ECOMOD — An ecological approach to radioecological modelling

A unified methodology is proposed to simulate the dynamic processes of radionuclide migration in aquatic food chains in parallel with their stable analogue elements. The distinguishing feature of the unified radioecological/ecological approach is the description of radionuclide migration along with dynamic equations for the ecosystem. The ability of the methodology to predict the results of radioecological experiments is demonstrated by an example of radionuclide (iron group) accumulation by a laboratory culture of the algae Platymonas viridis. Based on the unified methodology, the “ECOMOD” radioecological model was developed to simulate dynamic radioecological processes in aquatic ecosystems. It comprises three basic modules, which are operated as a set of inter-related programs. The “ECOSYSTEM” module solves non-linear ecological equations, describing the biomass dynamics of essential ecosystem components. The “RADIONUCLIDE DISTRIBUTION” module calculates the radionuclide distribution in abiotic and biotic components of the aquatic ecosystem. The “DOSE ASSESSMENT” module calculates doses to aquatic biota and doses to man from aquatic food chains. The application of the ECOMOD model to reconstruct the radionuclide distribution in the Chernobyl Cooling Pond ecosystem in the early period after the accident shows good agreement with observations.