Bio Regs Final Flashcards
what are the three types of radiation?
- Alpha: particles consists of 2 protons and 2 neutrons. carries a positive charge, barely able to penetrate skin. (can be stopped by a sheet of paper). east to protect against.
*Beta: fast moving electrons ejected from nucleus. More penetrating than Alpha (can be stopped by book or human tissue)
*Gamma: emitted immediately after ejection of alpha or beta particles. High energy photons. Very penetrating (can pass through human body but mostly absorbed by dense materials such as concrete). difficult to protect against
Explain Ionizing vs Non-Ionizing radiation
most atoms have equal protons and electrons so = neutral charge
non-ionizing: low energy. does not cause change to atom
eg: radiowaves, microwaves
ionizing: high energy. can cause change in atoms = equally charged atoms = ions
eg: Uv light, a, B, G radiation, x rays
What are some effects of ionizing radiation?
production of free radicals, breaking of chemical bonds, damage to DNA, RNA, protein.
at low doses, cell can repair itself.
at high doses, cell death, cancer, birth defects
What is radioactive decay?
since the radioisotopes are unstable, they release energy until it becomes stable and non-radioactive.
What does half-life mean?
the amount of time it takes for half of the radioactive atoms to decay.
what is the trefoil?
the universal symbol for radiation. Warns of potential exposure to radiation
what are the two main ways people are exposed to radiation?
a) Natural sources: 80% of exposure includes things like soil, cosmic radiation, nuclides in tissue
b) Man-made sources: 20% of exposure. includes: medical x rays, consumer products (tobacco, tanning beds), nuclear medicine
-workers may have higher exposure: mine workers, reactor technicians, radiologists, lab workers
What are the Radiation Protection Principles?
As
Low
As
Reasonably
Achievable
(ALARA) -Dry work first. Practice with water
what are the three basic principles to achieve for protection for radiation workers?
1) Distance: stay as far away from source as possible
2) Time: decreased time near source decreases chance of exposure
3) Shielding: thick, dense shield around the source for less exposure
What is a Dosimeter?
device that workers wear who are routinely exposed to radioactive sources. It measures exposure
What is a Geiger counter?
Used to detect ionizing radiation in the lab during and after experiment to detect any contamination
what is a radioisotope?
in some isotopes, the # of protons and neutrons causes the atom to be unstable.
* in attempt to become stable, it releases energy in the form of radiation.
What is an isotope?
Atoms with the same number of protons but different numbers of neutrons (different mass)
eg: C has 6 protons and 6 neutrons = Carbon 12
6 protons and 8 neutrons = Carbon 14
Both C12 and C14 = isotopes of Carbon
What is radiation?
energy in the form of waves or streams of particles
eg: sound, visible light, UV radiation, IR, Radio & tv signals
What is the main method used to control radioactive materials employed by CNSC?
Licensing System
