Processing of Radioactive Waste Solution with Zeolites (II) : Leachability of Cesium and Strontium from Calcined Zeolites

The leachability of Cs from the calcined zeolites A and X saturated with Cs (CsA and CsX) decreased extremely between 900 and 1100℃ by the recrystallization of pollucite and nepheline. The leachability of Sr from the calcined SrA and SrX also decreased extremely above 1000℃ by the recrystallization of SrAl_2Si_2O_8. The values of leaching rate of Cs for the calcined synthetic zeolites were about 10^g/cm^2・day in distilled water, 10^～10^ in artificial sea water and those of Sr were 10^～10^ in distilled water, 10^～10^ in artificial sea water, respectively. These values were lower by two orders than those of glass product. These leaching rates decreased rapidly with the time elapsed and after a few days reached to 10^～10^～10^ and 10^～10^>-11< g/cm^2・day, respectively. Ion-exchange capacity for Cs and Sr was measured by the radio-isotopic method