PSI - Issue 36

Volodymyr Sydorenko et al. / Procedia Structural Integrity 36 (2022) 318–325 Volodymyr Sydorenko, Sergiy Yeremenko, Viola Vambol et al. / Structural Integrity Procedia 00 (2021) 000 – 000

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on fires in the form of charred organic matter, and part in the form of fine solid particles of smoke and dust can be carried by the wind. The concentration of radionuclides in such materials can be hundreds of thousands and millions of Becquerel’s (Bq) per 1 kg of their mass (1Bq is a unit of nuclide activity, in which one act of radioactive decay occurs in 1s -1 = 2,703 10 -11 Curies, but very often use another unit of activity - curie (Ki)).

Fig. 1. Fire in the Chernobyl zone, April 2020 (a) aerial photo; (b) quadcopter photo.

Fig. 2. Fragments of NASA space image, April 2020

3. Research technique Based on the above materials, it was concluded that the main contribution to the ecological and radiation situation of the territory is made by forest fires as a source of the spread of radioactive combustion products. The main factor in the occurrence of large forest fires is the effect of strong winds, at high air temperatures and low relative humidity. Climate change is another factor. The climate in this region is getting warmer and the amount of precipitation is decreasing. Therefore, trees, as a source of combustible material, become more susceptible to burning. Consequently, this factor deserves serious attention and further study for the implementation of preventive measures. An example of such forecasting of precipitation is the study, since machine learning methods allow one to obtain forecasts with a high degree of accuracy and, as a result, have become widespread (Sihag et al. (2021); Singh Nain et al. (2019)). Also, an important factor is the speed of fire propagation, which also depends on the conductor of combustion, such as forest litter, dry grass and mosses, lichens, fallen leaves, branches, fragments of bark, etc. Thus, the main elements of influence on the ecological and radiation environment during and after a fire, such as the intensity and direction of migration of radioactive combustion products were determined. Today there are a sufficient number of radionuclide deflation models. The most famous models are: a qualitative assessment of the expected intensity of deflation; unpredictable deflation; deflation intensity; deflation forecast