铀吸、放氘/氚的热力学同位素效应

实验测定了铀吸收氘和氚单质气体的p-c-T曲线及解吸氘和氚气体的p-t曲线，获得了不同温度下吸气和解吸的平衡压，根据范德荷夫方程得到了铀吸收和解吸氘、氚的热力学参数ΔHΘ和ΔSΘ。数据显示，铀吸收氘和氚气体时，在相同温度相同原子比下，吸氘的平衡压比吸氚的平衡压低，解吸氘的平衡压也比解吸氚的平衡压低，且存在明显的滞后效应。从反应的焓变和熵变来看，铀吸、放氘/氚气体时存在较小的热力学同位素效应。

Thermodynamic Isotope Effects of D2 and T2 Reaction With Uranium

The p-c-T curves of deuterium and tritium absorption by uranium and p-t curves of desorption were measured. The balance pressure of absorption and desorption on different temperatures were got and then the thermodynamic parameters were determined according to the Van’t Hoff equation. It shows that the balance pressure of deuterium absorption is lower than that of tritium absorption on the same temperature and atom ratio. It has the same phenomena for desorption but there are obvious hysteresis effect for reversible process of absorption and desorption. There are a little thermodynamic isotope effects when deuterium and tritium absorption and desorption by uranium estimating from enthalpy and entropy values.