Development of sodium aerosol sensor using Na - β - Al2O3 powders synthesized by gel - to crystallite conversion

Liquid sodium is used as the heat transfer fluid in fast breeder reactors (FBR). In the event of accidental leak, high temperature sodium reacts with oxygen and moisture in air leading to sodium fires. These fires produce sodium aerosol containing oxides of sodium (Na2O and Na2O2) and NaOH. For early detection of sodium fires, sensor systems based on sodium ionization detector, pH measurement and modulation of conductivity of graphite films are known in the literature. Sensors based on solid state galvanic cells have become increasingly important in practical applications for process control automation and environmental pollution protection. The present study deals with the development of an electrochemical sensor based on sodium-ion conductor. Among various sodium ion conducting solid electrolytes, sodium beta alumina is a promising electrolyte due to its phase stability, very low electronic conductivity and negligible dilatometric variations. Fabrication of an electrochemical sensor with β- Al2O3 electrolyte and its characteristics are dealt in this paper