What is a leakage test for sealed sources, and how often is it typically required?

• A. A test to detect radioactive leakage from sealed sources; typically annually.
• B. A test to measure shielding integrity; required daily.
• C. A test to verify source activity decay; required every decade.
• D. A test to check physical constitution of the device; required weekly.

Answer: (B)

A leakage test looks for any escape of radioactive material from a sealed source. The usual method is a wipe test: a small piece of filter paper or a swab is wiped over the surface and accessible seal areas of the source, then the wipe is counted with a calibrated detector. If activity on the wipe is above a defined limit, it indicates leakage and the source is removed from use and handled per protocol.

This kind of test is about containment, not shielding, decay, or the physical shape of the device. The test frequency is typically once a year, though some regulations or specific source types may require more frequent checks (for example, every six months) depending on the activity and licensing.