Abstract: Krypton-85 in ambient air is an important nuclide to be monitored in the surrounding air of spent fuel reprocessing facilities. Generally, monitoring krypton-85 in the air requires the use of freezen adsorbents to adsorb krypton gas under low temperature conditions. During the gradual heating process, different gases with different boiling points are used to separate krypton; By using chromatographic separation methods, the pre-concentrated sample gas is further concentrated to obtain a sample that meets the measurement requirements. The measurement method usually chooses to measure the beta particles of krypton-85. Liquid scintillation method is a feasible method, but it also has some inherent disadvantages. Further research is needed to establish a stable and reliable monitoring technology for krypton-85 in ambient air.

Key words: krypton-85, concentration analysis, ambient air