CRI Radiation Safety & Protection 2 — Questions and Answers
Question 1: What is the annual occupational dose limit for the lens of the eye according to NRC regulations?
- 50 mSv
- 150 mSv (Correct answer)
- 500 mSv
- 20 mSv
Correct answer: 150 mSv
The NRC sets the annual occupational dose limit for the lens of the eye at 150 mSv (15 rem).
Question 2: Which type of radiation has the greatest penetrating power?
- Alpha particles
- Beta particles
- Gamma rays (Correct answer)
- Neutrons
Correct answer: Gamma rays
Gamma rays have the greatest penetrating power and can pass through several centimeters of lead.
Question 3: In the ALARA principle, what does the 'R' stand for?
- Radiation
- Reasonable (Correct answer)
- Restricted
- Radiographic
Correct answer: Reasonable
ALARA stands for As Low As Reasonably Achievable, guiding radiation dose reduction efforts.
Question 4: A radiation worker receives a skin dose of 300 mSv in one year. How does this compare to the regulatory limit?
- It exceeds the limit of 150 mSv
- It is within the limit of 500 mSv (Correct answer)
- It exceeds the limit of 250 mSv
- It equals the limit of 300 mSv
Correct answer: It is within the limit of 500 mSv
The NRC annual skin dose limit is 500 mSv (50 rem), so 300 mSv is within regulatory limits.
Question 5: Which dosimeter provides a real-time reading of radiation exposure in the field?
- Film badge
- Thermoluminescent dosimeter (TLD)
- Pocket ionization chamber (Correct answer)
- OSL dosimeter
Correct answer: Pocket ionization chamber
Pocket ionization chambers (direct-reading dosimeters) provide immediate, real-time radiation exposure readings.
Question 6: What is the primary purpose of a posted radiation area sign in industrial radiography?
- To document the source activity
- To warn personnel of elevated radiation levels (Correct answer)
- To indicate shielding thickness
- To identify the isotope in use
Correct answer: To warn personnel of elevated radiation levels
Radiation area signs warn personnel that dose rates in the area may exceed regulatory thresholds.
Question 7: Which factor does NOT reduce radiation exposure in the workplace?
- Increasing distance from the source
- Using shielding materials
- Reducing exposure time
- Increasing source activity (Correct answer)
Correct answer: Increasing source activity
Increasing source activity increases radiation output and thus increases worker exposure rather than reducing it.
CRI Radiation Safety & Protection 2
What is the annual occupational dose limit for the lens of the eye according to NRC regulations?