Uranium Research Articles

Enhancing Commercially Iron Powder Electron Transport by Surface Biosulfuration to Achieve Uranium Extraction from Uranium Ore Wastewater.

The zero-valent iron (ZVI) has attracted increasing attention due to the enhanced reactivity of ZVI to uranium wastewater. However, ZVI practical application is hampered due to its susceptibility to oxidation and the formation of passivation layers during storage and in situ restoration. To address these issues, we used a biosulfuration approach to modify ZVI for application in uranium ore wastewater treatment. A series of physicochemical characterization tools and photoelectronic analyses showed that BS-ZVI considerably increased carrier separation efficiency and visible light absorption capacity, resulting in a significant photoassisted enhancement effect on uranium extraction. Accordingly, the uranium removal efficiency of BS-ZVI reached 91% within 60 min, and its maximum adsorption capacity was 336.3 mg/g. By analyzing the mechanism, the improved U(VI) removal performance was mostly responsible on the dissolution of the passivation layer on the surface of ZVI, the generation of Fe(II) and FeS, and the important role of Shewanella putrefaciens extracellular polymers (EPS). Overall, the BS-ZVI biohybrid merges with the high activity of ZVI, bio-FeS, and self-regeneration ability of bacteria, expanding a promising new approach for sustainable treatment of uranium mine wastewater.

Effect of di-butyl phosphate on the distribution behavior of uranyl ions in PUREX solvent

ABSTRACT Di-butyl phosphoric acid (HDBP) is one of the major hydrolytic and radiolytic degradation product of tri-n-butyl phosphate (TBP) employed for the extraction of U(VI) and Pu (IV) from the spent nuclear fuel dissolver solution. The presence of HDBP in the solvent phase limits the recovery of actinides during stripping. In view of this, the extraction and stripping behavior of uranyl nitrate in 1.1 M TBP in n-dodecane (n-DD) was studied in presence of di-butyl phosphate (HDBP). The distribution ratio (D) of uranium (VI) in HDBP/n-DD was negligible and the D value increased gradually with an increase in HDBP content in the organic phase. An alternate method was developed for estimation of HDBP in TBP/n-DD system based on uranium metal retention in organic phase. Based on the results it was found that 1 M HDBP in 1.1 M TBP/n-DD retained about 0.63 M of uranium (VI) in the organic phase during stripping. The results were further validated using irradiated solvent. FT-IR spectroscopic investigation also revealed the retention of U(VI) in 1.1 M TBP/n-DD containing HDBP even after several stripping with 0.01 M HNO3.

Quantitative Measurement of Uranium in Ore Using Fiber‑Optic Laser‑Induced Breakdown Spectroscopy and Multivariate Calibration

Quantitative Measurement of Uranium in Ore Using Fiber‑Optic Laser‑Induced Breakdown Spectroscopy and Multivariate Calibration

Research of hydrodynamic processes in in-situ leaching of uranium

Hydrodynamic processes in the selective transfer of uranium underground to solution were theoretically considered. The effect of the initial filtration gradient on the flow process of underground water flow of weakly permeable and poorly saturated uranium ores by the method of selective transfer of uranium to solution was studied. The hydrodynamic parameters of subsurface selective dissolution of uranium ores with low water saturation were analyzed. The consumption equations and drawings of the injection and production wells by the method of selective transfer of uranium to the solution were developed. Using the consumption equations of the injection and production wells, a calculation program was created in the C++ programming language and the analysis of the obtained results was studied.

Unearthing the Chicago Piles: A Monte Carlo perspective

The divergence of the Chicago Pile 1 (CP-1) on December 2nd, 1942, marks the birth of the nuclear age. Built under the West Stands of the Stagg Field in Chicago in slightly over two weeks, CP-1 was the first man-made nuclear reactor, conceived as a proof-of-principle physics experiment to demonstrate the feasibility of a self-sustained neutron chain reaction. The fuel consisted in a mixture of uranium oxide and metal uranium, with lumps of several sizes and shapes stacked within bricks of graphite used as moderator to form a cubic lattice. After only three months of operation, CP-1 was dismantled due to safety reasons and rebuilt at the Argonne Site in twenty-one days, under the name of Chicago Pile 2 (CP-2): the new pile had a longer life, contributing vastly to research on material science and nuclear reactor theory, and was finally decommissioned in 1954. Prompted by the eightieth anniversary of the Chicago Pile(s), in this talk we celebrate these astonishing scientific artifacts by building fully detailed three-dimensional digital twins of CP-1 and CP-2 using TRIPOLI-4®, the Monte Carlo code developed at CEA. Technological data for the models have been retrieved from published and unpublished documents of the Manhattan Project. We compare the simulation results to the available experimental measurements, encompassing the reactivity of the piles, the control rod worth, the kinetics parameters and several reactivity coefficients. For each, we examine the associated uncertainties due to missing or incomplete technological data as well as the bias due to nuclear data libraries.

Association of heavy metals exposure with lower blood pressure in the population aged 8-17 years: a cross-sectional study based on NHANES.

The existing evidence regarding the joint effect of heavy metals on blood pressure (BP) in children and adolescents is insufficient. Furthermore, the impact of factors such as body weight, fish consumption, and age on their association remains unclear. The study utilized original data from the National Health and Nutrition Examination Survey, encompassing 2,224 children and adolescents with complete information on 12 urinary metals (barium, cadmium, cobalt, cesium, molybdenum, lead, antimony, thallium, tungsten, uranium, mercury and arsenic), BP, and core covariates. Various statistical methods, including weighted multiple logistic regression, linear regression, and Weighted Quantile Sum regression (WQS), were employed to evaluate the impact of mixed metal exposure on BP. Sensitivity analysis was conducted to confirm the primary analytical findings. The findings revealed that children and adolescents with low-level exposure to lead (0.40 μg/L, 95%CI: 0.37, 0.42), mercury (0.38 μg/L, 95%CI: 0.35, 0.42) and molybdenum (73.66 μg/L, 95%CI: 70.65, 76.66) exhibited reduced systolic blood pressure (SBP) and diastolic blood pressure (DBP). Conversely, barium (2.39 μg/L, 95%CI: 2.25, 2.54) showed a positive association with increased SBP. A 25th percentile increase in the WQS index is significantly associated with a decrease in SBP of 0.67 mmHg (95%CI, -1.24, -0.10) and a decrease in DBP of 0.59 mmHg (95% CI, -1.06, -0.12), which remains statistically significant even after adjusting for weight. Furthermore, among individuals who consume fish, heavy metals have a more significant influence on SBP. A 25 percentile increase in the WQS index is significantly associated with a decrease of 3.30 mmHg (95% CI, -4.73, -1.87) in SBP, primarily attributed to mercury (27.61%), cadmium (27.49%), cesium (17.98%), thallium (8.49%). The study also identified a declining trend in SBP among children aged 10-17, whereas children aged 11-18 exhibited lower levels of systolic and diastolic blood pressure, along with a reduced risk of hypertension. Some heavy metals demonstrate an inverse association with the BP of children and adolescents, particularly notable in groups with fish consumption and older children and adolescents. Future studies are warranted to validate these findings and delve deeper into the interplay of heavy metals.

DRGD-linked charged EKKE dimeric dodecapeptide: pH-based amyloid nanostructures and their application in lead and uranium binding.

Peptides have been reported to undergo self-assembly into diverse nanostructures, influenced by several parameters, including their amino acid sequence, pH, charge, solvent, and temperature. Inspired by natural systems, researchers have developed biomimetic peptides capable of self-assembling into supramolecular functional structures. The present study explored a newly designed peptide sequence, EKKEDRGDEKKE, where E = glutamic acid, K = lysine, D = aspartic acid, G = glycine, and R = arginine, with a metal binding DRGD sequence incorporated between the exclusively charged EKKE peptide. We investigated the formation and the potential of the EKKEDRGDEKKE peptide in retaining the structure and morphology adopted by the individual EKKE peptide. According to a combination of experimental techniques such as thioflavin T fluorescence, field emission-scanning electron microscopy, atomic force microscopy, and circular dichroism, it was evident that the EKKEDRGDEKKE peptide displayed a pH-dependent propensity to adopt amyloid-like structures. Furthermore, the self-assembled entities formed under acidic, basic, and neutral conditions exhibited morphological variations, which resembled that observed for the exclusively charged EKKE peptide. Furthermore, the incorporation of the functional DRGD motif resulted in promising binding to two toxic metal ions, lead (Pb) and uranium (U), as evidenced by a range of spectroscopic techniques, including UV-visible spectroscopy, atomic absorption spectroscopy, fluorescence spectroscopy, and X-ray photoelectron spectroscopy. The use of the amyloid-forming EKKEDRGDEKKE scaffold can also be extended to potential biomedical applications.

Simulation analysis of enhanced fluidization leaching process and geothermal synergy in deep ground metal mines

Based on the mining of deep metal mineral resources and the current in-situ leaching mining process of uranium ore, combined with the technological characteristics of ?fluidized mining of metal ore? and ?deep geothermal development?, an innovative concept of strengthening the fluidized leaching process of deep metal ore - geothermal co mining is proposed, A numerical simulation method was used to analyze the turbulent flow and heat transfer characteristics of a new type of heat transfer enhancement element - a swirl plate as a support between tubes. The renormalization two equation turbulence model was used for numerical simulation, and the SIMPLEC algorithm was used for pressure and velocity coupling, and the enhanced wall treatment method was used for wall treatment. The periodic changes in the cross-sectional flow field and turbulence intensity of the unit flow channel were analyzed, as well as the synergistic relationship between the flow field and temperature field on the cross-section. The corresponding variation trends of the average Nusselt number and the average synergy angle of the cross-section were compared. The experimental results show that the 270-4.25 cyclone sheet can more fully utilize the enhanced heat transfer of the spin flow, and the overall average Nusselt number is higher than 180-2.0, which is consistent with the experimental results. That is, ?m is low where high Nub and ?m is high where low Nub is low, indicating that the changing trend of the two is fully consistent with the field synergy principle. This paper systematically analyzes the basic theoretical bottleneck, key technical problems and future development trend in the process of geothermal joint mining of deep metal mine, and aims to provide reference for the strengthening of geothermal joint mining and geothermal joint mining of deep metal ore.

Precise and accurate isotopic analysis of uranium and thorium in uranium ore concentrates using ICP-MS and their age dating for nuclear forensic analysis

Precise and accurate analysis of 235U/238U, 234U/238U, 230Th/234U and 230Th/232Th in 15 uranium ore concentrates (UOCs) was achieved using ICP-MS for nuclear forensic applications. A novel method was developed to dating UOCs.

Improving uranium oxide pathway discernment and generalizability using contrastive self-supervised learning

In the field of Nuclear Forensics, there exists a plethora of different tools to aid investigators when performing analysis of unknown nuclear materials. Many of these tools offer visual representations of the uranium ore concentrate (UOC) materials that include complimentary and contrasting information. In this paper, we present a novel technique drawing from state-of-the-art machine learning methods that allows information from scanning electron microscopy images (SEM) to be combined to create digital encodings of the material that can be used to determine the material’s processing route. Our technique can classify UOC processing routes with greater than 96% accuracy in a fraction of a second and can be adapted to unseen samples at similarly high accuracy. The technique’s high accuracy and speed allow forensic investigators to quickly get preliminary results, while generalization allows the model to be adapted to new materials or processing routes quickly without the need for complete retraining of the model.

Compacting the core of a commercial high-power lead-cooled fast reactor

Two options for the layout of a fast reactor with lead coolant are being considered. The design of the fuel assemblies and core fuel rods is identical to the BREST-OD-300 reactor. One of the layouts is traditional with a flattened core. The other layout is the most compact. It has an elongated core and is characterized by an optimal ratio of core diameter to height in terms of minimal neutron leakage. The electric capacity of the first of them is about 2.9 GW, the second - 13.3 GW. The second layout is a high-temperature reactor. When operating at rated power, the maximum coolant temperature reaches 1631 K. The use of cermets fuel based on UN-PuN mononitride micrograins and uranium metal nanopowder, coolant based on lead thorium ores and tungsten fuel rod coatings made it possible to ensure the safety of reactors in emergency modes such as "anticipated transients without scram". A distinctive feature of the layouts is to reduce the danger of emergency modes when they are applied simultaneously. In all emergency modes, large reserves are maintained up to the maximum permissible temperatures of fuel, coolant and structural materials.

Extension of the D3 and D4 London dispersion corrections to the full actinides series.

Efficient dispersion corrections are an indispensable component of modern density functional theory, semi-empirical quantum mechanical, and even force field methods. In this work, we extend the well established D3 and D4 London dispersion corrections to the full actinides series, francium, and radium. To keep consistency with the existing versions, the original parameterization strategy of the D4 model was only slightly modified. This includes improved reference Hirshfeld atomic partial charges at the ωB97M-V/ma-def-TZVP level to fit the required electronegativity equilibration charge (EEQ) model. In this context, we developed a new actinide data set called AcQM, which covers the most common molecular actinide compound space. Furthermore, the efficient calculation of dynamic polarizabilities that are needed to construct CAB6 dispersion coefficients was implemented into the ORCA program package. The extended models are assessed for the computation of dissociation curves of actinide atoms and ions, geometry optimizations of crystal structure cutouts, gas-phase structures of small uranium compounds, and an example extracted from a small actinide complex protein assembly. We found that the novel parameterizations perform on par with the computationally more demanding density-dependent VV10 dispersion correction. With the presented extension, the excellent cost-accuracy ratio of the D3 and D4 models can now be utilized in various fields of computational actinide chemistry and, e.g., in efficient composite DFT methods such as r2SCAN-3c. They are implemented in our freely available standalone codes (dftd4, s-dftd3) and the D4 version will be also available in the upcoming ORCA 6.0 program package.

Utilizing fluctuation asymmetry to assess the effects of U-238 radioactivity on the marine ecosystem around the Madras nuclear power plant, India

The monitoring of marine ecosystems is crucial due to the growing threat posed by nuclear power plants and other nuclear anthropogenic emissions. In our work, we used a straightforward and low-cost biomonitoring technique called fluctuation asymmetry (FA) to examine the variation between the left and right sides (developmental instability) of organisms’ traits that were influenced by genetic and environmental variables in the early stages of ontogenesis. The specimens of fish (Leiognathus sp.) and crabs (Portunus sanguinolentus) were collected seasonally and used as bioindicators to determine the effects of Uranium-238 (U-238) radioactivity around a nuclear power plant. The obtained results revealed that FA values were not considered typical values (FA = 0) in all seasons. Moreover, FA values of Leiognathus sp. exhibited insignificant fluctuation for a particular characteristic through the different seasons, while a significant fluctuation occurred amongst the characteristics themselves throughout the same season. Inversely, FA values of the four characteristics in Portunus sanguinolentus displayed seasonal variation amongst them all. Statistically, there was a strong positive correlation (r = 0.5, p < 0.05) between U-238 radioactivity in the flesh of both organisms and the fluctuation asymmetry of different traits but it is not a sign that any radioactive pollution exists.

Geological and geostatistical analysis for equivalent uranium and thorium mineralization, Gattar-V Eastern Desert, Egypt

Purpose. This paper aims to assess the distribution of uranium and thorium ore grade distribution to produce a uranium potential map and estimate of the uranium ore reserves in the Gattar-V area, Eastern Desert, Egypt. Methods. Multidisciplinary approach is applied to determine the equivalent uranium mineralization in the Gattar-V area. It includes geological (petrographical, mineralogical and geochemical) and geostatistical (kriging analysis and variogram models) methods. Findings. Geological studies show that the U-mineralization located along or near the contact between younger granites and Hammamat sediments exhibits episyenitization and bleaching alteration, respectively. Geochemical studies indicate a strong relationship between U-mineralization and Chemical Alteration Index (CIA), alteration features, and associated hydrothermal solution mineralization. The geostatistical method is used to study the behavior and distribution of U and Th in both younger granites and Hammamat sediments. The Total Gamma, eU, and eTh values are used in kriging analysis and variogram models to determine their spatial dependence and perform a spatial interpolation of sparse measurements and deposition level map. Originality. The use of a multidisciplinary method combining petrographical, mineralogical and geochemical investigations with geostatistical analysis allowed for a quantitative evaluation of the spatial location of geological objects such as uranium mineralization in the area. Practical implications. Variogram models and kriging analysis can also be used to assess the lithological composition of rocks and mineralogical phases, and they also provide a clear vision of the elements distributed in the ore, which is very useful during the planning and production stages.

PECULIARITIES OF THE GROUNDWATER CHEMICAL COMPOSITION WITHIN THE SAKSAGANSK-SURSK ORE DISTRICT OF THE DNIPROPETROVSK REGION

The purpose of the research: to study the groundwaters in the Saksagansk-Sursk ore district of the Dnipropetrovsk region, which are used to ensure the economic and drinking needs of the local population. Data and Methods: A wide range of methods of obtaining, processing and interpreting of ecological-hydrogeochemical data, including field, chemical-analytical, comparative and graphical, were used. Mathematical and statistical methods were used in the processing of the obtained data. Visualization of the general chemical composition was performed with the help of specialized software tool GW_Chart. Results. The chemical composition of underground waters was studied, an assessment of their quality and suitability for potable use was made, the range of risks for the health of local residents-consumers of water was outlined, and the rationale for possible reasons for changes in their chemical composition during 42 years of operation (from 1978 to 2020) was provided. During the research, the authors found signs of metamorphosis of the chemical composition of groundwater. On the other hand, in the multi-year section, a general regularity was observed regarding the restoration of the state of the studied waters resources to the natural one, which is probably related to the decrease in the level of man-made load on the water environment over 42 years due to a significant decline in the rate of industrial development of uranium and iron ores within the Dnipropetrovsk region in general and the Saksagansk-Sursk ore district in particular. A preliminary conclusion was obtained that the ecological-hydrogeochemical conditions of the studied groundwater are primarily determined by: insignificant occurrences of water-bearing rocks (up to their emergence to the surface), close hydraulic connection with surface waters and adjacent aquifers, weak protection against surface pollution due to the lack of regionally sustained confining bed in its roof, the chemical composition of water-bearing rocks, as well as the tectonic conditions of the territory. The authors consider it necessary in further research to take into account the structural and geological features of the crystalline foundation of the studied area in connection with the spread of a wide range of metamorphic rocks and their weathering products, as well as the presence of tectonic faults within the first structural floor.

Distribution and migration of uranium, chromium, and accompanying metal(loid)s in soil-plants system around a uranium hydrometallurgical area

The extraction and utilization of uranium (U) ores have led to the release of significant amounts of potentially toxic metal(loid)s (PTMs) into the environment, constituting a grave threat to the ecosystem. However, research on the distribution and migration mechanism of U, chromium (Cr), and their accompanying PTMs in soil-plant system around U hydrometallurgical area remains insufficient and poorly understood. Herein, the distribution, migration, and risk level of PTMs were evaluated in soil and plant samples around U hydrometallurgical area, Northern Guangdong, China. The results demonstrated that the maximum content of U and Cr found in the analyzed soils were up to 84.2 and 238.9 mg/kg, respectively. These values far exceed the soil background values in China and other countries. The highest content of U (53.6 mg/kg) was detected in Colocasia antiquorum Schott, and the highest content of Cr (349.5 mg/kg) was observed in Pteridium aquilinum, both of which were enriched in their roots. The risk assessment of PTMs demonstrated that the study area suffered from severe pollution (PN > 3), especially from U, Cr, Th, and As, suggesting the non-negligible anthropogenic impacts. Hence, in light of the significant ecological hazard posed by the U hydrometallurgical area, it is imperative to implement appropriate restoration measures to ensure the human health and maintain the stability of the ecosystem.

Mediterranean-like “fall dump” events in the Baltic Sea

In the Mediterranean Sea, organic carbon-rich sapropels have been deposited periodically over the last fifteen million years. Some sapropels are characterized by high contents of the mat-forming, planktonic diatom Pseudosolenia calcar-avis and the planktonic diatom Thalassionema nitzschioides as a result of their mass sinking in autumn (the so-called “fall dump”). The present study shows that fall dump events also occurred in the brackish Baltic Sea around 6300–5800 calibrated years before present (cal yr BP; present = AD 1950). In sediments from the northern Baltic Sea these events are evidenced by high contents of a lipid specific for P. calcar-avis (a C25:2 highly branched isoprenoid alkene) and corroborated by fossil remains of both P. calcar-avis and T. nitzschioides. A biomarker index based on long-chain alkyl diol lipids indicates that mat-forming Proboscia diatoms were also present. High contents of calanoid resting eggs further suggest that the copepod population was stressed being unable to feed on such large diatoms. The fall dump events occurred during a complete stratification of the water column and euxinic conditions, as reflected by the redox-sensitive trace metal uranium, allowing upward diffusion of nutrients and the growth of rhizosolenid mat-forming diatoms in a deep chlorophyll maximum. Synchronous remains of P. calcar-avis in the central Baltic Sea further suggest that these events occurred on a basin-wide scale.

Hyphae and organic acids of Aspergillus Niger promote uranium recovery by destroying the ore surface and increasing the porosity and permeability of ores

To elucidate the mechanism of damage caused by hyphae and organic acids produced by Aspergillus Niger on the surface and internal structure of uranium ore, direct uranium leaching, indirect uranium leaching and semi-direct uranium leaching were conducted, and the surface morphology, strength, mineral crystallinity, porosity, and permeability of the ore were analyzed. The results demonstrated that the combination of biomechanical forces exerted by hyphae and the complexation effects of organic acids led to the dissolution of SiO2 and other substances on the surface of ore, resulting in exfoliation from the exterior to the interior, thereby promoting uranium recovery. Furthermore, the proton exchange involving H+ and the complexation of organic acids resulted in the dissolution of cations within the ore, causing destruction to the crystal lattice structure of minerals and increasing the porosity and permeability inside the ore. The dominant factor contributing to ore damage during recovery was organic acids.

Electrolytic Reduction of UO2 Microspheres Synthesized Via Internal Gelation Method

Pyroprocessing is the combination of process steps to extract and recycle actinides from fission products in spent nuclear fuels in high-temperature molten salt media. Pyroprocessing has been studied extensively over the past decades. One of the key sub-processes is the electrolytic reduction of uranium oxides. The electrolytic reduction process originated from the FFC Cambridge process, an approach for electrochemically reducing titanium dioxide into titanium metal in molten CaCl2. In the electrolytic reduction of uranium oxides, the uranium oxide feed is applied as the cathode in LiCl-Li2O molten salt electrolyte at 650°C. LiCl appears more promising than conventional CaCl2 owing to the lower melting point (878 K), and higher decomposition voltage (3.46 V at 923 K). Additionally, Li2O is expected to speed up the reduction via an additional chemical reduction pathway with the participation of Li metal, and prevents the direct dissolution of the Pt anode.This work aims to study the morphology effect of the oxide feed on the reduction kinetics and the incorporation of impurities during the electrolytic reduction process. The electrolytic reduction of UO2 is carried out on sintered UO2 pellets, as well as various UO2 microspheres synthesized via internal gelation. The introduction of uranium oxide microspheres holds several advantages. The spheres provide a higher surface area, which is expected to improve the overall reduction efficiency of uranium oxide during electrolysis. In addition, it is easier to handle the feed during loading and unloading of the cathode basket compared to powder feeds.The potentiostatic and galvanostatic electrolysis of UO2 is performed, and the comparison between the electrolytic reduction of UO2 pellets and microspheres is investigated. The SEM micrographs in figure 1show the morphology change of a UO2 pellet to uranium metals particles. A significant morphology change between the flat surface of the sintered UO2 feed and the reduced U particles is observed at the surface. Further characterization is performed using XRD and TGA to identify the products of the electrolytic reduction process qualitatively and quantitatively. Results show that galvanostatic electrolysis shows a better reduction efficiency compared to potentiostatic electrolysis, applied both below and above the Li formation onset potential. Overall, there is barely un-reacted UO2 visible in the XRD patterns of the reduced feed after galvanostatic electrolysis. U metal and UO are identified in the XRD patterns depending on electrolysis parameters. The presence of UO can be as an intermediate of UO2 reduction during electrolysis, which is a rare compound to be reported in literature. Overall, the reduction of microspheres does improve the overall reduction efficiency compared to the conventional pellet feeds. Figure 1

Therapeutic efficacy of S-adenosylmethionine in chronic uranium intoxication in rats

Introduction. Chronic exposure to uranium compounds causes adverse cytotoxic and immunopathological effects in the body. The aim of the work was to evaluate the therapeutic efficacy of S-adenosylmethionine when administered intragastrically with respect to hepato-, nephro- and immunotoxic effects in chronic intoxicationwith uranyl acetate dihydrate (UAD). Materials and methods. Chronic intoxication was modeled by injecting 85 male rats with UAD solution (5.0 mg/kg/day by element) for one month. S-adenosylmethionine was administered to animals at a dose of 72.7 mg/kg for 21 days. Results. In chronic poisoning with UAD, 65% lethality, decrease of liver mass ratios (MR) and increase of renal MR were observed. Decrease in alkaline phosphatase activity, glucose level, lactic acid, number of CD4+ T-lymphocytes, increase in lactate dehydrogenase activity and creatinine level, number of CD8+ T-lymphocytes and apoptotic cell death, formation of catabolic pool of low and medium molecular weight substances (LMSMS) of blood plasma were registered. The results of urine analysis revealed the development of hyposthenuria, signs of glucosuria, hematosuria, proteinuria and leukocyturia, appearance of bilirubin in the urine. S-adenosylmethionine contributed to the decrease in the degree of target organ damage (reduction of fibroplastic and dystrophic changes in the liver and kidneys), normalization of immune system parameters (increase in CD4+ T-cells, decrease in CD8+ T-cells and frequency of apoptotic death of lymphocytes in immunocompromised animals) and endotoxicosis (decrease in the level of LMSMS from the catabolic pool area). Discussion. According to the totality of all revealed pathological changes, UAD poisoning led to the development of tubulointerstitial nephritis, metabolic disorders of detoxification functions of the liver. The causes of animal death during the first week of the experiment were acute kidney damage or confluent pneumonia. The appearance of bilirubin in the urine was associated with porphyrin metabolism disorders. In the remote period of intoxication an imbalance of the T-cell link of the immune system developed, as well as, probably, a decrease in nonspecific resistance, which led to the development of pneumonia in rats. Conclusion. S-adenosylmethionine therapy of hepato-, nephro- and immunotoxic effects in chronic UAD intoxication contributed to a decrease in the degree of damage to target organs, normalization of immune system parameters and endogenous intoxication.