Methodology for evaluation of possible consequences of accidental atmospheric releases of hazardous matter

Sites exist with high levels of risk of accidental atmospheric releases. These releases can be hazardous nuclear, chemical, and biological matter. Such accidents may occur during transport of waste, or they may be due to natural hazards, human errors, terror acts or various operations at high risk. Considering the operation of lifting and transport of the sunken Kursk nuclear submarine as an example, a methodology for risk assessment is described. This methodology includes two approaches: (1) probabilistic analysis of possible atmospheric transport pathways using trajectory modelling, and (2) evaluation of possible contamination and consequences using real-time operational atmospheric dispersion modelling. The first approach can be applied in advance of an operation during the preparation stage, the second in real time during the operation stage. For the cases considered in this study, the results of trajectory modelling are supported by the operational dispersion modelling, i.e., the westerly flow is dominant during fall occurring 79% of the time. Hence, September-October 2001 was more appropriate for the lifting and transport of the Kursk nuclear submarine in comparison with summer months, when atmospheric transport toward the populated regions of the Kola and Scandinavian Peninsulas was dominant. The suggested methodology may be applied to any potentially dangerous object involving a risk of atmospheric release of hazardous material of nuclear, chemical or biological nature.