Speakers
Description
Council Directive 2013/51/Euratom requires to consider any source of radon including the building materials. Assessing the radon activity that exhales from building structures is crucial to identify the best strategies to prevent radon from entering a building or reducing its concentration in the inhabited spaces. According to the current state of knowledge and technology, the radon surface exhalation rate from building structures may be estimated through i) the modelling of the radon transport inside the structure [1], ii) the theoretical correlation with the radon exhalation rate measured on a sample of the same building material [2], or iii) the direct measurement performed on the manufact [3].
Among the three approaches, only the third one is suitable to consider the influences of the environmental parameters and the installation conditions, i.e., the width and geometry of the slab, how units are laid in and bound together, the presence of binding elements and covering layers. In the framework of the European project RadoNORM, a study has been designed to investigate the possible correlation existing between the radon exhalation rate measured in closed containers on a building material sample [4] and the actual radon exhalation rate from a building manufact (a wall) made of the same material. The radon exhalation rate measurements on the wall have been performed through an experimental apparatus developed at the Italian National Institute of Health.
The design and objectives of the study are presented as well as the preliminary results obtained with some high-exhaling building materials. These results include the comparison between the radon exhalation rate obtained from the material sample and the exhalation rate measured directly on two walls having different sizes. The influence of the superficial treatment on the resulting radon exhalation rate is discussed as well.
References:
[1] Di Carlo C, Maiorana A, Ampollini M, Antignani S, Caprio M, Carpentieri C, et al. Models of radon exhalation from building structures: General and case-specific solutions. Sci Total Environ. 2023;885:163800.
[2] Orabi M. Estimation of the radon surface exhalation rate from a wall as related to that from its building material sample. Can J Phys. 2018;96(3):353-7.
[3] International Organization for Standardization. ISO 11665-7 Measurement of radioactivity in the environment – Air: radon-222 – Part 7: Accumulation method for estimating surface exhalation rate. 2012.
[4] Ishimori, Y., Lange, K., Martin, P., Mayya, Y.S., Phaneuf, M., 2013. Technical Reports Series no. 474 - "Measurement and Calculation of Radon Releases from NORM Residues". International Atomic Energy Agency (IAEA), Vienna.