Radionuclides 137Cs Research Articles

Radionuclide sorption dynamics in the Rhone River: Experimental and modelling approach.

The transfer of radionuclides discharged into rivers by nuclear facilities are conditioned by their solid/liquid fractionation, commonly represented by an equilibrium approach using the distribution coefficient Kd. This coefficient, largely used in modeling, assumes an instantaneous and completely reversible reaction. However, such assumptions are rarely verified. Compared to instantaneous adsorption of radionuclides onto particles, slower reactions may lead to an underestimation of the dissolved fraction, and modifications of environmental conditions (e.g. at confluences, dams …) may induce a change in solid/liquid partition. Considering this background, this study aims to assess whether models incorporating one or more kinetics to describe this fractionation allow more accurate estimations than the equilibrium approach. A large dataset has been obtained experimentally to compare and test fractionation models. The exchanges of four radionuclides (137Cs, 60Co, 54Mn, and 110mAg) between solution and riverine suspended particulate matter (from the Rhone River, France) were followed in laboratory. Adsorption kinetics were monitored starting from 30min up to 2 months. They stabilized only after several days and up to 2 weeks. Dilutions of the contaminated suspension were carried out after 1h, 3 days, 10, 21 and 31 days of prior adsorption, to simulate a change in environmental conditions, such as the input of uncontaminated water from a tributary. The dilution induced a quick release from solid to liquid at first, followed by a non-expected re-adsorption for all four radionuclides. 31-days sorption data were used to fit the parameters of a Kd model and derived models involving one (EK) or two fractionation kinetics (KK). Predictions were then carried out to evaluate the model capacities to react to a dilution of the contamination. Unlike the Kd model, which is a constant, the kinetic models predicted a variation in the solid/liquid activity ratio over time and when environmental conditions changed. However, models developed on one-step sorption showed limitations to reproduce the adsorption kinetics observed after a dilution, especially when a previous steady-state was reached.

Sorbents Based on Polyacrylonitrile Fiber for Complex Recovery of Artificial 137Cs and Natural Radionuclides from Natural Media

Sorbents Based on Polyacrylonitrile Fiber for Complex Recovery of Artificial 137Cs and Natural Radionuclides from Natural Media

New data on potential mobility of artificial radionuclides in bottom sediments of the Yenisei River

The present study shows that after the shutdown of the nuclear reactor at the Mining-and-Chemical Combine (MCC) of Rosatom in 2010, artificial radionuclides (60Co, 137Cs, 152Eu, and 241Am) are still detected in the bottom sediments (BS) of the Yenisei River in the MCC affected area. The paper, for the first time, reports results of the study comparing potential mobility of artificial radionuclides in the surface and lower layers of the Yenisei BS long after the shutdown of the MCC nuclear reactor. The mobility of radionuclides was estimated using the well-known procedure of sequential extraction of BS. A new finding is that potential mobility of 60Co is higher in the lower (older) BS layers compared with the upper ones. Radionuclide 137Cs is strongly bound with mineral solids of BS (approaching 100%) regardless of the time factor. The new data showing that 241Am and 152Eu retain their high potential mobility in the BS over long periods and that 60Co potential mobility increases over time suggest potential bioavailability of these radionuclides in the Yenisei River ecosystem.

High efficiency removal of Cs+ by Fe-Co framework PBAs from radioactive wastewater

The widespread application of nuclear energy has increased the risk of contamination by radionuclide 137Cs. Prussian blue analogues are considered to be excellent materials for the removal of 137Cs from wastewater due to their unique structure. In this work, Cs+ adsorbent for PBAs with Fe-Co framework, potassium iron hexacyanocobaltate (PBAFe), was synthesized by room temperature precipitation method. Systematic structural characterization and performance results of PBAFe showed that it has a specific surface area of 452.8 m2/g and an average pore size of 8.6nm, providing more active sites for Cs+. The adsorption of Cs+ on PBAFe exhibited fast reaction kinetics (within 10min) and high adsorption capacity (82.90mg/g), and the removal rate of Cs+ reached 98.57%. The efficient removal of Cs+ by PBAFe in various real water environments showed its excellent selectivity and potential for practical application. In addition, adsorption mechanism studies showed that the adsorption of Cs+ was achieved by ion exchange with K+ in the PBAFe lattice. PBAFe has the advantages of simple synthesis and good selectivity, and has potential application in the harmless treatment of Cs+ in radioactive wastewater.

METHODOLOGY OF RECONSTRUCTION OF INTERNAL DOSES FROM 137Cs AND 134Cs OF RESIDENTS OF RADIOACTIVELY CONTAMINATED SETTLEMENTS IN UKRAINE NOT COVERED BY WBC MONITORING.

Scientific justification of the methodology for calculating radiation internal doses from 137Cs and 134Cs intake for residents of Ukrainian settlements radioactively contaminated as a result of the Chornobyl (Chernobyl) accident in which measurements of incorporated radiocesium isotopes in humans using whole-body counters (WBC) were not carried out. The paper presents a new methodology for reconstructing doses due to internal irradiation from Chornobyl fallout for both surface (in 1986) and root (in 1987-2023) contamination of vegetation with 137Cs and 134Cs and their transfer into the human body. The methodology for calculating the dose due to surface contamination of vegetation was based on the theoretical model of the transfer of radiocesium isotopes through the food chain with further adjustment of this model to the results of WBC measurements carried out between 15 July and 31 December 1986. For root intake, an ecological dosimetric model is used with the parameters determined by the types, quality and completeness of cow's milk and WBC monitoring carried out in radioactively contaminated territories in 1987-2013. In the absence of WBC measurements, the doses were estimated considering the properties and specifics of radioactive contamination of environmental objects in each region: soil type, levels of soil and milk contamination, and milk equivalent. A new methodology for reconstruction of internal doses from radionuclides 137Cs and 134Cs to residents of the territories of Ukraine radioactively contaminated due to the Chernobyl disaster is substantiated. The methodology is based on the analysis of all data obtained as the result of radioecological and dosimetric monitoring carried out in Ukraine after the accident. According to the methodology developed in the work, the calculation of annual internal doses to residents of settlements that were not covered by WBC monitoring is based on the measurements of the 137Cs activity in the milk of private farms, which were carried out in these settlements. In the absence of such measurements, a linear regression model which connect the incorporated in human body 137Cs with four groups of soils in the vicinity of the settlement is used for doses calculation. The doses calculated according to the new methodology agree with the dosesderived directly from the results of WBC measurements.

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.

Dust resuspension rates in Kuwait: insights from 7Be and 137Cs radionuclides.

Dust resuspension rates in four different landscapes in Kuwait were estimated over a 2-year period using 7Be and 137Cs radionuclides. The average rates of resuspension of particles labeled with 7Be (2 × 10-3 ± 3.9 × 10-4 s-1) were much higher than those of particles labeled with 137Cs (1.6 × 10-6 ± 2.15 × 10-7 s-1), which indicates increased short-term fluctuations in recently deposited dust. Conversely, the resuspension rates for particles labeled with 137Cs were considerably lower, which better reflects long-term variations in dust resuspension. This evaluation approach may provide a foundation for future studies assessing the impact of suspended dust particulates on the performance of solar power systems, in conjunction with other influencing factors like vertical mass flux.

Phytohormonal balance and differential gene expression in chronically irradiated Scots pine populations from the chernobyl affected zone.

The impact of chronic radiation exposure on phytohormone content and expression of phytohormone- and stress-related genes of Scots pine in the zone affected by the Chernobyl accident was studied. Needle samples were collected from three plots with contrasting levels of radioactive contamination in the Polesye State Radiation-Ecological Reserve, Republic of Belarus, and two reference plots in the Kozeluzhsky forest in June 2022. The experimental plots were located within the artificial plantations of Scots pine established in 1982, before the accident in 1986. The activity of radionuclides 137Cs, 90Sr, 241Am, 238Pu, and 239+240Pu in soil and needles ensured dose rates ranging from 3.3 to 87 mGy × year-1, while at the reference plots, the range was 0.7‒0.8 mGy × year-1. Concentrations of plant hormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), zeatin, and abscisic acid (ABA) in needles were evaluated using high-performance liquid chromatography (HPLC). We demonstrate that chronic radiation exposure is a significant stress factor that affects both phytohormonal balance and the expression of some important phytohormone- and stress-related genes. We found a tendency toward decreased ABA and auxin concentrations in trees from plots contaminated with radionuclides. The ratio (IAA + IBA + zeatin)/ABA was drastically raised at the most contaminated plots Masany and Kulazhin, reflecting the functional rearrangements of cellular metabolism that ensure plant adaptation under chronic radiation exposure. Changes in gene expression indicated modulation of ABA and Ca2+ signalling pathways, decreased potential of zeatin biosynthesis, and activation of heat shock proteins biosynthesis.

Radionuclides determination by alpha (210Po, 228,230,232Th) and gamma (226,228Ra, 137Cs, 40K) spectrometry in children's food in Croatia with assessment of cumulative ingestion dose for infants

This work presents comprehensive results of alpha (210Po, 228,230,232Th) and gamma (40K, 226,228Ra, 137Cs) radioactivity measurements in selected food typically consumed by infants (< 1 year) in Croatia. The samples of readily available infant’s food on Croatian market were categorized according to the growth of an infant, from their first nourishment: adapted powdered milk, to their first solid food. The aim was to estimate ingestion doses and the potential radiological risks for infants. In addition to anthropogenic radionuclides, the study focused on naturally occurring radionuclides often underrepresented in similar researches. 40K prevails in activity concentrations in all types of samples. 210Po was determined in all sample types reaching up to 502 mBq/kg. Maximum values of activity concentrations for 228Ra, 226Ra and Th isotopes were 230 mBq/kg, 1.29 Bq/kg and 52 mBq/kg, respectively. The most important contributors to the annual effective dose were 40K, 226Ra, 210Po and 228Ra contributing with 29 % 28 %, 24 % and 17 %, respectively. Th isotopes contributed with less than 2 %, while the contribution of anthropogenic radionuclides 137Cs and 90Sr were negligible (less than 1 %). Cumulative effective ingestion dose for infants was calculated to be 0.69 mSv/y, which is below the recommended limiting dose of 1 mSv/y. Largest proportion comes from the intake of fruit (33 %), followed by the intake of vegetables 19 %) and cereals 19 %). Although national radioactivity monitoring programs usually focus on anthropogenic radionuclides, this study highlights that naturally occurring radionuclides are dominant contributors to the cumulative effective ingestion dose in infants. Overall, the estimated cumulative effective ingestion dose for infants from consuming food available in Croatia is below recommended dose limits and therefore does not present a radiological concern.

The study of radionuclide activities in the sediments of deep areas of Skagerrak and Southern Baltic

This study investigates the activities of radionuclides (137Cs, 210Pb, 214Pb, 239,240Pu, and 40K), carbon isotopes (δ13C and 14C), and grain size compositions in surface bottom sediments across the southern Baltic and Skagerrak Strait. Our findings reveal significant connections between these parameters and their dependence on sediment transport dynamics. The distribution patterns of natural and artificial radionuclides were studied to understand the factors influencing their transport to the deep areas. The results show that 137Cs activity in surface bottom sediments (0–5 cm) ranges from 8 to 11 Bq/kg in the Skagerrak area and reaches 220 Bq/kg in the southern Baltic, closer to the vicinity of river discharges. The activity ranges of 239,240Pu are similar between the study areas, but the mean value at the Skagerrak site is higher at 1.6 Bq/kg. The transport of 210Pbex to the bottom is mainly dependent on the number of fine particles (0–20 μm) in the water column, while the transport of 137Cs primarily driven by scavenging by marine organics from the water column. In the southern Baltic, a strong correlation indicates that a significant share of 137Cs most likely originates from fluvial input. The particle size distribution reflects calm conditions in the deep waters, while in the Curonian Lagoon reference areas there are pronounced contrasts between stations with strong and calm hydrodynamic conditions. The δ13C values in the surface bottom sediments decrease towards river discharge areas, reflecting an increased terrestrial component of the organic fraction, and the number of coarse particles also increases.

The Impact of Different Light-Reflecting Materials Compositions of (LaBr&lt;sub&gt;3&lt;/sub&gt;:Ce) Scintillation Detector on Spent Nuclear Fuel Gamma Spectrum

The Scintillation detectors are extensively employed in nuclear safeguards, nuclear security fields, radioactive material testing, and physics research. Light-reflecting materials of (LaBr3:Ce) scintillation detectors positively affect their ability to capture light. Our goal is to investigate the characteristics of various reflectors by MCNPX code. In this paper, high-activity fission products from the spent fuel, identified as the utilized radionuclides 152Eu, 154Eu, 134Cs, 137Cs, and 243Cm, have been used in the simulation. Also, short-lived fission products, and short-lived actinides (239U and 239Np), which have decay heat in the timeframe of severe accident analysis, have been included. The findings of this investigation are consistent with the discovery that LaBr3:Ce delivers superior resolution. Additionally, some closely spaced peaks in the spectra of numerous radioisotopes could be resolved by the LaBr3:Ce detector. With different energy lines, the spectral responses of the scintillators' various reflectors were evaluated.

Application of fallout radionuclide—137Cs for estimating soil erosion in steep hillslopes with diverse land use of North-western Indian Himalayas

Hilly and mountainous regions are significantly impacted by soil erosion, primarily due to rainfall-runoff processes occurring on the hillslope scale. Assessing soil erosion is crucial for quantifying the loss of soil carbon and nutrients, which diminishes the potential of soil ecosystem services and is critical for mitigating the impacts of climate change on food security. However, the Himalayan landscape poses serious challenges for assessing soil erosion due to its steep and rugged terrain, which hinders the use of conventional and modelling methods. The fallout radionuclide—137Cs has been extensively utilized as an environmental marker for investigating soil redistribution processes. Despite its potential, there is a notable lack of 137Cs-based soil erosion studies in the Himalayan region. In this context, we assessed the applicability of the fallout radionuclide—137Cs method in quantifying soil erosion rates and identifying erosion hotspots on two hillslopes of the Higher Himalayas. On the hillslope scale, we observed that soil erosion rates vary based on slope gradient and land use/land cover. Forested areas exhibited the lowest soil erosion rates compared to cultivated areas, while flat hillslope positions experienced lower erosion rates than steeper positions. The average net erosion rate for the Harsil hillslope varied among different hillslope positions, ranging from – 2.9 to – 15.6 t ha−1 yr−1. Similarly, in the Gangnani hillslope, the net erosion rates varied across different positions, ranging from – 5.6 to – 39 t ha−1 yr−1. Our findings confirm that the middle and lower hillslope positions are the most critical source areas with higher soil erosion rates, while hillslope positions with forest cover demonstrate the lowest erosion rates, identified as helpful in controlling soil erosion. The study has demonstrated the applicability of FRN as a soil erosion measurement method in the complex, rugged, and steep terrain of the Himalayas, highlighting the need for targeted conservation efforts to mitigate soil erosion and preserve ecosystem integrity.

Does it run in the family? - Improving radiological risk assessment in the coastal environment using taxonomic and phylogenetic perspectives in macroalgae species

Marine macroalgae are widely used indicator species for monitoring environmental radioactivity. Empirical studies have demonstrated a range in radionuclide transfer coefficients, or concentration ratios (CRs), between taxonomic groups, however the CR values used for dose estimation assume that macroalgae are a homogenous group, represented by a single CR. This study demonstrates the presence of a taxonomic signal in macroalgae CRs for multiple anthropogenic and naturally occurring radionuclides (137Cs, 241Am, 239+240Pu, 210Po) based on a collation of available data. A Residual Maximum Likelihood (REML) mixed model was applied, producing relative estimate CRs specific to each species within the datasets. The collated data was also analysed for a phylogenetic signal, but only a weak signal was found for one radionuclide in one group (239+240Pu in Phaeophyceae). A theoretical case study using the estimated CRs and the ERICA tool was carried out to demonstrate the implications of these findings in a real-world scenario.

Review and statistical analysis of activity values reported for coastal sands worldwide

The activity of natural radionuclides is unevenly distributed across the Earth's crust, with certain areas exhibiting significantly higher levels than others, known as High Background Radiation Areas (HBRAs). This study presents a statistical analysis of reported activity values for coastal sands globally. Through this statistical analysis, costal sands were classified into four categories based on their activity levels, providing a standardized framework to compare the natural radioactivity of these sands. This classification is a valuable tool for identifying populations exposed to different radiation levels, which is essential for the study of stochastic effects. The study proposes thresholds to define HBRAs as regions with activity values exceeding 203 Bq/kg for 238U, 517 Bq/kg for 232Th, or 960 Bq/kg for 40K. Regions with lower values are classified as NonHBRAs. Further subdivision of these categories resulted in four distinct regions: NonHBRA−, NonHBRA+, HBRA−, and HBRA+. The activity values for these subdivisions are 92 Bq/kg and 2,903 Bq/kg for 238U, 94 Bq/kg and 7,230 Bq/kg for 232Th, and 901 Bq/kg and 2,298 Bq/kg for 40K. By calculating the external dose rates from the reported activity data, a threshold of 357 nGy/h was identified as the dose boundary separating NonHBRAs from HBRAs. The values for the subdivisions resulted 101 nGy/h and 3,867 nGy/h. The study also explores the content of these natural radionuclides in relation to their bearing minerals and discusses correlations between the reported activity values and the characteristics of the sands. Additionally, the activity of the anthropogenic radionuclide 137Cs (reported values ranging from the detection limit to 63 Bq/kg) is examined.

Spark plasma sintering of cenosphere-derived Cs/Sr-aluminosilicates for 137Cs and 90Sr immobilization in mineral-like ceramics

In this study, a promising method of spark plasma sintering (SPS) was investigated for the fabrication of ceramic matrices designed for the reliable immobilization of highly radioactive radionuclides 137Cs and 90Sr. The ceramic matrices were derived from a mixed composition of two aluminosilicate mineral-like phases – pollucite (Cs,Na)AlSi2O6 and gehlenite Sr2Al2SiO7. The originality of the developed approach lies in the utilization of hydrothermal synthesis for obtaining granulated precursor material. Hollow aluminosilicate microspheres (cenospheres) from coal fly ash served as the initial raw material, which were treated with alkaline solutions containing Cs+ and Sr2+ ions as simulants for the corresponding radionuclides. This method facilitated the achievement of high efficiency in cation removal from solutions exceeding 98 %. For a comprehensive examination of the composition and morphology of cenosphere-derived precursor particles, and the influence of sintering temperature on phase and structure formation of ceramic matrices under non-equilibrium conditions of spark plasma heating, various analytical techniques were employed. These included thermogravimetry/differential thermal analysis (TG/DTA), powdered X-ray diffraction analysis (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), as well as the method of low-temperature nitrogen adsorption for determining the specific surface area. The obtained ceramic samples exhibited high values of specific density (2.688–2.915 g/cm³), compressive strength (666–808 MPa), and Vickers microhardness (1.8–2.5 GPa), attesting to their high quality and stability. The results of the hydrolytic stability assessment revealed that the leaching rates of Cs+ and Sr2+ ions from the ceramics are extremely low, within the range of 10−5–10−6 g/cm²·day. These values fully satisfy the requirements of GOST R 50926–96 and the international standard ISO 6961:1982 for solidified forms of high-level waste.

Glacier mice as a temporary sink for fallout radionuclides and heavy metals on the Norwegian glacier Austerdalsbreen

Glacier mice are peculiar rolling or stationary moss balls found on the surface of some glaciers. They may harbour an ecological habitat for cold-adapted invertebrates and microorganisms, but little is known about their potential to accumulate and disseminate harmful elements and substances. In this study, we investigate the presence of fallout radionuclides (137Cs, 238Pu, 239Pu, 240Pu, 210Pb) and heavy metals (Pb, As, Hg, Cd) in glacier mice and compare the results to bryophytes from adjacent glacier ecosystems. Samples were collected at Austerdalsbreen, a Norwegian outlet glacier from Jostedalsbreen ice cap.Maximum activity concentrations for bryophytes are 552 ± 12 Bq kg−1 for 137Cs, 3485 ± 138 Bq kg−1 for 210Pb, 0.0223 ± 0.065 Bq kg−1 for 238Pu and 4.34 ± 0.43 Bq kg−1 for 239+240Pu while maximum heavy metals concentrations are 70.5 mg kg−1 for Pb, 1.0 mg kg−1 for As, 1.6 mg kg−1 for Hg and 0.13 mg kg−1 for Cd. Maximum activity concentrations in cryconite are 1973.4 ± 5.0 Bq kg−1 for 137Cs, 3632 ± 593 Bq kg−1 for 210Pb, 0.51 ± 0.11 Bq kg−1 for 238Pu and 13.1 ± 1.4 Bq kg−1 for 239+240Pu and maximum heavy metal concentrations are 50.4 mg kg−1 for Pb, 3.4 mg kg−1 for As, 1.5 mg kg−1 for Hg and 0.082 mg kg−1 for Cd. We find that glacier mice show lower activity concentrations of radionuclides compared to cryoconite. The major source of plutonium isotopes is related to global fallout, whereas detected radio-cesium may be additionally affected by post-Chernobyl fallout to an unknown extent. Comparison between glacier surface and adjacent glacial habitats shows higher concentrations of heavy metals in glacier mice on the glacier ice surface and medial moraines compared to bryophytes in the glacier forefield. Glacier mice exported from a receding glacier may affect the cycling of radioactive and metal pollutants in developing proglacial ecosystems.

Influence of Na-Al phosphate glass leachates in clays sorption behavior toward radionuclides

The article presents the results of the study of the sorption of 90Sr, 137Cs, 233U, 237Np, 239Pu,and 241Am radionuclides from model groundwater, model leachate of aluminophosphate glass and Na2HPO4 solutions of different concentrations on bentonite clays of Kamalinskoye (Krasnoyarsk Territory), Desyaty Khutor (Republic of Khakassia), and Dinozavrovoye (Republic of Kazakhstan) deposits. We determined that the presence of aluminophosphate glass leachate in the liquid phase reduced the sorption activity of the studied clays towards caesium. The distribution coefficients of strontium depend more on the clay properties than on the liquid phase composition. However, with increasing concentration of phosphate ion, we observed an increase in the strength of sorbed strontium retention by clay. The sorption of uranium, neptunium, plutonium and americium, increased in the presence of components leached from the aluminophosphate glass-like matrix, and the strength of their fixation by clay increased.

Evaluating the impact of soil erosion on soil quality in an agricultural land, northeastern China

The impact of soil erosion on soil quality is still not systematically understood. The purpose of this study was thus to quantify the impact of soil erosion on soil quality and its change with slope morphology in an agricultural field, northeastern China based on radionuclide 137Cs, unmanned aerial vehicle derived high resolution digital elevation model, and soil sampling. 137Cs method yielded an average soil erosion rate of − 275 t km−2 yr−1 ranging from − 1870 to 1557 t km−2 yr−1. The soil quality index derived from total dataset (SQI_TDS) can be well explained by that derived from minimum data set (SQI_MDS) with a determination coefficient R2 of 0.874. SOM, sand, and cation exchange capacity in the MDS play more important roles than other soil indicators. Soil quality was significantly affected by soil erosion, with Adj. R2 of 0.29 and 0.33 for SQI_TDS and SQI_MDS, respectively. The spatial variations of soil erosion and soil quality were both affected by slope topography. Soil erosion must be controlled according to topographic and erosion characteristics in northeastern China.

Immobilization of 137Cs in NaY type zeolite matrices using various heat treatment methods

The accumulation of liquid radioactive waste presents a significant global challenge, necessitating effective strategies for safe management. This study investigates the immobilization of 137Cs radionuclides, a prominent component of liquid radioactive waste, in ceramic matrices based on 137Cs-saturated NaY Faujasite zeolite. Various thermal methods were employed, including cold pressing and sintering, cold pressing and sintering with microwave assistance, hot pressing, and spark plasma sintering, to enhance immobilization capabilities. Zeolite powder was saturated with 137Cs radionuclides using an adsorption technique with low-activity model liquid radioactive waste. In-situ XRD and dilatometry methods were used to study the thermal behavior during NaY Faujasite annealing. The influence of calcination temperature on lattice parameters and crystallite size was assessed. Immobilization effectiveness was evaluated through relative density, Vickers microhardness, compressive strength, and metal ion leaching kinetics. Mechanistic evaluation was performed using XRD and SEM-EDX studies. Results showed that spark plasma sintering exhibited the highest efficiency for immobilizing 137Cs radionuclides in NaY Faujasite matrices. This research contributes to liquid radioactive waste management by providing insights into the thermal behavior and enhanced immobilization capabilities of ceramic matrices.

Results of modern radiation-hygienic surveys of settlements of Bryansk Oblast of the Russian Federation bordering the Republic of Belarus. Part 3: Radionuclide content in agricultural food products

The third article in a series of publications devoted to the results of studying the current radiation situation in the territories of the Bryansk region bordering the Republic of Belarus presents results of studies of the content of radionuclides (137Cs and 90Sr) in samples of agricultural food products produced in the personal subsidiary plots of the population. The regularities of changing 137Cs and 90Sr content in samples of cow’s milk and potatoes depending on the level of radioactive contamination of the territory were studied; the present values of the quantities characterizing the distribution of the ratio of the activity concentration of radionuclides in agricultural food products to the density of radioactive contamination of the soil of the territory were deter -mined. The ratios of average values of 137Cs activity concentration in milk from stalled and grazing periods for cattle were analyzed. The results of the study show that some dairy product samples (less than 1%) do not meet the radiological safety criterion. Exceedances of the hygienic standards were not found in the studied samples of potatoes, vegetables, and meat of farm animals.