Cedo Definitions Flashcards
What is Activity
A measure of the disintegration rate
What is specific activity
A measure of the activity per unit weight of a radiographic source usually measured in curi’s or bequral per gram
What is characteristics Intensity
A measure of the amount of energy passing through a given area in a given amount of time. Usually measured in milli sieverts per hour @ 1 meter or mill Rankin per hour @ 1 meter.
Radiation intensity
A measure of the amount of radiation energy absorbed by any matter in a radiation field
What is radiation absorbed dose
A measure of the energy deposited in a material as the radiation passes through that material
What is relative biological effectiveness
A measure of the relative harmfullness of the types of radiation
What is roentgen Equivalent man (dose equivalent)
Equates to the biological damage from various forms of radiation
What is half life
The time it taken by a particular isotope for the activity to decay to one half the original level
What is absorbed dose
The radiation that has been absorbed by some substance usually human tissue
Alarming dosimeter
A small electronic instrument that a person wears on the the trunk of the body. It will sound an alarm when a high radiation dose rate is encountered usually at 5 mill sieverts per hour or when the total dose reaches 2 milli sieverts. Must be calibrated with in a 12 month period.
What is an atom
The smallest unit of an element consisting of a nucleus made of protons and neutrons, with orbiting electrons
What is attenuation
The reduction in intensity of radiation as it passes through any material
Battery check
A function of the Survey meter used to verify the condition of the batteries
What is a Becquerel
Si unit of activity equal to one disintegration per second
What is calibration
The act of checking by comparing to a known standard the accuracy of a measuring instrument.
What is the Canadian nuclear safety commission
Federal agency responsible for regulating the development, application and use of nuclear energy in canada
What is a certified exposure device operator
A person who has the qualifications to safely operate industrial radiography exposure devices in canada and is certified by the cnsc to do so
What is cobalt 60
An Industrial isotope used in radiography with a half life of 5.3 years.
What is a collimator
A radiation shield found at the end of the source guide tube. Usually made of tungsten depleted uranium or lead
What is contamination
The spread of radioactive material when the source capsule leaks
What is decay (radioactive decay)
The process by which an unstable atom loses energy by emitting ionizing radiation
What is Delayed effects
Those effects caused by radiation that do not become evident until years or generations after the exposure.
Depleted uranium
Often used as a shielding material. It contains less of the isotope u 235 than in natural uranium.
What is a direct reading dosimeter
A small air filled ionization chamber used to measure radiation dose. Often referred to as a pocket dosimeter.
What is disintegration
Refers to decay
What is dose (radiation absorbed dose)
Quantity measure of the amount of radiation imparted to matter per unit mass.
What is dose rate
Also referred to as radiation intensity. It is a measure of radiation dose per unit time. The si system are sieverts per hour or roentgen per hour
What is a dosimeter
A device used to measure personal radiation dose.
What is electromagnetic radiation
Radiation energy that has no rest mass. It’s pure energy and travels at the speed of light. Two examples are x-rays and gamma rays
What are electrons
A subatomic particle with a negative charge that orbit the nucleus
What is an element
A pure chemical substance of which the smallest unit is an atom
What is exposure
Being exposed to radiation
What is gamma radiation
High energy photons of energy emitted from the nucleus of an unstable atom
What is gamma radiography
The process of using radioactive materials that emit gamma radiation for the purpose of industrial radiography
What is half value lay
The thickness of a material required to reduce penetrating radiation to one half
What is half life
The time taken by a specific isotope for the activity to decay to one half the original level
What is industrial radiography
The use of penetrating radiation to inspect material for flaws.
What is a ion
An atom or molecule in which the total number of electrons is not equal to the to the number of protons resulting in a positive or negative charge
What is ionization
The process of adding or removing electrons. from atoms or molecules thereby creating ions
Ionizing radiation
Radiation capable of displacing electrons from atoms, thereby producing ions
What is iridium 192
A isotope used in gamma radiography. It has a half life of 74 days
What is a isotope
A nuclide of an element having the same number of protons but a different number of neutrons
What is a leak test
A test used to determine radioactive material has been released from the source capsule
What is lethal dose
The dose of radiation expected to cause death to those exposed. In the average human this represents approximately 5 sievert whole body dose
What is a licensee
A person who is licensed to possess, transfer, import, use or abandon a nuclear substance. License are granted by cnsc
What is a molecule
The smallest element of a chemical compound still having the chemical properties of that compound
What is non ionizing radiation
Radiation that does not carry enough energy to ionize atoms or molecules. Ie radio waves, microwaves, infrared radiation
What is a Placard
The sign on a vehicle that indicates the vehicle is carrying radioactive material.
What is a pocket dosimeter
Refered to as a direct reading dosimeter
What are prompt effects
The health effects resulting from radiation exposure appearing within a day or few weeks
What is the radiation dose limits
Legal limits of the radiation dose that a person may receive as established by regulations. Max allowed is 50 milli sieverts per year or 1 milli sievert per week on a 50 week schedule with two weeks of vacation
Define Radiation safety officer
A person appointed within an organization to ensure all cnsc requirements are followed.
What is radiation survey
A measurement of radiation taken using a radiation survey meter
What is radioactivity
The process of spontaneous transformation of the nucleus of an isotope emitting alpha or beta particles often accompanied by gamma rays
What is a radiograph
A photographic record produced by passage of x-rays or gamma rays through an object on to a film
What is a radio isotope
An isotope of an element that have an unstable nucleus
