Impact assessments of radioactive discharges into rivers: Application to the appraisal of the Chernobyl dyke project on the Pripyat river

Centre d'Étude sur l'Évaluation de la Protection dans le Domaine Nucléaire (CEPN), BP. 48, 92263 Fontenay-aux-Roses, France

Abstract

The rise of the water level of the Pripyat river and the erosion associated with ice-jam events lead to the periodic inundation of the contaminated plain surrounding the Chernobyl power plant. This results in the re-suspension and dissolution of radioactive particles and their discharge into the Pripyat and Dnieper waters. This re-contamination of the Dnieper cascade is a significant source of exposure for the Ukrainian population living along the river. To reduce this radiological impact, a project of construction of a dyke on the right bank of the Prypiat river was elaborated. This paper gives an appraisal of this project. In a first phase, the estimated collective dose reduction associated with the construction of the dyke is presented. Then, the construction and maintenance costs of the dyke, as well as the expected benefits associated with dose reduction, are evaluated. The cost-benefit ratios which can be calculated on this basis are around unit, which tends to show that the benefits associated with the construction of the dyke would just compensate the construction and maintenance costs of the project. Taking account of the positive side effects on various sectors of the economy, this project would globally positively contribute to improve the living conditions of the Ukrainian population in a long term perspective.