The behavior of spent nuclear fuel exposed to groundwater is crucial in the safety assessment of a deep geological repository for spent nuclear fuel. For this reason, leaching experiments on spent nuclear fuel as well as non-radioactive analogues have been conducted for several decades. Although the processes involved can be considered to be fairly well understood, there is a need for further experimental studies whenever new fuel types are introduced. Fuels with burnable absorbers are now in use but very little is known about their behavior under repository conditions. In this work, the impact of burnable absorbers doping (Gd, 3–8%wt.) on the oxidative dissolution of UO₂ in an aqueous system was studied in H₂O₂ and γ-irradiation induced dissolution experiments. The results showed a significant decrease in uranium dissolution and lower reactivity towards H₂O₂ for (U,Gd)O₂ pellets compared to standard UO₂. The resulting decrease in the final oxidative dissolution yield was mainly attributed to decreased redox reactivity of the UO₂-matrix upon doping. The results of the gamma radiation exposures display an even larger effect of Gd-doping. These findings indicate that other processes are involved in the radiation-induced dissolution of Gd-doped UO₂ compared to pure UO₂.

暴露于地下水的乏核燃料的行为对于深层核废燃料地质处置库的安全评估至关重要。因此，几十年来已经对乏核燃料以及非放射性类似物进行了浸出实验。尽管可以认为所涉及的过程相当了解，但是每当引入新的燃料类型时，都需要进行进一步的实验研究。现在正在使用带有可燃吸收剂的燃料，但对其在储存条件下的性能知之甚少。在这项工作中，研究了在H ₂ O ₂中可燃吸收剂掺杂（Gd，3–8％wt。）对UO ₂在水体系中的氧化溶解的影响。和γ射线诱导的溶出实验。结果显示，与标准UO ₂相比，（U，Gd）O ₂颗粒的铀溶出量显着降低，并且对H ₂ O _2的反应性降低。最终氧化溶解产率的最终降低主要归因于掺杂时UO _2-基体的氧化还原反应性降低。伽玛射线曝光的结果显示出更大的Gd掺杂效应。这些发现表明，与纯UO ₂相比，其他过程参与了辐射诱导的掺Gd的UO _2的溶解。