The GIS-based SafeAirView Software for the Concentration Assessment of Radioactive Pollutants after an Accidental Release

The European Commission Joint Research Centre (JRC) in Ispra (Italy) has long been running nuclear installations for research purposes. The Nuclear Decommissioning and Facilities Management Unit (NDFM) is responsible for the surveillance of radioactivity levels in nuclear emergency conditions. The NDFM Unit has commissioned the implementation of a specifically developed decision support system, which can be used for quick emergency evaluation in the case of hypothetical accident and for emergency exercises. The requisites were to be a user-friendly software, able to quickly calculate and display values of air and ground radioactive contamination in the complex area around JRC, following an accidental release of radioactive substances from a JRC nuclear research installation. The developed software, named "SafeAirView", is an advanced implementation of GIS technology applied to an existing MS-DOS mode dispersion model, SAFE_AIR (Simulation of Air pollution From Emissions_Above Inhomogeneous Regions). SAFE_AIR is a numerical model which simulates transport, diffusion, and deposition of airborne pollutants emitted in the low atmosphere above complex orography at both local and regional scale, under non-stationary and inhomogeneous emission and meteorological conditions. SafeAirView makes use of user-friendly MS-Windows type interface which drives the dispersion model by a sequential and continuous input-output process, allowing a real time simulation. The GIS environment allows a direct interaction with the territory elements in which the simulation takes place, using data for the JRC Ispra region represented in geo-referenced cartography. Furthermore it offers the possibility to relate concentrations with population distribution and other geo-referenced maps, in a geographic view. Output concentration and deposition patterns can be plotted and/or exported. In spite of the selected specific databases, the SafeAirView software architecture is a general structure, therefore the decision support system could be easily modified to be applied in a region different from the JRC one. Beside the description of SafeAirView, the present paper presents a statistical evaluation of the software, which has considered three well known tracer experiments: Copenhagen, Indianapolis and Kincaid. The data sets related to these experiments are all included in the so called Model Validation Kit.JRC.C.1-Nuclear decommissioning and facilities managemen