1. Module 1 Introduction to Radiation
Ver 0.4 October 28, 2002
Module 1: Introduction to Radiation
Estimated Presentation Time:
1 ¼ hour
Materials and Supplies:
Whiteboard (or chalkboard, flip chart, etc.)
Projector for PowerPoint slides
Slides 1 through 27
Instructor Preparation:
Make sure that there are enough copies of the following items for each student:
Notepad and pen/pencil
Chem-light stick or a flashlight
Student Manual
Appropriate Handouts
Module one will give you an overview of some of the fundamentals of radiation.

2. Introduction to Radiation
Terminal Objective:
DEFINE the fundamentals of radiation, radioactive material, ionization, ionizing radiation, and contamination.
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Show slide 2
At the end of the module, students will be able to:
DEFINE the fundamentals of radiation, radioactive material, ionization and ionizing radiation, and ALARA.

3. Enabling Objectives LIST the three basic components of an atom.
DESCRIBE the differences between ionizing radiation and non-ionizing radiation.
DEFINE radioactivity.
Show slide 3
Students will learn six supporting objectives, three on the next slide, allowing them to:
1. IDENTIFY the three basic components of an atom.
DEFINE ionization, ionizing radiation, radioactive material, and radioactive contamination.
DISTINGUISH between ionizing radiation and non-ionizing radiation.

4. Enabling Objectives STATE the four basic types of ionizing radiation.
DESCRIBE the shielding materials and biological hazards for each of the four types of ionizing radiation.
LIST the three techniques for minimizing exposure to radiation and radioactive material (ALARA).
Show slide 4
READ slide
The three other supporting objectives are:
DEFINE radioactivity
STATE the four basic types of ionizing radiation.
IDENTIFY the shielding materials and biological hazards for each of the four types of ionizing radiation.

5. Radiation Basics Video
Show slide 5
Show video.
Video from the Department of Energy (DOE) Transportation Emergency Preparedness Program (TEPP)

6. Parts of an Atom Protons Neutrons Electrons Show slide 6
To understand how radiation is created, we need to understand atoms. Atoms are the building blocks of all matter and are themselves made up of three basic components: electrons, protons, and neutrons.

7. Protons Protons Neutrons Electrons Show slide 7 Protons
Protons are located in the center, or nucleus, of the atom and have a positive electrical charge.
The number of protons in the nucleus determines the element.
For example if an atom has one proton, it is hydrogen.
An atom with 2 protons is helium, …
6 protons is carbon,
7 protons is nitrogen,
8 protons is oxygen, etc

8. Neutrons Protons Neutrons Electrons Show slide 8
Neutrons are located with the protons in the atom’s nucleus.
Neutrons have no electrical charge.
The number of neutrons in the nucleus determines if that atom is radioactive or not.

9. Electrons Protons Neutrons Electrons Show slide 9
Electrons are in orbit around the nucleus of an atom, similar to the way the planets orbit around the sun.
Electrons have a negative electrical charge.
Electrons determine the chemical properties of an atom.
When atoms form chemical bonds to make molecules those atoms are sharing electrons. Heating up a material involves making some of the electrons move faster. Electricity is electrons moving from one atom to the next.

10. Stable and Unstable Atoms
An atom with too many or too few neutrons contains excess energy and is not stable.
Unstable atoms give off excess energy (radiation).
Unstable atoms are radioactive.
Show slide 10
Stable and Unstable Atoms
•The ratio of neutrons to protons is a good predictor of whether an atom will be stable or unstable.
•If there are too many or too few neutrons for a given number of protons, the resulting nucleus will contain excess energy in it and will not be stable.
•The unstable atom will try to become stable by giving off excess energy in the form of particles or waves (radiation.) These unstable atoms are also known as radioactive atoms.

11. Removing electrons from atoms or molecules
Ionization
Radiation
Show slide 11
Ionization
Ionization is the process of removing electrons from atoms or molecules.
Removing electrons from atoms or molecules

12. Ionizing Radiation
Excess energy (from unstable atoms), capable of removing electrons from an atom
Radiation
Show slide 12
Ionization Radiation
Ionization is the process of removing electrons from atoms or molecules.
Ionizing radiation is excess energy (from unstable atoms) capable of removing electrons from an atom.
This results in electrically charged particles called ions.
Ionizing radiation has enough energy to remove electrons. Nuclear radiation is ionizing radiation.

13. Non-Ionizing Radiation
Show slide 14
Non- Ionization Radiation
Non-ionizing Radiation that does not have enough energy to ionize an atom
Radio Waves, Microwaves, Visible Light, and most Ultra-violet are all non-ionizing radiation.
These non-ionizing radiation waves can still hurt you (for example, sunburn from ultraviolet)

14. Radioactivity
Radioactivity is the process of unstable (radioactive) atoms trying to become stable by emitting ionizing energy.
Show slide 17
Radioactivity
Radioactivity is the process of unstable (radioactive) atoms trying to become stable by emitting energy that is at a level high enough to ionize other atoms’ electrons.

15. Radioactive Material Radioactive Material
Material containing unstable (radioactive) atoms
Radioactive Contamination
Radioactive material in an unwanted place
Show slide 15
Radioactive Material
Any material containing unstable atoms that emits ionizing radiation (alpha, beta, gamma, or neutron radiation).
Even when this radioactive material is properly contained, it still emits radiation and may be a hazard
The radioactive material is not contamination until is is released from its container.

16. “Radiological” vs. “Nuclear”
“Radiological” deals with radiation or material that emits radiation.
Example Radiological WMD: “Dirty Bomb”
“Nuclear” refers to processes that involve splitting a nucleus (fission) or combining nuclei of atoms (fusion).
Example Nuclear WMD: atomic bomb
Show slide 18
Radiological vs. Nuclear
RADIOLOGICAL deals with radiation or material that emits radiation, such as industrial radiological material, or medical radiological sources.
NUCLEAR refers to processes that involve splitting a nucleus (fission) or combining nuclei of atoms (fusion), such as, nuclear power plants, nuclear weapons, or nuclear explosions.

17. Measuring Radiation Radiation Dose
Radiation energy absorbed by the human body
Dose is measured in units of rem.
A millirem (mrem) is one thousandth of a rem.
Show slide 19
Radiological Units
•There are many units used in the study of radiation. In this course, we will use the units of “millirem” or mrem.
•The unit “rem” is a measure of the radiation dose, or the radiation energy absorbed by the human body and takes into account the biological effect on the body.
•A more practical unit for our purposes is the millirem (mrem), which is one thousandth of a rem.

18. Measuring Radiation Radiation Dose Rate
Radiation energy received over a period of time
Radiation dose rate is dose per time
mrem per hour = mrem/hr “strength” of radiation at a location
Show slide 20
Radiation Dose Rate
•Radiation dose rate is the dose of radiation energy received over a period of time.
•Radiation dose rate = dose/time
•As a measure of “how strong” the radiation is at a location, we will use measurements of millirem per hour (mrem/hr)

19. Types of Ionizing Radiation
Video from the Department of Energy (DOE) Transportation Emergency Preparedness Program (TEPP)

20. Types of Ionizing Radiation
Alpha radiation
Beta radiation
Gamma rays/X-rays
Neutron radiation
Some radioactive materials may emit more than one kind of radiation
Show slide 22
Types of Ionizing Radiation
There are four types of Ionizing Radiation. They are:
•Alpha Particles - an internal biological hazard only
•Beta Particles - both an internal and external biological hazard
•Gamma/X-rays - both an internal and external hazard
•Neutron Particles – both an internal and external body hazard
Note that radioactive material can emit one or more types of radiation: For example, alpha only or beta only or beta and gamma, etc.

21. Alpha Radiation Range: 1 to 2 inches Shielding: Paper, Cloth,
Dead Layer of Skin
Show slide 23
Alpha Particle
Alpha particle’s physical characteristics - Large mass consisting of two protons, two neutrons, and no electrons with a large positive charge
Ionization Occurs because the large positive charge causes the alpha particle to strip electrons from nearby atoms, as it passes through the material, thus ionizing those atoms.
Alpha Particle Range - The alpha particle deposits a large amount of energy in a short distance of travel. The range in air is only about 1 to 2 inches .
•Shielding - Most alpha particles are stopped by 1 to 2 inches of air, a sheet of paper, cloth, or the dead layer (outer layer) of skin.

22. Alpha Radiation (continued)
Biological Hazard
Not an external radiation hazard
Easily stopped by the dead layer of skin
Internal hazard – If material is inside the body, then the alpha radiation reaches live cells.
Show slide 24
Alpha particle (continued)
Biological Hazard
•Alpha particles are not considered an external radiation hazard. This is because they are easily stopped by the dead layer of skin and do not damage the internal organs (if the material is outside of the body)
Biological Hazard – Alpha is an Internal Hazard. If the material the emits the alpha radiation (energy) is inside the body then the alpha particles can reach the live cells and can deposit large amounts of energy in a small volume of unprotected body tissue.

23. Alpha Radiation (continued)
Sources
Uranium (nuclear power plant fuel and nuclear weapons)
Plutonium (nuclear weapons)
Americium (smoke detectors)
Thorium (high-temperature metals)
Show slide 25
Alpha particle (continued)
Alpha Radiation Sources
Sources - Alpha radiation are usually emitted by:
• Uranium (nuclear power plant fuel and nuclear weapons)
Plutonium (nuclear weapons)
Americium (smoke detectors)
Thorium (high temperature metals)

24. Thick Clothing, ¼ Inch Aluminum, ¼ Inch Plastic
Beta Radiation
Range:
about 10 feet
Shielding:
Thick Clothing, ¼ Inch Aluminum, ¼ Inch Plastic
Show slide 26
Beta radiation
Physical characteristics - small mass that is negatively charged and ejected from the nucleus at high speed.
Ionization occurs due to the beta particle “pushing against” the electrons in nearby atoms because both the beta particle and the electron have the same electrical charge.
Range - the beta particle has a limited penetrating ability. Range in air is about 10 feet.
Shielding - Most beta radiation can be shielded by plastic, aluminum, thick clothing, or safety glasses

25. Beta Radiation (continued)
Biological Hazard
External hazard to skin and eyes
Internal hazard if the material that emits the beta radiation is inside the body. Then beta radiation can deposit energy in a small area of body tissue.
Show slide 27
Beta radiation (continued)
Biological Hazard
Externally, beta radiation are potentially hazardous to the skin and eyes. The beta radiation cannot penetrate through the entire thickness of the skin to damage the internal organs.
Beta radiation is an internal hazard, if the material that emits the beta radiation is ingested or inhaled. Then the source of the beta radiation is in close contact with body tissue and can deposit energy in a small area of body tissue.  

26. Beta Radiation (continued)
Sources
Used nuclear reactor fuel
Nuclear weapons fallout (strontium)
Some industrial radioactive sources such as cesium
Tritium in glow-in-the-dark EXIT signs, watch dials, and night-sights on firearms
Radioactive nickel in chemical agent detectors
Show slide 28
Beta radiation (continued)
Sources - beta radiation are emitted from used nuclear reactor fuel and nuclear weapons fallout (strontium), and some industrial radioactive sources such cesium.

27. Inch of Lead, 3 Inches of Steel, 6 inches Concrete, 1 foot of Dirt
Gamma Rays/X-Rays
Range:
Hundreds of feet
Shielding:
Inch of Lead, Inches of Steel, 6 inches Concrete, 1 foot of Dirt
Show slide 29
Gamma Rays/X-Ray
Physical characteristics – Gamma and x-ray radiation are electromagnetic waves, like light or radio waves, but with more energy.
They have no mass and no electrical charge.
Gamma rays are very similar to x-rays. For this course, they can be considered to have the same properties, except that gamma rays typically have more energy, penetrate through shielding material more, and cause more damage to people than x-rays.
Gamma radiation ionizes atoms by knocking free electrons from the atoms in their path. A single gamma ray may ionize many thousand atoms along its direction of travel.
The more electrons it knocks loose (ionizes) the less energy it has left. Eventually the gamma ray gives up the last of its energy and disappears.
Range - Because gamma/x-ray radiation has no charge and no mass, it has a very high penetrating power. Range in air is several hundred feet.
Shielding – Shielded by very dense materials, such as concrete, lead, water, or thick steel.

28. Gamma Rays/X-Rays (continued)
Biological Hazard
Gamma rays and X-rays easily penetrate body tissues, outside or inside of the body.
Whole body (internal and external) hazard
Show slide 31
Gamma Rays/X-Ray (continued)
Biological hazard – Because gamma rays and x-rays easily penetrate body tissues, material that emits gamma rays/x-rays can damage the internal tissues when the material is outside or inside of the body. They are considered a whole body hazard (internal and external).
 Sources -
Uranium, Plutonium, Radioactive Cobalt and Cesium
Industrial radiation sources Medical sources, cancer treatment machines
Many beta-emitters also emit gamma radiation

29. Gamma Rays/X-Rays (continued)
Sources
Uranium, plutonium, radioactive cobalt, and cesium
Industrial radiation sources 
Medical sources, cancer treatment machines
Many beta-emitters also emit gamma radiation.
Potassium in soil, bananas, and potassium chloride (salt substitute)
Show slide 32
Gamma Rays/X-Ray (continued)
Sources –
 Uranium, Plutonium, Radioactive Cobalt and Cesium
Industrial radiation sources Medical sources, cancer treatment machines
Many beta-emitters also emit gamma radiation

30. Neutron Radiation Range: Hundreds of feet Shielding:
10 Inches of Plastic, 1 foot of Concrete, 3 feet of Dirt, feet of Water
Show slide 39
Physical characteristics
Neutron radiation consists of a neutron that ejected from a nucleus. A neutron has mass, but no electrical charge. 
Ionization occurs:
as the result of a collision between a neutron and a nucleus an atom. The neutron continues on, crashing into other atoms, until it uses up all of its energy.
when the atoms that the neutron crashed into, can also cause the ionization of other nearby atoms.
Shielding - Neutron radiation is best shielded by materials with a high hydrogen content, such as water or plastic. Thick concrete and water are very effective.

31. Neutron Radiation (continued)
Biological Hazard
Whole body hazard (external and internal neutrons are a whole body hazard).
Neutrons penetrate body tissues.
Neutrons cause damage whether the material is inside or outside of the body.
Show slide 34
Biological Hazard - Neutrons are a whole body hazard (internal and external).
Neutrons easily penetrate body tissues, and the material that emits neutrons can damage the body’s tissues whether this material is outside, or inside, of the body.

32. Neutron Radiation (continued)
Sources
Nuclear reactions inside nuclear reactor while reactor is operating
Burst of radiation from exploding nuclear weapon
Plutonium, industrial sources, moisture gauges with californium or mixture of americium and beryllium
Show slide 35
Neutron Radiation (continued)
Sources of neutron radiation are:
The nuclear reactions inside of a nuclear reactor
The burst of radiation from an exploding nuclear weapon
Plutonium and some industrial sources also emit neutrons, such as moisture gauges with californium or a mixture of americium and beryllium

33. Comparison of Ionizing Radiation
Aluminum Lead Concrete
Alpha Radiation
Gamma Rays
Stopped by a few inches of lead or six inches of concrete
Neutrons
Organic
Tissue
Radiation Source
Stopped by a
sheet of paper or dead layer of skin
Stopped by a foot concrete or water
Beta Radiation
Stopped by thick layers of clothing or by a quarter inch of aluminum or plastic
3 Inches
Lead
1 foot
Concrete
¼ Inch
Aluminum
Show slide 36
Comparison of Ionizing Radiation
Alpha radiation stopped by the outer layer of skin, sheet of paper, or clothing.
Beta radiation can penetrate into the skin, but cannot penetrate to the internal organs from outside of the body. Beta radiation can be stopped by thick clothing, aluminum, lead, or concrete.
Gamma radiation can penetrate through the human body (damaging cells along the way). Gamma radiation is stopped by dense material like lead, very thick concrete, or water.
Neutron radiation can penetrate through the human body (damaging cells along the way) and can penetrate lead. Neutron radiation is stopped by material containing water (like thick concrete) or by material containing hydrogen (like thick, dense plastic.)

34. Particle Size Comparison
Speck of Dust Atom Alpha Particle
Earth City Ping Pong Ball
Show slide 37
Alpha, Beta, and Neutron “Particles”
Even though alpha, beta, and neutron radiation are all “particles,” they are not like any other kind of particle you are used to dealing with.
They are much smaller than even an atom, so they do NOT follow the wind (although the radioactive atoms in dust particles or radioactive gas atoms may flow with the wind).

35. Alpha, Beta, and Neutron “Particles”
Rifle Cartridge Bullet
Radioactive atom Alpha, Beta or Neutron “Particles”
Show slide 39
Alpha, beta, and neutron particles, travel at incredible speeds.
For example:
A “fast” neutron travels at about 12,000 miles per second (or 40 Mil mph)
A “slow” neutron travels at about 1.5 miles per second (or 3,600 mph)
Note: speed information from Nuclear Physics and Safety, Glossary. The Commissariat `a ĺ énergie atomique (CEA). France. URL: gb/institutions/clefs45/clefsgb/clefs45_glo_3a.htm

36. Comparison of Radiation and Contaminants
Radiation is energy.
Radioactive contaminants are materials that emit radiation.
Radioactive contaminants are radioactive atoms that get onto something unwanted or are in an uncontrolled place.
Radioactive atoms cannot be neutralized to make them non-radioactive.
Show slide 40
Radiation is an energy.
Radioactive Contamination is a material that emits radiation.
Contamination is the actual radioactive atoms getting into or onto something.
Radioactive atoms cannot be neutralized, sterilized, or killed in order to make them non-radioactive. The atoms themselves must be removed from the person or object to decontaminate it.

37. Exposure vs. Contamination
Show slide 49
Demonstration with Chem-light stick or flashlight. A chem-light works better, but you can do this with a flashlight.
The light source is the radioactive material and the light is the radiation.
The glowing atoms inside the source are the simulated radioactive material
Put your hand up to the light source so that it is illuminated.
Exposure to the light does not make the hand radioactive.
The hand does not glow or emit light when you take it away from the light source,
So the hand was irradiated, not contaminated. Radiation does not build up on a person or thing, and make it radioactive.
The actual radioactive atoms in the form of dust, gas, or liquid must move onto an object to contaminate it.
Remember, Alpha, Beta, and Neutron particles do not accumulate on a object and make the object radioactive.
When we talk about radioactive particles causing contamination, it means small particles of dust or liquid that contain radioactive atoms have gotten onto something.
Discuss (but do not actually do it) that if you cut open the chem-light and spilled the liquid on your hand,
Then the hand would be contaminated. The actual radiation-emitting atoms are now on your hand.
Of course, the radioactive material on the hand is also irradiating the hand as well.
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External Exposure
External Contamination

38. Internal Contamination and Internal Exposure
Radioactive material inside the body
Both contaminated
and exposed
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Show slide 52
Internal Contamination and Internal Exposure
Internal contamination will occur when unprotected people ingest, inhale, or are wounded by radioactive material, or when the skin absorbs radioactive material
Internally contaminated victims present a minimal risk to responders.
The internally contaminated victim may also be externally contaminated.
The skin, mouth and nose are the most obvious routes to internal contamination.

39. ALARA As Low Reasonably Achievable Show slide 45 ALARA
There are some simple methods to minimize radiological exposure and contamination. Ideally you want to keep exposure and contamination “As Low As Reasonably Achievable” (ALARA). To do this you can use the principles of time, distance, and shielding.

40. ALARA Video

41. ALARA Minimize time Maximize distance Use shielding
Show slide 46
Time
Limit the time that you are near a source of radiation, and leave the area as quickly as possible.
“Minimizing Time: The less time you are exposed to radiation source the less dose you receive.”
Distance
Keep as much distance as possible between you and the source of radiation. The farther you are from the source, the lower the dose that you will receive.
“Maximizing Distance: The further you are from the radiation source the less dose you receive.”
Shielding
Keep as much protection between you and the source as possible.
“Using Shielding: If you can place other material between you and the radiation source you will receive less dose”

42. Review
What’s the difference if I get exposed or if I get contaminated?
How do I protect myself from alpha, beta, gamma, or neutron radiation?
How can I practice the principles of ALARA in this situation?
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43. Questions?
Show slide 56
Review material that the students may still have trouble grasping, and/or direct them to sources for further information.
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