Biological Effects and Radiation Dose Flashcards
Define Roentgen
(R) A measure of Ionization produced in air by X-ray or gamma radiation .
1R = amount of x-ray or gamma radiation producing 1 electrostatic unit of charge (ESU) in on cc of dry air at STP
RAD (Radiation Absorbed Dose)
A measure of the absorbed dose of any ionizing radiation in terms of energy absorbed per unit mass
1 RAD = 100 ergs of energy per gram of material
REM (Roentgen Equivalent Man)
Dose Equivalent REM=RAD x Quality Factor Alpha - 20 Neutron (fast) - 10 Neutron (slow or Thermal) - 2 Beta, gamma - 1
SI unit Sievert (1 Sv = 100 REM)
What are good Gamma shields and why?
Accomplished through photon interaction in the electron shell
More electrons = better shielding Generally, the more dense a material the better it is at providing shielding Lead Steel Concrete Water
What are good Neutron shields and why?
Remove the kinetic energy.
Collisions with particles of similar size is most effective.
Hydrogen atoms are excellent at slowing down neutrons
Water, Polyethylene, Concrete
Classify the four types of radiation as an internal or external hazard
ALPHA & BETA - internal
GAMA & NEUTRON - external
what is the difference between Direct and Indirect cellular damage
Direct is radiation that interacts with important molecules (DNA) causing damage
Indirect - interact with a molecule in the cytoplasm of the cell which results in the formation of ions or radicals which could react with important molecules resulting in permanent damage.
Given a list of tissues, rank them in order of radiosensitivity
Lymphoid Immature Blood Cells Gastro Intestinal Cells Gonads Skin Blood Vessels Liver and Adrenal Cells Bone Muscle Nerve Cells
State the 4 stages of the Radiation Syndrome
Radiation illness
Apparent Recovery
True Illness
Death or Recover
Define LD 50 and LD 100
LD 50 - The dose at which 50% of the people exposed would die within 30 days without medical treatment. References vary but LD 50 ~ 400 Rem.
LD 100 - The dose at which 100% of the people exposed would die within 30 days without medical treatment. LD 100 ~ 600 Rem
What are the Lines of demarcation between a Point, Line, and Plane source for calculation purposes
Line is treated as a Point source < 3x the length
Plane is treated as a constant < 3x the shortest side and as a Line source < 3x the longest side then it is treated as a Point source
Describe the methods by which tritium is produced including appropriate equations
i. Soluble Boron production. (B10)
ii. Soluble Lithium Reactions. (Li7, Li6)
Where in the plant is Tritium likely to be found
Containment
Spent Fuel Pit/Refueling water
What Protective actions may be implemented to reduce the effects of tritium in the nuclear industry
Engineering Controls - Purge containment prior to entry
Limit stay times or wear a respirator
Waterborne - since often carried in water and the absorption through the skin must be avoided, use of WATERPROOF CLOTHING can be implemented
