Authors & Affiliations

Shelemetiev V.M., Martynov P.N., Storozhenko A.N., Chernov M.E., Ulyanov V.V.
A.I. Leypunsky Institute of Physics and Power Engineering, Obninsk, Russia

Abstract

Currently, the new nuclear power plants (NPP) are developed in Russian Federation wherein are used different liquid metal, sodium and heavy lead-based liquid-metal, as coolants. In respect to these NPP control tools of hydrogen and oxygen in gas environment are required. For sodium-cooled NPP the usage of hydrogen and oxygen control tools is required for solution of the security problems at a steam leak and depressurization of cooling circuit. For NPP with a heavy liquid-metal coolant the hydrogen control tools are required is not only for control of possible a steam leak in steam generator, but also for conducting the technological actions using hydrogen for cleaning of a coolant and the first cooling circuit. Oxygen control is required to diagnose the development of the various negative processes (occurrence of depressurization of cooling circuit, oxygen and air leaks, etc.) at the early stages. Also, oxygen control allows to perform indirect identification of the thermodynamic activity of oxygen in the melt, the beginning and the degree of completion of the oxidation of the molten liquid metal. In depends on the type of a coolant, control hydrogen and oxygen tools meet the different requirements for sensitivity and response speed. For example, the most important parameter for hydrogen and oxygen control tools in sodium-cooled NPP is the response speed and for NPP with the lead-based coolant is hydrogen sensitivity. IPPE has a great many-years' experience in the development of various control devices both for liquid and gaseous media. The most promising oxygen and hydrogen control tools are solid electrolyte sensors. Also conductometric sensors (the principle of operation of which is based on the ability of palladium alloys reversibly absorb hydrogen gas from the surrounding environment and thus change its electrical resistance depending on the partial pressure of hydrogen) show good results in control of hydrogen. At the moment, these devices have been applied to the existing nuclear power plants in Russia and abroad, in the hydrogen safety systems for beyond design basis accidents.

Keywords
nuclear power plant, heavy liquid metal coolant, sodium coolant, protective gas, hydrogen control, oxygen control, hydrogen and oxygen tools, solid electrolyte sensors, conductometric sensors

Article Text (PDF)

References

UDC 621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, issue 3:9, 2015