CRI Radiation Safety & Protection 3

Question 1

A radiographer is working with an Ir-192 source. What is the approximate half-life of Ir-192?

Accepted Answer

74 days

Answer

Iridium-192 has a half-life of approximately 74 days, requiring periodic source replacement.

Question 2

What minimum survey meter reading at the surface of a radiography camera indicates the source is fully retracted?

Accepted Answer

Background level only

Answer

When the source is fully retracted, readings should return to background levels at the device surface.

Question 3

Which regulation governs the transportation of radioactive materials by road in the United States?

Accepted Answer

49 CFR Part 173

Answer

49 CFR Part 173 (DOT regulations) governs the classification and packaging of hazardous materials including radioactive sources during transport.

Question 4

What does a transport index (TI) of 1.0 on a radioactive package indicate?

Accepted Answer

The dose rate at 1 meter is 0.1 mSv/hr

Answer

A TI of 1.0 means the maximum dose rate at 1 meter from the package surface is 0.1 mSv/hr (10 mrem/hr).

Question 5

In industrial radiography, what is the purpose of the source guide tube?

Accepted Answer

To guide the source to the exposure position

Answer

The source guide tube directs and positions the source at the desired exposure location away from the camera body.

(CRI) Certified Radiographic Interpreter Practice Test