Scientific peer-reviewed journal "NNC RK Bulletin"
Национальный ядерный центр Республики Казахстан
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MEASUREMENT OF FIRST WALL AND DIVERTOR REGION SURFACE TEMPERATURES IN THE KTM TOKAMAK USING IR THERMOMETRY METHODS
The paper presents the results of the first measurements of the heating temperature of the walls of the vacuum chamber on the KTM tokamak using non-contact methods during plasma discharges. The technical features and placement of the IR diagnostics used in the KTM tokamak are presented. The first experimental results of measuring the heating temperature of the graphite elements of the first wall of the KTM are demonstrated, which showed the operability of the diagnostics under KTM conditions.
CREATION OF SIMULANTS OF LIQUID RADIOACTIVE WASTE OF THE BN-350 REACTOR
This research is devoted to the development of simulants of liquid radioactive waste (LRW), which are necessary for methodical testing of technologies to convert LRW into a non-flowing state. The main goal is to eliminate direct handling of radioactive LRW by personnel during the testing of various technological procedures. The paper presents the results of studies on the essential basic physicochemical properties of LRW generated during the operation and decommissioning of the BN-350 reactor facility, to determine the main requirements for simulant solutions. Additionally, a methodology for preparing different types of LRW simulants is described, aimed at selecting sorbents and optimizing mixing and conditioning technologies.
CONCEPTUAL DESIGN OF THE THOMSON SCATTERING DIAGNOSTICS FOR THE KTM TOKAMAK
The article is devoted to the development of a conceptual design for Thomson scattering diagnostics (TSD) for the KTM tokamak, intended for conducting experimental studies, measuring the dynamics of temperature profiles and the electron concentration of high-temperature plasma. The work shows an extensive literature review of TSD implemented on similar installations. Schemes for plasma probing and collection of scattered laser radiation of TSD are presented. Based on an analysis of the structural features of the KTM tokamak and existing technical constraints, the choice of a tangential diagnostic layout in the equatorial plane has been justified as the most reliable and practically feasible option. Key technical requirements for the Thomson scattering diagnostic system have been defined: an electron temperature measurement range of 50 to 3100 eV, an electron density range of 1·1019 to 2.5·1020 m−3, and coverage of at least 10 spatial observation points. Various diagnostic configurations, including vertical viewing schemes, were analyzed, and their implementation on KTM was shown to be infeasible due to a number of engineering and physical limitations. The proposed configuration ensures alignment stability, protection against parasitic radiation, and high spatial resolution. This work represents a well-substantiated design of a Thomson scattering diagnostic system, the implementation of which will significantly enhance the diagnostic capabilities of the KTM tokamak for plasma and material research under controlled thermonuclear fusion conditions.
RICE HUSK-DERIVED ACTIVATED CARBON AS A POTENTIAL ANODE MATERIAL FOR LITHIUM-ION BATTERIES
This work investigates the synthesis and application of activated carbon derived from rice husk (RH) as a sustainable anode material for lithium-ion batteries (LIBs). The RH precursor underwent a sequence of pretreatment steps including washing, drying, pyrolysis at 500 ℃ in argon atmosphere, chemical activation with KOH at 850 ℃ , and subsequent desilication. The resulting material exhibited a well-developed micro/mesoporous structure with a high specific surface area (>900 m²/g) and structural stability. Morphological analysis confirmed a uniform porous carbon matrix, while XRD revealed the formation of amorphous carbon. Electrochemical performance tests showed that the RH-derived carbon retained a reversible capacity of ~280–300 mAh/g over 50 charge–discharge cycles, indicating excellent cyclic stability and lithium-ion intercalation capability. Cyclic voltammetry and galvanostatic tests demonstrated predominant pseudocapacitive behavior, associated with surface functionalities and structural defects induced by KOH activation. Compared to conventional graphite (372 mAh/g), this bio-derived carbon offers competitive capacity with lower cost and better sustainability. The study highlights the potential of RH-based activated carbon as a scalable and eco-friendly alternative for next-generation energy storage devices, particularly in LIBs and supercapacitors. Future work will focus on optimizing activation parameters and exploring heteroatom doping to further enhance conductivity and rate performance.
DETERMINATION OF SORPTION CHARACTERISTICS OF MATERIALS FOR THE TRANSFORMATION OF LIQUID RADIOACTIVE WASTE INTO A NON-FLOWABLE STATE
In 1999, the Government of the Republic of Kazakhstan adopted a decision to decommission the BN-350 reactor facility (RF). The decommissioning concept consists of three main stages: the first stage involves bringing the reactor to a safe condition, the second stage ensures storage for approximately 50 years, and the third stage includes the dismantling of buildings and structures, followed by the disposal of the resulting radioactive waste. During the first stage of decommissioning, the placement of spent nuclear fuel for long-term storage, handling of heat-transfer media, liquid and solid radioactive waste, as well as preparation of buildings and structures for safe storage are planned. Liquid radioactive waste (LRW) accumulated during the reactor’s operational period is currently stored in specially designated containers. Due to the long service life of these containers and the potential risk of their integrity being compromised, developing effective methods for converting LRW into a non-liquid (solid or gel-like) form is an urgent scientific and technical task. Such methods allow for the prevention of radioactive substance release into the environment even under potential accident conditions. One of the promising approaches to LRW immobilization is the use of sorbent materials, which efficiently isolate liquid waste and limit the migration of radionuclides [1–3]. This study presents a methodology for determining the sorption properties of various materials offered by manufacturers for converting liquid radioactive waste into a non-liquid form. The results of the investigation of the sorption characteristics of a number of industrial and experimental sorbent samples are provided, and their effectiveness was evaluated during interaction with model LRW solutions.
ENHANCEMENT OF HYDROGEN ABSORPTION KINETICS IN THE Mg-Al SYSTEM THROUGH CONTROLLED FORMATION OF THE Mg17Al12 PHASE
This paper presents the results of a study on the Mg-Al system aimed at enhancing hydrogen absorption kinetics through optimization of phase composition and synthesis parameters. To determine the optimal synthesis conditions, three- dimensional thermodynamic modeling was performed using Thermo-Calc, which enabled identification of the temperature–composition stability regions of the Mg17Al12 intermetallic phase while preserving the Mg solid solution. Based on these results, mechanical alloying of powders followed by spark plasma sintering at 350 ℃ was carried out. X-ray diffraction analysis confirmed that the experimentally obtained phase composition is consistent with the predicted results. Samples containing an optimal fraction of Mg17Al12 (30 wt.%) exhibited a twofold increase in hydrogen absorption rate compared to pure Mg at 300 ℃ and a pressure of 20 bar. The obtained results demonstrate the effectiveness of combining thermodynamic modeling with high-intensity synthesis techniques for the development of solid-state hydrogen storage materials with improved kinetic performance.
EFFECT OF NEUTRON IRRADIATION ON MECHANICAL PROPERTIES OF 316LN STEEL IN CAST AND COLD ROLLED CONDITIONS
The mechanical properties of AISI 316LN steel and its 211L–213L modifications were investigated in both cast and cold- rolled conditions, as well as after neutron irradiation up to a fluence of 2·1019 n/cm2, using the Shear Punch and Small Punch testing methods. The results showed that the modified steels exhibited higher strength compared to 316LN, with 211L demonstrating the most favorable combination of properties. The 2–3-fold reduction in the strength of cast steels was attributed to coarse grain size and casting defects. Neutron irradiation led to significant hardening of cast steels due to the formation of radiation-induced defects, whereas stress relaxation was observed in cold-rolled structures. Microstructural analysis revealed distinct differences in the deformation and fracture mechanisms between the cast and cold-rolled conditions.
ASSESSMENT OF THE IMPACT BY THE SEMIPALATINSK TEST SITE ON THE PERSONNEL AND THE OUTPUT PRODUCTS OF THE COAL DEPOSIT “KARAZHYRA”
This paper presents data on the radiological monitoring (2021–2025) of the produce of the coal deposit “Karazhyra” located within the Balapan test location at the former Semipalatinsk Test Site. Coal mine was found to pose not hazard to the public by its radionuclide composition and can be used in the economic activities with no limitations. Ash produced by combusting coal products of the “Karazhyra” deposit is classed as radiation hazard I and is usable in residential and public buildings under construction and reconstruction with no limitations. Recommendations were given to continue the radioecological monitoring with a view to assure safety for further deposit development.
DEVELOPMENT OF A WEB APPLICATION FOR SUSTAINABLE MANAGEMENT OF LAND AND WATER RESOURCES IN THE TERRITORY OF THE FORMER SEMIPALATINSK TEST SITE LOCATED IN AREAS PLANNED FOR ECONOMIC USE
The article presents the results of developing a web application for sustainable management of land and water resources in the territory of the former Semipalatinsk Test Site (STS), located in areas planned for economic use. The study describes the process of creating a spatial database using PostGIS, implementing server-side logic in Django, and visualizing geospatial objects with Leaflet.js. The developed application provides tools for displaying, filtering, and editing radiation and environmental data, including soil and water sampling points, geological structures, and infrastructure elements. The paper outlines the stages of developing a REST API (Representational State Transfer Application Programming Interface), mechanisms for importing data in CSV (Comma-Separated Values) format, and tools for interactive layer management on the map. The system is designed to support decision-making in the field of radiation safety and environmental planning.
RARE EARTH NANOMATERIALS: PREPARATION METHODS AND ENERGY STORAGE APPLICATIONS
Rare earth materials exhibit unique hydrogen storage properties compared to other materials due to their distinct electron shell structure. Among them, rare earth nanomaterials possess higher specific surface areas, and a greater number of reactive active sites compared to traditional rare earth materials, leading to more stable and superior adsorption processes. Regarding the preparation methods and morphology control of rare earth nanomaterials, this article introduces preparation techniques such as solid-phase, liquid-phase, and vapor-phase methods. It discusses the influencing factors and control strategies of different methods on nanomaterial morphology, analyzes the advantages and disadvantages of each method and the research progress in different countries and regions. Simultaneously, it summarizes the applications of rare earth nanomaterials in solid-state hydrogen storage, electrochemical hydrogen storage, liquid hydrogen storage, catalytic combustion, and other areas. This study examines the relationship between preparation routes, morphological control and hydrogen storage performance, with particular emphasis on rare-earth-based nanomaterials. It highlights the challenges and prospects for their practical application in energy storage. The mechanisms of rare earth hydrogen storage and achieved research results are summarized. Prospects for the development of the rare earth nanomaterials field are also presented.
STUDY OF THE INFLUENCE OF IONIC MODIFICATION ON ENHANCEMENT OF THE STRENGTH PROPERTIES OF xZnO - (1-x)TiO2 CERAMICS
The paper presents the assessment results of the influence of ionic modification of the near-surface layers of composite ceramics based on titanates on changes in resistance to external mechanical influences. The method of irradiation with O+ ions with an energy of about 28 MeV was chosen as the main method for modification of composite ceramics; irradiation fluences were selected in the range from 1011 to 1014 ion/cm2. According to the data obtained, a change in the ratio of components during mixing leads to the formation of two-phase ceramics, in which the main phase is ZnTiO3, and impurities in the form of ZnO and TiO2 are also present, depending on the weight contributions of the initial components. It was determined that the phase composition alteration associated with an increase in the ZnTiO3 phase in the composition results in hardness and cracking resistance growth, which is due to a combination of changes in phase composition and size effects. During experiments related to the ion modification of the studied xZnO - (1-x)TiO2 ceramics, it was established that at irradiation fluences of 1011–5·1012 ion/cm2, the formation of a strengthening effect of the near-surface layer, caused by the effect of ions on the crystal structure, and the associated effects of dislocation strengthening, is observed. At fluences above 5·1012 ion/cm2, a decrease in the degree of strengthening of ceramics, associated with an increase in the density of structural defects, their agglomeration and subsequent destabilization of the near-surface layer, which reduces resistance to external influences, including mechanical pressure, leading to crack formation, is observed.
ANALYSIS OF INTERNATIONAL AND NATIONAL REGULATORY AND LEGAL ACTS IN THE FIELD OF PHYSICAL PROTECTION OF NUCLEAR POWER PLANTS
The article presents a comparative legal analysis of international and national regulatory legal acts regulating the physical protection of nuclear power plants (NPPs). The provisions of the Convention on the Physical Protection of Nuclear Material and Nuclear Installations (CPPNM) and the 2005 Amendment, as well as the IAEA recommendations of the Nuclear Securita Series (NSS) are being studied. International requirements were compared with the current legislation of the Republic of Kazakhstan, taking into account the beginning of the practical implementation of the first nuclear power plant project in August 2025. Particular attention is paid to the analysis of the project threat (Resign Basis Threat). levels of physical protection and integration of cybersecurity. Key gaps in national regulation have been identified and a step-by-step model for harmonizing the regulatory framework is proposed Kazakhstan with IAEA international standards.
THE ROLE AND POTENTIAL OF SMALL MODULAR REACTORS IN THE DEVELOPMENT OF THE WESTERN KAZAKHSTAN ENERGY SYSTEM
The development of nuclear energy is a strategic objective for ensuring energy security and supporting sustainable economic development in Kazakhstan. This goal was clearly outlined in the address of the President of Kazakhstan dated September 8, 2025, “Kazakhstan in the Era of Artificial Intelligence: Current Challenges and Their Solutions through Digital Transformation.” Given the availability of a resource base, nuclear fuel cycle production facilities, and the stated goal of achieving carbon neutrality, Kazakhstan has begun implementing a nuclear energy development program. Kazakhstan's energy system consists of three zones – Northern, Southern, and Western. The Western zone operates separately from the Unified Energy System (UES) of Kazakhstan. An analysis of the energy balance of the Western zone demonstrates the feasibility of using power units with a capacity of up to 300 MW, which will ensure uninterrupted power supply to the region and the stability of the energy system. This article examines the feasibility and effectiveness of implementing nuclear power plant (NPP) construction and operation projects in Kazakhstan using small modular reactors (SMRs) as an example in the Western Zone of the country's power grid. The paper analyzes the state of the Western Zone's power supply, develops power and electricity balances, power distribution scheme options, performs electrical calculations, develops principles for relay protection and emergency automation, and organizes dispatch and process control systems. The scope of grid construction and estimated capital investment are determined.
INVESTIGATION OF THE POSSIBILITY OF IRRADIATING SAMPLES IN THE UPPER PART OF THE TECHNOLOGICAL CHANNELS OF THE IVG.1M RESEARCH REACTOR
The design of the IVG.1M research reactor provides the possibility for long-term irradiation of small samples (60/160 mm) in the upper part of the water-cooled technological channels. The placement of samples in these positions ensures low heat generation and does not affect significantly the reactor’s reactivity. However, this capability has not been utilized. The conversion of the reactor to low-enriched uranium fuel resulted in an increased reactivity margin, making the use of additional irradiation positions of interest for expanding the reactor’s experimental capabilities. To justify this possibility, neutron-physical characterization of these positions must be performed using computational modeling. The existing reactor model is limited to the core and does not include structural components located above it. This work is devoted to extending the computational model of the IVG.1M reactor and evaluating the neutron-physical characteristics of the additional irradiation positions.
FORMATION OF CARBON COATINGS FROM THE GAS PHASE USING MICROWAVE PLASMA
The study examines the formation of carbon coatings produced by plasma-enhanced chemical vapor deposition (PECVD) in the PM-6 system developed at the Laboratory of Hydrogen and Plasma Technologies of the Branch of the Institute of Atomic Energy of the National Nuclear Center of the Republic of Kazakhstan. For the first time, the PM-6 setup has been used to obtain carbon-based coatings. The influence of key technological parameters such as microwave discharge power, gas mixture composition, and silicon substrate temperature on the morphology, phase composition, and physicomechanical properties of the resulting coatings was investigated. The morphology and elemental composition of the coatings were analyzed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), while the phase composition was determined by X-ray diffraction (XRD) and hardness was measured using the Vickers method. It was established that increasing the plasma discharge power to 1.1 kW and raising the silicon substrate temperature enhance the carbon content in the coating (up to 87,66±5,6 at.%) and improve deposition uniformity. X-ray diffraction analysis revealed the formation of thin carbon layers with a predominantly graphitic structure. Following deposition, the surface hardness reached 1137 HV, which is twice that of the initial silicon substrate (416 HV). These results demonstrate the feasibility of controlled synthesis of carbon coatings through optimization of PECVD process parameters.
APPLICATION OF ADDITIVE TECHNOLOGIES FOR THE FABRICATION OF LABORATORY SAMPLES OF CEMENT MATRICES
The preparation of laboratory samples of cement matrices, required for the immobilization of solid radioactive waste, is a labor-intensive process. A standard laboratory sample should be in the form of a cube with a 100 mm side, featuring well-defined and smooth surfaces, and must comply with GOST R 71913-2024 requirements. Accordingly, special molds are needed for casting cement-based mixtures. This work demonstrates the potential of additive technologies, in particular, layer-by-layer forming methods (3D printing with plastic), for creating such molds. The design and optimization of the mold were carried out using 3D modeling software, and prototypes of both monolithic and separable molds were fabricated, which were then used to produce test samples of cement matrices. The prototypes were 3D printed on a modern Bambu Lab printer using the most common and widely used plastic – polylactic acid (PLA). Based on the results of the study, the design of a reusable separable mold was tested, enabling the production of cement matrix samples of the required size and shape.
STUDY OF THE KINETICS OF PHASE TRANSFORMATIONS IN COMPOSITE (1-x)ZrO2 - xSiC CERAMICS WHEN THE RATIO OF COMPONENTS IN THE COMPOSITION CHANGES
The paper presents the results of the assessment of reaction phase transformations in composite (1-x)ZrO2–xSiC ceramics associated with a change in the ratio of components in the composition of ceramics during thermal sintering. The analysis was carried out using X-ray phase analysis, Raman spectroscopy and optical spectroscopy methods. According to the results of X-ray phase analysis of the studied samples of composite (1-x)ZrO2–xSiC ceramics, it was established that an increase in the proportion of SiC to 0.5 in the composition of ceramics leads to the initialization of reaction phase transformations of the m-ZrO2 → SiO2+ZrO2 → t-ZrSiO4 type, which result in the formation of the tetragonal phase of zircon. It was established that the formation of the zircon phase occurs due to the thermal oxidation of silicon carbide, which results in the formation of silicon oxide and an increase in the concentration of oxygen vacancies in the composition of ceramics. It was determined that at a SiC concentration of 0.5 M, the phase composition of ceramics is represented by a mixture of zircon ZrSiO4 phases and a hexagonal SiC phase with a small admixture of silicon oxide SiO2 in the composition. An analysis of the optical transmission spectra of the studied ceramics showed that the formation of ZrSiO4 is accompanied by an increase in oxygen vacancies, as well as a shift in the fundamental absorption edge.
ATOMISTIC INSIGHTS INTO CHOLINE CHLORIDE–GLYCEROL DEEP EUTECTIC SOLVENTS AND THEIR COMPLEXATION WITH AMMONIA FOR SENSOR APPLICATIONS
Ammonia is a harmful air pollutant that is frequently released by industrial activities, agricultural, and waste treatment facilities, posing major threats to human health and the environment. The development of sensitive, selective, and longlasting ammonia sensors is thus critical for accurate air-quality monitoring. Choline chloride-glycerol-based deep eutectic solvents (DESs) are presented as attractive sensing media due to their strong hydrogen-bonding capacity, customizable physicochemical features, and environmental friendliness. DFT computations were used to study the atomistic interactions between ammonia and the choline chloride-glycerol DES. Geometry optimizations were carried out to determine the most stable DES-ammonia complexes, followed by extensive electronic structure investigations. Charge redistribution was visualized using molecular electrostatic potential (MEP) maps, which also identified preferential interaction sites for ammonia adsorption. Mulliken charge analysis offered quantitative information about charge transfer pathways during complex formation, whereas frontier molecular orbital (HOMO-LUMO) study indicated changes in electronic characteristics relevant to sensing performance. The findings show strong and directed interactions between ammonia and DES components, which are predominantly regulated by hydrogen bonding and electrostatic forces, resulting in notable changes in electronic structure upon ammonia attachment. These results demonstrate the suitability of choline chloride-glycerol DESs as active materials for ammonia sensing. Future research will concentrate on dynamic simulations, temperature impacts, and experimental validation to connect atomistic discoveries with practical sensor development.
PHYSICO-DOSIMETRIC ANALYSIS OF 2D AND 3D TREATMENT PLANNING IN CLINICAL BRACHYTHERAPY: EXPERIENCE OF THE CENTER FOR NUCLEAR MEDICINE AND ONCOLOGY (SEMEY, KAZAKHSTAN)
This study presents a retrospective physico-dosimetric analysis of differences between two-dimensional (2D) and three-dimensional (3D) treatment planning approaches in high-dose-rate (HDR) brachytherapy for 20 patients with locally advanced cervical cancer. The research was conducted at the Center for Nuclear Medicine and Oncology of the Abai Region between 2023 and 2025 and included two independent cohorts of 10 treatment plans each, generated using the GammaMed Plus iX after loading system and the BrachyVision treatment planning software. A key methodological feature of the study was the use of a dedicated CT topometric provider table, enabling indexed patient positioning and eliminating geometric uncertainties during preparation for 3D treatment planning. The aim of the study was to quantitatively assess differences in clinical target volume coverage and dose exposure to organs at risk during the transition to 3D planning. To ensure methodological comparability, in accordance with GEC-ESTRO recommendations and ICRU Report 89, retrospective contouring of the high-risk clinical target volume (HR-CTV) and organs at risk (OARs) was performed on archived CT images for the 10 plans in the 2D cohort, followed by recalculation of volumetric dosimetric parameters. The primary dosimetric endpoints included HR-CTV D90 and OAR D2cc for the bladder, rectum, and sigmoid colon. Statistical analysis of independent samples demonstrated that 3D planning, supported by precise target fixation, is associated with reduced variability of HR-CTV D90, improved dose distribution conformity, and the ability to accurately assess volumetric dose exposure to organs at risk. The obtained results are consistent with international guidelines and highlight the advantages of three-dimensional planning in improving the accuracy, quality, and safety of brachytherapy in oncological practice in Kazakhstan.
IMPACT OF RESPIRATORY GATING ON DOSE DISTRIBUTION AND PROTECTION OF CRITICAL ORGANS IN RADIOTHERAPY FOR BREAST CANCER
This study is dedicated to the dosimetric evaluation of the Deep Inspiration Breath Hold (DIBH) technique as a cardioprotective method during adjuvant radiotherapy for left-sided breast cancer. The primary objective of the research was to compare the dosimetric parameters of radiation exposure to the heart in the DIBH mode with those obtained in the conventional Free Breathing (FB) mode, while maintaining adequate coverage of the Planning Target Volume (PTV). To achieve this objective, a retrospective dosimetric analysis of three-dimensional conformal radiotherapy (3D-CRT) plans for 10 patients was performed. Key dose–volume metrics for the PTV, lungs, heart, esophagus, spinal cord, and contralateral breast were assessed. The results demonstrated that, despite the dosimetric equivalence in PTV coverage and protection of lung parenchyma (V20 Gy), the DIBH technique provides a pronounced protective effect on cardiac structures. In the DIBH mode, a statistically significant reduction of more than 50% in the mean heart dose (Dmean) was observed – from 33,16±3,79 Gy to 15,49±4,50 Gy (p  0,001). The most substantial reduction in radiation exposure was recorded for the left anterior descending coronary artery (LAD). This sparing effect is explained by the physiological caudal displacement of the heart during deep inspiration, effectively increasing the distance between the heart and the irradiation field. Thus, the DIBH technique ensures excellent cardioprotection, significantly reducing long-term cardiovascular risks – particularly those associated with LAD exposure – without compromising the oncological adequacy of treatment. These findings confirm the necessity of implementing DIBH as a gold standard in regional clinical radiotherapy protocols.
OPTIMIZATION OF DOSIMETRIC PLANNING PARAMETERS FOR RADIOTHERAPY OF HEAD AND NECK TUMORS
The study was conducted at the Center of Nuclear Medicine and Oncology of the Abai Region (Semey, Kazakhstan) and was aimed at the quantitative evaluation and optimization of dose planning parameters in patients with head and neck tumors. A retrospective analysis included seven patients (N = 7) treated in 2024, for whom radiotherapy plans were generated using intensity-modulated radiation therapy (Intensity-Modulated Radiation Therapy, IMRT) and volumetric modulated arc therapy (Volumetric Modulated Arc Therapy, VMAT) on a TrueBeam linear accelerator within the Eclipse treatment planning system. The objective of the study was a comparative physical-dosimetric assessment of plan quality with analysis of key dosimetric metrics and logistical efficiency of dose delivery. The analysis demonstrated comparable coverage of the planning target volume (PTV) for both techniques, while clinically significant differences were observed in dose distribution to organs at risk. The use of VMAT resulted in a reduction of the mean dose to the parotid glands by 4,65 Gy compared with IMRT (19,60±7,97 Gy vs. 24,26±3,75 Gy), achieving values below the critical threshold of 25 Gy and contributing to preservation of glandular function. The mean dose to the spinal cord was also lower with VMAT (37,96±4,16 Gy vs. 41,37±1,94 Gy), thereby enhancing radiation safety of treatment. Logistical analysis revealed a clear advantage of VMAT, characterized by more than a 60% reduction in monitor units and dose delivery time compared with IMRT, which contributes to decreased radiation exposure of organs at risk and supports the feasibility of VMAT as a preferred technique in routine clinical practice.
THE EFFECT OF SHORT-DURATION SENSITIZING ANNEALING ON THE SUSCEPTIBILITY OF 12X18H9 AUSTENITIC STAINLESS STEEL TO PITTING AND INTERGRANULAR CORROSION
The article is devoted to the study of changes in the corrosion properties of 12X18H9 austenitic stainless steel as a result of provoking annealing of short durations (1/2 hour, 1 hour, 2 hours) at temperatures of 450, 650, and 850 ℃. The susceptibility of heat-treated steel to pitting corrosion in a 5% solution of iron (III) chloride crystallohydrate FeCl3·6H2O was studied using the gravimetric method, and to intergranular corrosion (IGC) in a boiling aqueous solution of sulfuric acid and copper sulfate CuSO4·5H2O, using the AMU method. It was shown that the corrosion behavior of steel samples in aggressive solutions depends on the degree of steel sensitization during provoking annealing. Differences in the kinetics of pitting corrosion and the susceptibility to IGC for steel annealed at 450 ℃ and 650 ℃ are related to the nature of the grain-boundary precipitates formed. At 650 ℃, a quasi-continuous network of Cr23C6 carbides forms, leading to the formation of extended Cr-depleted zones. This facilitates the directed development of corrosion along grain boundaries, contributing to the acceleration of pitting corrosion and the susceptibility to IGC. After annealing at 450 ℃, carbide precipitates and Cr-depleted zones are less pronounced, limiting the development of intergranular dissolution and ensuring the retention of resistance to IGC. Samples annealed at 850 ℃ are characterized by a low rate of pitting corrosion and a tendency to IGС, which may be attributed to residual electrochemical heterogeneity of grain boundaries and the presence of discrete carbide precipitates.
COMPARATIVE ANALYSIS OF DOSE DISTRIBUTIONS AND ORGAN DOSES IN 3D-CRT, IMRT AND VMAT ACCORDING TO QUANTEC AND RTOG PROTOCOLS: PLANNING FEATURES, ADVANTAGES AND LIMITATIONS
The study was conducted at the Center of Nuclear Medicine and Oncology (Semey) and is devoted to a comparative dosimetric analysis of external beam radiotherapy planning parameters for locally advanced cervical cancer. Three- dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT) were compared in terms of dose distribution quality and dose burden to organs at risk. Treatment planning was performed for 25 patients using a TrueBeam linear accelerator with daily patient setup verification based on IGRT/CBCT. Plan quality was evaluated using dose–volume histograms, including D95% for the planning target volume (PTV), conformity index (CI) and homogeneity index (HI), as well as absolute dose parameters (Dmean, Dmax) for organs at risk, in accordance with RTOG criteria and QUANTEC recommendations. The analysis demonstrated that VMAT provided the most favorable dosimetric performance, with a high conformity index (CI = 1,03±0,02) and a low homogeneity index (HI = 0,09±0,02), ensuring more uniform and accurate PTV coverage compared with IMRT and 3D-CRT. A key finding was a substantial reduction in dose burden to pelvic organs at risk: VMAT resulted in an average 25–30% reduction in overall dose compared with 3D-CRT, while the mean dose to the rectum (Dmean) decreased to 33,0 Gy. In addition, VMAT significantly reduced the average treatment delivery time to 5–7 minutes, thereby lowering the risk of intrafraction motion. The obtained results confirm the dosimetric advantages of VMAT and substantiate its feasibility for routine clinical use in a regional oncology center.
SURFACE HARDENING AND STRUCTURAL-PHASE STATE OF STAINLESS AUSTENITIC STEELS 12Х18Н10Т AND 08Х18Н9 AFTER HEAT TREATMENT AND SPRAYING OF A COATING
The features of the structural-phase state and changes in the surface properties of stainless steels 12Kh18N10T and 08Kh18N9 after heat treatment, rolling, and coating deposition have been investigated. The application of a treatment method involving aluminum spraying followed by annealing at 700 ℃ (1 h) with slow heating (250 ℃/h) to the target temperature made it possible to significantly increase the microhardness and wear resistance of the surface of 12Kh18N10T steel. The substantial improvement in microhardness and wear resistance after such treatment is attributed to the formation of a new ordered Fe₃Al phase with an FCC lattice.
LONG-TERM STORAGE OF SPENT NUCLEAR FUEL FROM THE BN-350 REACTOR IN A SILO-TYPE STORAGE FACILITY
The paper presents the scientific and technical basis for the long-term storage of spent nuclear fuel (SNF) from the BN- 350 reactor in a dedicated silo-type storage facility. The key conceptual provisions and engineering solutions aimed at ensuring nuclear safety and corrosion resistance of the storage system are described. Safety analyses were performed to substantiate the safety of SNF storage. Thermal analysis of an individual storage cell demonstrated that, even in the absence of forced cooling, the maximum temperatures of the fuel and structural components remain within established safety limits. The adopted layout and design solutions ensure subcriticality of the system under all considered conditions, including off-normal scenarios. The results of this study may be used to support the evaluation of further options for the management of SNF from the BN-350 reactor.
ANALYSIS OF OPTIONS FOR FURTHER MANAGEMENT OF SPENT NUCLEAR FUEL FROM THE BN-350 REACTOR FACILITY
The paper analyzes the options for further management of spent nuclear fuel (SNF) from the BN-350 reactor facility, which was in operation from 1973 to 1999. Based on the established international experience, recommendations of international organizations and requirements of national legislation, as well as the technologies currently available, possible scenarios for the management of the spent nuclear fuel from the BN-350 reactor facility, including the long-term storage, processing and direct disposal, have been considered. The paper is oriented at forming the recommendations for developing a further strategy for the SNF management in the Republic of Kazakhstan, taking into account long-term safety.
Erratum to: “RESULTS OF THE FORESIGHT STUDY IN THE FIELD OF “ENERGY” IN THE REPUBLIC OF KAZAKHSTAN: INTERNATIONAL EXPERIENCE AND NATIONAL PERSPECTIVES” A. S. Serikkanov, L. D. Baiseit, M. E. Kalmenov, A. A. Kibarin, Ye. V. Shevchenko, A. А. Omirbekova, S. S. Verendeyev NNC RK Bulletin. 2025; 4(104):178–189