NDT Radiographic Testing Safety 4

Question 1

What is the primary biological target of ionizing radiation that leads to long-term cancer risk?

Accepted Answer

DNA in the cell nucleus

Answer

Ionizing radiation's primary long-term risk comes from DNA damage in the cell nucleus, which can cause mutations leading to cancer.

Question 2

A 'direct reading dosimeter' (DRD) is required during field radiography in addition to a passive dosimeter because it:

Accepted Answer

Gives the radiographer real-time dose rate feedback

Answer

DRDs provide immediate, real-time dose rate information so radiographers can take protective action during a shoot.

Question 3

The 'controlled area' boundary during a radiographic exposure is typically established where the dose rate does not exceed:

Accepted Answer

2 mSv/hr (200 mrem/hr)

Answer

In practice, the controlled (restricted) area boundary is placed where dose rates reach or exceed 2 mSv/hr (200 mrem/hr), limiting access to radiation workers.

Question 4

A radiation survey meter reads 'off-scale high' when pointed at the source container. This most likely indicates:

Accepted Answer

The source has failed to retract into its shielded position

Answer

An off-scale high reading near the source container strongly suggests the source is exposed or partially retracted, requiring immediate evacuation.

Question 5

Scatter radiation during industrial radiography primarily originates from:

Accepted Answer

Interaction of the primary beam with the work piece and surroundings

Answer

Scatter radiation is produced when the primary beam interacts with the test object, nearby structures, and the ground, radiating in all directions.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Radiographic Testing Safety 4