Piano di monitoraggio della discarica di materiali TENORM del Passo a Campalto dopo la realizzazione della messa in sicurezza

Phosphogypsum (=PG) is an acidic by-product, formed during the wet processing of phosphate rocks by sulphuric acid and produced worldwide at a rate of about 300x106 t y-1. PG has a significant environmental impact characterised by elevated levels of impurities and enhanced radionuclides concentrations. In order to avoid environmental contamination it is necessary to properly confine PG. In the past 20 years in an uncontrolled discharge area in Campalto (Venice) a volume of about 400.000 m3 of PG has been deposited. The problems caused by such a dump in the lagoon bordering are: the presence of radioactive dust, the dispersion of radionuclides due to erosions caused by the tidal waters and meteorological agents towards the lagoon, the uncontrolled radon exhalation and the bioaccumulation of the radioactive substances. In order to understand the severity of the PG impact a research program has been carried out. The results of these studies and field surveys allowed the realization of a constrained contamination work. This thesis shows the results of the environmental monitoring conducted over the area in order to assess the effectiveness of the work.