Transcript 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!
Atomic Structure of
Iron
ATOMIC NUMBER
(# of protons)
ATOMIC
SYMBOL
26
55.85
Fe
IRON
ELEMENT NAME
ATOMIC MASS
(total # of
protons &
neutrons)
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
OR
waves
RADIATION
Non-Ionizing
•
•
•
•
•
Visible Light
Microwaves
Infrared
TV – Radio Waves
Radar Waves
Ionizing
•
•
•
•
•
High Energy UV
Radioactive Atoms
Gamma Rays
Neutrons
X-Rays
Ionizing Radiation
Neutrons
and Protons
Ejected
Electron
Ionization
Radiation
Radiation with enough energy to
remove an electron from its atom.
Radioactivity vs. Radiation
Radioactive Atom
Ionizing Radiation
Alpha Particle
Neutron Particle
Beta Particle
Gamma Ray
Alpha Particle a
Characteristics
Range
Shielding
Hazards
Sources
• +2 charge
• 2 protons
• 2 neutrons
• Large mass
• Very short
range
• 1" -2" in air
• Paper
• Outer layer
of skin
• Internal
• Plutonium
• Uranium
• Radium
• Thorium
• Americium
a
a
a
a
a
Beta Particle b
Characteristics Range
Shielding
Hazards
Sources
• -1 charge
• Small mass
• Plastic
safety
glasses
• Thin
metal
• Skin and
eyes
• Can be
internal
• Radioisotopes
• Activation
Products
• Sealed
sources
• Short range
• About 10'
in air
Gamma Ray g
Characteristics Range
Shielding
Hazards
Sources
• No charge
• No mass
• Similar
to x-rays
• Lead
• Steel
• Concrete
• External
(whole body)
• Can be
internal
• X-ray
machines
• Electron
microscopes
• Sealed
sources
• Accelerators
• Nuclear
reactors
• Radioisotopes
• Long range
• About 1100'
in air
Paper Plastic Lead
Neutron Particle h
Characteristics Range
Shielding
Hazards
Sources
• No charge
• Found in
nucleus
• Water
• Plastic
• External
(whole body)
• Fission
• Reactor
operation
• Sealed
sources
• Accelerators
• Extended
range
Paper Lead
Water
Radioactive Contamination
• Radioactive atoms ON or
IN an unwanted place or
material.
• Nearby objects may be
irradiated.
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.
Radiation
Radioactive
Atoms
=
millirem
Abbreviation:
mrem
1000 mrem = 1 rem
millirem - is the basic unit of radiation dose
equivalent. It measures biological risk in humans.
The average annual dose to the general
population from natural background
and man-made sources is 620 mrem.
Terrestrial Sources
Radon
Cosmic Radiation
Radon
Internal Sources
Other
Average Annual Dose
Comparison of Radiation Dose
1 10
Lethal Dose
Radiation
Worker Limit
Argonne
Control Limit
Natural
Background
Average ANL
Radiation Worker
General
Employee Limit
Chest X-Ray
100
1,000
10,000
100,000
800,000 mrem = 800 rem
1,000,000
Basic Protective Measures
Time
Distance
Shielding
Detecting Radiation
¨
Geiger-Muller
Tube
Four Ways Radioactive
Material Can Enter the Body
Inhalation
• Breathing
• Smoking
Absorption
Wound or Cut
Ingestion
• Eating
• Drinking
• Chewing
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