NRRPT Contamination and Airborne Control 5

Question 1

A worker receives a bioassay (urine) result showing detectable Cs-137. What is the most appropriate immediate next step?

Accepted Answer

Perform dose assessment to estimate committed effective dose equivalent and determine if an intake occurred

Answer

A positive bioassay triggers a formal intake assessment to calculate the committed effective dose equivalent (CEDE) and determine if regulatory limits were exceeded.

Question 2

Which surface material is generally the most difficult to effectively decontaminate of radioactive contamination?

Accepted Answer

Unpainted concrete or porous masonry

Answer

Porous materials like concrete allow radioactive material to penetrate into micro-crevices and pores, making complete removal extremely difficult compared to non-porous surfaces.

Question 3

What is the significance of the 'inhalation class' (F, M, or S) assigned to airborne radioactive materials?

Accepted Answer

It indicates the rate of absorption from the lung to blood, affecting dose distribution and biokinetics

Answer

ICRP lung absorption classes (Fast, Moderate, Slow) describe how quickly inhaled material transfers from the lung to systemic circulation, which determines dose to lung vs. other organs.

Question 4

Under what condition must personnel performing entry into a high contamination area use a supplied-air respirator (SAR) rather than an air-purifying respirator (APR)?

Accepted Answer

When the oxygen concentration is below 19.5% or airborne concentrations would exceed APR protection limits

Answer

SARs are required in oxygen-deficient atmospheres (below 19.5% O₂) or when airborne concentrations are too high for an APR's assigned protection factor to adequately limit intake.

Question 5

During a facility decommissioning project, elevated airborne activity is detected unexpectedly. What is the correct sequence of actions?

Accepted Answer

Stop work, direct workers to evacuate upwind, activate emergency air monitoring, and notify supervision

Answer

Unexpected elevated airborne activity requires immediate work stoppage and evacuation to prevent further intake, followed by emergency monitoring and supervisory notification.

(NRRPT) National Registry of Radiation Protection Technicians Practice Test

(NRRPT) National Registry of Radiation Protection Technicians Practice Test

NRRPT Contamination and Airborne Control 5