[en] Low melting alkaliborosilicate glasses have been considered for use in the immobilization of high level radioactive wastes for years. A recent study comparing the surface behavior of two nuclear waste glasses concluded that ''Addition of Fe₂O₃ to a soda borosilicate nuclear waste glass significantly reduces damage by water attack because of a Fe-rich film that forms on the glass surface''. However, in the previous study there were significant differences in the concentration of SiO₂, B₂O₃, CaO and simulated fission products in the glasses which made it impossible to ascribe the improved leach resistance solely to Fe₂O₃ content. Thus, the objective of the present investigation is to compare the leaching and surface behavior of two nuclear waste glasses which differ only by the substitution of Fe₂O₃ for some of the ZnO in the glass. By this comparison the authors hope to establish whether Fe₂O₃ provides a unique contribution to improvements in the leach resistance of these complex glasses. Both glass compositions studied are compatible with the low melting temperature, <1150⁰C, required for the French AVM Process. The quantity of simulated waste products is 9%, characteristic of the Swedish nuclear waste program. (Auth.)