RSO Radiation Sources and Equipment Safety 2

Question 1

The inverse square law states that radiation intensity from a point source varies with distance by:

Accepted Answer

Decreasing proportionally to the square of the distance

Answer

The inverse square law states that radiation intensity from a point source decreases by the square of the distance: if you double the distance, intensity decreases to one-quarter the original value.

Question 2

Which shielding material is most appropriate for attenuating high-energy gamma radiation in a radiology facility?

Accepted Answer

Lead or concrete

Answer

High-density, high-atomic-number materials like lead and concrete are most effective for attenuating gamma radiation because photoelectric absorption and Compton scattering cross sections favor these materials.

Question 3

A survey meter reads zero after entering a high-dose-rate area. The RSO should suspect the detector is:

Accepted Answer

In saturation ('pinned') due to excessive dose rate overwhelming the detector electronics

Answer

Many ionization chamber and GM detectors can saturate or peg at full scale and then read zero ('pegged and stuck') at extremely high dose rates; this is a known detector failure mode in high-radiation fields.

Question 4

The half-value layer (HVL) for a specific radiation/shielding combination is the thickness of material required to:

Accepted Answer

Reduce radiation intensity by 50%

Answer

The half-value layer (HVL) is defined as the thickness of a specific shielding material that reduces the incident radiation intensity by 50% (one-half).

Question 5

A high-radiation area requiring a locked door or other physical controls is defined under NRC regulations where doses could exceed:

Accepted Answer

1 mSv/h (100 mrem/h)

Answer

Under 10 CFR 20.1601, a High Radiation Area is where dose rates could exceed 1 mSv/h (100 mrem/h) at 30 cm, requiring control measures such as locked access or continuous attended entry.

RSO - Radiation Safety Officer Practice Test

RSO - Radiation Safety Officer Practice Test

RSO Radiation Sources and Equipment Safety 2