Hydrodynamic Modeling of Radionuclide Effluent in Moticher Lake, Kakrapar Atomic Power Station, India

Abstract

Radioactive effluent is generated through a nuclear fuel cycle involving the use of radioactive materials in nuclear power plants. The concentration of the nuclear effluent is of concern if it is discharged into a natural water body and potentially used for human consumption. The present study involves numerical simulation of hydrodynamic parameters for prediction of near-field concentrations of tritium at various sampling points in a natural lake system in India. The modeling software with volume of fluid (VOF) two-phase model, for tracking the fraction of each fluid element, and k-ε model, as turbulence closure, is used to analyze the dispersion of tritium in the lake domain. The simulated results are validated using data on velocity and tritium (H3) concentrations measured at sampling locations in the lake system. The simulated hydrodynamic parameters are reported to be in agreement with their measured values at sampling locations, particularly with a wind effect on the lake surface. The simulated values of hydrodynamic parameters as well as tritium concentrations are found to be within ±10% of their respective measured values in the lake domain. The safe disposal practices of tritium within the lake system are indicated because simulated effluent concentrations are well within the permissible limits of international standards. The numerical model would be useful for real-time operation and management of the chosen lake system in future while simulating the concentration of tritium at different sampling locations, monitoring their concentrations within permissible limits, and ensuring passage of safe water further downstream in the canal system for municipal, industrial, and irrigation usages.