Reactions between U–Zr alloys and Fe at 923 K

Interdiffusion experiments were carried out at 923 K with the diffusion couples consisting of U–23 at.% Zr/Fe and U–23 at.% Zr–1 at.% Ce/Fe. The reaction layer adjacent to the Fe was a single Zr-depleted UFe₂ phase. The phases in the reaction layers were estimated consistently with the calculated U–Zr–Fe ternary isotherm. The diffusion path obtained in this study was similar to that reported for the U–Pu–Zr/HT9-steel couple at 923 K, when those paths were expressed on the (U+Pu)–Zr–(Fe+Cr) composition triangle. The reaction layers grew in proportion to the square root of the annealing time. The addition of approximately 1 at.% of Ce to the U–23 at.% Zr alloy has little effect on the reaction between U–23 at.% Zr and Fe.