Mitigation Techniques for Interior Radon in Refurbishment Work in High Radiation Areas of Galicia: An Experimental Model to Test Building Solutions

Radon is a naturally occurring radioactive gas, which tends to accumulate inside built structures. It is therefore necessary to include techniques to mitigate radon concentration during refurbishing work. The aim of this study is to assess the effectiveness of a number of mitigation techniques, under real conditions, to determine which is most suitable, in each case, for use in rebuilding solutions. The methodology consisted in performing four experimental tests on mitigation strategies recommended by the Código Técnico de la Edificación (Technical Building Code) (CTE-DB-HS6) and by the Government of the Autonomous Community of Galicia, (Xunta de Galicia, 2018). The concentration was measured with three different systems: radon in soil at 80 cm, passive detectors to confirm mean concentration, and continuous monitoring by devices calibrated at the LaRUC Laboratory of the University of Cantabria, in order to compare the results of the tests. The experiments were carried out in premises located in a high radiation area in Arteixo (La Coruña, Spain). Four experimental models were designed, corresponding to each of the building solutions under study, and tested over a period of 16 days in two repeated series of trials. The results obtained show that, of the different strategies tested, pressurising the living space achieves an efficient reduction of the radon concentration with a significant simplicity of construction. This solution, compatible with the minimal intervention and reversibility principles stablished in the charters of Venice, Krakovia and Nara, is shown to be especially useful when work is carried out on structures considered to be part of protected heritage.