Environmental Modeling for Radiation Safety

The newly launched IAEA project MEREIA (MEthods for Radiological and Environmental Impact Assessment; 2021- 2025), MEREIA continues some activities of previous IAEA exercises in the field of radioecological modelling and focuses on areas where the probabilistic approach determines the predictive capability of environmental models. The program offered the opportunity to set up well-designed and verified scenarios to collect and compare exposures predicted by particular models based on this scenario and then perform a validation study of contributing models. It consists of the comparison of model prediction with observed data or in the case where there is a lack of measurement data to perform a comparison within model prognoses. The previous international works have brought significant improvement in environmental modeling in terms of better understanding and mathematical description of complex physical and chemical phenomena that occur in various environmental media and also have promoted new areas for experimental investigations. The new experimental results yielded updated handbooks of a large number of environmental parameters for less-known elements. Moreover, the principal objective of the activities in environmental modelling was an integrated risk assessment of the reference group of population and biota associated with radionuclides releases from various kinds of nuclear facilities as from different types and power nuclear reactors, radioactive waste disposal and more complex nuclear research facility. This reflects recent international recommendations to extend protection against radiation hazards of humans to wildlife flora and fauna. However, the statistics supported knowledge on some essential environmental parameters still remain small. Therefore, one could be aware of some limitations of the probabilistic approach that required advanced methods of probabilistic prognosis Monte Carlo.