Development of a Sodium Vapor Pressure Meter Using Beta-Alumina Ceramics

A program was carried out to develop a sodium vapor pressure measuring system using beta-alumina ceramics for use in developing sodium vapor traps and monitoring sodium mist in cover gas for fast breeder reactors (FBRs) and test facilities. The sensor device was tested in a vacuum glass capsule. Its output agreed well with theoretical results. Moreover, it proved to have the capability of measuring a lower vapor pressure near 10⁻⁵ Torr without any calibrations. The measuring system, consisting of a beta-alumina sensor device, gas circulating pump, gas heater, and mist trap, is applicable to FBR plants and test facilities that contain much sodium mist and to a transient monitoring system. This system was tested in an isothermal sodium vapor circulation test loop under conditions involving much sodium mist.