Radiation Health and Safety Test Radiation Health and Safety Test Radiation Protection & Shielding 1 — Questions and Answers
Question 1: What are the three fundamental principles of radiation protection?
- Filter, focus, and frame
- Time, distance, and shielding (Correct answer)
- Monitor, record, and report
- Absorb, reflect, and scatter
Correct answer: Time, distance, and shielding
The three cardinal principles of radiation protection are minimizing time of exposure, maximizing distance from the source, and using appropriate shielding.
Question 2: What does ALARA stand for in radiation protection?
- All Licensed Areas Require Authorization
- As Low As Reasonably Achievable (Correct answer)
- Authorized Limits for Acceptable Radiation Areas
- Absorbed Level of Annual Radiation Allowance
Correct answer: As Low As Reasonably Achievable
ALARA is the guiding principle of radiation protection, requiring that radiation exposure be kept as low as reasonably achievable, considering economic and social factors.
Question 3: What is the NRC annual occupational whole-body effective dose limit for radiation workers in the United States?
- 1 mSv (100 mrem)
- 5 mSv (500 mrem)
- 50 mSv (5 rem) (Correct answer)
- 20 mSv (2 rem)
Correct answer: 50 mSv (5 rem)
The NRC sets the annual occupational dose limit at 50 mSv (5 rem) whole-body effective dose for radiation workers, as specified in 10 CFR Part 20.
Question 4: Which material is most commonly used as shielding against gamma radiation in diagnostic radiology facilities?
- Aluminum
- Concrete and lead (Correct answer)
- Wood
- Plastic
Correct answer: Concrete and lead
Lead (for portable/secondary barriers) and concrete (for primary barriers in walls/floors) are the most commonly used shielding materials for gamma and X-ray radiation in medical facilities.
Question 5: What is the purpose of a personal dosimeter worn by radiation workers?
- To block radiation from reaching the body
- To monitor and record an individual's cumulative radiation exposure (Correct answer)
- To warn of nearby radioactive sources by sound
- To measure room radiation levels
Correct answer: To monitor and record an individual's cumulative radiation exposure
A personal dosimeter (e.g., film badge, TLD, OSL badge) measures and records the cumulative radiation dose received by the wearer for regulatory and safety monitoring.
Question 6: What is the annual dose limit for radiation exposure to the lens of the eye for occupational workers?
- 5 mSv
- 15 mSv
- 150 mSv (Correct answer)
- 500 mSv
Correct answer: 150 mSv
The NRC limit for occupational dose to the lens of the eye is 150 mSv (15 rem) per year, as the lens is particularly radiosensitive and prone to radiation-induced cataracts.
Radiation Health and Safety Test Radiation Health and Safety Test Radiation Protection & Shielding 1
What are the three fundamental principles of radiation protection?