Radiation Protection Flashcards
The principles of radiation protection and safety on which the safety standards are based are those developed by the ____. CONDUCTS research
International commission on Radiological Protection (ICRP) - NO legal power
FORMULATES AND PUBLISHES scientifically researched recommendations on radiation protection and measurements
National Council on Radiation Protection and Measurements
Enforces radiation protection standards relating to radioactive material at the federal level
Nuclear Regulatory Commision (NRC)
Annual effective dose limit
Occupational exposure - 50mSv
Cumulative effective dose
Age (in years) x 10mSv
General public annual effective dose limit for FREQUENT exposure
1mSv
General public annual effective dose limit for INFREQUENT exposure
5mSv
Exposure
Embryo-fetus
For gestation
Per month
5mSv
0.5mSv
ALARA
As Low As Reasonably Achievable
Collimator that automatically restrict the beam to the size of the image receptor
Positive Beam Limitation(PBL)/Automatic collimation
Metal cylinders that attach to the bottom of the collimator. Used to restrict the beam tightly to a small circle
Cylinder cones
Flat piecenof lead with a circle or square opening in the middle. Placed as close to the xray tube window as possible
Aperture diaphragm
Beam limitations materials
Collimator
Cylindrical cone
Aperture diaphragm
Reduction by gonadal shields
Female
Male
50%
95%
Flat piece of lead or a lead apron placed over the gonads
Flat contact shield
Suspended from the xray tube housing and placed in the xray beam light field
Shadow field
Increased risk for fetal doses
> 15 rad
Most effective protection from ionizing radiation
Distance
Lead apron
Thyroid shield during flouroscopy
At least 0.25mm (recommended 0.5mm)
0.5 mm
Occupancy
1-office
1/5-corridors, lounges
1/20-restroom/storage area
Areas where personnel are not provided radiation exposure monitors or radiation safetuly training
Uncontrolled area
Occupied by persons trained irradiation safety and wearing personnel monitoring devices
Controlled area
Annual equivalent dose limit for deterministic effects
Lens -
Localized skin, hands and feet
150
500
Consistent of 1/16 inch lead equivalent
Primary protective barrier
Consist of 1/32 inch lead equivalent
Secondary protective barriers
Minimum for
Protective curtain
Bucky slot shield
0.25 mm lead equivalent
0.25 mm lead equivalent
Use aluminum oxide to record dose
Radiation absorbed causes electrons to be trapped
Sensitive to exposures of 1mrem
3 months at a time
Optically stimulated luminwscence dosimeter (OSL)
Use lithium flouride crystals
Excited by radiation exposure and release this energy on heating
Sensitive to exposures of 5mrem
Can be worn for longer periods
Thermoluminescent dosimeters
Sensitive to 10mrem
Sensitive to extreme temperature and humidity
Developed monthly
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