellow Background Color one of your own • Why must people use radioactive materials carefully? (Requirement 1a and 1b) 2006 Atomic Energy Boy Scout Merit Badge
