抄録
Relatively high concentration of radon, is released from radium in uranium are deposit and is accumulated in the mine gallery. When radon and its daughter products, they are inhaled into human body with the air, some daughter products, such as 218Po, closely attach respiratory tract and radiate high dose to the organ owing to their alpha particlea. So, the most important case of radiation exposure for the mine workers is an internal exposure carried by alpha irradiations of the inhaled radioactive elements. Therefore, if the attempts to remove radon or it daughter products are achieved, the radiation hazard in the mine will be reduced to the permissible level. One of the attempts for this purpose has been tried using the adsorption property of active carbon (type 2GM, used in gas mask).
According to the results, the saturated radon adsorption value As (μc/g) of the active carbon is expressed as following experimental equation.As=6.0×103×(288/t) 12.7×Cs
Where t is ambient temperature (°K) of the specimen and Cs is radon concentration (μc/cm) or tne the air. The equation may be correct for temperature range of between 275°K and 305°K. The caluculated value with the equation agrees with that of BET adsorption isotherms.
A practical device for radon removal was designed considering this result. And the device wastested in the closed gallery of uranium mine at Asabatake. According the experimental results, it is concluded that if a great deal of active carbon and slicagel are used as a adsorption materials, this method will be of great use for radon removal.
