Atomic Energy Overview

Atomic Energy Overview Boy Scout Merit Badge 2006 American Nuclear Society

Schedule • 9:00-9:55 Introduction • 10:00-10:40 Station 1 • 10:45-11:25 Station 2 • 11:30-12:10 Lunch • 12:15-12:55 Station 3 • 1:00-1:40 Station 4 • 1:45-2:25 Station 5 • 2:30-3:00 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 Democritus Atom • Long time (Romans  Dark Ages) • 1808 AD Dalton Plum Pudding • 1911 Rutherford Nucleus • 1913 Bohr Orbits • 1920’s Many People 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

Atomic Energy Overview