A study on natural radioactivity and radon exhalation rate in building materials containing norm residues: preliminary results

Abstract This paper contains preliminary results of a study on the physical and radiological characterization of concrete samples containing NORM. The natural radionuclides content in term of 226 Ra, 228 Ra, 232 Th, 40 K and the radon exhalation rate of the samples were determined. Two series of samples of concrete were prepared: samples belonging to both series were made of the same basic components (Portland cement CEM I 42,5R as binder, aggregate and plasticizer) but different amount of NORM residues and mineral additives were used. The concrete samples were characterize in term of absolute density, permeability, total and open porosity. The radiological content was evaluated by using gamma spectrometry and the radon exhalation rate measurements were performed using the dynamic method. Moreover, the Activity Concentration Index (I), introduced by the 2013/59/Euratom Directive, has been used in order to evaluate if concrete samples could exceed the reference level for effective dose due to gamma radiation in building materials.