Immobilisation of cesium in matrices based on the blast furnace slag incorporating zeolitic additives

Radioactive cesium and cobalt were sorbed from chloride solutions onto chemically treated, granular zeolitic tuff The granular active (10 or 20 wt.%) and the disperse non active tuffs (10 wt. %) were incorporated into cement slurries based on the blast furnace slag and water glass solution before their casting into rectangular moulds (1 x 1 x 3 cm). The compressive strength of specimens after their placement for 42 days in humid atmosphere and subsequently for 42 days in corrosive alkaline or acid water solutions was comparable or slightly higher than the compressive strength of specimens cured in humid atmosphere for 28 days. Leaching test in corrosive liquids showed good retention of radionuclides in observed matrices. A decrease of the radioactivity of specimens was more pronounced only for samples placed in acid solutions.