The article considers the possibility of using the method of multiphase fluid Volume of Fluid (VOF), the Ansys Fluent program, for numerical simulation of the melting process of the materials of the experimental device and their movement over the volume of the computational domain. For modeling the design of a typical experimental device tested in the reactor was selected, a two-dimensional computational model was developed, methods for solving the thermal problem were described, and the simulation results were presented.

The gradient of the neutron field in a nuclear reactor and the requirements for the permissible spread of the specific electrical resistance over the volume of the silicon ingot makes it necessary to develop an irradiation device. This is especially true for large silicon ingots. One of the options for reducing the gradient of the neutron flux along the height of the ingot is the use of neutron-absorbing screens in the design of the irradiation device. At the WWR-K reactor, cadmium with a natural isotopic composition is used as a neutron-absorbing screen material. The paper presents the results of a study of an irradiation device with a cadmium screen. The effect of a cadmium screen on the neutron-physical characteristics of an irradiation device for silicon doping is shown.

On the territory of the Plavsky radioactive hotspot of the Tula region of Russia, formed as a result of the accident at the Chernobyl nuclear power plant in 1986, an assessment of the radiation safety of growing carrots and beets was carried out in 2019. It has been established that at present the content of ¹³⁷Cs in arable leached chernozems of the surveyed lands is 90–170 kBq/m² , which is 2.5–4.5 times higher than the permissible level of density of surface radioactive contamination of soils. However, the specific activity of the radionuclide in carrot and beetroot crops does not exceed 5 Bq/kg, which is significantly less than the maximum permissible level of ¹³⁷Cs accumulation in vegetables (600 Bq/kg for absolutely dry weight). The accumulation coefficients of ¹³⁷Cs in the total biomass of carrots and beets are 2.0·10⁻² and 7.5·10⁻², and in eaten root crops – 1.1·10⁻² and 2.0·10⁻², respectively, which is in good agreement with the IAEA estimate for the intensity of the transition ¹³⁷Cs in the production of vegetable roots from loamy and clayey soils.

Kazakhstan’s nonproliferation initiatives are recognized worldwide. Kazakhstan is a party to almost all major nuclear treaties, a key driver in the creation of a Central Asian nuclear-weapon-free zone, initiated the Universal Declaration on Building a World Free of Nuclear Weapons, established a low-enriched uranium bank under the auspices of the IAEA in Ust-Kamenogorsk to be used for peaceful purposes in the event of a disruption in the supply of fuel for nuclear power plants.
While the foreign policy acts of Kazakhstan in non-proliferation are well known and internationally appreciated, the transfer of Kazakh experience in the governance of the nuclear sector is lesser known asset. For example, the experience of the Committee for Atomic and Energy Supervision and Control and KAZATOMPROM in uranium mining and transport was shared with countries from the Southern African Development Community, under an EU project, implemented by the International Science and Technology Center. This example reveals the great potential this themes have for the further input of Kazakhstan in international development cooperation.

The article is devoted to an issue of estimating the impurity gas amount in nuclear fuel in the aspect of the distracting contribution from released gases to the total pressure inside ampoule of the device in the simulating a severe accident with core melting. The paper presents a method based on measuring the pressure and temperature of gas in a closed values of the fuel elements during the fuel melting. The correctness of the developed methodology is confirmed by the results of experiments on the melting of fuel in a pulsed graphite reactor IGR with the implementation of a controlled neutron pulse.

This paper presents the results of a study of the formation of a carbidized layer under various experimental conditions and the choice of optimal parameters for carbidization of a tungsten surface under plasma irradiation. To study the effect of the surface temperature of a tungsten sample and the duration of plasma irradiation, experiments were carried out at a sample surface temperature of 1300 °C and 1700 °C with an irradiation duration of 300–2400 s. Analysis of the research results showed that the maximum formation of W₂C on the surface is observed at a test temperature of 1700 °C. At a temperature of 1300 °C, the phase composition of the carbidized layer depends on the duration of plasma irradiation. According to the literature analysis, the formation of WC occurs on the surface of tungsten, from which C diffuses into the particle and forms the underlying layer of W₂C. With an increase in the ion fluence, depending on the irradiation time and the temperature of the sample surface, the diffusion of C into W accelerates, the WC content decreases, and W₂C becomes the dominant carbide compound.