NRRPT Radiological Control & Safety Procedures 3 — Questions and Answers
Question 1: What is the correct sequence for donning personal protective equipment (PPE) when entering a contaminated area?
- Outer gloves → inner gloves → coveralls → booties → respirator
- Coveralls → inner gloves → booties → outer gloves → respirator
- Respirator → coveralls → inner gloves → booties → outer gloves (Correct answer)
- Inner gloves → coveralls → booties → respirator → outer gloves
Correct answer: Respirator → coveralls → inner gloves → booties → outer gloves
Respirator is donned first to protect airways before other PPE is put on, followed by coveralls, gloves, and booties to minimize contamination risk during donning.
Question 2: A high radiation area (HRA) is defined under 10 CFR 20 as an area where radiation levels could result in a dose equivalent exceeding what value in one hour at 30 cm from the source?
- 5 mrem (0.05 mSv)
- 100 mrem (1 mSv) (Correct answer)
- 500 mrem (5 mSv)
- 1000 mrem (10 mSv)
Correct answer: 100 mrem (1 mSv)
Per 10 CFR 20.1003, a high radiation area means radiation levels that could result in an individual receiving a dose equivalent in excess of 100 mrem in one hour at 30 cm.
Question 3: When performing a frisking (contamination survey) of a worker exiting a radiological area, which body region should be surveyed last?
- Feet and shoes
- Hands and wrists (Correct answer)
- Head and hair
- Torso and back
Correct answer: Hands and wrists
Hands and wrists are surveyed last because they often have the highest contamination potential and are used throughout the frisking process.
Question 4: What does the term 'stay time' refer to in radiological control planning?
- The duration a radioactive source remains active
- The calculated time a worker can remain in a radiation field without exceeding a specified dose (Correct answer)
- The time required for a contaminated area to decay to unrestricted release levels
- The holding period for radioactive waste before disposal
Correct answer: The calculated time a worker can remain in a radiation field without exceeding a specified dose
Stay time is the maximum duration a worker may remain in a radiation field to keep the received dose within planned limits.
Question 5: Which type of radiation is most effectively shielded by a thin sheet of paper or the dead layer of skin?
- Alpha (Correct answer)
- Beta
- Gamma
- Neutron
Correct answer: Alpha
Alpha particles have very low penetrating power and are stopped by a sheet of paper or the outer dead layer of skin, posing hazard mainly through internal exposure.
Question 6: A radiological posting that reads 'Airborne Radioactivity Area' indicates that concentrations of radioactive material in air exceed what fraction of the Derived Air Concentration (DAC)?
- 0.1 DAC (Correct answer)
- 1 DAC
- 10 DAC
- 100 DAC
Correct answer: 0.1 DAC
Per 10 CFR 20.1003, an airborne radioactivity area exists when airborne concentrations exceed 0.1 DAC or intake rates that would result in a dose exceeding 10% of the ALI in a week.
Question 7: What is the purpose of a 'two-person rule' in high radiation areas?
- To ensure one worker can monitor dose while the other performs the task
- To provide a witness for dose records
- To ensure a second person is present to assist or get help in the event of an emergency (Correct answer)
- To meet NRC minimum staffing requirements for licensed work
Correct answer: To ensure a second person is present to assist or get help in the event of an emergency
The two-person rule in high radiation areas ensures that if one worker becomes incapacitated, the second can provide assistance or summon emergency help.
NRRPT Radiological Control & Safety Procedures 3
What is the correct sequence for donning personal protective equipment (PPE) when entering a contaminated area?