Speaker
Description
This work falls within the framework of radiological emergency planning for accidents at nuclear reactors located beyond the Italian national border, with specific reference to the scenario of a severe accident at the Krško PWR nuclear power plant in Slovenia, the nearest nuclear facility to the Italian border. The geographical proximity of the plant to Italian territory makes it necessary to use forecasting tools capable of promptly supporting decisions regarding population protection measures, such as sheltering, relocation, evacuation, and the administration of stable iodine, whose reference levels are defined by the Decree of the President of the Council of Ministers (DPCM) of 29 April 2022.
To this end, the boundary conditions of the accident scenario were defined, namely the duration of the release, the amount of radioactive material emitted, and the main radioactive elements released into the environment. Based on these boundary parameters, atmospheric dispersion simulations were carried out using the ARIES lagrangian particle dispersion software, in use at the Italian National Inspectorate for Nuclear Safety and Radiation Protection (ISIN), calculating the integrated concentration of the elements in air and on the ground over a grid of points covering the map of Europe. By applying concentration-to-dose conversion coefficients from the handbook for dosimetric measurements and environmental assessments, the projected dose integrated over 2 and 7 days was calculated, defined as the sum of three contributions: inhalation dose (committed dose), external cloudshine dose from contaminated air, and external groundshine dose from contaminated ground.
The ARIES output data were subsequently mapped in a QGIS environment to generate contamination and dose maps of the territory, in order to identify critical points where the estimated levels exceed the reference thresholds established by the DPCM. The proposed approach thus provides a tool to support off-site emergency planning, functional to the timely and spatially targeted adoption of countermeasures for the health protection of the population.