Modelling and assessment of the impact of radiocesium and radiostrontium contamination in the Thermaikos Gulf, Greece

- The Decision Support System (DSS) MOIRA-PLUS was customised to Thermaikos Gulf.
- Model results were compared with empirical data to adjust parameter values.
- The environmental sensitivity of the Gulf to 90Sr and 137Cs pollution was assessed.
- Radiation doses from marine and fresh water pathways were compared.
- The dose from fresh water pathways is notably higher than that from marine pathways

A radiological model for 137Cs and 90Sr dispersion in the marine environment of the Thermaikos Gulf, Greece, and the river catchments draining into the Gulf, is presented. The model, developed and implemented within the MOIRA-PLUS decision support system, integrates appropriate site-specific information. The model's performance has been tested using the available empirical 137Cs activity concentration data in abiotic and biotic components of the gulf since the Chernobyl accident. Further, this paper describes the results of a modelling exercise performed within the IAEA's EMRAS II international modelling programme to estimate the environmental sensitivity of this characteristic Mediterranean coastal marine environment following radioactive contamination. The radiation doses to humans after a single hypothetical instantaneous deposition of 1000 Bq m− 2, assuming that all of their food intake from the marine pathway comes from the local environment, were calculated. The obtained results are consistent with estimates from other models for different coastal marine environments in the frame of the above-mentioned EMRAS exercise.