Detecting Radiation

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)

26 55.85

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

IonizingNon-Ionizing

Radiation with enough energy to remove an electron from its atom.

Ionizing RadiationIonizing Radiation

Ionization Radiation

Neutronsand Protons Ejected

Electron

Ionizing Radiation

Radioactivity vs. RadiationRadioactivity vs. Radiation

Alpha Particle

Neutron Particle

Beta Particle

Radioactive Atom

Gamma Ray

Characteristics

• +2 charge• 2 protons• 2 neutrons• Large mass

Alpha Particle 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 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 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

Paper Plastic Lead

Characteristics

• No charge• Found in nucleus

Neutron Particle Neutron Particle

Range

• Extended range

Shielding

• Water• Plastic

Hazards

• External (whole body)

Sources

• Fission• Reactor operation• Sealed sources• Accelerators

Paper Lead Water

•Radioactive atoms ON or IN an unwanted place or material.

•Nearby objects may be irradiated.

Radioactive ContaminationRadioactive 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

milliremmillirem

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

Radon

Average Annual DoseAverage Annual Dose

Comparison of Radiation DoseComparison of Radiation Dose

Lethal Dose

RadiationWorker Limit

ArgonneControl Limit

NaturalBackground

Average ANLRadiation Worker

GeneralEmployee Limit

Chest X-Ray

110 100 1,000 10,000 100,000 1,000,000

800,000 mrem = 800 rem

Time

Basic Protective MeasuresBasic 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 DamageFactors 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 DoseAcute Radiation Dose

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

Chronic Radiation DoseChronic Radiation Dose

Chronic radiation dose refers to persons who receive small amounts

of radiation over a long period of time.

Health EffectsHealth Effects

Somatic Effects observed in the exposed individual

Heritable Effects observed in future generations of exposed individual