A time-dependent method for characterizing the diffusion of 222Rn in concrete

Area of Science:

• Materials Science
• Environmental Science
• Nuclear Engineering

Background:

• Radon diffusion in concrete is crucial for understanding indoor air quality and radiation shielding.
• Accurate determination of concrete's porous structure is essential for predicting contaminant transport.

Purpose of the Study:

• To develop and validate a method for measuring concrete porosity and radon diffusion length.
• To assess the suitability of concrete as a homogeneous diffusion medium for radon.

Main Methods:

• Measuring time-dependent radon diffusion through concrete slabs.
• Collecting diffused radon over contiguous time intervals.
• Calculating porosity and diffusion length using total collected activity and steady-state flux.

Main Results:

• Porosity and diffusion length were determined for two concrete types (0.068 porosity/12.6 cm diffusion length and 0.32 porosity/16.9 cm diffusion length).
• Predicted radon activity for different time intervals and sample thicknesses showed good agreement with experimental data.

Conclusions:

• The developed method accurately determines concrete porosity and radon diffusion length.
• Concrete can be reliably modeled as a homogeneous diffusion medium for radon, supporting its use in various applications.