Procedure for removing alpha activity from liquid medium designed for long-term storage of spent nuclear elements from nuclear power facilities

Alpha activity is removed by coprecipitation of the transuranium alpha nuclides on hydrated zirconium oxides and magnesium oxides at pH>=10 in the static mode. The hydrated oxides form voluminous precipitates which sediment and, after adding Zr and Mg nitrates in the Zr:Mg ratio of 1:3, coprecipitate quantitatively all the alpha nuclides present. The precipitate can then be removed. The method is applicable with advantage to static conditions where stirring is hardly practicable. The precipitate is well soluble in acid media, which facilitates its subsequent handling. (M.D.)