DURABILITY OF AN LA2ZR2O7 WASTE FORM CONTAINING VARIOUS AMOUNTS OF SIMULATED HLW ELEMENTS

Durability of an La2Zr2O7 waste form containing various amounts of sim ulated HLW elements was examined at 90-degrees-C in three kinds of sol utions. In HCl solution of pH = 1, the leach rates of La, Nd and Ce fr om the La2Zr2O7 waste form decreased with increasing concentration of Nd and Ce which were solved in LaZr2O7 yielding solid solutions. In de ionized water of pH = 5.6 and NaOH solution of pH = 10, however, such a compositional effect on leach rates was not observed because of the formation of hydroxides or carbonates on the surface of the solid.