The effect of neutron irradiation on the M_d martensitic point in austenitic chromium-nickel steels X18H9T and 12X18N10T – structural materials of nuclear reactors is considered. It was established that up to a fluence of 2·10²⁰ n/cm² (E>0.1 MeV), the maximum possible temperature for the manifestation of the phase y→α transition for steel 12X18H10T varies in the range of 100–75 °C.

Based on the analysis of the experimental data obtained, it is proposed to consider another characteristic point M_p – a stretching temperature at which the values of the intensities of the direct martensitic y→α transformation are compared for deformable non-irradiated and irradiated steel.

Experimental results on the relaxation of internal stresses in structural stainless steels Х18Н9Т, 12Х18Н10Т and AISI 316 after neutron irradiation, effects of stationary or pulsed electrons of various powers are presented. It has been established that in steels irradiated with low neutron fluxes (10¹⁶ ÷ 10¹⁸ n/cm²), the deformation by extension as a result of relaxation phenomena is the martensitic γ → α transition begins at lower values of critical stresses than after austenization. At the same time, there is an anomalous effect of reducing the yield strength and reducing the amount of mechanical workexpended on the destruction of the steel sample. The features of the relaxation of internal stresses and the formation of the α-phase in stainless steels under irradiation with electrons of various energies are revealed. It is shown that the radiation relaxation of internal stresses caused by the action of neutrons, pulsed or stationary electrons, changing the conditions for the formation of the α-phase, determines the level of mechanical and corrosion properties of irradiated stainless steel.

The phase-structural transformations were studied by the X-ray diffraction analysis, scanning electron microscopy and Mössbauer spectroscopy in transmission geometry and in the backscattering mode in the electronic channel in austenitic stainless steel 12Cr18Ni10Ti irradiated with ⁵⁷Fe ions in the heavy ions accelerator. The X-ray diffraction method and Mössbauer spectroscopy showed the austenitic mono-phase in the original steels. The austenite remains the dominant phase in the irradiated samples, and the radiation initiated martensitic phase is available in small amounts.

High-temperature nuclear reactors with coolant gas have several advantages for application in power generation and industry. For the design and implementation of reactor facilities of this type, the development of accompanying technologies is necessary. Such technologies include the production of nuclear-grade graphite, pyrocarbon protective coatings of nuclear microfuel, production of helium.
The Gas Institute of the National Academy of Sciences of Ukraine conducted a series of research and development works in this field. The research results allow to create energy-efficient and environmentally safe technology for purification of natural graphite to high levels of purity. Research of application of pyrocarbon coating on nuclear microfuel model was carried out in reactors with electrothermal fluidized bed. As a result, material with a wide spectrum of pyrocarbon content (from 2 to 97 % wt.) was obtained. Сryogenic technology for the production of helium concentrate from natural gas was developed. To continue research in the development of accompanying technologies for nuclear reactors with coolant gas, international consortium for participation in EURATOM and Horizon 2020 grant programs is being set up.

The question of the spatial distribution of fast and thermal neutrons in the Earth’s atmosphere is considered. The fields of fast neutrons from a flat radioactive source with a source energy not exceeding 1 MeV are correctly described by the age theory. The effect of atmospheric in homogeneity affects the height of the source, exceeding 20-25 km. The flux density of slow neutrons falls almost to zero at a distance of about two parameters of the atmospheric in homogeneity.

The article presents the calculated variants of current scenarios for the realization of ohmic breakdown of the hydrogen gas in the KTM tokamak. The magnetic configuration of the fields at the time of the breakdown and the main parameters of the breakdown in the vacuum chamber are given, taking into account the basic conditions and limitations for the KTM tokamak. Current scenarios are prepared using the Plasmaless Tokscen calculation code. Based on the calculated estimates of the feasibility of the breakdown, optimal values of the necessary parameters for starting work on the KTM tokamak were selected.

The paper deals with a complex of OHF diagnostics of tokamak KTM, designed to measure the electron density of the plasma. The composition of the OHF diagnostics, their technical features of execution and placement are discussed, and the first experimental results on the measurement of the electron density of the KTM plasma using them are presented. Special attention is paid to the principle of operation of OHF devices and the location of diagnostics on the tokamak.

Applicability of the work is caused by the fact that tungsten was selected as plasma faced material of FR diverter. In this regard, Institute of Atomic Energy implements the work to obtain and study carbide coatings on tungsten. Following methane plasma affect tests under plasma-beam installation conditions, phase composition of samples surface layer is monitored. The X-ray phase analysis is carried out in the Laboratory for Structural and Fuel Materials Testing. Phase state definition is a typical task for X-ray phase analysis. The transformation processes of the tungsten crystal structure may precede the structural transformations occurring when the phase composition changes. Interpretation of the results requires additional information about the analyzed substances. The paper considers variations of phase transformations when interaction between tungsten surface and carbon, structural properties of tungsten were analyzed before and after methane plasma affect. In addition, it refers to peculiarities of their change and calculation. There are calculation results of structural parameters. Presented method is reasonable in terms of the physical basis of modern methods of structural and phase state studying of materials.

This article discusses the results of mechanical testing of highly enriched uranium (HEU) and low enriched uranium (LEU) fuel materials of the IGR reactor after thermal cycling at different temperatures and the quantity of “heating-cooling” cycles. The strength changes in characteristics of LEU and HEU fuel were determined depending on the thermal cyclic test modes.

The report provides determination of parameters for sources of delayed energy release, prepared mathematical model of the reactor point kinetics taking into account time distribution of fission energy. The calculation research will contribute to more correct selection of necessary power diagram during experiment preparation at IGR reactor.

This paper presents the result of experimental testing of the methodology auto-oscillating mode probe, which is based on a previously developed mathematical model of the secondary emission instability of a plasma-surface contact. The method of auto-oscillating mode probe is designed to measure the plasma parameters of beam-plasma discharge (BPD) in the near-axial zone of a beam-plasma installation with a longitudinal magnetic field. A scheme had been developed for measuring the current and voltage of the probe using a low-inductance resistive voltage divider, the Rogowski coil with the current shunt, and current meter on the Hall effect. The ion current density in the near-axial zone of the SPR was determined.

In this paper, the experience of using and testing experimental thermocouple assemblies in core of IGR reactor is considered; a new design of thermocouple assembly is proposed.

The paper presents results of neutronic parameter calculations of experimental device intended for studying processes of core materials melt movement into the area with restricted amount of coolant – sodium melt – and its cooling with presence of residual energy release in the melt. Calculated values of energy release distribution along the height of model fuel assembly have been obtained. The value of ratio of energy release in melt and structural materials of the experimental device to the energy release in the reactor core have been estimated.

A test object is a water-cooled technological channel with low-enriched uranium fuel (WCTC-LEU # 24) of the IVG.1M reactor. A porous two-dimensional axisymmetric model of IVG.1M WCTC was designed using the Ansys Fluent computation program, available operating model of a fuel assembly (FA) was optimized, which was simplified to a segment of one fuel element (FE). Computation models have been checked through comparison of stationary computation results with experimental data of the P17-08 start-up. Designed models enable performing thermophysical computations in emergency situations for safety substantiation.

This paper is devoted to evaluation of activity of the IVG.1M reactor coolant and estimation of the fission products (FP) yield from the fuel rods of experimental water-cooled technological channels with low enriched uranium (WCTC-LEU) using a sampling gamma spectrometric method. The article presents the results of studies of two experimental WCTC-LEU to determine the yield of FP into the coolant of the IVG.1M reactor using a sampling gamma spectrometric method. A comparative analysis of changes in the FP yield from both experimental WCTC-LEU and regular WCTC is presented in the considered range of energy release in the reactor up to 630 MW·hour. Research results show that the FP yield remains unchanged within fluctuations when conducting more than 30 reactor experiments. The paper shows that the FPyield from the experimental WCTC-LEU averaged over all registered FPs to R/B = 5·10⁻⁷ can be considered acceptable compared to the calculated yield for sealed fuel rods R / B = 7·10⁻⁷.

The paper deals with detailed analysis of seismic noise characteristics at “Podgornoye” station for the purposes of analyzing the impact of seismic instrumentation parameters on the efficiency of the stations’ work.

The paper presents data on longstanding hydrogeological monitoring at Kosshoky site that is studied for radioactive waste (RW) geological storage, where the results of the study of hydrogeological conditions of this area have been generalized for the period of 7 years, the locations are estimated for the facility, which can be used for RW isolation. Based on the results of conducted works, a map-scheme has been built on values of filtration coefficients, iso-lines map was created, and an assessment of seasonal and temporal change of underground waters has been obtained.

The paper presents the results of works on creation of a seismic bulletin of earthquakes in Central Asia based on archive digital seismograms of IGR NNC RK stations network for the period of 1994–2002. The methodology of data processing is provided, the processing results as well as the tasks for application of the bulletin are described. The created bulletin is actively used in a number of seismology tasks, for instance, to assess seismic hazard of Kazakhstani regions, which previously were considered aseismic ones, also to monitor technogenic seismicity, etc.

The paper provides procedure of «Micronuclear Test with Cytogenesis-Block in Lymphocytes of Peripheral Blood of Humans» cytokinesis-block micronucleus test method adoption in the Institute of Radiation Safety and Ecology of the NNC RK. Micronuclear test with blockage of cytogenesis was tested using automated cytogenetic platform based on digital fluorescent microscope Carl Zeiss AxioImager Z2, Metafer 4/MSearch, automated system for search and analysis of metaphases (MetaSystems, Germany). It was found, that base micronuclei frequency of the researched groups ranges between 2.12 and 18.1 per 1000 of binuclear cells, that corresponds to standard background values in the world (according to the bookish data).

This paper is a calculation of the differential cross section for the elastic scattering of hydrogen nuclei on exotic nuclei of a neutron-rich lithium-11 isotope by determining the optimal parameters of optical potential via the FRESCO 2.8 software using the strongly coupled nuclear reaction channel method with the spin-orbit and Coulomb interaction included. For lithium, the J^P=3/2⁻- state was selected. The shapes of the elements of the scattering potential were chosen in the Woods-Saxon form. The selection of the parameters of the potential was based on the data extracted from the p+¹¹Li scattering experiment conducted at 62 MeV in the laboratory coordinate system on the RIKEN cyclotron in Japan in 1992. In this work, it was found that the volume and spin-orbital parts of the potential, as well as the diffusion of the interaction, have values of zero or close to zero. The resulting cross section in the forward hemisphere of scattering is 70–75 times largerтthan the corresponding Rutherford cross section, and in the rear hemisphere, on the contrary, Coulomb forces dominate. The theoretical values confidently coincide with the experimental ones.

The experimental data on mass and energy distributions of fission fragments of compound nuclei ²³⁶U, ^{237, 240, 242}Pu, ²⁴⁴Cm formed in ²³²Th (α, f), ^{233, 236, 238}U (α, f) и ²⁴⁰Pu (α, f) reactions at incident alpha particle energies of Eα = 29 MeV is presented. Excitation energy of the compound nuclei for all reactions was 21±2 MeV. Experiments were carried on the isochronous cyclotrone U-150M at The Institute of Nuclear Physics, Almaty city.тIt was shown that behavior of mass distributions Y(m) depends mainly on proton number in heavy and light fragmentsтthat are being formed. For isotopes of one element (^{237, 240, 242} Pu) charge distributions ofтfragments Y(Z) are almost the same. The discovered differences between behaviors of fragments mass distributions Y(m) and their energy distributions (Ek(m) и σ²(m)) points to these characteristics being formed at a different stages of fission process. Kinetic energy is determined by the conditions at rupture point, mass distributions are formed at earlier stages of fission process, when future fragments are still connected by a thick neck.

Experimental studies on the effect of static stress (σ), electron dose (D) and temperature (T) on the deformation (α) in time (t) of unirradiated and irradiated fluoroplastic were carried out. The combined effect of electron irradiation and stress leads to a significant increase in the strain up to rupture. With mechanical effects, with an increase in the absorbed dose, the stress and relative elongation of the fluoroplastic decrease, which is associated with the degradation of the main circuits of the fluoroplastic. Irradiation of polytetrafluoroethylene during thermomechanical testing leads to a decrease in deformation compared to unirradiated material.

The article describes a method of obtaining porous tantalum at heat treatment in vacuum, from tantalum-cadmium coatings with a different ratio of tantalum and cadmium. The BET method estimated the surface area and showed that an increase in the specific surface area of the samples in terms of porous tantalum is 277.52 m2/g. A study was made of the ability of the obtained porous structure to accumulate charge and the processes occurring in porous tantalum during forming in an acid electrolyte.

The results of a study of the degree of DNA damage in peripheral blood lymphocytes in residents of Dolon (Semipalatinsk region, East Kazakhstan region) are presented. The spontaneous level was analyzed after in vitro exposure to γ-radiation at a dose of 1 Gy and the assessment of the efficiency of repair 2.5 hours after irradiation. A cytogenetic study of the spontaneous frequency of chromosomal aberrations and radiosensitivity with additional radiation exposure was also conducted. A significant increase in the degree of DNA damage and cytogenetic disorders in the inhabitants of the Dolon pod was shown compared with the control in the study of the spontaneous level. The repair efficiency, determined usinga Comet-test and radiosensitivity based on cytogenetic analysis with additional irradiation of the cells of the patients, varied significantly within different individuals. These parameters in specific individuals may be of great importance for individual retrospective dose assessment during acute or chronic exposure or when living in radiocontaminated regions. A comparative analysis of the data obtained using the methods used revealed a significant positive correlation between the spontaneous frequency of chromosomal abnormalities and the efficiency of repair.

The computer simulation of cascade-probabilistic functions (CPF) and the concentration of vacancy clusters depending on the depth h and the number of interactions n is carried out. By the example of titanium implantation in iron and aluminum in titanium, it is shown that the CPF as a function of both n and h are in a very narrow range of the domain of determination, while the concentration of clusters in a fairly wide range. There is an extensive maximum, and the concentration drops to zero at the end of the ion run.

The work provides results of research of concentrations of ¹³⁷Cs, ⁹⁰Sr, ²⁴¹Am, ^239-240Pu artificial radionuclides in pine forest at the part of the radioactive fallouts plume of the first nuclear test (29.08.49), conducted at Semipalatinsk Test Site. The maximum specific activity values in soil were found to be typical for ^239+240Pu and ¹³⁷Cs, lower values were found for ⁹⁰Sr and in single case it was registered for ²⁴¹Am. In the phytogenous objects, represented by structural elements of pine (Pinus silvestris) trunk, mainly ^239+240Pu and ⁹⁰Sr was accumulated, at that the maximum values were registered in the cortex.

The work provides results of complex research of the levels and character of the distribution of radionuclide contamination in the system of "bottom sediments - water - plants" of technogenic water bodies at the Semipalatinsk Test Site (STS). The objects of research were craters formed as a result of nuclear tests, filled with water, located at the test sites "Experimental Field", "Balapan", "Telkem" and "Sary-Uzen". Samples of sediments, soils, waters, aquatic, semiaquatic and waterside plants were taken for determination of ²⁴¹Am, ¹³⁷Cs, ⁹⁰Sr, ^239+240Pu concentration for this research. As the result of experiments distribution coefficient (Kd) for sediments and water and concentration ratio (FV) for aquatic and semiaquatic plants and sediments, waterside plants and soils were calculated. Based on the obtained results comparative analysis of the redistribution of radionuclide contamination in technogenic water bodies at the STS was done.