A Simple Laboratory System for Diffusive Radon Flux Measurements

This study designed a simple system to estimate the diffusive radon flux from all types of solid materials (e.g., sediments, soils, building materials). Determination of the radon flux is based on the measurement of the radon activity in air over time inside a closed loop system. For sediments, the system consists of wet sediment and water inside a gas-tight flask connected in a closed loop to a drying system and a radon analyzer (Durridge RAD7). The flux is determined from the slope of the plot between radon activities vs. time during approximately the first 12 hours (ⁱnitial slope method⁾. The slope is then multiplied by the total air volume and divided by the exposed sediment area to obtain the radon flux. Our study also determined the minimal thickness or mass of sediment needed to acquire a reliable radon diffusive flux.