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The results of a model experiment on removing fission products and process impurities from a melt consisting of the salts NaCl-2CsCl by precipitation of weakly soluble phosphates are described. x-Ray phase analysis, scanning electron microscopy, emission spectral analysis, and the MSS-1 test are used to study the chemical and phase composition as well as the thermal and chemical stability of a ceramic produced from the phosphate precipitate. It is shown that the main phase of the ceramic is monazite, which incorporates many rare-earth elements and processing impurities. The ceramic obtained possesses high hydrolytic and thermal stability, making it a promising material for immobilizing wastes.

Investigations to validate a method of immobilizing high-level wastes from pyroelectrochemical reprocessing of spent nuclear fuel in mineral-like crystal matrices have been conducted. Methods for obtaining and the microstructure, elemental and phase compositions, and chemical stability of a ceramic matrix based on the mineral kosnarite, intended to be used for immobilizing wastes of alkali-metal chloride melts, are studied using inactive model materials, x-ray phase analysis, scanning electron microscopy, x-ray microspectrometry, and leach tests.

The results of investigations of the vitrification of chloride wastes produced during test reprocessing of spent BOR-60 fuel by the pyroelectrochemical method are presented. A method is proposed for converting chlorides into metaphosphates beforehand, which makes it possible to introduce up to 46% wastes into the glass matrix. The optimal composition of the glass matrix is determined, and the properties of the model and real samples obtained are presented. The hydrolytic and thermal resistance of the samples is investigated.

The history and basic results of work on nuclear rocket motors (NRMs) in Russia are presented. S.P. Korolev, I.V. Kurchatov, M. V. Keldysh, A. P. Aleksandrov et al. stood at the source of the work in this direction. Our NRM reactors used a heterogeneous scheme with a modular core. This enable component-by-component debugging of the reactor experimentally to the required degree of reliability. Ultimately, the costs of the complex tests were minimized, and technical characteristics obtained exceeded those obtained abroad. The energy-release density in the fuel elements reached 30 kW/cm3, and the temperature and rate of heating of the working body (hydrogen) reached 3100 K and 1000 K/sec, respectively.