Authors & Affiliations

Osipov A.A., Niyazov S.-A.S.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Osipov A.A. – Senior Researcher, A.I. Leypunsky Institute for Physics and Power Engineering. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7(484) 399-42-19; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Niyazov S.-A.S. – Senior Researcher, A.I. Leypunsky Institute for Physics and Power Engineering.

Abstract

This paper deals with the problem of modeling the thermodynamic activity (TDA) of oxygen (a measured parameter) in metal melts, in particular, heavy liquid metal melts based on lead and lead-bismuth. With regard to promising nuclear power plants with a heavy liquid metal coolant (HLMC), the issue of the interaction of oxide films with a liquid metal is relevant, since oxide films on the surfaces of structural steels act as a protective barrier that prevents the steels from dissolving in HLMC. The thermodynamic stability of oxide films and their diffusion properties depend on the TDA of oxygen in HLMC. At the same time, oxygen TDA in HLMC substantially depends on impurities (mainly iron, as the main component of structural steels). Currently, thermodynamic models of multicomponent metallic solutions based on lead and lead-bismuth are still in their infancy, while the thermodynamic model of Me–O solutions is a fundamental component of more complex systems. Therefore, the success of more complex models describing the thermodynamic properties of real multicomponent solutions based on metal melts depends on the adequacy of the thermodynamic concepts of Me–O solutions. Analysis of the experimental data shows that the solubility of oxygen near the melting point of the metal is much less than unity, therefore, the solutions of Me–O are highly diluted (metal activity equals a unit). In the present work, a thermodynamic model of dilute solutions of Me–O is considered. Within the framework of this model, Me–O solution is considered as a “multicomponent” system, where by components are meant various forms of the existence of oxygen in a metal solution (for example, O, MeO, O2–, Me2O, etc.). As a result of this consideration, it becomes possible to generalize Henry's law to metallic dilute solutions, in which oxygen exists in various forms. The considered approach is of a general nature and can be applied to other diluted multicomponent systems in which the solute can interact with the solvent and with each other.

Keywords
liquid metal coolant, the activity coefficient of oxygen, liquid metal, first order interaction parameter, dilute solution, Henry's law, Haber-born cycle, reactor plant, chemical thermodynamics, lead

Article Text (PDF, in Russian)

References

UDC 621.039.534

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2018, issue 5, 5:2