Abstract
Results of the analysis of influence sacrificial layer (SL) composition on the base of titanate ceramics on the processes in external core catcher are submitted.
It was being supposed that SL not only have to mitigate action of corium on refractory layer but then immobilize high level radioactive wastes (HLW). Titanate ceramics was selected as a SL material for this purpose. This ceramics is formed during interaction zirconium and zirconia from corium with refractory concrete of SL on the base of calcium aluminate and barium aluminate with filler from TiO2. The composition of indurated melt represents such well-known compounds as rutile TiO2, perovskite CaTiO3, zirconolite CaZrTi2O7 and phase hollandite type BaTi6Al2O16 which produce Synroc.
Minimization quantity material SL for their total deployment in under reactor space was made leaded. For immobilization of uranium there may be used zirconia from corium (55,5 t) and SL (21,5 t) and zirconolite as uranium yields a continuous range of solid solutions with these substances.
Crystallization processes of the model compositions without uranium oxide were studied. It was determined that perovskite, zirconolite, hollandite and after that crystallization eutectic systems were formed depending on melt crystallization velocity.
