Radiation Protection Flashcards
Which agency oversees materials produced by a nuclear reactor?
NRC
Which agency oversees radiopharmaceuticals?
FDA
Which agency oversees linear accelerators?
State agency
What are the dose limits for the following structures per year for general population?
1) Total body
2) Lens
3) Orgnas
1) 5 mSv
2) 15 mSv
3) 50 mSv
What are the dose limits for radiation workers:
1) Total body
2) Lens
3) Organs
Multiply the genpop x 10:
1) 50 mSv
2) 150 mSv
3) 500 mSv
What is the dose limit for an undeclared pregnancy? Declared?
5 mSv
0.5 mSv/mo (~5 total)
What is the Workload (W) factor?
Beam-on time essentially. This is the weekly dose delivered at 1 m from the source (cGy/week at 1m)
What is the Use (U) factor?
Proportion of time that a source is directed at a particular barrier (e.g. half the time the beam is on it’s directed at the floor, so the U for the floor is 0.5)
What is the Occupancy (T) factor?
fraction of operating time the area is occupied. E.g. offices or workstations = 1, restrooms = 1/4, waiting rooms = 1/8 etc.
What is the transmission factor (B) of a barrier?
It is the thickness of a barrier required to reduce a radiation level to within an acceptable standard (P).
What is the equation for B?
B= P x d^2/WUT
where P = the permissible dose equivalent of an area
What are the purposes of secondary barriers?
To protect against scatter and leakage
How thick is a primary barrier typically? a secondary?
Primary = 8.6 ft Secondary = 4.3 ft
What is the U of a secondary barrier?
1, always 1 (it’s scatter, so any time the beam is on it’s getting hit)
How much leakage is allowed from treatment heads?
<0.1% of the treatment beam
