Heavy-ion irradiation effects on U 3 O 8 incorporated Gd 2 Zr 2 O 7 waste forms.

In this research, the heavy-ion irradiation effects of U-bearing Gd2 Zr2 O7 ceramics were explored for nuclear waste immobilization. U3 O8 was designed to be incorporated into Gd2 Zr2 O7 from two different routes in the form of (Gd1-4 x U2 x )2 (Zr1- x Ux )2 O7 (x = 0.1, 0.14). The self-irradiation of actinide nuclides was simulated by Xe20+ heavy-ion radiation under different fluences. Grazing incidence X-ray diffraction (GIXRD) analysis reveals the relationship between radiation dose, damage and depth. The radiation tolerance is promoted with the increment of U3 O8 content in the discussed range. Raman spectroscopy testifies the enhancement of radiation tolerance and microscopically existed phase evolution from the chemical bond vibrations. In addition, the microstructure and elemental distribution of the irradiated samples were analyzed as well. The amorphization degree of the sample surface declines as the U content was elevated from x = 0.1 to x = 0.14.