Nukes Flashcards
What are the two types of radiation
Ionizing and Non-Ionizing
Ionizing and Non-Ionizing
Ionizing - X-Ray, Gamma, alpha, beta, neutron
Non-Ionizing - Microwave, Radio, light.
What is a quality factor
A value of relative biological effectiveness of an absorbed dose of radiation.
What are the quality factors for all radiation types?
X-ray, Gamma, Beta — 1
Neutrons — 10
High Energy protons — 10
Alpha, multiple charged particles, fission fragments, heavy particles — 20
Explain ionizing vs. non ionizing radiation
Ionizing - Has enough energy to displace electrons from atoms or molecules.
Non-Ionizing - Does not have enough energy to displace electrons from atoms or molecules.
What is alpha radiation?
A positively charged particle ejected from the nucleus of a radioactive atom (Identical to a helium atom with no electrons)
How far does alpha travel?
1-2 inches
How do you shield from alpha?
Just about anything. Paper and skin can even stop alpha radiation
What are the associated hazards of alpha radiation?
Inhalation, ingestion, absorption through open wounds
What is beta radiation?
Either a negatively or positively charged electron (positron) ejected from a radioactive atom
How far does beta travel?
6 to 10 feet
How do you shield from beta?
Clothing and gloves. It will penetrate into the skin
What are the associated hazards of beta radiation?
Inhalation, ingestion, absorption through exposed skin
What is neutron radiation?
An uncharged elementary particle (nucleon)
How far do neutrons travel?
Hundreds or thousands of feet in air.
How do you shield from neutrons
Low atomic number (Z) materials such as water or carbon
What are the associated hazards of neutron radiation?
Inhalation, ingestion, absorption through exposed skin
What is gamma radiation?
Extremely high energy electromagnetic radiation that originates from the nucleus of a radioactive atom.
How far does gamma radiation travel?
Potentially forever but disperses due to the inverse square law
How do you shield from gamma radiation?
High Z material
What are the associated hazards of gamma radiation?
Difficult to shield, absorption into skin/organs.
What is X-ray radiation?
High energy electromagnetic radiation that originates from the valence shell of a radioactive atom.
How far do x-rays travel ?
Potentially forever but disperses due to the inverse square law
How do you shield from x-rays?
High Z material
What are the associated hazards of x-ray radiation?
Difficult to shield, absorption into skin/organs.
When do you need respiratory protection for radiological response
When cpm on the PDQ-6 is above 159,840. SCBA required for cpm above 799,200.
When there is known or suspected contamination
List common emitters of each type of radiation
Alpha: radium-226, radon-222, uranium-233, uranium-235, uranium-238, plutonium-239
Beta: strontium-90, carbon-14, tritium, sulfur-35
Gamma: iodine-131, cesium-137, cobalt-60, radium-226
Neutron: americium-241, californium-252, plutonium-239
What is an atom
The smallest component of an element.
What are the parts of an atom
Neutron
Proton
Electron
What is a proton
A subatomic particle with a positive charge contained within an atom’s nucleus
What is a neutron
A subatomic particle with a neutral charge contained within an atom’s nucleus
What is an electron
A subatomic particle with a negative charge and is significantly smaller than a proton/neutron
What is an ion
An atom or molecule that has lost or gained one or more electrons
What is contained in the nucleus
Protons and Neutrons
What is an atomic number
A number equal to the number of protons within the nucleus of an atom.
What is atomic mass
The mass of an atom, equal to the number of protons & neutrons in an isotope.
What is an isotope
A variant of a particular atom that has a different number of neutrons but the same number of protons.
What determines radioactivity
The radioactivity of a particular isotope is determined by its specific activity which is determined by the isotope’s half-life.
What is specific activity
Curie per unit mass
Activity per unit weight of a given sample of radioactive material.
What is high z material? What is low z?
Material with high density or a large atomic number (big, heavy nucleus)
Material with low density or a small atomic number (small nucleus)
What is half life?
The amount of time it takes for a substance to decay to ½ of its original activity
What is a Voss book
A radiation worker’s field handbook
What can you find it in a Voss book?
Acute Radiation Effects
Half-Value Layer Calcs
Common emitters and their progenies
What is a half value layer?
A shielding layer of material that is sufficient thickness to ½ the amount of radiation detectable on the skin of the shield.
How do you compute it half value layers?
I = I. 0.5n → n = [log(I/I.)]/log(0.5)
I = Shielded Exposure Rate
I0 = Unshielded Exposure Rate
n = number of half value layers
What is fission
The process of splitting a heavy atom into two lighter atoms
What is fusion
The fusing of two light nuclei that forms a heavier atom along with a release of energy
What is criticality?
When a neutron that is emitted during fission causes a second nucleus to fission and this process becomes a self sustaining chain reaction
A way of describing change in fission rate
What are the three types of criticality?
Super-Critical - When the change in fission rate is increasing
Critical - When the change in fission rate is constant
Sub-Critical - When the change in fission rate is decreasing
What are the factors affecting criticality
Mass
Interactions
Density - (high density lowers critical mass)
Shape - (Sphere bad, disk good)
Purity - lack of contaminates
Enrichment -
Reflection - reflecting of neutrons
Moderation - slowing of neutrons
What is tritium?
Hydrogen atom with one proton and two neutrons
What is deuterium
Hydrogen atom with one proton and one neutrons
What is the NAVMED for radiation heath
NAVMED 5055
What is ARS?
Acute Radiation Sickness
An acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a very short period of time
How does ionizing radiation affect the body?
It destroys your cells and DNA
What symptoms are expected at different dose levels? (In REM)
Bone Marrow: 70-1000 rads
Gastro-Intestinal: 600 to over 1000 rads
CNS: Over 5000 rads