Effects caused by the Nuclear Power Plan Atucha I on the fish larvae of the Paraná de las Palmas River (Argentina)

Abstract

&stria& EEects caused by the Nuclear Power Plant Atucha I onthe fishlarvae ofthe Parana de las Palmas Eiver (Argentina). Certain effects caused by the Nuclear Power Plant Atucha I (3P 58's -59" 12' W) on the Ash larvae of the Parand de las Palmas River (lower Paranb) were identified. Surveys were carried out every 45 days from March 1995 to August 1996. Larvae were sampled in five stations: upstream and downstream the plant, at the entrance and exit of the refrigerating circuit and at the exit of the central derivation channel. Physical and chemical variables were measured except for the last station. Larvae of the families Curimatidae, Characidae, Sciaenidae and Pimelodidae were identified. Total larval average length was measured, as well as the average length for each particular taxan. Percentage of larvae impacted by thennal and mechanical effects was calculated through subsampling. Simulation bioessays were performed in order to assess the thennal impact caused hy the nuclear plant. It was observed that the main factor which accounts for the larval mortality would not be the thcmal impact but the mechanical impact produced upon larvae when passing through the plant refrigerating circuit. This impact consisted in rapid pressure changes, retention by the metal strainers which are used to Alter water hefore entering the circuit, and the intense turbulence produced in it.Key words: fish larvae, nuclear plant, Paranb ltiver, environmental impact.La cuenca de! Kio Parana es el quinto sistema fluvial en importancia a nivel mundial y el segundo en America del Sur, despues del Amazonas. Posee u n area de 3