Three-dimensional modelling of the tide-induced dispersion of radionuclides in the sea

Abstract

A three-dimensional marine dispersion model for radionuclides has been developed. ¹he model solves the three-dimensional hydrodynamic equations and, simultaneously, the three-dimensional advective—diffusive dispersion equation. ¹hus, the tide-induced dispersion of radionuclides is obtained. ¹he equations are solved using a finite difference explicit scheme, using a time step of a few seconds, with appropriate boundary conditions. As an example, the model has been applied to study the dispersion of 137Cs in the Irish Sea, which is released from the nuclear fuel reprocessing plant at Sellafield. ¹idal amplitudes and current profiles obtained with the model have been compared with observations in the Irish Sea: both sets of data are in good agreement. Observed and computed 137Cs distributions in waters have also been compared. ¹he model gives a good representation of the dispersion of this radionuclide in the Irish Sea. ( 1998 Elsevier Science ¸td. All rights reserved