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Research activities of Vinca Institite have been based on two heavy water research reactors: a 10 MW one, RA, and zero power, RB. Reactor RA was operational from 1962 to 1982. In 2010, spent fuel has been sent to the country of origin, and the reactor now is in decommissioning. During the operational phase of the reactor there were no recorded accidental releases into the environment, only operational ones. Results of the environmental impact assessment of the assumed emission of radionuclides from the ventilation of nuclear reactor RA in Vinca to the atmospheric boundary layer are presented in this paper. Evaluation was done by using the Gaussian straight-line diffusion model and taking into account characteristics of the reactor ventilation system, the assumed emission release of radioactivity (from the literature), site-specific meteorological data for six-year period and local topography around nuclear reactor, and corresponding dose factors for inventory of radionuclides. Based on the described approach, and assuming that the range of appropriate meteorological data for six year period for the application of described mathematical model is enough for this kind of analysis, it can be concluded that the nuclear reactor RA, in the course of its work from 1962 to 1982, had no influence on the surrounding environment through the air above regulatory limits.

In this study, we point to loss of accuracy in representing a field of air pollution concentration due to reduction of number of monitoring points or changes in their location. Using a Gaussian-type diffusion model, a high resolution concentration field was generated from 17 points representing the actual distribution of possible pollution sources. The starting grid consisted of 90 601 points. Then we reduced number of points by two orders of magnitude, forming the grid of 961 points. After that, the second reduction to 36 points was performed, still forming a regular grid. Finally, we had 16 points whose positions are in a qualitative agreement with the actual distribution of sampling stations in the area.

The paper presents a system for automatic prevention of raising of ashes from dedicated landfills based on a simple mathematical model which has modest entry requirements for meteorological data. Such an approach is efficient enough and enables fast information retrieval, Le., zones with different concentrations of dust in the air, enabling quick start of counter measures to reduce emissions of ashes into the air. The system hardware consists of an automatic weather station, set of meters that determine moisture of ash, set of remotely managed sprinklers, computers, microprocessor and microcontroller based elements for the local acquisition and management of the executive elements and modules for wireless data transfer. An original software application for the system management has been developed. Within the application there is a module that allows entering of all data necessary to configure the system, as well as data about sensors and sprinklers. Based on the meteorological input data, measured moisture content of the ashes, and on the basis of determined functional dependencies, special software module operates sprinklers for soaking the surfaces from which the ashes is emitted into the air, in order to eliminate these emissions. The system, based on the developed mathematical model, predicts the propagation of ashes through the air, as well as dry and wet deposition, in real-time. The system automatically stores all the data relevant to the future analyses and reporting. The system is designed and implemented as modular and open. A custom developed graphical user interface serves as Man-Machine Interface (MMI). By using the TCP/IP connection it could be easily connected with the other information systems.

Thermal power plants Nikola Tesla A and B are large sources of ash from their ashes/slag deposit sites Total sizes of ashes/slag depots are 600ha and 382ha, with active cassettes having dimensions similar to 200 ha and similar to 130 ha The active cassettes of the disposal sites are covered by rather large waste ponds the sizes of vary depending on the working condition of a sluice system and on meteorological conditions Modeling of ash lifting was attempted using results from the dust lifting research The relation between sizes of ponds and air dust concentration in the vicinity of ash disposal sites was analyzed As expected, greater sizes of dried disposal site surfaces in combination with stronger winds gave greater dust emission and greater air dust concentration