Proceedings of the conference

Fiskov A. Kritskii V.G. Makaseev A.U. Makaseev U.N.

The study of the behavior of coatings based on silica-organic composition OS 51-03 of the containment during severe accidents at NPP

The work describes an experimental study of the determination of chemical stability of protective coatings under conditions of severe accidents at nuclear power plants. Another task of the work was to evaluate the thermal degradation of the coatings and the analysis of the resulting solids (debris), which can cause overload of cooling systems, as well as be a source of release of combustible gases.

To ensure reliable corrosion protection of the inner containment shell was used the protective coating including plating the steel surface of the shell is aluminum, with the subsequent drawing on it organic silicate composition OS-51-03. This coating has been proven as stable in chemically aggressive environments and in streams of radiation at temperatures up to 200 °C.

In conditions of a severe accident environment inside the containment shell becomes highly aggressive because of high temperatures, pressure and high radiation levels. When conducting an experimental study of coating parameters for such a corrosive environment was simulated dynamically.

In the course of the work have been obtained and investigated technology solutions, determined the by their viscosity and density taking into account the dynamics in the course of a severe accident. Was determined the particle density of the chemical debris and conducted their sedimentation analysis to determine fractional size. Also was evaluated the corrosion and hydrogen security of operation of a covering veneer protective shell.

The data obtained allow to justify the choice of type of coverage and its compliance with requirements of regulatory authorities. The behavior of the organic silicate composition OS-51-03, was applied on a the aluminum surface of the protective shell of a nuclear power plant, in conditions of a severe accident can be described using the obtained data. Composition OS-51-03 has shown itself resistant to high temperatures, pressures, high radiation levels, aggressive liquid and gaseous media, so it is recommended for use as a protective coating for the design, construction and operation of NPP.

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