[en] The paper describes basic provisions of the physical and technical substantiation and application of hot isostatic pressing (HIP) for solving the problem of reliable radioactive waste consolidation. Different approaches for the HIP process to be used for radioactive waste immobilization in protective matrices and spent nuclear fuel encapsulation in protective containers are proposed. Basic research and development results in this area are presented. Application of HIP in nuclear industry is promising for creation of radiation- and corrosion-resistant protective ceramic compositions (ceramization of high-level waste), in particular, with the purpose of high-level waste immobilization. Protective forms for encapsulation of spent nuclear fuel is the second area of using HIP. The role and efficiency of the HIP technology are shown on the example of laboratory process to encapsulate a simulated spent fuel assembly of the RBMK reactor in a protective ceramic form. The development of technologies for conditioning of radioactive waste in mechanically durable, radiation-resistant and corrosion-resistant protective ceramic forms with the use of HIP assists in solving the problem to reliable radioactive waste isolation.

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[en] We investigated the properties, regularities of the phase- and structure-formations and the strength characteristics of composite ceramics of the W₂B₅-TiB₂B₄C system. The promising technology of the reaction hot-pressing with the possibility of replacing up to 50% of metal borides in the starting material by a cheap blend containing the appropriate metals, oxides, and boron carbide. Chemical reactions during the sintering of ceramics activate the consolidation and can significantly lower the temperature of hot pressing, which decreases the cost of finished products while maintaining their strength properties.

[en] A method for assessing the release of radioactivity to the environment from radioactive waste storage containers of different shapes is developed. The method is based on mathematical modeling of radionuclide migration using a one-dimensional differential equation of non-stationary diffusion in spherical coordinates in a single-layer hollow sphere. The results obtained with the method satisfactory agree with the data obtained by other authors.

[en] On the base of the formulated scheme of the underground disposal of radioactive wastes of nuclear power stations as the spent nuclear fuel, the simplified mathematical model of thermo- and mass transfer in a granite massive and computer program to realize this model was created. The program allows to calculate temperature fields and distribution of radionuclide concentration in any point of a geological layer for the given scenario of the radioactive waste disposal. The results of calculations of temperature field distribution at various moments of time for the concrete density of placing encapsulated spent nuclear fuel of RBMK under the condition of limiting maximal temperature (100 degree) in geological environment of disposal medium are submitted. The estimation of space and time distribution of radionuclide concentration in a granite massive at leaching them from spent oxide fuel after the destruction of the protective capsule is carried out

[en] The mathematical model of thermophysical processes taking place in canisters, tunnels and granite has been developed for determining the parameters of deep disposal of radioactive waste and spent nuclear fuel. The scheme of geological disposal is chosen and its parameters are calculated

[en] Radiation dose levels of radioactive waste in the KTZV-0.2 container are simulated by the Monte Carlo method. In order to increase the lifetime and improve the characteristics of the container as a radiation shield, the possibility of using high-density composite ceramics is considered. Characteristics of radiation exposure for ceramics and reference material are compared.

[en] From powder compositions on a basis kaolin were manufactured mullite-tridymite ceramic materials. The content of glass phase in materials were controlled by introduction of Al₂O₃ additive and parameters of roasting. Nuclei forming burning and the subsequent hot isostatic pressing-processing allowed to carry out controlled crystallization of glass phase resulting to formation of α-and β-krystobalite

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