NRRPT Dosimetry and Exposure Control 2

Question 1

A radiation worker receives 150 mrem from external exposure and 50 mrem from internal deposition in a calendar quarter. What is the total effective dose equivalent for that quarter?

Accepted Answer

200 mrem

Answer

Total effective dose equivalent combines both external and internal contributions: 150 + 50 = 200 mrem.

Question 2

Which dosimeter type uses lithium fluoride (LiF) crystals to measure accumulated radiation dose?

Accepted Answer

Thermoluminescent dosimeter (TLD)

Answer

TLDs use lithium fluoride crystals that store energy from radiation and release it as light when heated, proportional to dose received.

Question 3

Under NRC regulations, the annual occupational dose limit for the lens of the eye is:

Accepted Answer

15 rem

Answer

10 CFR 20.1201 sets the annual occupational dose limit for the lens of the eye at 15 rem (150 mSv).

Question 4

What principle requires radiation protection programs to keep doses as low as reasonably achievable, considering economic and social factors?

Accepted Answer

ALARA

Answer

ALARA (As Low As Reasonably Achievable) is the radiation protection principle requiring dose minimization beyond just meeting regulatory limits.

Question 5

A direct-reading pocket dosimeter reads 0 mR at the start of a shift and 340 mR at the end. If the worker's legal dose limit is 1250 mR/quarter, what percentage of the quarterly limit was used?

Accepted Answer

27.2%

Answer

340 mR ÷ 1250 mR × 100 = 27.2% of the quarterly limit was used.

(NRRPT) National Registry of Radiation Protection Technicians Practice Test

(NRRPT) National Registry of Radiation Protection Technicians Practice Test

NRRPT Dosimetry and Exposure Control 2