Abstract: A method of and apparatus for separating krypton from radioactive waste gs which become free during the chemical dissolution of burnt-off fuel particles and contain krypton and xenon. Simultaneously with the core fuel particles conveyed to the chemical dissolution, such quantity of chemically inactive carrier gas intermixable with the waste gases is added to the substances bringing about the chemical dissolution that after purification of the waste gas mixture from gas components such as oxygen, carbon dioxide, nitrous oxide, hydrocarbons and water steam and after subsequent cooling of the waste gas mixture to the boiling temperature of the liquid nitrogen, the quantity of xenon contained in the waste gas mixture is quantitatively precipitated in solid form. Thereupon the waste gas mixture is by means of liquid nitrogen, while simultaneously increasing the pressure, cooled to such an extent that krypton is precipitated.

Abstract: A fluid operable rotary piston device having a housing with gas inlet and tlet means and a hollow cylinder rotatable therein having gas inlet and gas outlet ports which communicate with the gas inlet and outlet means during rotation of the cylinder. A rotary piston is rotatable on an eccentric axis inside the cylinder and the cylinder and piston have interengageable means forming contact free working chambers. Axial sealing strips are mounted on one of the piston and cylinder and form contact free sealing gaps between adjacent working chambers. The cylinder rotates in the housing in contact free relation therewith and a transmission connects the piston and cylinder for rotation at respective speeds.