Gd-doped UO2의 상분리 및 UO2에 고용된 Gd 함량 측정 |
김건식, 양재호1, 송근우1, 김길무2 |
한국원자력연구소 경수로연료개발부, 충남대학교 재료공학과 1한국원자력연구소 경수로연료개발부 2충남대학교 재료공학과 |
Phase Separation of Gd-doped UO2 and Measurement of Gd Content Dissolved in Uranium Oxide |
|
|
|
|
|
ABSTRACT |
The change of structure and morphology in ( $U_{0.913}$G $d_{0.087}$) $O_2$ during oxidation at 475$^{circ}C$ and heat treatment at 130$0^{circ}C$ in air were investigated using XRD, SEM, and EPMA. The ( $U_{0.913}$G $d_{0.087}$) $O_2$ cubic phase converted to ( $U_{0.913}$G $d_{0.087}$)$_3$ $O_{8}$ orthorhombic phase by oxidation at 475$^{circ}C$ in air. The XRD and EPMA result of the 130$0^{circ}C$ heat treated powder revealed that ( $U_{0.913}$G $d_{0.087}$)$_3$ $O_{8}$ orthorhombic phase was separated into $U_3$ $O_{8}$ and ( $U_{0.67}$G $d_{0.33}$) $O_{2+}$x/ cubic phase. The weight variations of (U,Gd) $O_2$ with various Gd contents were measured using TGA at the same heat treated condition. The weight variation during the heat treatment of Gd dissolve (U,Gd) $O_2$ in air can be expressed in terms of phase reaction equations related with oxidation and phase separation. Based on these phase reaction, a initial content of Gd dissolved in (U,Gd) $O_2$ can be exactly calculated by measuring the weight change during the heat treatment.t. |
Key words:
Phase separation, (U,Gd)$O_2$, Fuel pellet, Oxidation |
|
|
|