CRI Radiation Safety & Protection 4

Question 1

What is the maximum permissible dose rate at 2 meters from a radiography camera while the source is in the shielded (retracted) position?

Accepted Answer

2 mSv/hr

Answer

NRC regulations in 10 CFR Part 34 require that cameras not exceed 2 mSv/hr (200 mrem/hr) at 2 meters when the source is in the shielded position.

Question 2

Which isotope used in industrial radiography emits primarily gamma radiation at 662 keV?

Accepted Answer

Cesium-137

Answer

Cesium-137 emits gamma radiation at a characteristic energy of 662 keV with a half-life of about 30 years.

Question 3

What personal protective equipment (PPE) is MOST effective at reducing gamma radiation exposure to a radiographer?

Accepted Answer

Distance and time management

Answer

For gamma radiation, increasing distance and minimizing time are far more effective protective measures than the thin lead aprons used for X-rays.

Question 4

Under NRC regulations, how soon must a licensee notify the NRC after discovering a lost or stolen radioactive source?

Accepted Answer

Immediately by telephone

Answer

10 CFR 34.85 requires immediate telephone notification to the NRC Operations Center upon discovering a lost or stolen source.

Question 5

What is the radiation weighting factor (wR) for X-rays and gamma rays used in dose equivalent calculations?

Accepted Answer

1

Answer

X-rays and gamma rays have a radiation weighting factor of 1, meaning their dose equivalent in sieverts equals their absorbed dose in grays.

(CRI) Certified Radiographic Interpreter Practice Test