Abstract: Several factors can influence the activated charcoal adsorption coefficients of gaseous radwaste treatment by activated charcoal delay beds in nuclear power plants. This paper analyzes the effects of temperature, relative humidity, gases concentration and gases flow rates on the activated charcoal adsorption coefficients（mainly to krypton and xenon） based on the treatment process by activated charcoal delay beds. Especially, the rationality of gaseous radwaste system process parameters in AP1000 nuclear plants has been discussed. There are several factors impacting the selection of activated charcoal such as adsorption capacity, adsorption selectivity and service lifetime. In order to improve the treatment effects of gaseous radwaste process, the gas superficial velocity should be within the range of 0.1 to 0.7 centimeter per second, the temperature of chilled water should be decreased appropriately, the relative humidity of gaseous radwaste should be lowered than 25% and the operational pressure should be increased correctly.