NRRPT Radioactive Material Control 2 — Questions and Answers
Question 1: Under 10 CFR Part 20, what is the maximum permissible surface contamination level (removable) for beta-gamma emitters on unrestricted area surfaces?
- 1,000 dpm/100 cm²
- 200 dpm/100 cm² (Correct answer)
- 5,000 dpm/100 cm²
- 100 dpm/100 cm²
Correct answer: 200 dpm/100 cm²
NRC limits removable beta-gamma contamination to 200 dpm/100 cm² on surfaces in unrestricted areas.
Question 2: Which document must accompany a shipment of radioactive material when transported by highway in the US?
- Radiation Work Permit
- Shipping papers (Hazmat manifest) (Correct answer)
- ALARA Action Plan
- Bioassay report
Correct answer: Shipping papers (Hazmat manifest)
DOT regulations (49 CFR) require shipping papers describing the radioactive material to accompany all hazmat highway shipments.
Question 3: A 'fixed contamination' reading differs from a 'removable contamination' reading in that fixed contamination is:
- Measured only with a Geiger-Müller detector
- The activity that cannot be transferred by wiping (Correct answer)
- Always above regulatory limits
- Detected exclusively by gamma spectroscopy
Correct answer: The activity that cannot be transferred by wiping
Fixed contamination is the activity bound to a surface that does not transfer to a standard smear wipe, unlike removable contamination.
Question 4: What is the primary purpose of a Radioactive Material (RAM) inventory?
- To calculate occupational dose for all workers
- To verify accountability and detect losses or theft of licensed material (Correct answer)
- To determine shielding requirements for new facilities
- To establish annual radiation dose budgets
Correct answer: To verify accountability and detect losses or theft of licensed material
RAM inventories ensure all licensed material is accounted for and enable prompt detection of unauthorized removal or loss.
Question 5: When a radioactive spill occurs in a laboratory, what is the FIRST action a worker should take?
- Notify the Radiation Safety Officer immediately by phone
- Evacuate and post the area to prevent others from entering (Correct answer)
- Begin decontamination using soap and water
- Survey the spill area with a Geiger counter to quantify activity
Correct answer: Evacuate and post the area to prevent others from entering
Immediately evacuating and posting the area prevents additional personnel from becoming contaminated before trained responders arrive.
Question 6: Which of the following best describes the concept of 'confinement' in radioactive material control?
- Using lead shielding to reduce external dose rates
- Physically containing material to prevent its spread into the environment (Correct answer)
- Limiting the number of workers allowed in a radiation area
- Scheduling work to minimize time near radioactive sources
Correct answer: Physically containing material to prevent its spread into the environment
Confinement uses barriers such as glove boxes, fume hoods, and sealed containers to prevent radioactive material from escaping into the workplace or environment.
Question 7: A survey meter reads 0.5 mR/hr at a drum labeled as radioactive waste. What additional measurement is needed to assess internal contamination hazard from the drum?
- Neutron flux measurement
- Surface smear/wipe test for removable contamination (Correct answer)
- Whole-body dosimetry reading of the nearest worker
- Airborne radon concentration
Correct answer: Surface smear/wipe test for removable contamination
A wipe test detects removable contamination on the drum exterior, indicating whether radioactive material could be transferred by contact and potentially inhaled or ingested.
NRRPT Radioactive Material Control 2
Under 10 CFR Part 20, what is the maximum permissible surface contamination level (removable) for beta-gamma emitters on unrestricted area surfaces?