Radiation Safety and Protection Flashcards

Under NRC regulations, what is the annual occupational dose limit to the lens of the eye?

Answer: 150 mSv (15 rem)

10 CFR 20.1201 sets the lens-of-eye occupational limit at 0.15 Sv (15 rem) per year.

A radiation therapist declares her pregnancy in writing. What is the NRC dose limit to the embryo/fetus for the entire gestation period?

Answer: 5 mSv (0.5 rem)

10 CFR 20.1208 limits the embryo/fetus of a declared pregnant worker to 5 mSv (0.5 rem) over the pregnancy.

What is the annual occupational dose limit for a 17-year-old student working with radiation?

Answer: 10% of the adult limits

NRC limits for minors are 10% of the annual adult occupational limits.

In an unrestricted area, NRC regulations limit the dose from external sources to no more than how much in any one hour?

Answer: 0.02 mSv (2 mrem)

10 CFR 20.1301 limits dose in unrestricted areas to 0.02 mSv (2 mrem) in any one hour.

Which type of biologic effect has a threshold dose and increases in severity as dose increases?

Answer: Deterministic (tissue reaction) effect

Deterministic effects such as skin erythema and cataracts appear above a threshold and worsen with dose.

An area where a person could receive more than 1 mSv (100 mrem) in one hour at 30 cm from the source must be posted as what?

Answer: High Radiation Area

NRC defines a High Radiation Area as one exceeding 1 mSv (0.1 rem) per hour at 30 cm.

Which ALARA principle states that no practice involving radiation exposure should be adopted unless it produces a net benefit?

Answer: Justification

Justification requires that the benefit of a radiation practice outweighs its risk.