Modelling marine radioactive spills in the context of the current war in the Middle East

In the current geopolitical context, the possibility of a radiological incident resulting from an attack on nuclear infrastructure or a nuclear-powered naval vessel in active maritime theaters of conflict cannot be entirely dismissed. This paper presents a suite of Lagrangian radionuclide transport models covering the marine domains most directly affected by the present Middle East war: the Red Sea, the Persian Gulf, and the Northern Indian Ocean. The models incorporate advection by currents derived from a global ocean model, three-dimensional turbulent mixing, radioactive decay, and dynamic water-sediment interactions described through reversible kinetic adsorption-release reactions. Tidal transport, which is particularly relevant in semi-enclosed basins such as the Persian Gulf and the Red Sea, can be optionally included via tidal currents obtained from a previously validated tidal propagation model. The modelling framework is consistent with the recommendations of the International Atomic Energy Agency MODARIA programme regarding the availability of marine radionuclide transport tools for rapid deployment in nuclear emergency scenarios. Some illustrative simulations of a hypothetical release of ¹³⁷Cs from a nuclear facility located in the southern Persian Gulf and from a ship in the entrance of the Gulf of Oman are presented. The models are ready to be operationally applied should a radiological emergency arise in any of these regions.