A study was conducted on the vitrification of the rare earth oxide waste generated from the PyroGreen process. The target rare earth waste consisted of eight elements: Nd, Ce, La, Pr, Sm, Y, Gd, and Eu. The waste loading of the rare earth waste in the developed borosilicate glass system was 20wt%. The fabricated glass, processed at 1,200℃, exhibited uniform and homogeneous surface without any crystallization and precipitation. The viscosity and electrical conductivity of the melted glass at 1,200℃ were 7.2 poise and 1.1 S·cm−1, respectively, that were suitable for the operation of the vitrification facility. The calculated leaching index of Cs, Co, and Sr were 10.4, 10.6, and 9.8, respectively. The evaluated Product Consistency Test (PCT) normalized release of the glass indicated that the glass satisfied the requirements for the disposal acceptance criteria. Furthermore, the pristine, 90 days water immersed, 30 thermal cycled, and 10 MGy gamma ray irradiated glasses exhibited good compressive strength. The results indicated that the fabricated glass containing rare earth waste from the PyroGreen process was acceptable for the disposal in the repository, in terms of chemical durability and mechanical strength.

1. Introduction
2. Experimental
    2.1 Fabrication of Glass
    2.2 High Temperature Viscosity
    2.3 High Temperature Electrical Conductivity
    2.4 Chemical Durability
    2.5 Mechanical Strength
    2.6 Microstructure
3. Result and Discussion
4. Conclusions
Acknowledgements

• Young Hwan Hwang(Central Research Institute, Korea Hydro & Nuclear Power, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon 34101, Republic of Korea) Corresponding Author
• Mi-Hyun Lee(Central Research Institute, Korea Hydro & Nuclear Power, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon 34101, Republic of Korea)
• Cheon-Woo Kim(Central Research Institute, Korea Hydro & Nuclear Power, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon 34101, Republic of Korea)