NRRPT Radiological Protection Standards 4 — Questions and Answers
Question 1: Which EPA guidance establishes Protective Action Guides (PAGs) for nuclear incidents in the US?
- EPA 400-R-92-001
- EPA 520/1-75-001
- EPA PAG Manual (EPA-400/R-17/001) (Correct answer)
- EPA 402-R-93-081
Correct answer: EPA PAG Manual (EPA-400/R-17/001)
The EPA PAG Manual (EPA-400/R-17/001, 2017) establishes the Protective Action Guides for radiological incidents in the United States.
Question 2: Under ICRP Publication 103, the recommended annual effective dose limit for occupational workers is:
- 20 mSv averaged over 5 years, not exceeding 50 mSv in any year (Correct answer)
- 50 mSv per year with no multi-year average requirement
- 100 mSv per year for planned special exposures
- 10 mSv per year with no exceptions
Correct answer: 20 mSv averaged over 5 years, not exceeding 50 mSv in any year
ICRP 103 recommends 20 mSv/year averaged over a defined 5-year period, with no single year exceeding 50 mSv.
Question 3: The concept of 'effective dose' combines organ doses with tissue weighting factors to represent:
- The maximum dose received by any single organ
- The total risk-equivalent uniform whole-body dose (Correct answer)
- The dose rate at 30 cm from the source
- The absorbed dose from a single radiation type
Correct answer: The total risk-equivalent uniform whole-body dose
Effective dose uses tissue weighting factors to express the total radiation detriment as an equivalent uniform whole-body dose for risk comparison purposes.
Question 4: Under 10 CFR Part 20, the annual dose limit to members of the public from licensed operations is:
- 25 mrem (0.25 mSv)
- 100 mrem (1 mSv) (Correct answer)
- 500 mrem (5 mSv)
- 1000 mrem (10 mSv)
Correct answer: 100 mrem (1 mSv)
10 CFR 20.1301 limits the annual dose to individual members of the public to 100 mrem (1 mSv) from licensed operations.
Question 5: Which of the following correctly describes an 'Annual Limit on Intake' (ALI)?
- The maximum permissible concentration of a radionuclide in air
- The quantity of a radionuclide that would result in an occupational dose equal to the annual limit (Correct answer)
- The dose limit for a declared pregnant worker
- The surface contamination limit for unrestricted release
Correct answer: The quantity of a radionuclide that would result in an occupational dose equal to the annual limit
The ALI is the activity of a radionuclide that, if taken into the body in a year, would result in a dose equal to the relevant annual occupational dose limit.
Question 6: The 'derived air concentration' (DAC) in 10 CFR Part 20 is based on:
- The concentration causing 0.5 rem in one hour
- Breathing 2400 mL/min for 2000 working hours per year receiving one ALI (Correct answer)
- The average concentration in ambient air at the site boundary
- Surface contamination per unit area normalized to air volume
Correct answer: Breathing 2400 mL/min for 2000 working hours per year receiving one ALI
The DAC is derived by dividing the ALI by the volume of air breathed in a working year (2.4 L/min × 2000 hr), giving the air concentration that delivers one ALI.
Question 7: Which regulation governs radiation protection standards for DOE contractor workers?
- 10 CFR Part 20
- 10 CFR Part 835 (Correct answer)
- 29 CFR Part 1910.1096
- 40 CFR Part 190
Correct answer: 10 CFR Part 835
10 CFR Part 835 (Occupational Radiation Protection) establishes radiation protection standards specifically for DOE and DOE contractor workers.
NRRPT Radiological Protection Standards 4
Which EPA guidance establishes Protective Action Guides (PAGs) for nuclear incidents in the US?