Comparison of Adsorption Coefficients of Argon, Krypton, and Xenon on Various Activated Charcoal Grades in Static Conditions

Abstract

Coefficients of adsorption (Henry's constants) of noble gases (argon, krypton, xenon) on activated charcoal grades AG-3, VSK-5, SKT-3, NWC 12x40 in the temperature range of 15 °C to 80 °C were determined. Temperature dependence parameters of Henry's constants were determined with a calculation of isosteric adsorption heat values. The experimental data were used to calculate stationary operating conditions of a radiochromatographic column in NPP's noble gas delay system. Out of all the studied charcoals, the results show that coconut charcoals VSK-5 and NWC 12x40 have the highest decontamination factor to airflow purification from radioactive noble gases. They far outweigh sulfur−potassium activated peat charcoal SKT-3 used presently at most Russian nuclear power plants. Activated charcoal AG-3 does not ensure the decontamination level required. The results also show that the overall decontamination factor depends heavily on temperature. Precooling gas flow at the adsorber's input can considerably increase air decontamination factor from radioactive noble gases.