Estimation of the front-to-total activity ratio for wire screens using CFD simulation

Area of Science:

• Environmental Science
• Nuclear Engineering
• Aerosol Science

Background:

• Wire screens are essential for radioactive aerosol sampling.
• The self-shielding effect of wire screens is crucial and influenced by the front-to-total activity ratio.
• Understanding aerosol deposition on screens is vital for accurate sampling.

Purpose of the Study:

• To computationally simulate aerosol deposition on various wire screen types.
• To investigate the front-to-total activity ratio for different particle sizes (1 nm to 10 µm).
• To experimentally verify simulation results in a radon chamber.

Main Methods:

• Computational Fluid Dynamics (CFD) modeling was employed for aerosol deposition simulation.
• Four distinct wire screen types were analyzed.
• Experimental validation was performed using a radon chamber for aerosol sampling.

Main Results:

• CFD simulations demonstrated good agreement with experimental data for aerosol interception.
• Significant variations in the front-to-total activity ratio were observed for particle sizes below 20 nm.
• The type of wire screen significantly impacts the front-to-total activity ratio for sub-20 nm particles.

Conclusions:

• CFD is a reliable method for simulating aerosol deposition on wire screens.
• The self-shielding effect of wire screens is highly dependent on particle size, particularly for sub-20 nm aerosols.
• Different wire screen designs exhibit distinct deposition characteristics, affecting radioactive aerosol sampling efficiency.