Chernobyl Accident Research Articles

Chernobyl Disaster Optimizer-Based Optimal Integration of Hybrid Photovoltaic Systems and Network Reconfiguration for Reliable and Quality Power Supply to Nuclear Research Reactors

Chernobyl Disaster Optimizer-Based Optimal Integration of Hybrid Photovoltaic Systems and Network Reconfiguration for Reliable and Quality Power Supply to Nuclear Research Reactors

Optimisation of decision-making on risk management strategy for the hydromelioration systems in biosphere reserves

The field of nature conservation in Ukraine is currently experiencing a profound crisis. In light of the mounting risks to Ukraine’s ecosystems, it is of paramount importance that conservation planning incorporates risk management strategies. In the aftermath of the Chernobyl disaster, the management of water bodies in the Exclusion Zone assumed paramount importance, given that the rivers had become the primary conduit for the transportation of radioactive substances. It is therefore imperative to evaluate the risks and vulnerabilities of climate change on Ukraine’s most developed economic sectors, population, and natural ecosystems. This will facilitate comprehension of the prospective consequences of climate change, ascertain the extent of potential losses, and inform decision-making aimed at reducing or preventing such losses in a timely manner. One of the primary challenges facing specialists at the Chornobyl Radiation and Ecological Biosphere Reserve, in addition to other organisations and enterprises of the State Agency of Ukraine on Exclusion Zone Management and scientific institutions, is the assessment of the feasibility of hydromelioration systems. It is of the utmost importance that a scientifically sound methodological approach be employed in order to ensure the reliability and validity of the results obtained through the assessment of risks and vulnerabilities to climate change. In this context, the utilisation of adaptive methodologies is of paramount importance for the development of risk management strategies. One such methodology is the Methodology for Risk Analysis and Information Management for Strategic Ecosystems (MARISCO). This article considers the potential deployment of the MARISCO adaptive method as a universal methodology for the analysis of environmental issues, with a view to informing decision-making on risk management strategies in the Chornobyl Radiation and Ecological Biosphere Reserve.

Novel modified Chernobyl disaster optimizer for controlling DC motor

This article presents the modified Chernobyl disaster optimizer (CDO) method for DC motor control to find the optimal proportional integral derivative (PID) settings. DC motors are widely used machinery. DC motors are also simple to use. The detonation of the Chernobyl nuclear reactor core served as the inspiration for the idea and guiding principles of the CDO. CDO has limitations in the stability of exploration and exploitation areas. This research aims to obtain a new balance of exploration and exploitation. This study suggests incorporating the levy flight and chaotic algorithm (CA) techniques to enhance the CDO method. This study was conducted with the MATLAB/Simulink software. A comparative technique, which included the marine predator algorithm (MPA), golden jackal optimization (GJO), and CDO, was utilized to determine the performance of the MCDO method. According to the study’s findings, the MCDO method’s overshoot value outperformed all other approaches.

Comparative analysis of the dispersion modeling and dose projection results performed under BARCO international project

Radiological assessments on zones to take protective actions in case of a nuclear or radiological emergency involve a series of real-time forecasts of radiological impact on the public at various distances from the release point, using actual weather or forecast data, information on the source term or facility status, and primary radiation monitoring data. This practice is implemented during the operation of emergency centers around the world in order to promptly report the occurrence and possible consequences of radiological accidents in the country and abroad in the event of a possible transboundary impact. Since the Chornobyl disaster, a lot of emergency exercises, research programs and projects, in particular, benchmarking, have served as international platforms for improving modeling capacity in atmospheric dispersion. This activity is carried out both on the basis of past severe accidents with significant atmospheric releases and corresponding radiological consequences, and on the basis of specific conditional (hypothetical) events that are developed in accordance with the purpose of the study. The paper is focused on the comparison results performed under the international project “Benchmarking on Assessment of Radiological COnsequences” (BARCO) conducted in 2020–2021 between five technical support organisations – members of the European Technical Safety Organisations Network (ETSON). The work contains a short overview of relevant international activity conducted in the past, a description of the BARCO project and its objectives, a list of participants, project tasks, initial data (source term, meteorology, list of benchmarking quantities, approach to data exchange, codes used). The study presents some of comparative analysis results obtained via two techniques such as code-to-code analysis (CTCA) and matched-pair analysis (MPA). The results discussion concentrates on the overall recommendations for code users. Conclusions provide the main outputs of the project.

Dose response analysis of protracted absorbed organ dose and site-specific cancer incidence in Sweden after the Chernobyl accident

Dose response analysis of protracted absorbed organ dose and site-specific cancer incidence in Sweden after the Chernobyl accident

Educational Center of the Republican Scientific and Practical Center of Radiation Medicine and Human Ecology

The results of the work of the educational center based on the Republican Scientific and Practical Center for Radiation Medicine and Human Ecology, the lead organization for the provision of specialized medical care to the population affected by the Chernobyl disaster, are presented. It is noted that the institution has created opportunities and provided optimal conditions for the actual receipt of continuous medical education.

Automating execution of surveillance procedures for NPP main control rooms

ABSTRACT For the past 30 years, progress in the automation of control processes in the nuclear industry has been much slower compared to other industries. In the same timeframe, other complex industrial and/or high-risk processes (e.g., aviation) have been revolutionized by the exponential increase of technology capability in computing and information systems. The reason for the relatively slow trickling of technology advancements in the nuclear field is multi-faceted: i) resistance to change from a traditionally proven solution (partially due to very specific regulation requirements); ii) the cost to adopt Computerized Procedure Systems for existing NPPs, without having a quantified and proven safety benefit; iii) relatively low number of new NPPs being built following the Chernobyl and Fukushima disasters; iv) possible negative impact on the human factors aspect. After a short introduction to automation in another high-risk industry (aviation), this paper focuses on the practical approach required for automating Surveillance Procedures, and at the same time taking into consideration the human factors impact of this approach.

Radioactivity and food safety in Serbia: Chernobyl accident and 4 decades later

Radioactivity and food safety in Serbia: Chernobyl accident and 4 decades later

Recent insights into trends of thyroid cancer incidence in Lithuanian population exposed to Chernobyl fallout early in life

In the last three decades, an increase in thyroid cancer incidence has been observed worldwide, as well as in Lithuania. Although the rise was linked to overdiagnosis, the role of lifestyle and environmental factors, including exposure to ionizing radiation, cannot be excluded. In our retrospective study, we aimed to assess the association between the average age-specific thyroid dose due to the radioactive iodine uptake during childhood and adolescence from the Chernobyl fallout in Lithuania, and the trends of incidence of thyroid cancer from 1991 to 2015 in different regions. Averaged age-dependent thyroid doses were estimated for every municipality based on radioiodine activity in milk, reconstructed from available 131I activity measurements in the grass. Thyroid cancer incidence rates were calculated for the entire population and for two age at the time of exposure groups: 0–19 years and 0–9 years. Thyroid cancer relative risk (RR) was estimated for three municipality-specific thyroid dose (for 0-year-old babies) categories: less than 100 mGy (reference group), 100–199 mGy, and ≥200 mGy. Over the study period (1991–2015), a total of 5664 cases of thyroid cancer were registered in the entire Lithuanian population; 817 cases in the age group from 0 to 19 years at the time of the Chernobyl accident, and 266 cases in the age group from 0 to 9 years. Age-standardized thyroid cancer incidence rates have notably increased since 2000, peaked in 2009 (especially in females), and then slightly decreased and stabilized. The estimated average municipality-specific age-dependent thyroid doses ranged from 270 mGy in western Lithuania to 1.5 mGy in central and northern Lithuania. For the age group of 0–19 years at the time of the accident, in the period 1991–1995, the thyroid cancer relative risk was significantly increased (RR 3.91; 95 % CI: 1.27–10.29, p=0.01) in the highest dose category, compared to the lowest (although based on a small number of cases). For the age group 0–9 years at the time of the accident, a tendency of increased RR in the highest dose category appeared in the most recent period, 2011–2015. Our observations need to be confirmed by further following trends of thyroid cancer incidence in the cohort of 0–19-year-old Lithuanians at the time of the Chernobyl accident.

Literature survey and analysis of phytoremediation strategies for Cs-137 decontamination

Phytoremediation has become a sustainable solution for mitigating cesium-137 (Cs-137) contamination and has been implemented in areas affected by the Chernobyl and Fukushima nuclear disasters. Despite the absence of nuclear power plants in Indonesia, incidents of Cs-137 contamination have been reported in Batan Indah Housing Complex, emphasizing the need for effective decontamination techniques. The aim of this study was to analyze the bibliometric characteristics of research works on phytoremediation in addressing Cs-137 contamination during the last ten years (2013–2022) by foreign and Indonesian authors. This research is important both globally and in specific contexts, such as Indonesia, particularly in the context of policy and practical applications. For example, when facing issues like Cs-137 decontamination in the BATAN Indah area, the research can have local relevance and contribute to solving immediate problems. This study utilized the Scopus database and retrieved 2,123 article titles within this topic over the last decade. Several indicators were used to examine the publications: productivity of authors, collaboration between countries, top-cited articles, keywords analysis, and publication trends. The results show that the number of publications fluctuated over previous decade with an average publications age of 5.54 years. Onda Y from the University of Tsukuba, Tsukuba, Japan become the most prolific and collaborative author. Japan being the most productive and collaborative country, while Indonesia ranked 42nd with only 9 publications regarding the topics. The bibliometric analysis provides a foundation for understanding the development of science on this topic and uncovers that there is still plenty of space to conduct phytoremediation research in Indonesia, especially for Cs-137 contaminated soils, which have increased over the years.

Analysis of the radiation effect on the activity of thyroid blood transport systems: connection with the features of thyroid status

Thyroid-binding proteins play an important role in regulating thyroid status. However, the question of the radiation effect on the functional state of thyroid blood transport systems remains insufficiently studied. The aim of the work was to assess the indicators of thyroid status and thyroid blood transport in persons exposed to radiation as a result of the Chernobyl accident. The task of the work was also to analyze the results of an oral test for thyroxine pharmacokinetics in patients with thyroid carcinoma who received radioiodine therapy. Screening studies conducted 5−6 years after the Chernobyl accident indicate the radiation effect on the free thyroxine content in the blood and the functional activity of thyroid protein transport in children and adolescents living in the territories of the Khoiniki district of the Gomel region. The dose-dependent effect of an absorbed dose of 131I was also detected in children and adolescents displaced from the 30 km zone of the Chernobyl accident. The results of an oral test for thyroxine pharmacokinetics demonstrate an increase in the free T4 content against the background of a stable total T4 fraction in patients with thyroid carcinoma who received high dose loads as a result of radioiodine therapy. The conducted studies confirm the possibility of the influence of a high dose of 131I on thyroid blood transport systems and on the ratio of free and bound fractions of thyroid hormones in the blood.

Preferred techniques for forest mushrooms cooking by residents of contaminated areas of the Bryansk region in the remote period after the Chernobyl accident

The article presents results of the analysis of questionnaire survey data on preferences in the choice of cooking methods of different types of forest mushrooms by residents of the most contaminated south-western districts of the Bryansk region in the remote period after the Chernobyl accident. In the period from 2019 to 2022, the employees of Federal Budgetary Institution of Science «Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev» conducted a face-to-face questionnaire survey of the adult population. In addition to general questions about the respondent, the questionnaires included questions about the species composition of the mushroom basket, the volume and proportion of consumption of each type of mushroom by the respondent and his family members (both in the current and last year), as well as methods of culinary processing of the mushrooms consumed. Based on the analysis of individual survey data, a group of 1 311 respondents, whose diet included various types of mushrooms, was selected. Analysis of the survey results showes that respondents prefer to process a large proportion of freshly picked forest mushrooms (59%) for long-term storage (pickling, freezing, drying, salting, etc.); 41% of mushrooms are consumed immediately. The most popular pretreatments of freshly picked mushrooms are washing and boiling (34 and 26%, respectively). When freezing, pickling and pickling up to 97% of respondents carry out pre-treatment (rinsing, soaking and / or boiling) of freshly picked mushrooms. Less popular methods of the mushroom preparation (from 2 to 4%) are pickling, drying and frying of fresh mushrooms with their subsequent preservation. Thus, the majority of respondents actively use various types of culinary processing with the use of preliminary stages of technological processing in the form of rinsing, soaking and (or) boiling. The use of the above methods of pre-cooking of freshly harvested mushrooms leads to a decrease in the 137Cs content in the consumed product.

Distribution of 137Cs specific activity in river sediments of the Barents Sea basin (Nenets Autonomous Okrug, Russian Arctic).

This article focuses on the study of the distribution of 137Cs in the bottom sediments of Arctic rivers of the Barents Sea basin (using the example of the Nenets Autonomous Okrug, Russian Arctic). This research is relevant due to the poorly studied region and the significant number of radiation-hazardous facilities in the Arctic zone of Russia, both those currently in operation and those that are "nuclear heritage sites". The study of 137Cs specific activity in bottom sediments was carried out in the period from 2020 to 2023 in the rivers Chizha, Nes, Vizhas, Oma, Pechora (river delta), as well as the rivers Kolva and Usa (first and second order tributaries, respectively, of the Pechora River). A total of 199 samples were collected. In addition to 137Cs specific activity, the samples were analysed for sediment particle size distribution, organic matter content, carbonate content and ash content. The 137Cs specific activity mainly ranged from the minimum detectable specific activity to 5.4 ± 0.8Bq·kg-1. In the Nes River basin (Kaninskaya tundra), the 137Cs content in bottom sediments reached 36.0 ± 3.2Bq·kg-1 (in the case of lake sediments) and 22.9 ± 3.7Bq·kg-1 (in the case of river sediments), values that are higher than those of the North-West of Russia. Considering the large area of the study area (Kaninskaya tundra, Pechora river delta, southern part of Bolshezemelskaya tundra) and the similarity of physical and chemical parameters of the studied rivers, it is possible to assume the existence of a zone of increased radionuclide content in the Nes river basin. This may be due to the runoff from the Nes River catchment area, its hydrological features, and the accumulation of 137Cs in the small fractions of bottom sediments. The results confirm the conclusions of previous soil studies in the Nes river basin. The main sources of elevated 137Cs content are global atmospheric deposition and the Chernobyl Nuclear Power Plant accident.

The surface of small glaciers as radioactive hotspots: Concentration of radioisotopes during predicted intensive melting in the Alps

Glaciers are considered secondary sources of pollutants, including radioisotopes such as Cesium or Plutonium, with heightened concentrations compared to other ecosystems. The predicted melting of glaciers poses a substantial risk of releasing stored radioisotopes, yet understanding the glacier-specific factors influencing their concentration remains limited. This study investigates the relationship between glacier altitude, surface area, organic matter content in dark supraglacial sediment (cryoconite), precipitation, and activity concentrations of natural (210Pb) and anthropogenic radionuclides (137Cs and 241Am) across 19 Alpine glaciers. Results indicate that radioisotope concentrations depend on organic matter content in the cryoconite, highlighting the role of biotic-abiotic interactions in pollutant accumulation on glaciers. Moreover, 210Pb activity concentration decreases with glacier altitude, likely due to atmospheric variations in 222Rn. Water precipitation events, such as during peaks in 137Cs deposition and after the Chernobyl Nuclear Power Plant disaster, do not impact current activity concentrations. Importantly, radioisotope concentrations in cryoconite are higher on smaller glaciers. This directly supports the hypothesis that the cryoconite retains a significant share of radioisotopes stored in the ice during intensive melting. Since many small glaciers in the Alps are predicted to disappear within the next 50 years, we anticipate release of radioisotopes to mountain ecosystems might be higher than previously forecasted.

Угруповання мишовидих гризунів на ділянках з різним ступенем ураження пожежами: чорнобильські полігони

As a result of climate change, forest fires are becoming a common factor in the dynamics of ecosystems in the forest zone of Ukraine, but the assessment of the consequences of this shift in the ecological situation is in the process of pilot studies. In the spring of 2020, a number of large ecosystem fires occurred in the Central Polissia region, which affected forests the most. Among other things, a large fire occurred in ecosystems located in the Exclusion Zone and the Zone of Unconditional (Mandatory) Resettlement, which was formed as a result of the Chornobyl accident. The ecosystems of the Chornobyl Radiological and Ecological Biosphere Reserve located within its boundaries were also affected by the fire. The consequences of this fire were assessed a year later, using mouse-like rodents as a model group. The purpose of the study was to assess and compare the communities of mouse-like rodents in areas that were affected by two degrees of fire damage—where there was a surface fire and those that were most affected (highland fire). Four polygons were created in the control-impact scheme. Each of the pairs of plots was identical in terms of typical forest vegetation conditions. Sherman traps were used for trapping. A total of 560 trap-days were processed, and 101 animals were captured. The presence of four species of rodents from the genera Apodemus, Sylvaemus, and Myodes was recorded, namely the striped field mouse, the yellow-necked wood mouse, the European wood mouse, and the bank vole. The main indicators of species diversity were calculated using information indices—species richness, evenness, and similarity. The surveys revealed both negative and positive changes in areas affected by fires. Areas characterised by relatively higher values of species diversity indices compared to the control had a high intensity of vegetation recovery. They belonged to areas with wet, relatively fertile (sugrud) and infertile (subor) forest types. The plots with low intensity of vegetation recovery had a depleted community structure and belonged to fresh and dry boreal forest. Based on this, it is possible to create a forecast of ecosystem restoration by assessing the type of forest vegetation conditions.

About holding the III International Internet conference «Current issues of Formal and Non-Formal Education in Environmental Monitoring and Conservation»

On April 26, 2024, the the Karazin Institute of Environmental Sciences hosted the III International Internet Conference "Current issues of Formal and Non-Formal Education in Environmental Monitoring and Conservation", organized by the Department of Environmental Monitoring and Conservation. The conference featured presentations on the following topics: The impact of military operations on the environment and ways of post-war revitalization of natural complexes; Problems and prospects of reserve management in Ukraine and the world; Environmental monitoring: science, education, practice; Formal and non-formal education in reserve management; The Chornobyl disaster: consequences of the tragedy and warnings for the future. Three reports-presentations of the certificate educational programs of the Institute of Ecology of Karazin University (speakers O. Gololobova, A. Kleshch and S. Burchenko) deserve special attention.

Prevalence of Thyroid Nodules in Residents of Ukraine Exposed as Children or Adolescents to Iodine-131 from the Chornobyl Accident.

Background: Although childhood exposure to radioactive iodine-131 (I-131) is an established risk factor for thyroid cancer, evidence for an association with thyroid nodules is less clear. The objective of this study is to evaluate the association between childhood I-131 exposure and prevalence of ultrasound-detected thyroid nodules overall and by nodule histology/cytology (neoplastic/suspicious/non-neoplastic), size (<10 mm/≥10 mm), and number (single/multiple). Methods: This is a cross-sectional study of radiation dose (mean = 0.53 gray, range: 0.0003-31 gray) and screen-detected thyroid nodules conducted in 1998-2000 (median population age 21.5 years) in a cohort of 13,243 residents of Ukraine who were under 18 years at the time of the Chornobyl accident on April 26, 1986. Excess odds ratios per gray (excess odds ratio [EOR]/Gy) and confidence intervals (CIs) were estimated using logistic regression. Results: Among 13,078 eligible individuals, we identified 358 (2.7%) with at least one thyroid nodule. Significantly increased dose-response associations were found for all nodules and nodule groups with doses <5 Gy except individuals with non-neoplastic nodules. Among individuals with doses <5 Gy, the EOR/Gy for neoplastic nodules (5.35; CI: 2.19-15.5) was significantly higher than for non-neoplastic nodules (0.24; CI: 0.07-0.74), but the EOR/Gy did not vary by nodule size or number. Conclusions: Childhood exposure to I-131 is associated with an increased risk of thyroid nodules detected 12-14 years following exposure, and the risk for neoplastic nodules is higher than for non-neoplastic nodules. Analyses of incident thyroid nodules may help clarify dose-response patterns by nodule characteristics and provide insights into thyroid nodule etiology.

Behavior of &lt;sup&gt;137&lt;/sup&gt;Cs in the soil-plant system in the floodplain landscapes of the Sozh River basin

Studies were carried out in the most affected by the Chernobyl accident part of the Bryansk region, in the ecosystems of floodplains of the Iput, Besed and Unecha rivers, in zones with different 137Cs pollution density. The purpose of the work is to study the peculiarities of the vertical distribution of 137Cs in the soil–plant system of the floodplain landscape long after the Chernobyl accident. As a result of studies, it was revealed that the vertical distribution of 137Cs, in the 0–20 cm layer, is determined by the position on the relief and the genesis of the soils of floodplain subsystems. The distribution character can be uniform, decreasing with depth, or with accumulation in certain layers. In the floodplain ecosystem, the concentration of 137Cs in the 0–20 cm layer increases from the river channel to the terrace above floodplain subsystems. Currently, the use of the territory of the west of the Bryansk region with a 137Cs pollution density above 555 kBq/m2 in feed production is strictly limited. The coefficient of 137Cs transition from soil to plants decreases from the central part to the near-channel one and to terrace above floodplain.

Sex-specific Infant Mortality Trends in Switzerland (1950 - 2022) and Test of the Null Hypotheses of No Trend Changes after the Chernobyl Accident in 1986

Sex-specific Infant Mortality Trends in Switzerland (1950 - 2022) and Test of the Null Hypotheses of No Trend Changes after the Chernobyl Accident in 1986

Temporal trajectories of artificial radiocaesium 137Cs in French rivers over the nuclear era reconstructed from sediment cores

137Cs is a long-lived man-made radionuclide introduced in the environment worldwide at the early beginning of the nuclear Era during atmospheric nuclear testing’s followed by the civil use of nuclear energy. Atmospheric fallout deposition of this major artificial radionuclide was reconstructed at the scale of French large river basins since 1945, and trajectories in French nuclearized rivers were established using sediment coring. Our results show that 137Cs contents in sediments of the studied rivers display a large spatial and temporal variability in response to the various anthropogenic pressures exerted on their catchment. The Loire, Rhone, and Rhine rivers were the most affected by atmospheric fallout from the global deposition from nuclear tests. Rhine and Rhone also received significant fallout from the Chernobyl accident in 1986 and recorded significant 137Cs concentrations in their sediments over the 1970–1985 period due to the regulatory releases from the nuclear industries. The Meuse River was notably impacted in the early 1970s by industrial releases. In contrast, the Seine River display the lowest 137Cs concentrations regardless of the period. All the rivers responded similarly over time to atmospheric fallout on their catchment, underlying a rather homogeneous resilience capacity of these river systems to this source of contamination.