Naturally occurring radioactive materials in construction: radon

Abstract

In the transition to a circular economy, the valorization of industrial by-products in construction materials is gaining increased interest because (1) it reduces the need for Ordinary Portland cement, and (2) landfilling of by-products is avoided. However, by-products can be characterized by elevated levels of hazardous elements, such as heavy metals or naturally occurring radionuclides. In order to avoid secondary pollution, construction materials must be capable to immobilize these hazardous elements. In this study, the valorization of bauxite residue and phosphogypsum in cementitious materials is investigated. Both by-products contain naturally occurring radionuclides from the 238U decay serie, which can give rise to the release of 222Rn gas (further called “exhalation”). From the radiation protection point of view, 222Rn exhalation should be kept as low as possible.