Radiation Protection Principles Flashcards

The linear no-threshold (LNT) model assumes which of the following about radiation risk at low doses?

Answer: Risk increases linearly with dose starting from zero

The LNT model postulates that cancer risk is directly proportional to dose with no safe threshold, even at very low doses.

Which quantity is used to compare the biological effectiveness of different types of radiation on a specific tissue?

Answer: Equivalent dose (Sv)

Equivalent dose accounts for radiation type by multiplying absorbed dose by the radiation weighting factor (wR).

A worker receives 150 mrem to the hands and 5 mrem whole-body dose. Which limit is most relevant to assess?

Answer: Extremity dose limit of 50 rem/year

Extremity (hands, feet, elbows, knees) have a separate NRC annual limit of 50 rem (500 mSv), which governs this exposure.

What is the primary purpose of a radiological survey meter calibration?

Answer: To ensure accuracy of dose rate measurements against a traceable standard

Calibration verifies instrument response against a known source traceable to national standards (NIST), ensuring measurement accuracy.

In the ALARA principle, which of the following is NOT one of the three primary factors considered?

Answer: Dose rate alarm threshold

ALARA practice uses time, distance, and shielding as the three fundamental tools to reduce radiation exposure.

A radiation worker's occupational dose limit under 10 CFR 20 for the whole body is:

Answer: 5 rem per year

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

Which type of dosimeter provides an immediate real-time readout of accumulated dose?

Answer: Electronic personal dosimeter (EPD)

EPDs provide instantaneous digital dose and dose rate readouts, unlike passive dosimeters (TLD, OSL, film) which require laboratory processing.