WWR-K is the research tank-type light-water heterogeneous reactor. Reactor operation started in 1967 with enrichment36 % in uranium-235. In 2016 reactor conversion to low-enriched uranium fuel (19.7 % in uranium-235) was implemented with the VVR-KN-type fuel assemblies (FA). In view of reactor operation, compact configuration of the core was chosen, where, following fuel burning up, side water reflector is gradually changed by beryllium one. Besides, an amount of work elements of the reactor control and protection system is increased in the new reactor core.
Following results of measurement of the thermal neutron flux density, carried out in the core center in course of reactor physical startup, it has increased up to 2·10¹⁴ cm^-2s^-1. Thus, in terms of experimental capacities, reactor has gained after conversion in attractiveness.
As is known, uranium fission is accompanied by generation of neutrons, which energies obey the Watt’s spectrum, that is, the spectrum peak is associated with the neutrons having the energy 0.7 MeV, whereas the neutron average energy comprises 2 MeV. Due to an enhanced amount of uranium-238 in the new low-enriched uranium fuel FA, neutron spectrum is making «harder».
In the presented paper, neutron spectra in the core irradiation channels of re calculated by means of the computer code MCNP, and comparison of neutron spectra in the WWR-K reactor core with high-enriched uranium fuel against lowenriched fuel is conducted.

The paper presents results of the regional background frequency of stable translocations using in situ fluorescent hybridization in different age groups, which ranges from 1.42±0.3 to 4.9±0.5 per 1000 cells. It found that frequency of stable chromosome aberrations revealed by FISH-technique increases with age. This is due to the fact that with age chromosome stability, DNA reparation and regeneration reduction progressively decelerate. The impact of bad habits such as smoking is the most studied sign affecting the level of translocations; therefore, correlation was made between the level of stable chromosome damage and this bad habit in age groups of interest. Background frequency of stable chromosome damage was calculated by means of equipment of automated cytogenetic platform based on the electronic Carl Zeiss AxioImager Z2 fluorescent microscope, automatic Metafer 4/M Search, ISIS (MetaSystems, Germany) metaphase search and analysis system and using commercial whole chromosome DNA probes for chromosomes 1, 4, 12.

In this article we study the application of the Radon transform, as one of the types of numerical information in discretization problems of functions from the Sobolev classes. The main distinction of the scientific statement is the use information of a new type, we state the problem to find out the characteristics of the solution of the reconstructing problem using the Radon transform in the context of the Computational (Numerical) diameter. Subsequent computational implementation has a very wide scope in science, and thus, on the scale of Kazakhstan, proposes further research on promising subjects, which implements a new direction at the international level.

This paper shows the results of mechanical tests in a wide temperature range of reactor graphite and beryllium oxide. It is established that the compressive strength of graphite with increasing temperature test up to 1000 °C increases by ~10 %, while the fragile nature of the destruction is preserved. An increase in the test temperature leads to a sharp decrease in the strength properties of BeO by ~10 times. As shown by bending tests with increasing temperature, the destruction mechanism changes from brittle to brittle-viscous.

The article addresses determinations of features of ground water formed at places of radionuclide contaminations. It is found that the major source of ground water recharge is winter atmospheric precipitation. It is also revealed that ground water discharge into surface water occurs in August. This data is confirmed by measured results of stable isotopes as well as my measured level of ground water occurring in the bed of the Shagan river. During this period at places of ground water discharge there is a maximum concentration of man-made radionuclides in surface water of the Shagan river and Kishkensor lake. This is attributed to the fact that when the level of ground water increases radionuclides are washed out of cavities of “warfare” boreholes.

The paper presents quality evaluation results of tritium determination technique (³Н) for soil – distillation technique used for determining its speciation in free water. To evaluate the impact of matrix structure on ³Н extraction process by distillation, soil, earth silicon and salt were used as samples. In the course of the experiment a tracer of various activity – from 100 to 100,000 Bq/l was used to assess completeness of extraction and impact of ³Н content. All of the experiments were conducted in several replications. At each experimental stage a blank experiment was conducted to assess its integrity. It is found that efficiency of distillation technique is on average 80–98 %. Distillation technique proved its efficiency except where soil is slightly wetted (with moisture of less than 10 %). When using the distillation technique stable minor losses that are corrected with a correction factor can be observed for soils of low moisture.

Research results are presented on determination of the ultimate composition of standard fine dust sample for adapting available air aerosol particulate matter preparation procedure by autoclave decomposition. Optimal types of reaction mixtures have been determined for a more complete leaching of certain element groups – highly volatile, rare earth, hardly soluble, from dust to a test solution. It is shown that combination of a standard technique and the suggested sample preparation procedure allows expansion of a range of elements to be determined from one assay.

The article provides results of calculation studies of the IGR reactor temperature field under long-term and short start-up with integral power of 5.2 GW with subsequent cooling down of the reactor.
It is shown that during long start-up which takes more than one hour it is possible to exceed the declared maximum integrated power of the reactor without disfunction of its operating temperature limits.

Article presents a short overview of the modern power engineering condition and its impact on global ecology. The main advantages of thermonuclear power engineering are highlighted as a potential solution of power crisis in the future. KTM facility overview is presented, meant for solution the issue on large-scale study of materials, planned to be used for intrachamber plasma facing elements production for future thermonuclear reactors. The problem of the basic technological systems development, introduction and commissioning is exposed on the example of power supply pulse system.

At present the most efficient methods of detection of actinides and lanthanides in solutions are methods based on registration of actinides with time resolution, time-resolved laser induced fluorescence (TRLIF) spectroscopy. TRLIF may be applied for biological samples analysis. Pu, Np, and some U compounds do not produce direct luminescence in solutions, but when excited by laser radiation, they can induce chemiluminescence of chemiluminogen (luminol in our experiments).
The presence of a time delay between the pulse of laser radiation and the chemiluminescence pulse allows using time resolution (TR) procedure for detection of chemiluminescence (TRLIC). Using chemiluminescence of solutions, we found an approach to registration of plutonium, uranium, and other elements in solutions with a high sensitivity in excitation of plutonium and uranium with a pulse laser with tunable wavelength. A multi-step scheme of chemiluminescence excitation makes this procedure not only highly sensitive but also highly selective method of detection of substances.

Soil phyto-remediation technology is proposed, that lies in plants seeding with maximal ability for radioactive elements accumulation, forage content disposition and its further utilization. Accumulation ability of 67 vegetation types (both cultivated and native) were studied, range of transition factors change, reaching three orders (from thousandths to tenth of units). During research an approximate theory of phyto-remediation was proposed.
Technology was experimentally approved during field study of the East-Uralsk radioactive trail. Phyto-remediation time evaluation in condition of Semipalatinsk Test Site enables to assume, that the current technology is prospective for other territories also.

Construction of Semipalatinsk Test Site (STS) at the territory of East Kazakhstan was initiated in 1947. During military and civil tests conduction a large amount of valuable information was accumulated, the major part of which remained classified. In 1991 after USSR collapse the test site was closed by N. Nazarbayev, the President of Kazakhstan, Decree # 409. Since that time STS became the object for study of consequences of radioactive contamination in environment, seismic activity during explosions. The current paper includes scientometric analysis of information array on STS, presented in the largest international database Web of Science (WoS).

Investigations of mechanical properties of textolite and glass fiber in the test for flat straight bending were carried out. To study the deformation dependence e voltage s was designed and manufactured corresponding to the experimental setup. It was found that the strength properties of glass better in 1,5 at destruction than the PCB, and the deformation characteristics are almost the same. The measured experimental curves are satisfactorily described by the exponential model proposed by the authors. It is shown that the experimental dependences of s on lgt are nonlinear, which indicates the dependence of the mechanical stress of the textolite and glass-textolite material on the load speed.

Complex experimental studies on the effect of electron irradiation on the deposition rate of activated sludge in water systems by optical method were carried out. To determine the parameters of activated sludge (biomaterial), an experimental setup was created. Silt in an amount of 1 g, placed in a flask of water with a volume of 25 ml, was carefully shaken and installed between the laser and the detector. The dependence of light intensity (green and red laser lines) on time was removed. The obtained dependences of the density (r) on time (t) have the same nature for different radiation sources. The experimental curves of the dependence of the activated sludge density on time are satisfactorily described by the exponential model.

The measurements of geometrical and physical parameters of the processed medical products were carried out. The density of samples was measured both in industrial packaging and in individual products. Experimental studies on the passage of electrons with an energy of 2 MeV through medical products: cotton wool, syringes. The absorption coefficients of the electron beam for two materials (cotton wool, syringes) are obtained. It was found that when irradiating products from the sides there is a greater uniformity of dose distribution in samples of cotton wool and syringes. From the results of the experiment it follows that such irradiation leads to the fact that the unevenness of the dose of the impact on the thickness of the sample for cotton wool is about 5 %, and for syringes – 3 %.

A facility for studying the properties of bottom sediments of water bodies by optical method has been developed. From the obtained curves of dependence of density (I) on time (t) the regularities having the same nature for different radiation sources are revealed. Given the intensity of red and green rays, depending on the time, are almost the same, therefore, the effect of these radiations on the bottom sediments is similar. The curves of intensity (I) versus time (t) are satisfactorily described in the framework of the exponential (cascade-probabilistic) model proposed by the authors. Material irradiated in 2016 is less active than material irradiated in 2018. The reason for this behavior is the partial extinction of microorganisms within two years in containers. The flux of gamma radiation in turn increases the activity of the biomaterial immediately after its irradiation.

In this paper we consider the effect of high-energy electron irradiation, load and temperature on the mechanical properties of Mylar films. The simplest physical model is developed. Studies have shown that with an increase in the dose of electron irradiation to 10⁴ Gy, there is a slow decrease in deformation for Mylar, and a further increase to 10⁶ Gy leads to a sharp decrease in it. At the same time, with increasing temperature, the relative elongation increases by more than 50 %, associated with the growth of destructive processes in the material. The dependences of strain and stress on the dose of electron irradiation are described by exponential functions and are in satisfactory agreement with experimental data.

The work is devoted to the study of the effect of various fillers and electron irradiation on the physico-mechanical properties of a number of composite films; fracture models are proposed. A composite material based on polyimide (PI) with various concentrations of the second component: polyethyleneterephthalate, polycarbonate, montmorillonite, hightemperature superconductor, and a polyimide film metallized on both sides was investigated. Samples obtained by the method of mechanical mixing based on polyimide varnish and solutions of the second component. The irradiation was carried out on an electron linear accelerator of the type ELU-6 in air at 25 °C with an energy of 4 MeV. It has been established that the introduction of PET, PC, MM and HTSC fillers makes it possible to obtain materials with desired properties. The concentration of the additive, the features of its internal structure, as well as the technology of synthesis determine the features of the physic mechanical properties of the resulting composite materials.
Electron irradiation causes an improvement in the mechanical properties of some composites, while in others, their deterioration. Various models have been proposed for uniaxial loading of materials and an exponential model gives the best agreement with experiment.

For scince and nuclear industry popularization through basic knowledge dissemination, technical education guidance of the youth, the Nuclear Energy Information Center in Astana being as organization department of the “Nuclear Society of Kazakhstan” JSC, launched the Project “Nuclear Walkers” in 2017 aimed at acquisition of skills by pupils and students in working with dosimeters as well as studying “ionizaing radiation” term. The realized studies resulted in activation of children’s interest in physics and biology, geology and chemistry.
In perspective laboratory experiments and measurements may be conducted using methodical results of Gumilyov Eurasian National University and Obninsk Nuclear Energy Institute, enabling to predict with certainty appearance of students’ and pupils’ scientific works and projects related to nuclear theme.

This paper presents the results of an experiment on high-temperature oxidation of SiC coating of a prototype HTGR fuel in an oxygen environment under the following experimental conditions: the maximum temperature of the samples with linear heating is 1400 °C; heating rate – 10 °С/min.
According to the results of the experiments, dependences of the change in the composition of the gas mixture in the corrosion chamber with linear heating of the sample were obtained. A qualitative analysis of corrosion data and microstructural research data was carried out before and after the corrosion experiment.
The results obtained allow us to estimate the corrosion resistance and the loss of the operational properties of SiC coatings on prototype HTGR fuel.

This article presents the first stage of work on the implementation of the project for the creation of an installation for testing fusion materials at WWR-K reactor using the vacuum extraction method. In particular, the data of calculations of the vacuum system of the installation for various geometries of the vacuum path are presented. The developed model made it possible to estimate the range and distribution of pressures along the length of the irradiation device and the vacuum system.
The obtained values of the pressure distribution showed that, in general, the physical ability to register the flow of tritium and helium into the system will be sufficient for the levels of production of tritium and helium in the samples under study above 10^-11 mol/s.

This article presents the results of work on the development of the installation and the experimental and calculated substantiation of the method of TDS studies of metal samples using an induction heating system. The results of the methodical TDS experiments with samples of stainless steel X18H10T of various thickness, performed under pumping conditions at heating rates from 0.5 to 2 K/s, are presented. The main technical characteristics of the facility, and the methodological procedures for conducting TDS studies were identified.

An important technical problem in the study of high-temperature corrosion of graphite materials and SiC-C structures in water vapor in vacuum is to ensure a stable partial pressure (0.001–1.0 Pa) of water vapor in the sample zone. Since the temperature in the sample zone can reach 1400–1700 K, then it is not possible to locate sensors for measuring the vapor pressure there. The paper proposes a method of using metal surfaces of existing or specially introduced elements of a vacuum system (receivers, tanks, pipelines) as a source of water for their controlled heating. Using the computer model of the gas-vacuum environment of the corrosion plant, the ratio of water pressures at the point of sample location and at the point of sampling of the mass analyzer is calculated. The resulting ratio and the analog signal of the mass analyzer (water peak, 18 amu) are used for PID control of the desorption temperature to achieve the required vapor pressure.

The conversion of research reactors to low-enriched uranium (LEU) fuel is assumed on the base of the National Nuclear Center of the Republic of Kazakhstan. The high-enriched uranium (HEU) fuel will be down blended up to the condition that prevents proliferation of nuclear weapons.
Material testing have been carried out in order to determine the properties of non-irradiated HEU fuel important for transportation and future down blending of the fuel. Non-irradiated IGR reactor HEU fuel will be used for fuel down blending method development. LEU fuel was studied to obtain information about properties for comparison with HEU fuel. Determination of structural and phase analysis of material is one of the key point in material studies of IGR reactor fuel. Literature overview revealed the absence of technical standard documentation specifying requirements for structural specifications of graphite of uranium-graphite fuel and, correspondently, for application of X-ray structural analysis to define graphite structural specifications.
The paper presents main results of material research and focused on analysis of x-ray specifications of uranium-graphite fuel.
The progress report was presented at VIII International Conference “Semipalatinsk Test Site: Legacy and Prospects for Scientific and Technical Potential Development”.

The articles gives experimental data on ³Н, ⁹⁰Sr, ^239+240Pu, ¹³⁷Cs leaching from soil of various contaminated areas of the Semipalatinsk test site to natural water. Leaching degree has been determined. Leaching process of radionuclides from soils to natural water is noted to be one of the main contamination mechanisms, which is quantitatively characterized by leaching degree. Leaching of radionuclides from soils of STS sites of interest is not dependent on soil contamination level. It is found that le4aching process of radionuclides is characteristic of each site but its intensity for different radionuclides is not the same. This is due to chemical properties of radionuclides and their speciation in soil.