Radiation Protection Principles Flashcards
7 cards from real CHP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Radiation Protection Principles flashcards as text
What is the purpose of a derived air concentration (DAC) value in radiation protection?
Answer: To define the airborne radionuclide concentration that would give a worker 5 rem/year if inhaled for 2,000 hours
DAC is the airborne radionuclide concentration (Bq/m³ or µCi/mL) that, if inhaled for a full work year (2,000 hours), would result in the 5-rem annual occupational CEDE limit.
Which shielding material is most effective for attenuating high-energy gamma radiation?
Answer: Lead or dense concrete
High atomic number (Z) and high-density materials like lead and dense concrete provide the greatest photoelectric and Compton attenuation for gamma rays.
A health physicist needs to determine the half-value layer (HVL) for a photon source. The HVL is defined as the thickness that:
Answer: Reduces the dose rate to 50% of its original value
The HVL is the thickness of a specified material required to reduce the intensity (dose rate) of radiation to half its incident value.
Stochastic effects of radiation are characterized by:
Answer: Probability of occurrence increasing with dose, with no threshold
Stochastic effects (cancer, hereditary effects) have a probability that increases with dose, but their severity is independent of dose if they occur.
A sealed radioactive source must be leak tested at what maximum interval per NRC regulations?
Answer: Every 6 months
10 CFR 20 and specific NRC regulations generally require leak testing of sealed sources at intervals not to exceed 6 months.
The annual limit on intake (ALI) for a radionuclide is defined as the activity that would result in a CEDE of:
Answer: 5 rem
The ALI is the annual intake of a radionuclide by ingestion or inhalation that would commit the worker to the 5-rem (50 mSv) annual occupational dose limit.
Deterministic (tissue reaction) effects of radiation differ from stochastic effects in that they:
Answer: Have a threshold dose and increasing severity above that threshold
Deterministic effects (e.g., erythema, cataract) have a dose threshold below which they do not occur, and severity increases with dose above that threshold.