Natural radiation sources: a study on NORM in industrial sectors

In Italy some industrial processes involving Naturally Occurring Radioactive Materials (NORM in the following) are regulated by the Legislative Decree of 31 July 2020 n. 101 [1] which transposes the Council Directive 2013/59/Euratom[2]. For several sectors, the entry into radiation protection system is entirely new. The topic of NORM is quite recent in radiation protection system; in fact, it is only in the last few decades that more attention has been paid to this issue. Therefore, the information available is far less than for other topics in the radiation protection field and some aspects, such as sampling protocols, are still being defined. For these reasons, this thesis aims to provide an overview of natural radioactivity content in some NORM-involving industries, selected from the Italian legislative decree 101/2020. The study carried out in this research project can help to understand which kind of material is more critical from the radiation protection point of view or which radionuclides usually occur in it and can therefore be expected from the analysis of such a sample. A great collection of data about the content of radioactivity in four categories of materials (raw materials, residues, products and effluents) from twelve NORM involving industrial sectors has been carried out. The collection considers radiological data (in terms of activity concentrations of 238U, 226Ra, 210Pb, 210Po, 232Th, 228Ra and 40K) for more than 6200 samples, taken from international and national literature. Collected radiological data have been analyzed and the most significant results will be shown here. Complete data, instead, are reported in Appendix. An inventory of the industries currently operating in Italy was updated in order to understand the impact of the Italian radiation protection legislation on NORMrelated industrial activities and to identify the industrial sectors with an important radiological impact on population and workers. Moreover, given the large number of industrial sectors, a general methodological approach was developed, which can be adapted and declined for the different NORM industry sectors indicated in the legislation. The methodology, elaborated taking into account a graded approach, consinsts of two phases and provides indications about the characterization of the most critical exposure scenarios and of the radiological content of NORMs involved in the different phases of the industrial processes. Lastly, all data collected and analyzed in this study will be soon available online. In fact in the framework of the research project it is nearing completion a database on the “Physical Agents Portal (PAF)” website (https://www.portaleagentifisici.it/) that will allow not only data consultation, but also dose assessment for different scenarios.