process for removal of radioactive krypton and xenon from the exhaust air of nuclear reactors.

摘要

Alternation of the radioactivity of Kr and Xe isotopes contained in gaseous effluents of nuclear reactors to a level permitting the release of Kr and Xe into the atmos. by passing the gaseous effluents through column filled with active carbon having a heaping density of 450-650 g/l. at a linear flow speed of 6-1000 cm/min. for Xe and 6-10,000 cm/min. for Kr, is improved by using an active carbon which has such a methanol-adsorption isotherm that the difference of methanol adsorption at p/ps = 0.025 and p/ps = 0.007 exceeds 15 x 10-3 cm3. of methanol per cm3 of heaped active carbon (p/ps being the methanol satn. value). The radioactive isotopes of Kr and Xe are short-lived, and the passage of Kr and Xe through the active carbon column should be sufficiently delayed to reduce the radioactivity of the gas effluent stream to an admissible level. It has been found that the retention time can be conveniently assessed by measuring the adsorption of methanol on the active carbon as described above.