John C. White, CNMT RSO
The University of Texas Southwestern Medical Center at Dallas

-Certified Nuclear Medicine Technologist
-Radiation Safety Officer
-President, Health Physics Society North and South Texas
-30 years experience with radioactives and radiation
-A/TC WMD Working Group
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This lesson will discuss:
 Basic Radiation Principles
 Perspectives on Risk
 Radiological Incident Sources
 Radiological Incident Response
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 To gain a better understanding about radiation and radioactivity
 To provide an understanding of the harmful effects of radiation on the human body
 How to safely respond to an emergency involving radioactive materials
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 Radiation exposure
–
Radiation is everywhere and can be found in many forms
–
Some are very harmful to the human body
– Radiation injuries can take a long time to present. But when they do, it is usually in the form of cancer or birth defects
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


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Does Not Have Enough Energy to Remove
Electrons From Surrounding Atoms

 Non-ionizing radiation
–
Waves of energy. Large wavelength
– Low frequency
Non-ionizing radiation comes from ultraviolet and infrared energy waves
 *Note*:
– This type of radiation causes “sunburn” and is not a major concern for the hazmat responder
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 Ionizing radiation
– Energy emitted in the form of electromagnetic waves or particles from the nucleus or electron cloud of an atom


Energy produced:
– Alpha particles
–
Beta particles
– Gamma or X rays
–
Neutrons
All of these sources may cause damage at the cellular level
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Energy Can Be Deposited in Neighboring Atoms
Resulting in the Removal of Electrons.
alpha x-ray
 High
Frequency
 Small
Wavelength gamma ray neutron

 beta

 Alpha radiation
– Alpha particles will travel 3 - 4 inches in air and cannot penetrate the outer layer of skin
–
Alpha particles can invade the body by other means, such as:
 Injection
 Inhalation
 Ingestion
 Absorption
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 Not an external risk
 Densely ionizing (internal exposure)
 Easily shielded by skin, clothing, etc.
 Internal risk
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 Beta radiation
–
Beta particles can travel 3 to 100 feet and may penetrate the skin.
* A firefighters gear can deflect beta particles
–
Personnel can be exposed through:
 Inhalation
 Ingestion
 Injection
 Absorption
 Penetration
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


Can penetrate thin sheets of aluminum and skin
External skin hazard
Internal hazard, like alpha, through ingestion, inhalation or injection
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 Gamma radiation.
– Gamma radiation is a naturally occurring or man-made high energy electromagnetic wave.
– It has a high penetrating power and can travel at the speed of light.
– Gamma rays will penetrate the skin and can cause injury to internal organs.
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 Gamma Radiation Effects
–
Routes of entry into the body
 Ingestion
 Inhalation
 Injection
 Absorption
 Penetration
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 External and internal hazard
 Best shielded with dense materials (e.g., lead or concrete)
 Will easily penetrate Level A PPE
 Easily detected
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
– No electrical charge
– Can travel hundreds of feet in air
– Can easily penetrate Level A PPE
– External hazard
– Best shielded w/materials that are hydrogen rich (elastic collisions)
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ALPHA PARTICLE
Penetration capability of types of radiation
BETA PARTICLE
GAMMA RAYS
Neutron
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Radon - 55%
Other < 1%
Consumer Products - 3%
Nuclear Medicine - 4%
Rocks, Soil - 8%
Cosmic Rays - 8% X-rays - 11%
Water, Food - 11%
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 Roentgen (R) (C/Kg)
–
A unit of exposure: the amount of ionizing radiation
(energy) produced in a specific volume of air
 Radiation absorbed dose (RAD) (Gy)
–
A unit of absorbed dose: the amount of energy absorbed in a given volume of material.
 Radiation equivalent in man (REM) (Sv)
– A unit of dose equivalent: the amount of radiation that has been absorbed times a quality factor
(biological effects)
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2.58 x 10 -4 C /kg -1 = 1 R
1 R = 0.97 Rad (tissue)
0.97 Rad x 1 = 0.97 Rem
Therefore: 1R ~ 1 Rad ~ 1 Rem
1 R = 1000 mR (milliRem)
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- the rate at which radioactive materials emit radiation
 The number of nuclear disintegrations occurring in a given quantity of material per unit of time – usually referred to as dps or cpm
 A curie (Ci) is the number of radioactive atoms that will decay and emit radiation in one second, not a function of weight of volume
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-A Curie (Ci) is 37 billion disintegrations per second
3.7 x 10 10 dps = 1 curie (Ci) or 1000 millicuries
-A Becquerel (Bq) is 1 dps
1 Bq = 27 pCi = 0.000027

Ci
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 Radioactivity
– Ionizing energy spontaneously emitted by a material or combination of materials.
 Radioactive material
– One that spontaneously emits ionizing radiation
 Radioactive contamination
–
Radioactive material in an unwanted place
– Internal / external
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 Curie
–
A unit of activity:
 Milli-curie
–
One-thousandth of a curie
 Micro-curie
–
One-millionth of a curie
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
- The amount of time a radioactive material takes to decay to 1/2 of its original activity
 Each radioactive material (Isotope = Source) has a unique half-life
– Sodium 25
–
Iodine 131
– Cobalt 60
–
Plutonium 239
60 seconds
8.04 days
5.27 years
24,139 years
 After 7 half lives < 1% remains
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 Identify hazards
 Types of radiation
 External
 Magnitude
 Identify affected media
 Identify nuclide(s)
 Offsite analysis (of media samples)
 Field spectroscopy
May read in mR/hr or microrem/hr – know your meter!
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 Alpha Detectors
– Alpha scintillators (zinc sulfide, ZnS)
– Air proportional detector
– Pancake G-M (Geiger Mueller)
 Beta Detectors
– Pancake G-M
– Thin Wall G-M
 Gamma Detectors
– Sodium Iodide (NaI)
– Geiger Mueller Tube,
Pancake G-M, Thin Wall G-M
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 Acute Exposure - Local or Total Body
Exposure occurs in hours or minutes
–
Repairable damage to cells
– Irrepairable damage to cells, but not causing death
–
Irrepairable damage resulting in death
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 Chronic Exposure
Small amounts of exposure over a long period of time
–
Birth defects of a Teratogenic or Mutagenic nature
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(Radiation Workers)
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 Radiation Risks
(bomb survivors)
Risk of developing a fatal cancer, non-fatal cancer, genetic effects, and length of life lost
0.0725 %/rem or 0.0000725 %/mrem
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Dose Limit
(whole body)
5 rem
10 rem
25 rem
>25 rem
Emergency Action Dose Guidelines
Activity Performed
All activities
Protecting major property
Lifesaving or protection of large populations
Lifesaving or protection of large populations, only by volunteers who understand the risks.
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 The Maximum Lifetime exposure from a single incident is:
 25 Rem
NCRP Report No. 138
 50 Rem Whole Body , 500 Rem Skin
 Justification, understanding risks
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Los Alamos Wildfires Lost Sources
Three Mile
Island
Space Launches




Nuclear facility accidents
Nuclear weapon and device accidents
Nuclear terrorism
Satellite re-entry





Contaminated imports
Transportation accidents
Sabotage
Orphan sources*
Foreign incidents*
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 The nature of these attacks (i.e., materials used, facilities involved, method of contamination, destructive intent) can vary greatly
– Assault or attack on power plants/nuclear facilities
– Improvised Nuclear Weapon/lost or stolen weapon
– Radiation Dispersal Device with or without explosives
– Radiation Exposure Device
– Water system contamination
– Purposely contaminated consumer products
– Orphan and lost sources
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Element
Cesium–137
Cobalt–60
Strontium-90
Iridium–192
Half Life
30 years
5.3 years
29.1 years
74 days
Type of Radiation
Beta, gamma
Beta, gamma
Beta, Bremsstrahlung (quantity)
Beta, gamma
Hydrogen-3
Plutonium-238
Plutonium-239
Americium – 241
Uranium-235, 238, DU
12.3 year
86 years
24,400 years
430 years
Beta (low energy)
Alpha (gamma contaminant)
Alpha, beta, gamma
Alpha, gamma
710M – 4.5B yrs.
Alpha, gamma (beta from daughters)
Medical and research isotopes:
Technetium-99m
Iodine – 131
Phosphorus-32
Gallium-67
Carbon-14
6 hours
8 days
14 days
78 hours
5730 years
Beta
Beta, gamma
Beta
Gamma
Beta 39




Terrorists pack a conventional explosive around radioactive material
– In the U.S., the sources would likely be radiography-type
(cesium, cobalt, iridium), which are fairly easy to detect if intelligence gives a general location
Terrorists purposely contaminate an area with radioactive materials through some aerosol spraying method
– Lethality is low
– Panic is high
Event is intended to panic the public and severely tax the resources of Federal and state government
– Many follow-up measurements would have to be made to assess the total contamination picture
– Even a small event may take years of study to understand
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41
Source: Knight-Ridder Tribune

 Thermal Burn as Opposed to Radiation
Burn
- No sensation or recollection of immediate pain
 Delayed Response
 RDD as opposed to Atomic Blast
- Difference in Debris Field
- Flash
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 Radioactive material that is intended to expose people in the vicinity of the device to emitted radiation
– RED could be a sealed source or a material within some type of container (e.g., a shoebox)
– The radioactive material could be in the form of a contained powder, a contained liquid, or a solid object
 Example: if the radioactive material in an industrial radiography device is left without shielding, a person standing one meter from the source would have to stand at that location for about 5 hours to get a dose that would probably prove lethal (death within 2 months…)
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 WIPP transports
 Industrial Radiography
 Passenger / Air Cargo Flights
 Rail Transport
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 The Department of transportation (DOT) serves as the regulatory agency involving radioactive materials if:
– A radioactive material having a specific activity of 70 Bq per gram (0.002 micro-curies per gram) of material
 The DOT determines what type of packaging the material shall be encased and shipped in
 ICAO/IATA determines types of packages acceptable on passenger/cargo aircraft
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•
Radiation presents minimal risk
• Undamaged packages are safe. Contents of damaged packages may cause increased exposure or possible internal/external contamination
• Type A packages contain non-life endangering amounts
• Type B packages, and the rarely occurring Type C packages including [B(U)F, B(M)F, CF] contain the most
(potentially) hazardous amounts of material. Life threatening conditions may exist only if contents are released or package shielding fails or in utmost severity.
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FIRE OR EXPLOSION involving Radioactive Material
• Some of these materials may burn, but most do not ignite readily.
• Radioactivity does not change flammability or other properties of materials.
• Type B packages (AF, IF, B(U)F, B(M)F and CF) are designed and evaluated to withstand total engulfment in flames at temperatures of 800°C (1475°F) for a period of 30 minutes.
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* Initial Alarm Level – 10 mR/h
* Turn Around – 10, 000 mR/h (10 R/h)
* Rule of Thumb
3000 - 4000 cpm = 1 mR/h
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 Radiation Safety Officer
 USNRC
 State – TxDSHS
 Nuclear Medicine Professionals
 FEMA
 EPA
 USDOE
 Several Other Federal Agencies
 Health Physics Society
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 Familiar with Instruments
 Practical Advice
 Ability to Calculate
 Credential
 Familiarity with Contamination
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•
Stay upwind.
• CALL Emergency Response Telephone Number on Shipping
Paper first.
• Priorities for rescue, life-saving, first aid, and control of fire and other hazards are first.
• Keep unauthorized personnel away.
• Detain or isolate uninjured persons or equipment suspected to be contaminated; delay decontamination and cleanup until instructions are received from Radiation Authority.
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• Radiation Authority must be notified of accident conditions.
Radiation Authority is usually responsible for decisions about radiological consequences and closure of emergencies.
• Isolate spill or leak area immediately for at least 25 to 50 meters (80 to 160 feet) in all directions.
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 Shipping papers and labels indicate the level of
“ activity ”
 The type of transportation container (A, B or C) is determined by the Ci content and level of exposure
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 Radioactive Material
–
Shall be packaged, at a minimum, in a
Cardboard Box. This is called “Type A
package”.
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HAZARD
CATEGORY
CONTENTS
ACTIVITY
Contents Cs-137
Activity 37 GBq (1.0 Ci)
2.0
TRANSPORT INDEX
TRANSPORT
INDEX
HAZARD CLASS
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 Radioactive White - I
–
One vertical red stripe
– Low level hazard (activity)
–
Surface radiation level,maximum of 0.5 mR/hr
 Radioactive Yellow - II
– Two vertical red stripes
–
Moderate hazard (activity)
– Surface radiation level, maximum of 50 mR/hr
–
1 mR/hr maximum at one meter from package
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 Radioactive Yellow III
– Three vertical red stripes
–
Highest level hazard (activity)
–
Surface radiation level – maximum of 200 mR/hr
–
10 mR/hr maximum at one meter from the package
EXCLUSIVE USE
– 1000 mR/h on package surface,
200 mR/h outer surface vehicle, 10 mR/h at 2 meters
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 A number placed on the label to designate the degree of control to be exercised during transport
 TI is the maximum radiation level in mR/hr per hour) at 1 meter from package
 If TI is 2, the maximum radiation level at 1 meter would be 2 mR/hr
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NFPA Objective 4-2.1.4
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 Placards are only required to be displayed on vehicles for
Type III shipments
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 Protective overpacks
–
Cylindrical configuration
–
Boxlike configuration
 Casks
–
Rigid metal packaging
–
Reinforcing rings and cooling fins
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Fiberboard
Wooden
Boxes
Steel Drums

 Designed to meet standards for performance under hypothetical accident conditions
 Tests Conducted
– Dropped from a height of 30 feet
–
Dropped on a steel spike from 40 inches
– Exposed to fire at 1,475 0 F for 30 minutes
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 TRUPACT I and II
 Certified by NRC
 Meets USDOT safety requirements
 TRUPACT I will hold 7 - 55 gallon drums
 TRUPACT II will hold 14 - 55 gallon drums
 Weight
– 12,700 lbs
–
19,250 lbs
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Trupact I
Trupact II
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 When responding to a radiological emergency, personnel MUST remember three (3) important characteristics:
 We Cannot Smell it
 We Cannot Taste it
 We Cannot See It
 Rushing in to a radiological emergency spells trouble!!
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 Personnel Safety
–
Responders shall ensure the safety of themselves and co-workers, prior to performing rescues or evacuations of victims or potential victims.
 This can be done by performing a proper
size up of the scene prior to commitment of personnel.
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 Identifying Material
– Labels
–
Placards
– Bill of Lading
– Shipper’s Declaration
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 Other information may come from:
–
An operator of a transport vehicle
–
User
–
Manufacturer
–
Shipper
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 Monitoring
–
Monitoring should begin prior to arriving at the scene.
 Radioactivity can be monitored by:
 CD V-700
 CD V-715
–
The CD V-700 survey meter has a range of 0 to 50 mR/Hour.
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 In situations involving rescue, certain safety requirements must be considered and include:
 Knowing the characteristics of radiation
 Ensuring personnel safety
 Who should perform rescue
 Who should perform evacuation
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 Protection
– Protection can be achieved by:
 Time
 Distance
 Shielding
–
All of these should be in-place when working a Radiological Emergency
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
Small Fires
Dry chemical, CO 2, water spray or regular foam.
 Large Fires
Water spray, fog (flooding amounts).
 SPILL OR LEAK
 Do not touch damaged packages or spilled material.
Damp surfaces on undamaged or slightly damaged packages are seldom an indication of packaging failure. Most packaging for liquid content have inner containers and/or inner absorbent materials. If any radioactive contamination resulting from a liquid release is present, it probably will be low-level.
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
– the shorter the exposure time, the less the exposure
– Radiation exposures are additive in their effects upon the or any other subject
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
– the closer you are, the greater the exposure
– the energy emitted from a radioactive source declines as you move away from the source
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1. There is a wreck on I-20, on approach you recognize it as semi transporting a type B cask. The cask as it appears, has not cracked open. You determine that the TI is 10.
If you stand at 3 ft away from the cask for one hour, what is your exposure?
2. On further examination it appears the cask has been cracked, someone standing next to you measures 0.5 R/hr and you have been there for 30 minutes. What dose did you receive?
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If you double the distance from the source, the intensity is lowered by one fourth
 Inverse Square Law - The intensity of ionizing radiation declines with the square of the distance
 Protection Factor Formula = Distance 2
Quantity
Distance 2
= Amount of Radiation Received
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 Protection Factor
5 ft.
10 ft.
20 ft.
30 ft.
1000 mR/hr 40 mR/hr 10 mR/hr 2.5 m/hr 1.1 mR/hr
5 X 5 = 25
1000
= 40 mR/hr
25
10 mR/hr
4.4 mR/hr
30 X 30 = 900
1000
= 1.1 mR/hr
900
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You are at the scene of transport accident and find that on measurement you are standing in a 500 mR/h field which is one meter (3 ft) away from the source of radiation.
How far would you have to move away from the source to be less than an initial alert level of 10 mR/h?
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
–
Personnel protective equipment can offer protection against alpha particles
– PPE will offer limited protection against beta particles
–
PPE offers NO protection against gamma radiation
Positive pressure self-contained breathing apparatus (SCBA) and structural firefighters’ protective clothing will provide adequate protection against internal radiation exposure, but not all external radiation exposures.
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• Medical problems take priority over radiological concerns.
• Use first aid treatment according to the nature of the injury
• Do not delay care and transport of a seriously injured person.
• Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult.
• In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes.
• Injured persons contaminated by contact with released material are not a serious hazard to health care personnel, equipment or facilities.
• Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and prevent spread of contamination
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