Feasibility assessment of a remote krypton sampling system for emergency applications

Radioactive krypton ( 85 Kr) is a chemically inert fission product that serves as an important tracer for nuclear activities. Conventional monitoring systems require manual liquid nitrogen (LN 2 ) replenishment, limiting their use in remote sites and emergency situations. In this study, a cryogenic remote krypton sampling system was developed by integrating an LN 2 production and auto-supply module, vacuum-insulated dewars, and a remote-control program. Laboratory tests demonstrated that Bakelite flanges, EPS insulation, and embedded adsorption structures significantly reduced LN 2 boil-off. In the field, an auxiliary electric system improved insulation stability. Air sampling experiments conducted in parallel with the conventional method confirmed equivalent performance, with adsorption efficiencies of about 72 % and krypton activity concentrations of 1.32 ± 0.04 Bq/m 3 . These results indicate that the developed system maintains stable cryogenic conditions, achieves comparable sampling efficiency, and enables remote operation with automated LN 2 supply. The system is feasible for both routine krypton monitoring and emergency response applications.