Gerçek veya hipotetik nükleer güç santrali kazalarından salınan radyonüklidlerin normal veya uç meteorolojik koşullar altındaki atmosferik dağılımı ve risk değerlendirmesinin matematiksel modellenmesi

The impact of extreme weather events on the atmospheric dispersion of radioactive materials released from nuclear accidents has not been investigated. Therefore, this study presented a new comprehensive risk assessment methodology for nuclear accidents under normal and extreme weather conditions. With this methodology, many simulations were performed under all extreme meteorological conditions and one full year that represented year-round normal conditions. The WTEM (Weather Types and Extreme Meteorology) analysis tool developed in this study was used to analyze extreme conditions. The WTEM tool detected periods of extreme temperature, heavy rainfall, and low wind speeds between 1979-2021. Simulations were performed for Akkuyu Nuclear Power Plant (NPP) using FLEXPART dispersion model, and the source term was generated with the RARE (Radioactive Release) tool developed in this study. The results were used to calculate the 1-year total effective dose equivalent (TEDE) for adults and infants. In addition, more comprehensive TEDE calculations were applied for five worst-case scenarios, considering twenty radionuclides. All TEDE values were calculated with the SDEP (Simple Dose Estimation and Plotting) tool developed in this study. In simulations conducted throughout 1986, ground-level radio-cesium depositions were higher in the North and East of the Akkuyu NPP. On the other hand, radio-iodine concentrations were higher in the South of the.source. With the effect of precipitation and transport direction, the highest depositions and TEDE were detected in the North and West of Turkey in extreme rainy periods. In extreme warm and stagnant periods, radionuclides were transported mainly to eastern Mediterranean, and the highest depositions and TEDE were determined in this region.