Processing method for radioactive liquid waste

Ca compounds such as Ca(OH)2, CaO, CaCO3 and iron chloride are added under stirring to radioactive alkaline liquid wastes containing decayed radioactive uranium nuclides (UD), fission products (FP), transuranium elements (TRU) and fluorine, to remove mainly fluorine as fluorides in a first filtration step. Further, after shifting the filtrates to an acidic range at pH of not higher than 3, lanthanoide compounds, Ti compounds, Zr or Hf compounds are dissolved or mixed, to shift the pH to an alkali range of not lower than 9 again, thereby removing α and/or β decay nuclides in a second filtration step as coagulated precipitates such as of lanthanoide compounds, Ti compounds, Zr or Hf compounds. This can improve a decontamination coefficient of the liquid wastes by two digit for α radioactivity and by 1 digit for β radioactivity, so that any of them including fluorine can be processed to a concentration of not higher than a drainage control reference value. (T.M.)