scholarly journals Modeling Study of the Atmospheric Transport of Radioactivity Released into the Air as a Result of Forest Fires in the Exclusion Zone in April 2020

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.

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.


Open Physics ◽  
2006 ◽  
Vol 4 (4) ◽  
Author(s):  
Rimvydas Jasiulionis ◽  
Andrej Rožkov

AbstractResults of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric depositional fluxes of 7Be, 60Co and 137Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the 137Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the 137Cs activity concentration of up to 17.4 µBq m−3 on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium resuspension from the Chernobyl NPP accident polluted regions are sources of 137Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols — carriers of 137Cs — are discussed.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sümer Şahin ◽  
Muhammad Ali

Emergency planning zones (PAZ and UPZ) around the Karachi-2 and Karachi-3 nuclear power plants (K-2/K-3 NPPs) have been realistically determined by employing Gaussian puff model and Gaussian plume model together for atmospheric transport, diffusion, and deposition of radioactive material using onsite and regional data related to meteorology, topography, and land-use along with latest IAEA Post-Fukushima Guidelines. The analysis work has been carried out using U.S.NRC computer code RASCAL 4.2. The assumed environmental radioactive releases provide the sound theoretical and practical bases for the estimation of emergency planning zones covering most expected scenario of severe accident and most recent multiunit Fukushima Accident. Sheltering could be used as protective action for longer period of about 04 days. The area about 3 km of K-2/K-3 NPPs site should be evacuated and an iodine thyroid blocking agent should be taken before release up to about 14 km to prevent severe deterministic effects. Stochastic effects may be avoided or minimized by evacuating the area within about 8 km of the K-2/K-3 NPPs site. Protective actions may become more effective and cost beneficial by using current methodology as Gaussian puff model realistically represents atmospheric transport, dispersion, and disposition processes in contrast to straight-line Gaussian plume model explicitly in study area. The estimated PAZ and UPZ were found 3 km and 8 km, respectively, around K-2/K-3 NPPs which are in well agreement with IAEA Post-Fukushima Study. Therefore, current study results could be used in the establishment of emergency planning zones around K-2/K-3 NPPs.


Author(s):  
Martin B. Kalinowski ◽  
Halit Tatlisu

Abstract For the purpose of monitoring for compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the International Monitoring System (IMS) is being established that includes 40 sensor systems for atmospheric xenon radioactivity. Its purpose is to monitor the atmosphere for signatures that may indicate a nuclear explosion. Normal operational releases of radioxenon from nuclear facilities can regularly be observed by these very high-sensitive noble gas systems. Existing best estimates of releases for a generic year are unlikely to apply for any specific year at the level of individual facilities because their releases are highly variable and can change by several orders of magnitude from year to year. In this paper, best knowledge of the radioxenon emission inventory from nuclear power plants (NPPs) is collected for the calendar year 2014. The distribution function for each CTBT relevant radioxenon isotope is derived from all releases from NPPs as reported for 2014. The data of this paper can be used for developing and validating methods based on atmospheric transport modelling that are designed to enhance understanding of the impact of known sources on the IMS background observations.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-13
Author(s):  
John H. Perkins ◽  
Natalie Kopytko ◽  
Kathleen M. Saul

Energy poses challenges to environmental studies because of climate change and other effects, and field trips are indispensable aids to learning. They enable students to see situations first-hand, and many are joyous and fun, such as field trips to forests, wetlands, wildlife reserves, or communities exhibiting positive contributions to safeguarding the natural world. Field trips to the built environment, especially those illustrating sites with raging controversies or past catastrophes are equally important in helping students turn theory into understanding of real situations. Chernobyl, one of the two worst nuclear power plant disasters, provided the venue for a field trip examining the strengths and weaknesses of nuclear power. Students had 3 weeks of preparatory classwork before departing for Kyiv, Ukraine. They spent 2 weeks there, with 1 day touring the Exclusion Zone surrounding the Chernobyl plant. Background work included basic concepts and units for measuring radiation and their biological and medical effects, types of nuclear power plants, disaster planning and response, Ukrainian history, and details of the Chernobyl accident and its effects. Participants heard from a wide variety of speakers, who presented details of the accident, its lingering consequences, efforts of the Ukrainian government and various NGOs to deal with the consequences, and Ukrainian plans for new nuclear power plants. Participants also heard both strong pro-nuclear and anti-nuclear proponents. At the end, students prepared a paper on the lessons about nuclear power from Chernobyl. Evaluations of the experience indicated the trip’s objectives were achieved. For some, the expedition proved life-altering.


Author(s):  
Yoshifumi Wakiyama ◽  
Alexei Konoplev ◽  
Toshihiro Wada ◽  
Tsugiko Takase ◽  
Yasunori Igarashi ◽  
...  

Abstract. Closed and semi-closed water bodies, such as lakes and ponds, are important water resources in Fukushima area and they are the most sensitive environments to radioactive contamination after the Fukushima Dai-ichi nuclear power plant accident. Wakiyama et al. (2017) investigated 137Cs activity in water and bottom sediment in four ponds; Suzuuchi (SU), Funasawa (FS), Inkyozaka (IZ), and Kashiramori (KM), within 10 km zone from the FDNPP during 2015–2016. This study follows up their observation to address longer time trends of 137Cs activity concentration in pond waters and to show speciation of 137Cs in soil and bottom sediment. Mean total 137Cs activity concentration in water ranged from 2.5 to 29 Bq L−1. There was not found steady trend in the activity concentration of total and particulate 137Cs for four ponds. The concentration of dissolved 137Cs was usually low in winter during the entire observation period in all four ponds. A tendency to a decrease in the 137Cs activity concentration in suspended sediments was found for four ponds and the decreasing rate constants, including radiological decay, on SU, FS, IZ and KM were 0.33, 0.53, 0.29 and 0.25 yr−1, respectively. The results of sequential extractions of soil and bottom sediment samples showed higher proportion of bioavailable 137Cs, i.e., exchangeable and organic bound 137Cs, in bottom sediment than in the soil.


Author(s):  
Marjorie B. Bauman ◽  
Richard F. Pain ◽  
Harold P. Van Cott ◽  
Margery K. Davidson

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