Detecting Radiation in our Radioactive World

Nuclear Technology in our Lives Eaten Eggs? Driven over a Metal Bridge? Attached a Postage Stamp? Use Contact Lens Solution? Used a Photocopier?

The Anticipatory Set: Which of these things is not like the other, which of these things are kind of the same?

Detecting Radiation

What makes up glow sticks, ceramic plates, & people?

ATOMS! That’s what!

Fe ELEMENT NAME ATOMIC NUMBER (# of protons) ATOMIC SYMBOL ATOMIC MASS (total # of protons & neutrons) IRON Atomic Structure of Iron

ATOMIC PARTICLES PROTON: within the nucleus, large mass, positive charge, identifies the element. NEUTRON: within the nucleus, large mass, no charge. electron: outside the nucleus, very small mass, negative charge. +

RADIATION is the transmission of energy by means of: particles waves OR

Visible Light Microwaves Infrared TV – Radio Waves Radar Waves High Energy UV Radioactive Atoms Gamma Rays Neutrons X-Rays RADIATION Ionizing Non-Ionizing

Radiation with enough energy to remove an electron from its atom. Ionizing Radiation Ionization Radiation Neutrons and Protons Ejected Electron

Ionizing Radiation Radioactivity vs. Radiation Alpha Particle Neutron Particle Beta Particle Radioactive Atom Gamma Ray

Characteristics +2 charge 2 protons 2 neutrons Large mass Alpha Particle  Range Very short range 1" -2" in air Shielding Paper Outer layer of skin Hazards Internal Sources Plutonium Uranium Radium Thorium Americium     

Characteristics -1 charge Small mass Beta Particle  Range Short range About 10' in air Shielding Plastic safety glasses Thin metal Hazards Skin and eyes Can be internal Sources Radioisotopes Activation Products Sealed sources

Characteristics No charge No mass Similar to x-rays Gamma Ray  Range Long range About 1100' in air Hazards External (whole body) Can be internal Sources X-ray machines Electron microscopes Sealed sources Accelerators Nuclear reactors Radioisotopes Shielding Lead Steel Concrete PaperPlasticLead

Characteristics No charge Found in nucleus Neutron Particle  Range Extended range Shielding Water Plastic Hazards External (whole body) Sources Fission Reactor operation Sealed sources Accelerators Paper LeadWater

Radioactive atoms ON or IN an unwanted place or material. Nearby objects may be irradiated. Radioactive Contamination

Irradiation  Exposure of a material to ionizing radiation.  Does NOT make the material radioactive.  May cause a chemical or physical change in the material.  Possible to remove the material away from the radioactive atoms. Radioactive Atoms Radiation =

millirem - is the basic unit of radiation dose equivalent. It measures biological risk in humans. Abbreviation: mrem 1000 mrem = 1 rem millirem

Terrestrial Sources The average annual dose to the general population from natural background and man-made sources is 620 mrem. The average annual dose to the general population from natural background and man-made sources is 620 mrem. Cosmic Radiation Internal Sources Other Radon

Average Annual Dose

Comparison of Radiation Dose 800,000 mrem = 800 rem

Time Basic Protective Measures Distance Shielding

Detecting Radiation

Geiger-Muller Tube ¨

Inhalation Breathing Smoking Four Ways Radioactive Material Can Enter the Body Four Ways Radioactive Material Can Enter the Body Wound or Cut Absorption Ingestion Eating Drinking Chewing

Factors Affecting Biological Damage Factors Affecting Biological Damage Total radiation dose Dose rate Type of radiation Area of body exposed Cell sensitivity Individual sensitivity

Biological Effects of Radiation Cells are undamaged. Cells are damaged, repair damage, & operate normally. Cells are damaged, repair damage, & operate abnormally Cells are damaged & die.

Acute Radiation Dose Acute radiation dose refers to persons who receive large amounts of Radiation over a short period of time.

Chronic Radiation Dose Chronic radiation dose refers to persons who receive small amounts of radiation over a long period of time.

Health Effects Somatic Effects observed in the exposed individual Heritable Effects observed in future generations of exposed individual