Environmental studies at pre-operational and operational stages of nuclear power plants in Italy: Chemical and radioanalytical implications

Abstract

The criteria currently adopted by the Italian Electricity Board (ENEL) to assess the capacity of the aquatic environment to receive radioactive liquid discharges from nuclear power plants are described. The behaviour of radionuclides and their stable isotopes in coastal seawater, in the presence of suspended matter, and sediments was studied at Montalto di Castro, where a nuclear power plant is being constructed. The environmental concentrations of dissolved elements that might be discharged by a reactor were determined. Large fractions of the total trace elements in seawater were found, by ultrafiltration techniques, to be associated with the finest particle fraction (m.m. < 1000). Most of the elements could be leached from the particulates with 0.3 M hydrochloric acid. This indicates that the leachable elements may become available to organisms. Distribution coefficients (particulate/water) were determined. Investigations of Cs-137 concentrations in various sediments showed Cs-137 to have a preference for sandy-clay. The concentrations of trace elements in pore water were also determined. Similar studies were carried out in the Po river system after scheduled releases of low-level radioactive liquid waste. Concentration factors for Co-60, Mn-54 and Zn-65 in fish, aquatic plants and molluscs are reported. The concentrations of radionuclides found in the sediments, the aquatic plants, and fish were low and in most cases indistinguishable from the background. The aim of these studies is to obtain adequate knowledge of the ability of the environment to accept radioactive liquid wastes without being harmed.