Assessment of Environmental Impact Caused by the Release of Radionuclides in Ilha Grande Bay after an Accident at the Nuclear Power Plant

摘要

This study aimed to evaluate the impact of a postulated accidental release of radionuclides from a nuclear power reactor into the aquatic resources, using an environmental modeling. To achieve that, computational models of hydrodynamics and transport were used to simulate the radionuclides dispersion caused by an accident in a PWR. This exercise was accomplished with the aid of a code system (SisBAHIA) developed at Rio de Janeiro Federal University (COPPE/UFRJ). The nuclear power plant Angra 3 is a reactor that uses pressurized light water as moderator and coolant in the core. Where 431 m³ of soda almost instantaneously was lost. This inventory contained 1.87x1010 Bq/m³ of tritium, 2.22x107 Bq/m³ of cobalt, 3.48x108 Bq/m³ of cesium and 3.44x1010 Bq/m³ of iodine and was released in liquid form near the Itaorna cove, Angra dos Reis – RJ. Applying the model in the proposed scenario [1-2], the simulated dilution of the specific activity of radionuclide spots, reached values much lower than report levels for seawater (1,1x106 Bq/m³, 1,11x104 Bq/m³, 7,40x10² Bq/m³ and 1,85x103 Bq/m³) after 22 hours, respectively for ³H, 60Co, 131I and 137Cs.