HYDROGEN ABSORPTION PROPERTIES OF U-TH-ZR AND U-TH-TI-ZR ALLOYS

Hydrogen absorption properties of several U-Th-Zr and U-Th-Ti-Zr alloy s were investigated for the purpose of developing a new hydride nuclea r fuel. Both alloys consisted of two phases, Th and U-Ti-Zr phases for U-Th-Ti-Zr alloys, Th and U-Th-Zr phases for U-Th-Zr alloys. The main phase of hydrogenated alloys were ThZr2H7+/-x in both systems and hyd rogen holding abilities of both alloys were as high as that of Zr. Abs orption speed by U-Th-Zr alloys however were much higher than those by U-Th-Ti-Zr alloys. On hydrogenation of U-Th-Ti-Zr alloys the formatio n of a stable ternary Ti-Zr-H phase disturbed growth of ThZr2H7+/-x ph ase, whereas a significant solubility of Th in U-Zr solid solution at high temperatures assisted the growth of ThZr2H7+/-x, phase in the cas e of U-Th-Zr alloys.