PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY
Series: Nuclear and Reactor Constants

since 1971

Русский (РФ)

ISSN 2414-1038 (online)

Authors & Affiliations

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

Osipov A.A. – Senior Researcher, Cand. Sci. (Tech.). Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7 (484) 399-46-56; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Ivanov K.D. – Leading Researcher, Dr. Sci. (Tech.).
Niyazov S.-A.S. – Senior Researcher.

Abstract

With regard to the mass transfer processes associated with the interaction of the coolant with structural steels and with the behavior of solid-phase impurities based on iron oxides in the circulation circuit with HLMC, the question of the influence of changes in the physic-chemical state of the coolant due to the presence of iron impurities in it is considered. When operating nuclear power plants with heavy heat carriers, their physic-chemical state relative to the content of iron and oxygen impurities can vary quite widely.
It is shown that the degree of influence of the iron impurity depends on the ratio of its content with the content of the oxygen impurity, which in turn determines the resulting oxygen regime of the coolant in the form of the thermodynamic activity of the oxygen impurity. It is noted that the entire area of practically significant changes in this parameter can be conditionally divided into two areas: – the dominant influence of oxygen admixture (at high values of oxygen TDA) and, accordingly, the area of the dominant influence of iron admixture.
The main features of the flow of the analyzed mass transfer processes depending on the realized physic-chemical state of the coolant are considered.

The analysis of the available experimental data and theoretical estimates is carried out, which show that in the presence of an iron impurity in the HLMC, depending on the level of oxygen TDA, the nature of the interaction of the coolant with the surfaces of oxide films changes, as well as the behavior of solid-phase impurities based on iron oxides changes qualitatively.
An explanation of the observed effects is proposed, which consists in the fact that in the area of the dominant influence of iron admixture, solid-phase iron oxides in HLMC pass from a lyophobic state to a lyophilic one.

Keywords
mass transfer, thermodynamic activity, heavy liquid metal coolant, oxygen and iron impurities, oxides, oxygen, metal oxidation, structural steel, oxidation potential, lead, temperature, oxygen regime, oxide film

Article Text (PDF, in Russian)

References

UDC 621.039.534

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2022, issue 1, 1:14