IRRSP Source Management and Security 2 — Questions and Answers
Question 1: Where must exposure devices containing sealed sources be stored when not in use?
- In any locked room at the facility
- In a locked vehicle at the job site overnight
- In a licensed, secured storage location meeting NRC physical security requirements (Correct answer)
- At the device manufacturer's facility between jobs
Correct answer: In a licensed, secured storage location meeting NRC physical security requirements
Sealed sources must be stored in NRC-licensed locations that meet physical security requirements under 10 CFR 34 and 10 CFR 37.
Question 2: Which isotope is most commonly used in portable industrial radiography exposure devices due to its appropriate half-life and gamma energy?
- Cobalt-60 (Co-60)
- Cesium-137 (Cs-137)
- Selenium-75 (Se-75)
- Iridium-192 (Ir-192) (Correct answer)
Correct answer: Iridium-192 (Ir-192)
Ir-192 is the most widely used isotope in portable industrial radiography because its ~74-day half-life and average gamma energy (~0.38 MeV) are well-suited for field radiography of steel.
Question 3: What is the required immediate action if a sealed source leak test yields removable contamination above the regulatory limit?
- Increase the survey frequency and continue operations
- Remove the source from service immediately and notify the NRC (Correct answer)
- Perform a second confirmatory leak test before taking action
- Wait for additional activity decay before retesting
Correct answer: Remove the source from service immediately and notify the NRC
A leaking source must be immediately withdrawn from service and the NRC notified per 10 CFR 34.27, as a failed leak test indicates a loss of source containment.
Question 4: What is a 'pig' in the context of industrial radiography source management?
- A contaminated source that cannot be used
- A portable shielded container used to store or transport sealed sources (Correct answer)
- The lead collimator attached to the front of an exposure device
- The connecting cable between the control console and exposure head
Correct answer: A portable shielded container used to store or transport sealed sources
A 'pig' is a portable, heavily shielded container (typically lead or depleted uranium) used to safely store and transport a single sealed source.
Question 5: How frequently must radiographers physically account for all sealed sources in their possession to ensure source security?
- Daily at shift start
- Before and after each use (Correct answer)
- Weekly at minimum
- Monthly inventory audits
Correct answer: Before and after each use
Radiographers must account for all sealed sources before and after each use to immediately detect any loss or potential theft of radioactive material.
Question 6: Which of the following is NOT required on a source inventory record under 10 CFR 34?
- Identity of the isotope
- Serial number of the sealed source
- Name of the radiographer who used the source most recently (Correct answer)
- Estimated activity on a specified reference date
Correct answer: Name of the radiographer who used the source most recently
Source inventory records must identify the isotope, serial number, and estimated activity, but do not specifically require the name of each radiographer who has used the source.
Question 7: What type of transport package is required for moving industrial radiography sources between job sites under DOT regulations?
- A DOT Type A package meeting activity limits (Correct answer)
- Any container with posted radiation warning labels
- A standard locked metal toolbox with a survey meter attached
- A DOT Type B package regardless of source activity
Correct answer: A DOT Type A package meeting activity limits
Sealed sources used in portable industrial radiography are transported in DOT-approved Type A packages, provided the activity does not exceed Type A quantity limits.
IRRSP Source Management and Security 2
Where must exposure devices containing sealed sources be stored when not in use?