The analysis of radon diffusion, emanation and adsorption on different types of materials

Abstract

© 2015 by Nova Science Publishers, Inc. All rights reserved. Since people spend most of the time inside the buildings it is of great importance to analyze the radon diffusion through buildings materials in order to prevent indoor radon build-up. Insulating properties of different types of materials against radon were studied by means of radon diffusion coefficient. A method has been developed in our laboratory by using closed air circulation system which includes RAD 7 radon detector connected by tubes to tightly closed glass chamber with radon source materials covered by well known thickness of insulating materials. This experimental setup has been upgraded for radon emanation coefficient measurements. The granulation effects on the radon adsorption and radon emanation rate of several building materials (ceramic plates, sand, red brick and siporex brick) with different radium Ra-226 content were investigated and discussed. The possibility of using natural zeolite for radon concentration reduction was also considered. On the other hand powder and liquid substances which are stored within closed rooms and exposed to higher radon concentrations can adsorb a certain radon amounts, depending on characteristics and granulation of powder, as well as radon solubility in liquids. This can lead to increase of dose received by general public, if such substances are used as human food, components for food or cosmetics. Research of radon adsorption by liquids and powders is also useful for correction of gamma spectrometry determination of Ra-226 concentrations in such samples mostly based on post-radon gamma lines. Radon adsorption by zeolite on various granulation was explored in this chapter. The radon adsorption coefficients were calculated based on gamma spectrometry measurements of materials and countinuous monitoring of radon inside the chamber with examined material and radon source.