NDT Radiographic Testing Safety 2

Question 1

What is the primary unit used to measure absorbed radiation dose in tissue?

Accepted Answer

Gray (Gy)

Answer

The Gray (Gy) measures absorbed dose, defined as one joule of energy absorbed per kilogram of tissue.

Question 2

Which type of radiation has the greatest penetrating power?

Accepted Answer

Gamma rays

Answer

Gamma rays are highly penetrating electromagnetic radiation requiring dense shielding materials like lead or concrete.

Question 3

What does ALARA stand for in radiographic testing safety?

Accepted Answer

As Low As Reasonably Achievable

Answer

ALARA is the guiding principle that radiation exposure should be kept as low as reasonably achievable through time, distance, and shielding.

Question 4

A radiographer is setting up an exposure. Doubling the distance from the source reduces the dose rate by approximately:

Accepted Answer

25% of the original

Answer

Per the inverse square law, doubling the distance reduces dose rate to one-quarter (25%) of the original value.

Question 5

Which regulatory body in the US sets occupational radiation dose limits for NDT workers?

Accepted Answer

NRC (Nuclear Regulatory Commission)

Answer

The NRC sets occupational radiation dose limits under 10 CFR Part 20, which governs the use of radioactive materials in industry.

NDT - Non-Destructive Testing Practice Test