RAD GRAD COURSE

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RAD GRAD COURSE

• A radiation literacy course for teachers

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Definitions
Ionizing Radiation energy in the form of
particles or waves, given off by unstable
(radioactive) atoms or by accelerated charged
particles Radioactive Material any material
which emits ionizing radiation Radioactive
Contamination radioactive material in an
unwanted place
101-04
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Ionizing Radiation
Neutrons and Protons
Ejected Electron
Ionization Radiation
Ionizing Radiation - radiation with enough energy
to remove an electron from its atom.
S 05
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Radiation
Ionizing Radiation
Radioactive Atom
Alpha Particle Neutron Particle Beta Particle
Gamma Ray (X Ray)
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Alpha Particle a
Sources Plutonium Uranium Radium
Thorium Americium
Range Very short range 1" -2" in air
Shielding Paper Outer layer of skin
Hazards Internal
Characteristics 2 charge 2 protons 2
neutrons Large mass
a
a
a
a
a
S 9
6
RW II
Beta Particle b
Hazards Skin and eyes Can be internal
Sources Radioisotopes Activation
Products Sealed sources
Characteristics -1 charge Small mass
Shielding Plastic safety glasses Thin
metal
Range Short range About 10' in air
S 10
7
RW II
Gamma Ray g
Characteristics No charge No mass Similar
to x-rays
Hazards External (whole body) Can be
internal
Range Long range About 1100' in air
Sources X-ray machines Electron
microscopes Sealed sources Accelerators
Nuclear reactors Radioisotopes
Shielding Lead Steel Concrete
Paper
Plastic
Lead
S 11
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Neutron Particle h
Characteristics No charge Found in nucleus
Range Extended range
Shielding Water Plastic
Hazards External (whole body)
Sources Fission Reactor operation
Sealed sources Accelerators
Paper
Lead
Water
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Radioactive Material
Gamma Ray
Gamma Ray
Radioactive Material - any material containing
atoms that emit radiation.
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Contamination
External Radiation
Contamination
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Radioactive Contamination
Radioactive Contamination - is radioactive
material in an unwanted place.
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RW I
Radiation Units
roengten (R) measures exposure (ionization) of
air by X-rays gamma-rays rad (radiation
absorbed dose) measures energy deposited in any
material by any type of ionizing radiation rem
(Roengten Equivalent to Man) estimates
biological damage or health risk due to
absorption of ionizing radiation unit of dose
equivalent
101-06
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RW I
Radioactivity Units
measure the number of nuclear transformations
(disintegrations) which occur in a certain time
period Curie (abbreviated, Ci) 37,000,000,000
disintegrations per second (dps)
2,200,000,000,000 disintegrations per minute
(dpm) Radioactive contamination measures an
amount of activity over a unit of surface area.
e.g.
5000 dpm/100 cm
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101-07
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RW I
Prefixes Used with Radiation Units
Prefix Symbol Translation Numerical
Value Scientific Notation mega M
1 million 1,000,000
10 kilo k 1
thousand 1,000
10 milli m 1 thousandth
1/1,000 10
micro m 1 millionth
1/1,000,000 10 nano
n 1 billionth
1/1,000,000,000 10 pico p
1 trillionth
1/1,000,000,000,000 10
3
6
-3
-6
-9
-12
101-08
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RW I
Prefixes Examples
Nuclear plant - 1000 MegaWatts (MW) electric
power 1 kilogram (kg) weighs 2.2 pounds Chest
X-Ray dose 5 millirem (mrem) Biochemist might
use a 10 microCurie (mCi) source 10 nCi/100 cm
low level radioactive contamination Natural
radium content of soil 1 picoCi/gram (pCi/g)
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101-09
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millirem
Abbreviation mrem 1000 mrem 1 rem
millirem - is the basic unit of radiation dose
equivalent. It measures biological risk in
humans.
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The average annual dose to the general
population from natural background and man-made
sources is 360 mrem.
Terrestrial Sources
Cosmic Radiation
Radon
Radon
Internal Sources
Other
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Average Annual Dose
Cosmic 28 mrem
Terrestrial 28 mrem
Radon 200 mrem
Internal 40 mrem
Medical X-Rays 40 mrem
Nuclear Medicine 14 mrem
Consumer Products 10 mrem
Natural Sources Man-Made Sources
Other 3 mrem
102-06
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RW I
Comparison of Radiation Dose
102-17
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RW II
Four Ways Radioactive Material Can Enter the Body
Inhalation Breathing Smoking
Wound or Cut
Ingestion Eating Drinking Chewing
Absorbtion
S 22
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RW I
Acute Radiation Dose
Acute radiation dose refers to persons who
receive large amounts of Radiation over a
short period of time.
102-09
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RW I
Chronic Radiation Dose
Chronic radiation dose refers to persons who
receive small amounts of radiation over a long
period of time.
102-10
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Chronic Radiation Dose
Chronic radiation dose refers to persons who
receive small amounts of radiation over a long
period of time.
There is a slight risk that cancer may be caused
by chronic radiation doses.
This risk level is very small compared to the
natural occurrence rate of cancer.
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Basic Protective Measures
Time
Distance
Shielding
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RW I
Unit 2
BIOLOGICAL EFFECTS
102-01
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Cells are undamaged.
Cells are damaged, repair damage and operate
normally.
Cells are damaged, repair damage and operate
abnormally.
Cells die as a result of damage.
S 1
27
RW I
Health Effects
Radiation effects on cell chromosomes
Somatic Effects observed in the exposed
individual Heritable Effects observed in
future generations of exposed individual
102-11
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RW I
Factors Affecting Biological Damage
Total radiation dose Dose rate Type of
radiation Area of body exposed Cell
sensitivity Individual sensitivity
102-13
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The fetus is MORE sensitive than an adult.
102-14
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No Heritable Effects from Ionizing Radiation Have
Been Observed in Humans
Heritable effects have been observed in
laboratory animals.
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RW I
Relative risk of dying 1 in a million odds.
Smoking 1.4 cigarettes (lung cancer) Eating
40 tablespoons of peanut butter Eating 100
charcoal broiled steaks 2 days in New York City
(air pollution) Driving 40 miles in a car
(accident) Flying 2500 miles in a jet
(accident) Canoeing for 6 miles Receiving 10
mrem radiation dose (cancer)
102-15
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Risk Loss of Life Expectancy
Days of Average Life Expectancy Lost Due to
Various Causes
Being an unmarried male Smoking (1 pack/day)
Being an unmarried female Being a coal miner
25 overweight Alcohol abuse (U.S. average)
Being a construction worker Driving a motor
vehicle All industries Radiation 100 mrem/yr x
70 years Coffee
3500 2250 1600 1100 777 365 227 207 60 10 6
S 16