Semipalatinsk Test Site Research Articles

The character of Lake Kishkensor contamination in the area of underground nuclear explosions at the Semipalatinsk Test Site territory

The timely identification of areas where man-made radionuclides migrate through water streams is highly important for the territory of the former Semipalatinsk Test Site since the aquatic environment is currently a source of secondary contamination of environment. This article presents research findings on radioactively contaminated Lake Kishkensor located at the Semipalatinsk Test Site territory. As a result of this research, a new locally contaminated spot was discovered in the vicinity of the “Balapan” test site. Lake Kishkensor was found to be contaminated with man-made 3H and 90Sr. The 3H activity concentration in surface waters reached 430 kBq/L, and the concentration of 90Sr reached 100 Bq/L. In the sediments, the 3H activity concentration reached 700 kBq/kg, while that of 90Sr and 239+240Pu reached 310 Bq/kg and 250 Bq/kg, respectively. Ground water was found to be a source of surface water and sediment contamination. The monitoring results showed that the contamination level of the lake largely depended on the season and the inflow of contaminated ground water.

The Effect of Radionuclide and Chemical Contamination on Morphological and Anatomical Parameters of Plants

This article presents the results of a study of the influence of radionuclide and chemical pollution on the morphological and anatomical parameters of Calamagróstis epigéjos plants growing in the territory of “Degelen” at the Semipalatinsk Test Site (STS). Quantitative data of morphological and anatomical parameters are given, and the content of radionuclides and toxic elements in samples of plants obtained. Statistical processing of the obtained data was conducted. The results revealed that elevated concentrations of radionuclides 137Cs and 90Sr, and the calculated absorbed dose, do not have effects on plants. Changes in the anatomical parameters of leaves and stems were observed at elevated concentrations of the elements: for leaves—Al, Pb, Sr, U, Ni, Rb, Sm; for stems—Al, Cr, Cd, U, Cu, Be, Ni, Sm, Fe. The mesophyll of the leaves and the epidermis of the stems were the most exposed to toxic elements. The data of the anatomical parameters are recommended to be used as indicative parameters of plants grown in chemically contaminated areas.

Radioecological characteristics of Siberian roe deer (Capreolus pygargus Pal., 1771) inhabiting locations of nuclear weapon tests.

This paper reports the activity concentrations of 137Cs, 90Sr, 239+240Pu, 241Am, and 3Н in the form of tritiated water (НТО) and organically bound tritium (ОBТ) in the tissues and organs of roe deer (Capreolus pygargus Pal., 1771) that inhabit the 'Degelen' test location of the Semipalatinsk Test Site. Tissues and organs were sampled from six deer by killing. The activity concentrations of specific radionuclides in the samples were measured using γ-, α-, and β-spectrometry. The radionuclide activity concentrations in the tissues and organs showed considerable variation, for example, 0.6-170 Bq kg-1 for 137Cs and 0.3-2.8×103 Bq kg-1 for 90Sr. The activity concentrations of radionuclides in animal muscular tissue did not exceed permissible values for the meat of wild animals. The tissues and organs in the roe deer were arranged as follows in descending order of their ability to accumulate 137Cs and 90Sr: for 137Cs, muscular tissue-kidneys-lungs-spleen-heart-liver-bone tissue; for 90Sr, bone tissue-liver-lungs-muscular tissue-spleen-heart-kidneys. The activity concentrations of 241Am and 239+240Pu did not exceed the minimum detectable activity. Therefore, no quantitative values could be determined for 241Am, and the 239+240Pu activity concentration could be derived for only one sample: 0.5±0.1 Bq kg-1 (liver). The distribution pattern of these radionuclides in the tissues and organs of the roe deer could not be determined because of insufficient data. The HTO volumetric activity in the tissues and organs of the examined animals ranged from 2.6×10-2 to 77 kBq l-1; activity concentration of OBT, 3.0×10-2 to 16 kBq kg-1; and OBT-to-HTO ratios, 2.0×10-3 to 5.3×102. This ratio can serve as an indicator of how long the examined animals stay in radioactively contaminated ecosystems. Within the 'Degelen' site, the activity concentrations of 90Sr and tritium, in the form of HTO and OBT, are expected to be high in the bone tissues, soft tissues, and organs, respectively.

A PLL-Based Doppler Method Using an SDR-Receiver for Investigation of Seismogenic and Man-Made Disturbances in the Ionosphere

The article describes in detail the equipment and method for measuring the Doppler frequency shift (DFS) on an inclined radio path, based on the principle of the phase-locked loop using an SDR receiver for the investigation of seismogenic and man-made disturbances in the ionosphere. During the two M7.8 earthquakes in Nepal (25 April 2015) and Turkey (6 February 2023), a Doppler ionosonde detected co-seismic and pre-seismic effects in the ionosphere, the appearances of which are connected with the various propagation mechanisms of seismogenic disturbance from the lithosphere up to the ionosphere. One day before the earthquake in Nepal and 90 min prior to the main shock, an increase in the intensity of Doppler bursts was detected, which reflected the disturbance of the ionosphere. A channel of geophysical interaction in the system of lithosphere–atmosphere–ionosphere coupling was traced based on the comprehensive monitoring of the DFS of the ionospheric signal, as well as of the flux of gamma rays in subsoil layers of rocks and in the ground-level atmosphere. The concept of lithosphere–atmosphere–ionosphere coupling, where the key role is assigned to ionization of the atmospheric boundary layer, was confirmed by a retrospective analysis of the DFS records of an ionospheric signal made during underground nuclear explosions at the Semipalatinsk test site. A simple formula for reconstructing the velocity profile of the acoustic pulse from a Dopplerogram was obtained, which depends on only two parameters, one of which is the dimension of length and the other the dimension of time. The reconstructed profiles of the acoustic pulses from the two underground nuclear explosions, which reached the height of the reflection point of the sounding radio wave, are presented.

Artificial radionuclides in the plant cover around nuclear fuel cycle facilities.

This paper presents research on the assessment of the radioecological state of plant cover surrounding two research reactor facilities located within the Semipalatinsk Test Site (STS) as examples of nuclear fuel cycle facilities (NFC). Source data on the concentrations of artificial radionuclides in the plant cover were obtained. Quantitative values for 137Cs, 241Am, and 239+240Pu activity concentrations were determined in plants across the perimeters of the facilities, indicating that these compounds may be present in the associated media from the perspective of accumulative bioindication. The values determined for artificial radionuclides in the 'soil‒plant' system around the researched NFC facilities were attributed to radioactive contamination of the STS territory.

DEVELOPMENT OF AN APPLICATION FOR ASSESSING PUBLIC RADIATION EXPOSURE WHEN LIVING AND CARRYING OUT ANY ACTIVITIES AT THE SEMIPALATINSK TEST SITE

The article presents an overview of capabilities of developed software ‘Assessment of public radiation exposure when living and carrying out any activities at the Semipalatinsk Test Site’ and quoted the algorithm to calculate public individual annual effective exposure doses from the major dose-forming man-made radionuclides at the test site (137Cs, 90Sr, 239+240Pu, 241Am, 3H). The software developed takes into account such behavior scenario as a farmer engaged in subsistence farming and living in the study area together with his family members. The software was developed for Windows operating system and implemented in the development framework of cross-platform applications Embarcadero Delphi XE7 Professional in the object-oriented programming language Object Pascal.

ASSESSMENT OF DOSE LOADS OF WATER BODIES PLANTS AT THE SEMIPALATINSK TEST SITE TERRITORY

The paper presents results calculated for radiation exposure of plants (aquatic, aero-aquatic and coastal) growing at man-made and naturally occurring water bodies at the Semipalatinsk Test Site (STS). The peak overall exposure dose rate was 0.078 mGy/day for coastal plants of man-made water bodies that resulted from off-normal situations during underground nuclear tests. As part of the conservative assessment, the peak overall exposure dose rate was 1.3 mGy/day for aquatic plants of man-made water bodies that resulted from excavation blasts. A publication by the International Commission on Radiological Protection says that there is no information on the manifestation of any effects for the dose rate range of 0.01 to 10 mGy/day for these plant species. Based upon findings, exposure doses to plants calculated from the radioecological survey of STS water bodies were found to be well below the threshold level of the ‘dose limit’ from different reported data. The output indicates that nothing threatens (endangers) the ecosystem health of STS water bodies.

Identification of tritium-contaminated areas using a tritium survey on the snow cover, the case of Semipalatinsk test site

The article presents research findings on the content of tritium in the snow cover of test locations ‘Balapan’ and ‘Sary-Uzen’ in the territory of the Semipalatinsk Test Site. Based upon results, a number of tritium-contaminated areas were revealed. At the ‘Balapan’ site, elevated tritium concentrations in the snow were revealed in the vicinity of the ‘Atomic lake’ close to the ‘Karazhyra’ deposit and at the location of Lake ‘Kishkensor’. At the ‘Sary-Uzen’ site, elevated tritium concentrations in the snow were discovered near borehole 101, at object ‘Lazurite’ and at an unnamed creek outflowing from the mountain range. Maximal of tritium activity concentration in the snow were 45 Bq/kg and 36 Bq/kg at the ‘Balapan’ and ‘Sary-Uzen’ sites, respectively. Background tritium concentrations in the snow cover of the STS territory were found to be 4.6–12 Bq/kg.

On Monitoring of mining explosions conducted on the territory of the former Semipalatinsk Test Site

Several mineral deposits located on the territory of the former Semipalatinsk Test Site (STS) conduct active blasting activity. The largest number of explosions is carried out at the Karazhyra coal mine. These explosions are recorded by stations of the IGR NNC RK network, three of them are part of the International Monitoring System. These are seismic arrays Borovoye (AS057), Makanchi (PS23), Kurchatov-Cross (AS058). The distances to the mines from these stations are 668 km, 452 km, 68 km, respectively. In total, about 2800 explosions were recorded during 19 years of observations. The analysis of the results of routine processing on operational seismic bulletins of the IGR NNC RK Data Center has shown that the field of received epicenters of explosions exceeds the size of the quarry. A detailed processing of explosions waveforms was carried out to find out the reasons of this scatter. Geotool and DTK – GPMCC software included in the NDC-in-a Box package was used to process and analyze the waveforms. It was found that back azimuth values for different regional phases Pn, Pg, Sn, Lg differ from each other and have different dispersion. There are systematic deviations of back azimuths for some phases from the true one. A clear dependence of the epicenter determination accuracy on the energy (power) of the explosion was noted. Subjective factors in the work of analysts that affect the accuracy of estimates are also found. Processing recommendations to improve accuracy were given for analysts of Kazakhstan National Data Centre (KNDC).

Tritium distribution in the 'water-soil-air' system in the Semipalatinsk Test Site.

This article presents research findings on 3H in abiotic environmental compartments, specifically, the 'water-soil-air' system. All of the research areas are located within the Semipalatinsk Test Site (STS): the perimeter of the 'Degelen' site, the riverside zone of the Shagan river and the 'background' area-the southeastern part of the STS (SEP). As research progressed, numerical values of 3H and its species were revealed in various environmental compartments. The presence of 3H was registered not only in underground nuclear test locations but also in the 'background' area-SEP. Maximum 3H tritium concentrations in the water were detected at the 'Degelen' site (up to 57000±5000 Bq/kg) and the Shagan riv (up to 61500±6000 Bq/kg), in the air of the 'Degelen' site (up to 56±11 Bq/m3), in the soil of the 'Degelen' site (up to 5170±500 Bq/kg) and the Shagan riv (4100±400 Bq/kg) in the free water, at SEP (up to 1710±170 Bq/kg) in the organic constituent. Based upon all of the findings, 3H was found to be readily distributed in abiotic environmental compartments depending on certain conditions. Research suggests that water plays a key role in 3H migration processes in the natural system of interest. The second most but equally important constituent is soil and microorganisms of plant and animal origin living there. These assumptions are indirectly proven by research findings that show the HTO and HT air concentration dynamics depending on the sampling location.

OVERVIEW OF GIS-PLATFORMS TO DEVELOP GEOSPATIAL WEB APPLICATIONS BASED UPON THE ANALYSIS OF FUNCTIONALITIES AND APPLICABILITY IN THE CONTEXT OF THE SUSTAINABLE MANAGEMENT OF LAND RESOURCES AND WATER BODIES AT THE FORMER STS

The article addresses the basic tools for creating geospatial Web applications focusing on three key software products: ArcGIS Online, ArcGIS Experience Builder and ArcGIS Enterprise SDK. Functionalities have been analyzed and compared. This covers advantages and disadvantages of each platform in the context of developing a Web application for the sustainable management of land resources and water bodies at the former Semipalatinsk Test Site in areas planned to be released to the economic turnover. Findings provide a comprehensive insight into the choice of the best tool to efficiently work out geospatial Web applications given specific tasks and specificity of the test site area.

UPTAKE OF TIGHTLY BOUND TRITIUM BY PLANTS

A study of the bioavailability of a tightly bound tritium in the soil in situ under the conditions of the Semipalatinsk test site (STS) and in a laboratory vegetation experiment was conducted. Significant concentrations of organically bound tritium (OBT) were recorded in Stipa capillata plants growing on the territory of the STS. At the same time, tritium in the free water of plant tissues (TFWT) was not detected. In a model experiment using Cucumis sativus culture, the specific activity of tightly bound tritium in the composition of the solid phase of the soil and tritiated water (HTO) in the composition of the soil solution at the beginning and at the end of the experiment differed significantly. At the same time, TFWT activity in Cucumis sativus was 2 orders of magnitude less compared to the activity of tightly bound tritium in the soil and slightly differed from the activity of tritiated water in the soil solution, which is accessible to the root system of plants. The results of vegetation studies have shown that the direct source of tritium for experimental plants was a soil solution. However, changes in the tritium activity in the soil liquid and solid phases in vegetation vessels indicate that the source of tritiated water in the soil solution was a tightly bound form of radionuclide as a result of leaching processes. It is assumed that the possible causes of leaching of tightly bound radionuclide from the solid phase into the soil solution are the moisture regime, as well as the influence of the rhizosphere of plants.

Characterization of geological and lithological features in the area proximal to tritium-contaminated groundwater at the Semipalatinsk test site.

The article presents the results of a study of groundwater contaminated with tritium in the vicinity of the 'Atomic Lake' - a crater filled with water as a result of a thermonuclear explosion on the territory of the former Semipalatinsk test site. This crater was created as part of an experimental thermonuclear explosion in 1965 with the aim of creating an artificial reservoir in arid areas. The study was carried out to identify the source of groundwater contamination near the crater formed from a thermonuclear test. There were two possible factors of pollution: the influence of contaminated water from the crater on the groundwater of the adjacent area, or groundwater polluting the water in the crater. It was necessary to find out the source of groundwater contamination and its connection with the water in the funnel. For this purpose, a study of the geological and lithological conditions of the territory adjacent to the funnel was carried out, which was carried out using drilling operations and hydrological measurements. Drilling work made it possible to study the depth of distribution of groundwater, hydrological work made it possible to determine the conditions of distribution of groundwater, as well as to take samples of groundwater. The assessment of the degree of groundwater contamination was carried out through water sampling and laboratory analysis. As a result, it was established that the geological and lithological conditions of the area limit the flow of contaminated groundwater to the water in the crater - the 'Atomic Lake'. Despite the fact that the waters in the crater from a thermonuclear explosion and the groundwater of the adjacent territory are contaminated with the radionuclide tritium, they have different sources of contamination and are not interconnected. Radionuclide analysis of groundwater showed that increased concentrations of tritium with a specific activity of up to 95 000 Bq/l are found in groundwater near the river bed. Shagan and this is due to the influence of the flow of groundwater coming from other parts of the landfill.

Tritium uptake in crops in the area with a high level of atmospheric tritium oxide in the territory of the former Semipalatinsk test site.

During the period from 2019 to 2021, a series of experiments were carried out to study the uptake of tritium by crops in an area heavily contaminated with atmospheric tritium oxide (HTO), at the former Semipalatinsk test site in Kazakhstan. A quantitative assessment is given of the tritium uptake by typical crops (lettuce, tomatoes, peppers and beans) cultivated all over Kazakhstan in the case of a short-term tritium oxide vapor exposure. The plant samples were collected during and after exposure and analyzed for the tritium concentration in two chemical forms: tissue-free water tritium (TFWT) and organically bound tritium (OBT). During the entire series of experiments, the tritium concentration in free water from leaves and ambient air was of the same order of magnitude. The tissue water tritium concentrations of stems and edible parts was 1 to 2 orders of magnitude lower than in the surrounding air. The average value of the TFWT/HTOatm ratio in the leaves and the edible part was (0.73±0.2) and (0.04±0.002), respectively. The organically-bound tritium concentration is 1-2 orders of magnitude lower than the tissue water tritium and ambient air concentrations. Under aerial tritium oxide uptake, the distribution of tritium in non-leafy crops was as follows: leaf-stem-fruit (in decreasing order). After exposure, a non-significant amount of tritium is firmly retained in plants for a long time. The tissue water tritium concentrations correlate closely with atmospheric tritium oxid (r = 0.76), correlate weakly with temperature (r = 0.43) and relative humidity (r = -0.43), and correlate moderately with solar radiation intensity (r = 0.56). There was no reliable correlation between the concentration of tritium in organic matter and in ambient air. The concentration of tritium in the free water of leaves is closely correlated with the concentration in the free water of the stems (r = 0.95) and fruits (r = 0.78). The organically-bound tritium concentration in leaves is closely correlated with the organically-bound tritium concentration in stems (r = 0.99) and fruits (r = 98). The results of the study should be considered when evaluating the impact of tritium oxide emissions on the population living near nuclear power.

Malignant neoplasms of the respiratory tract and thoracic organs in the remote period in males of Altai krai affected by first nuclear test at Semipalatinsk test site

BACKGROUND: The study of remote effects of radiation exposure on tumor-related morbidity in population remains a matter of great social significance in Altai Krai.
 AIM: To investigate the incidence rate for malignant neoplasms of respiratory tract and thoracic organs in the remote period in the male population born in 1932–1949 and located in the zone of influence of the first nuclear test.
 METHODS: This retrospective cohort study was based on the analysis of anonymized data and surgical records on morphologically verified cases of primary malignant neoplasms in a male cohort for the period from 2007 to 2016. In this paper, we studied a cohort fixed by the date of the first nuclear test, with a total of 6383 male individuals. The main (exposed) cohort included 2291 men, while the control (non-exposed) cohort included 4092 men who lived in rural communities of the region that were not affected during the first nuclear test. The cohort included 156 cases of morphologically verified diagnosis of primary malignant neoplasms of the respiratory tract and thoracic organs (codes C30–C39 according to the International Classification of Diseases). Person-time incidence rate (PtR), standard error (mPtR) and confidence intervals (95% CI) were calculated. The incidence of respiratory and thoracic malignant neoplasms, structure and relative risk (RR) were assessed. Statistical processing of the data was performed using licensed Microsoft Office 2016 software.
 RESULTS: The number of person-years spent at risk for respiratory and thoracic malignancies in the male population in the main cohort was 16 731 person-years, and in the control cohort — 30 747 person-years. In the main cohort, PtR was 436.32×105 person-years, with an mPtR of 51.07 and 95% CI of 334.18–538.45; in the control cohort the PtR was 269.95×105 person-years with an mPtR of 29.63 and 95% CI of 210.68–329.21. The leading localizations of malignant neoplasms of the respiratory and thoracic organs in men in the main and control cohorts were bronchial and lung malignancies and laryngeal malignancies.
 CONCLUSIONS: An increased relative risk of respiratory and thoracic malignant neoplasms manifesting in the remote period in the male population born and living in rural areas of Altai Krai during the first nuclear test conducted at the Semipalatinsk test site was revealed: RR=1.616, 95% CI 1.180–2.214, with the standard error of relative risk equal to 0.160.

Cytogenetic Effects in the Populations of Dwarf Feather Grass from the Territory of Semipalatinsk Test Site

Cytogenetic Effects in the Populations of Dwarf Feather Grass from the Territory of Semipalatinsk Test Site

Analyzing the Natural–Technogenic Geosystem with Computer Interpretation Data (Using the Degelen Massif of the Semipalatinsk Test Site as an Example)

Analyzing the Natural–Technogenic Geosystem with Computer Interpretation Data (Using the Degelen Massif of the Semipalatinsk Test Site as an Example)

Bioaccumulation of radionuclides in hoofed animals inhabiting the Semipalatinsk Test Site.

The article assesses the content of radionuclides in hoofed animals inhabiting the Semipalatinsk Test Site by calculation. Hoofed animals' faeces were sampled to determine the content of radionuclides in their diets. Based on values determined for the content of radionuclides in animals; diets, the content of radionuclides in the meat and milk of farm animals-cows (Bos taurus taurus), sheep (Ovis), goats (Capra hircus) and horses (Equus caballus Lin., 1758) as well as in the meat of wild animals-european moose (Alces alces Lin., 1758), argali (Ovis ammon Lin., 1758), roe deer (Capreolus pygargus Pal., 1771) and saiga (Saiga tatarica Lin., 1766) was calculated. No excess of permissible values of the content of 137Cs and 90Sr in the meat of farm animals was found to be expected, even for a conventional 'conservative' scenario, in which maxima of the radionuclide activity concentration in a vegetable feed (faeces) are taken as a basis. 241Am and 239+240Pu in the meat of farm hoofed animals are not standardized. Their predicted maxima of activity concentration are very low, and even in the 'conservative' scenario, they do not exceed 1.8×10-2 Bq kg-1, 1.4×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively. In the milk of farm animals, the content of 137Cs and 90Sr does not exceed permissible values. 241Am and 239+240Pu in the milk of farm animals are not standardized. Their predicted activity concentration values in the milk of sheep and goats do not exceed 6.5×10-2 Bq l-1, for cows- 2.6×10-2 Bq l-1, for horses- 3.1×10-2 Bq l-1. Permissible values of 137Cs and 90Sr in the meat of wild hoofed animals are not exceeded either. In the meat of argali, roe deer and saigas, relatively high levels of 137Cs are predictable. 241Am and 239+240Pu in meat of wild animals are not standardized. Their predicted activity concentration values in the meat of moose and argali do not exceed 3.2×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively, for roe deer and saiga-5.4×10-2 Bq kg-1. Thus, in case of free grazing in the STS territory, no excess of permissible values of standardized radionuclides (137Cs and 90Sr) in the meat and milk of hoofed animals is predictable.

Peculiarities in accummulation of radionuclides by fruit and berry trees and shrubs

The paper provides results of a long-term natural experiment with fruit and berry crops, grown in conditions of radioactive contamination at the territory of the former Semipalatinsk Test Site. The aim of the research is to study peculiarities in accumulation of artificial radionuclides by different species of trees and shrubs. The paper considers only one pathway of the radionuclide's intake, i.e. absorption of the elements by roots from soil. As the result quantitative parameters of 241Am, 137Cs, 90Sr, 239+240Pu transfer and distribution in different parts of the fruit and berry crops were found. At that radionuclides are not uniformly distributed in plants' organs and in most cases, it obeys the following regularity: leaves > branches > fruits. The difference in accumulation of 137Cs, 90Sr, 241Am and 239+240Pu for various organs can be range as follows 1.8–77, 1.6–750, 1.9–76 and 3–182 times respectively. The maximum concentrations of 137Cs in leaves of the researched plants more often were registered at the initial stages of vegetation period. Unlike 137Cs concentration of 241Am and 90Sr in leaves of the researched plants grows usually from the very beginning till the end of the entire vegetation period. The character of transuranium radionuclides accumulation during several years was determined for researched plants. Data obtained can become input parameters for models used to describe the behavior of radioactive substances and assess the risk of contaminated fruit and berry crops for territories having unfavorable radiological situation.

ASSESSMENT OF THE BALAPAN SITE ACCORDING TO THE DEGREE OF DEVELOPMENT OF POSTEXPLOSIVE GEOLOGICAL PROCESSES AND ENVIRONMENTALLY SIGNIFICANT FEATURES

Modern territories of the Semipalatinsk Test Site (STS) are not sufficiently involved in economic activities due to environmental conditions and lack of appropriate infrastructure on them. However, sooner or later they can be used, for example, for development of available mineral and building resources on these territories. Since in these lands the geological environment contains many nuclear cavities that significantly affect the mechanical stability of the surface layers, special studies are required in order to assess the subsurface for their carrying capacity for various infrastructure and economic facilities.This paper presents data on assessing the compliance of the Balapan site boundaries with regard to the development of environmentally significant post-explosive processes. The boundaries of the site, which contain only territories posing direct ecological threat to economic activity, are proposed.