NANTeL Radiation Protection and ALARA 2

Question 1

Which of the three ALARA principle controls directly reduces the intensity of radiation reaching a worker?

Accepted Answer

Shielding

Answer

Shielding places absorbing material between the source and the worker, directly attenuating radiation intensity.

Question 2

A worker doubles their distance from a point radiation source. By what factor does dose rate change according to the inverse square law?

Accepted Answer

Decreases by a factor of 4

Answer

The inverse square law states that dose rate is proportional to 1/d², so doubling distance reduces dose rate by a factor of 4.

Question 3

In nuclear facilities, which type of radiation is most effectively shielded by high-density materials such as lead or concrete?

Accepted Answer

Gamma rays

Answer

Gamma rays are highly penetrating photons that require dense materials like lead or thick concrete for effective shielding.

Question 4

What is the primary purpose of a whole-body count (WBC) performed on nuclear plant workers?

Accepted Answer

Detect internal contamination from radionuclides

Answer

A whole-body count uses sensitive gamma detectors to identify and quantify radionuclides that have been internally deposited in the body.

Question 5

Under 10 CFR Part 20, what is the annual occupational dose limit for the whole body?

Accepted Answer

5 rem (50 mSv)

Answer

10 CFR 20.1201 sets the annual occupational total effective dose equivalent (TEDE) limit at 5 rem (50 mSv).

(NANTeL) National Academy for Nuclear Training e-Learning Practice Test