health physics Flashcards
First american fatality from radiation exposure
clarence dally
Concerned with providing ccupational radiation protection and minimizing radiation dose to workers and the general public
health physics
who reviews the recommended dose limits?
National council on Radiation protection and measurement (NCRP)
Responsibilities of NCRP include:
nongovernmental, nonprofit publish and incorporate radiation standards
Natural radiation exposure to public
82%
Medical radiation exposure to public
18%
Another name for alara
optimization
ALARA Concept
Keep occupational and nonoccupational dose as low as reasonable achievable.
LNT stands for
Linear non threshold
Whats LNT for?
follow stochastic effect
Cardinal principles of radiation protection
time, distance and shielding
Exposure formula
Exposure= exposure rate X exposure time
Inverse square law
I1/I2= (D2)^2 (D1)^2
What is the most important factor for protection
Distance
HVL
Half value layer; reduces the intensity to half of its original value
TVL
Tenth value layer= 3.3 hvl
Annual dose limit for Effective dose (EfD)
whole-body dose; annual dose limits for radiation worker 0.05Sv (5 rems)
Effective dose definition
the sum of the weighted equivalent doses for all irradiated tissues or organs.
Effective dose incorporates both the effect of the type of radiation used and the radiosensitivity of the organ or body part.
provides a measure of the overall risk of exposure to ionizing radiation.
Effective dose
RED stands for
Radiation exposure device
RDD stands for
Radiologic dispersal device
IND stands for
improvised nuclear device
if the distance from the source exceeds five times the source, it can be treated as a:
point source
TVL definition:
the thickness of absorber that reduces the radiation intensity to one-tenth its original value
___ TLV=____HVL
1; 3.3
We assume the occupational effective dose to be ___ of the monitor dose
10%
radioactive contamination is _____ life threatening.
rarely
RED is
-sealed source of radioactive material that directly exposes people
- will not disperse radioactive material
-
RDD is
- a bomb that when exploded disperses a radioactive contamination over a wide area
- may not be explosive, but rather radioactive material
- dispersed by hand in the form of powder, mist, or gas, into water or the ventilation system
IND is
- contains nuclear material that can produce a nuclear explosion
- a nuclear weapon, therefore it is unlikely to be the form of attack used by a terrorist
