scholarly journals Propagation Analysis of Pu Radionuclides as a Result of Fire Incidents in the Exclusion Zone of the Chernobyl NPP in April 2020

In consequence of nuclear accidents that have occurred in various parts of the world, radioactive contamination of the environment is observed. The risks of spreading pollution can increase during floods, fires and some natural disasters. The lack of effective measures that aimed at eliminating possible sources of fire in the meadow zone and forest lands in the Chernobyl exclusion zone (ChEZ) leads to a high risk of fire emergence. The temporal and spatial distribution of fires shows that they occur throughout the ChEZ, including in the most contaminated areas. The risk of fires increases with climate change and measures to prevent them should be considered in emergency programs. ChEZ area is contaminated with long-lived radionuclides such as 137Cs, 90Sr, Pu isotopes (238Pu, 239 + 240Pu, 241Pu) and 241Am. As a result of forest fires radionuclides contained in wood and underlying surface are carried out into the atmosphere along with smoke. Diseases arising under the influence of ionizing radiation from Pu and 241Am isotopes pose a serious problem for human health. To assess of the spatial distribution of Pu isotopes and 241Am we used data on forest fires that occurred in the Chernobyl zone in April 2020. To evaluatе the dynamics of the release of radioactive substances into the atmosphere during fire incidents on the ChEZ territory, the following software products were used: NASA WorldView, HYSPLIT program. The HYSPLIT program allows to reconstruct the trajectories of radionuclide propagation in the atmosphere using meteorological data and to obtain a reliable picture of the distribution of radionuclides in the study area. The maps of the volumetric activity of Pu isotopes in the air and the fallout on the soil as a result of fires were obtained. It was found that the radioactivity due to the presence of this element in the air and during the fallout of radioactive particles on the soil is low (it reaches 1.0E-7...0.1 Bq/m3 in the air, 1.0E-6...1 Bq/m2 on the soil). The analysis of the propagation of Pu isotopes as a result of the movement of air masses in the places of fires in the exclusion zone of the Chernobyl nuclear power plant and the associated dangers for the population and the environment has been carried out.

2021 ◽  
Vol 20 ◽  
pp. 81-95
Author(s):  
M. M. Таlerko ◽  
◽  
Т. D. Lev ◽  
V. O. Кashpur ◽  
◽  
...  

On April 16, 2020, a strong dust storm was observed in the northern regions of Ukraine, which coincided with the period of intense wildland fires in the Chornobyl exclusion zone. The activity of 137Cs in aerosol particles released into the atmosphere as a result of resuspension from burned areas in the meadow biocenoses in the exclusion zone is evaluated in the article. Resuspension of radioactively contaminated particles from burned areas formed after fires in meadow biocenoses of the exclusion zone can be a powerful source of air contamination in the zone itself, as well as increase of the radionuclides transport outside it. The total 137Cs activity that entered the atmosphere during the dust storm was estimated to be about 162 GBq, i. e. up to 20% of the total activity emitted in the air during the entire period of forest fires on April 3–20, 2020. The 137Cs emission from burned areas during the dust storm on April 16 and 17 amounted to 0.24% of the total stock of 137Cs activity in this territory. According to the results of modeling, the relative contribution of wildland fires and resuspension due to the dust storm on April 16 and 17 significantly depends on the distance to the emission sources. It was found that the resuspension of radioactive particles from burned areas during the dust storm determined 80–95% of the 137Cs activity concentration in the surface air near Chornobyl nuclear power plant and in Chornobyl city and the rest was due to the continuing forest fires in neighboring territories. The maximum 3-hour averaged value of the 137Cs activity concentration in the air due to resuspension from the burned areas was obtained for the location of the monitoring post VRP-750 of SSE “Ecocenter” to be about 28 mBq/m3 for the period 9–12 hours on April 16. In Kyiv, the 3-hour averaged 137Cs activity concentration due to the dust storm in the Exclusion Zone was calculated as 44 μBq/m3 in the period from 9 to 12 hours on April 17, 2020. This value was only about 4% of the total 137Cs activity in the air in this period.


2020 ◽  
Author(s):  
Mykola Talerko ◽  
Ivan Kovalets ◽  
Shigekazu Hirao ◽  
Mark Zheleznyak ◽  
Yuriy Kyrylenko ◽  
...  

<p>The highly contaminated Chernobyl exclusion zone (ChEZ) still remains a potential source of the additional atmosphere radioactive contamination due to forest fires there. The possible radionuclide transport outside the ChEZ in the direction of populated regions (including Kyiv, 115 km from the ChEZ borders) and its consequences for people health is a topic of a constant public concern in Ukraine and neighboring countries. The problem of additional radiation exposure of fire-fighters and other personnel within the ChEZ during forest fires is actual too. The reliable models of radionuclide rising and following atmospheric transport, which should be integrated with data of stationary and mobile radiological monitoring, are necessary for real-time forecast and assessment of consequences of wildland fires.</p><p>Results of intercomparison of models developed within the set of the national and international projects are presented, including: i) the point source term model of Atmospheric Dispersion Module (ADM) of the real -time online decision support system for offsite nuclear emergency – RODOS, which development was funded by EU; ii) the specialized new tool for modeling radionuclide dispersion from the polygons of the fired areas using the Lagrangian model LASAT incorporated into RODOS system; iii) the Lagrangian-Eulerian atmospheric dispersion model LEDI using a volume source term and including a module for calculation of  parameters of a convective plume  formed over a fire area; iv) the Lagrangian model of Fukushima University. All atmospheric transport models use the results of the numerical weather forecast model WRF as the input meteorological information.</p><p>The models evaluation was carried out using the measurement data during large wildland fires occurred in ChEZ in 2015 and June 2018, including the <sup>137</sup>Cs and <sup>90</sup>Sr volume activity measured with the monitoring network within the Zone and results due to special measurements with a mobile radiological laboratory outside it.</p><p>The sensitivity of atmospheric transport modeling results was estimated to: 1) internal parameterization of different models, first of all, parameterization of the value of the deposited radionuclide fraction re-entering into the atmosphere during forest fires, 2) different parameterization of the source term formed due to the forest fire; 3) quality of input meteorological information, including the space and time step of the used WRF model grid, and the impact of chosen parameterization of some WRF modules (e.g. the atmospheric boundary layer module) on the atmospheric transport model results. Additionally, results of forest fires consequences modeling was compared which were obtained with different sets of input meteorological data: the WRF forecast of metrological fields (on-line calculations) and the similar WRF calculations on the base of objective analysis results.</p>


2021 ◽  
Vol 23 (2) ◽  
pp. 57
Author(s):  
Udiyani Made Pande ◽  
Muhamad Budi Setiawan ◽  
Anik Purwaningsih ◽  
Nursinta Adi Wahanani ◽  
Muksin Aji Setiawan ◽  
...  

Radiation protection and safety documents for routine conditions are required to support the licensing requirements for nuclear power plant site. This research is focused in the assessment and analysis of the results of PWR safety study related to the routine release of radioactivity from the SMR subsystems and components of the 100 MWe-type PWR along with its consequences in the site. The core inventory calculation was done using  ORIGEN2 software, applying release parameters from the existing analysis and calculation results. The radiological consequences were calculated by the PC-CREAM program package. Environmental and meteorological data were obtained using Arc-GIS and spatial analysis. The Bangka Belitung (Babel) site was used as the specific footprint. Analyzing PC-CREAM output data the radiological consequences of routine operation of 3 100 MWe PWR modules on Sebagin site (South Bangka) and Muntok site (West Bangka) in 16 sectors and within a radius of 20 km were concluded. The calculation results for the Sebagin site is that the maximumdose within a radius of 500 m (exclusion zone) is 1.15E+02 µSv/year. For a radius beyond 500 m, the maximum dose is 4.71E+01 µSv/year. Whereas for Muntok site (West Bangka), the maximum dose in the exclusion area (<500m) is 9.47E+00 µSv/year, and outside exclusion area (>500m) is 3.10E+00 µSv/year. The individual dose for the Babel site in the exclusion area is below the dose constraint for non-radiation service workers as the general public of 0.3 mSv/year or 300 µSv/year, while the maximum dose for outside exclusion is also below the constraint as stipulated in BAPETEN Regulation No 4 Year 2013 on Radiation Protection and Safety.


2021 ◽  
Vol 9 ◽  
Author(s):  
Yi Liu ◽  
Samuel Ortega-Farías ◽  
Fei Tian ◽  
Sufen Wang ◽  
Sien Li

Near-surface air (Ta) and land surface (Ts) temperatures are essential parameters for research in the fields of agriculture, hydrology, and ecological changes, which require accurate datasets with different temporal and spatial resolutions. However, the sparse spatial distribution of meteorological stations in Northwest China may not effectively provide high-precision Ta data. And it is not clear whether it is necessary to improve the accuracy of Ts which has the most influence on Ta. In response to this situation, the main objective of this study is to estimate Ta for Northwest China using multiple linear regression models (MLR) and random forest (RF) algorithms, based on Landsat 8 images and auxiliary data collected from 2014 to 2019. Ts, NDVI (Normalized Difference Vegetation Index), surface albedo, elevation, wind speed, and Julian day were variables to be selected, then used to estimate the daily average Ta after analysis and adjustment. Also, the Radiative Transfer Equation (RTE) method for calculating Ts would be corrected by NDVI (RTE-NDVI). The results show that: 1) The accuracy of the surface temperature (Ts) was improved by using RTE-NDVI; 2) Both MLR and RF models are suitable for estimating Ta in areas with few meteorological stations; 3) Analyzing the temporal and spatial distribution of errors, it is found that the MLR model performs well in spring and summer, and is lower in autumn, and the accuracy is higher in plain areas away from mountains than in mountainous areas and nearby areas. This study shows that through appropriate selection and combination of variables, the accuracy of estimating the pixel-scale Ta from satellite remote sensing data can be improved in the area that has less meteorological data.


Author(s):  
D. Bazyka ◽  
◽  
P. Fedirko ◽  
V. Vasylenko ◽  
O. Kolosynska ◽  
...  

Objective.of this study was to determine the levels of radionuclides in the rescuers’ bodies of the SES during firefighting in the exclusion zone of the Chornobyl nuclear power plant and to assess the dose of internal radiation due to this receipt. Materials and methods. From 06.04.2020 to 19.05.2020 in the State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine» (NRCRM) measurements of the content of incorporated gamma radionuclides on whole body counters (WBC) operational class «Screener-3M» (Minimum detected activity (MDA) is 300–500 Bq for 5 minutes of measurement at 137Cs) and expert high-sensitivity WBC (MDA is 20 Bq for 10 minutes of measurement at 137Cs). 470 people (523 measurements) in three groups of personnel of the SES of Ukraine who took part in the forest fire liquidation in the exclusion zone in the period from April 4 to May 5, 2020 were examined. Mathematical and spectrometric methods are used in the work. Results and conclusions. In the vast majority (95 %) of the personnel of the SES of Ukraine, examined at the WBC operational class «Screener-3M» (more than 500 measurements), the assessment of the values of the individual effective dose of internal radiation due to 137Cs in the body during firefighting, assuming that it receipt occurred during operation in the exclusion zone, did not exceed the minimum dose detected by MDD (5–14 μSv). The average value of the effective dose of internal radiation in the group of personnel of the State Emergency Service of Ukraine in Kyiv, which participated in the elimination of forest fires in the exclusion zone from April 4 to May 5, 2020 (26 people) studied at the expert WBC, is 2.5 ± 1.1 μSv, in the group of personnel of the SES of Ukraine in Cherkasy region, which participated in the fire on April 19–24, 2020 (9 people) – 2.2 ± 0.6 μSv, in the group of personnel of the SES of Ukraine in the Kyiv region, which took part in the elimination of the forest fire in the exclusion zone on April 4 – May 5, 2020 (42 people) – 4.4 ± 2.4 μSv. Maximum values of 5.1 μSv, 3.5 μSv, 11.8 μSv in the groups of Kyiv city, Cherkasy and Kyiv regions, respectively, which is much lower than the basic dose limit for the population from man-made sources of 1000 μSv · year-1 according to the Law of Ukraine about protection of the person against influence of ionizing radiation. Key words: forest fire, Chornobyl Exclusion Zone, internal irradiation, whole body counters, 137Сs.


2013 ◽  
Vol 13 (3) ◽  
pp. 727-736 ◽  
Author(s):  
K. Papagiannaki ◽  
K. Lagouvardos ◽  
V. Kotroni

Abstract. This paper introduces the development of a database of high-impact weather events that occurred in Greece since 2001. The selected events are related to the occurrence of floods, flash floods, hail, snow/frost, tornados, windstorms, heat waves and lightning with adverse consequences (excluding those related to agriculture). The database includes, among others, the geographical distribution of the recorded events, relevant meteorological data, a brief description of the induced impacts and references in the press. This paper further offers an extensive analysis of the temporal and spatial distribution of high-impact weather events for the period 2001–2011, taking into account the intensity of weather conditions and the consequent impact on the society. Analysis of the monthly distribution of high-impact weather events showed that they are more frequent during October and November. More than 80 people lost their lives, half of which due to flash floods. In what concerns the spatial distribution of high-impact weather events, among the 51 prefectures of the country, Attica, Thessaloniki, Elia and Halkidiki were the most frequently affected areas, mainly by flash floods. Significant was also the share of tornados in Elia, of windstorms in Attica, of lightning and hail events in Halkidiki and of snow/frost events in Thessaloniki.


2021 ◽  
Vol 252 ◽  
pp. 03026
Author(s):  
Qiang Ge ◽  
Wenju Shen ◽  
Shenshen Li ◽  
Kun Cai

Using MODIS standard products, the temporal and spatial distribution characteristics of thermal anomalies in Henan Province in the past 12 years (2008~2019) were studied. The results found that in terms of spatial distribution, thermal anomalies were mostly concentrated in Luohe, Zhumadian, Pingdingshan, Puyang, and Shangqiu. The number of areas under the jurisdiction of Anyang, Hebi, Nanyang and Xinyang is relatively high. On the inter-annual trend, the number of thermal anomalies continued to increase from 2009 to 2013, with an average annual growth rate of 28.3%, and a continuous decline from 2013 to 2018. The decline rate was 18.4%, during which the number reached a peak of 5,843 in 2013. In terms of seasonal changes, the number of summer thermal anomalies is the largest, at 25,361, and thermal anomalies of summer are mostly concentrated in most areas of Zhumadian, Pingdingshan, Puyang and Shangqiu; the number of thermal anomalies in winter is the least, 3974, which are relatively mostly distributed in the mountainous areas of Nanyang and Xinyang. This study helps to understand the forest fires in typical areas in Henan Province, as well as heat caused by straw burning, industrial emissions, etc. Thermal anomalies changes provide technical support for regional disaster prevention and environmental monitoring.


2015 ◽  
Vol 19 (2) ◽  
pp. 435-446 ◽  
Author(s):  
Milan Radovanovic ◽  
Tomislav Pavlovic ◽  
Gorica Stanojevic ◽  
Misko Milanovic ◽  
Mila Pavlovic ◽  
...  

In mid-July 2012, hundreds of fires spread over forest stands in the south of Europe. Considering available satellite and meteorological data we have tried to determine a method using analogy, whether these fires were preceded by the intensified solar activity. The justification of this approach lies in the belief that it is impossible by direct or indirect activity of man to set fire at the same time to the sites that are geographically separated. In this paper we have tried to test the hypothesis claiming that charged particles coming to us from the Sun may be responsible for the number of forest fires. Unlike some other situations when the potential explanation could be a sudden influx of the protons of different energy ranges, in our study, there are electrons as carriers of the potential explanation. Many previous studies results have shown that there is statistically significant relationship between the processes on the Sun and certain movements of air masses in the atmosphere our planet. The presented results in this paper of the correlation relationships between the mean hourly flows of electrons and the mean hourly air temperatures in Belgrade and Rome and the analysis of the synoptic situation as a function of the suggested model so far, indicate that the number of fires that were occurring more than a week, from July 15, 2012, in the south of Europe, were caused by electrons coming from the Sun.


2020 ◽  
Vol 18 ◽  
pp. 86-104
Author(s):  
M. M. Таlerko ◽  
◽  
Т. D. Lev ◽  
I. V. Коvalets ◽  
Yu. V. Yatsenko

In April 2020, the largest forest fire occurred in the Chornobyl Exclusion zone in its history. The results of modeling the atmospheric transport of radioactive aerosols raised into the atmosphere as a result of fires in forest and grass areas in the Exclusion zone, as well as in radioactively contaminated forests outside it in Kyiv and Zhytomyr regions are presented in the paper. To assess the consequences of forest fires, a set of models of lifting, atmospheric transport and deposition of radionuclides on the underlying surface LEDI, developed at the Institute for Safety Problems of Nuclear Power Plants of the National Academy of Sciences of Ukraine, was used. Calculations of the dynamics of the 137Cs activity concentration field in the surface air on a regional scale (in Ukraine) and on a local scale (within the Exclusion zone) were performed. According to the simulation results, the maximum values of the 137Cs activity in the surface air of Kyiv in some periods during April 4−20 could reach 2−4 mBq/m3, and the integral value of 137Cs activity in the air of Kyiv for the whole period was about 450 mBq⋅s/m3. The obtained results are generally consistent with the data of measurements of radioactive contamination of the nearground air in Kyiv and areas of the nuclear power plants in Ukraine. The analysis of the consistency of the simulation results with the data of measurements of the 137Cs activity concentration in the air in the Exclusion zone was performed. The main ways to improve the methodology for assessing the consequences of forest fires by modeling the atmospheric transport of radionuclides are identified.


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