A novel material, Apatite II, obtained from a natural source, has been determined to be a good adsorbent for radionuclides of strontium, europium and trivalent actinides, but not caesium, from neutral aqueous solutions containing common chelating agents and inorganic salts at moderate concentrations. This inexpensive, easily available material seems to be a promising backfill for engineered barriers in nuclear waste repositories. However, encapsulation of the sorbent grains loaded with radiostrontium in the Portland cement matrix results in undesirably high leaching rate for this particular radionuclide.