An active program is a present underway to develop equipment to handle liquid metals. Among the metals being studied are sodium and sodium--potassium alloy (the latter commonly referred to as NaK). In many of the systems being studied this liquid metal is pressurized by inert gas in the lines. At times it is necessary to bleed off some of this gas from the system. Although the gas is allowed to escape at a temperature at which the vapor pressure of sodium is extremely small, it has been found that excessive amounts of sodium are present in this gas stream. Either this sodium collects in the lead-off pipes from the system as a solid, threatening to block the passage in which it is found, or it passes out into the atmosphere. In order to explain the presence of such a dangerous concentration of sodium in the exit gas stream, it has been proposed that the sodium vapor present in the the system at high temperatures condenses into a mist or aerosol on cooling. This aerosol is stable and will not readily de-entrain or condense onto the surfaces over which it passes. Another possibility is that the oxygen present with the inert …