[en] Procedures for separating the permanent gases have been developed as part of a study to characterize the gaseous radioactive effluents released from nuclear facilities. The gases being separated for internal gas-proportional counting include Ar, Kr, Xe, H₂, CH₄, and CO₂. Water vapor is cryogenically separated for liquid scintillation counting. Samples taken for processing within each facility range from 0.1 ml to several liters in volume. Sample volumes less than 10 ml are separated directly by chromatographic methods. Larger samples are processed using cryogenic-adsorption techniques for rough separation followed by chromatographic purification. Procedures for preventing cross-contamination from sample to sample, and between different radioactive gases within a sample, are considered. Processing requirements imposed by gas composition are also discussed