Italian National Institute of Health / National Center for Radiation Protection and Computational Physics, Viale Regina Elena, 299, 00161 Rome, Italy.
Italian National Institute of Health / National Center for Radiation Protection and Computational Physics, Viale Regina Elena, 299, 00161 Rome, Italy.
Sci Total Environ. 2023 Aug 10;885:163800. doi: 10.1016/j.scitotenv.2023.163800. Epub 2023 May 4.
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. The direct measurement is extremely difficult, so the common approach has consisted in developing models describing the radon migration and exhalation phenomena for building porous materials. However, due to the mathematical complexity of comprehensively modelling the radon transport phenomenon in buildings, simplified equations have been mostly adopted until now to assess the radon exhalation. A systematic analysis of the models applicable to radon transport has been carried out and it has resulted in four models differing in the migration mechanisms - only diffusive or diffusive and advective - and the presence of inner radon generation. The general solutions have been obtained for all the models. Moreover, three case-specific sets of boundary conditions have been formulated to account for all the actual scenarios occurring in buildings: both perimetral and partition walls and building structures in direct contact with soil or embankments. The corresponding case-specific solutions obtained serve as a key practical tool to improve the accuracy in assessing the contribution of building materials to indoor radon concentration according to the site-specific installation conditions in addition to the material inner properties.
评估从建筑物结构中散发的氡活动对于确定防止氡进入建筑物或降低居住空间中氡浓度的最佳策略至关重要。直接测量极其困难，因此常用的方法是开发描述建筑多孔材料中氡迁移和散发现象的模型。然而，由于全面建模建筑物中氡输运现象的数学复杂性，迄今为止，为了评估氡散发，大多采用简化方程。对适用于氡输运的模型进行了系统分析，结果得到了四个模型，它们在迁移机制（仅扩散或扩散和对流）和内部氡生成方面存在差异。获得了所有模型的一般解。此外，还制定了三组特定于案例的边界条件，以考虑建筑物中发生的所有实际情况：周边和隔断墙以及直接与土壤或堤岸接触的建筑物结构。获得的相应特定于案例的解决方案是一种关键的实用工具，可根据特定于现场的安装条件以及材料内部特性，提高评估建筑材料对室内氡浓度的贡献的准确性。
