The ¹²⁹I is a long-lived isotope, radiotoxic and highly mobile by-product of fission reactors. Its disposal in geological repositories requires matrix at least as durable as current nuclear waste glasses. The volatility of iodine at high temperature is a concern for nuclear waste glass processing, because its evaporation prior to vitrification, results in a low retention rate in the final glass. The present study investigates the use of pressure for immobilizing iodine during vitrification. For three different glass compositions: International Simple Glass (ISG), NH (a depolymerized glass similar to Low Activity Waste glasses, LAW) and boron-free trachytic glass; we conducted the experiments between 0.5 and 2.0 GPa for pressure and 1300–1500 °C for temperature. We determined the iodine solubility in glass compositions representative of the simplified nuclear waste glass simulants, and the influence of iodine on the structure of theses glasses.

In comparison to ambient atmosphere experiments, increasing pressure (up to 1.5 GPa) induces an increase in the iodine concentration in ISG and NH glass compositions at ∼1 and ∼2 mol.%, respectively; whereas the iodine concentration remains almost constant for boron-free trachytic glass composition suggesting the influence of boron in the iodine solution mechanism. The glass structure investigated via ²³Na NMR showed that sodium environment is modified by the presence of iodine in its surroundings. ¹¹B NMR highlighted the structural changes induced by iodine: polymerized glasses (ISG) tend to depolymerize with iodine dissolution, depolymerized glasses (NH) tend to polymerize with iodine dissolution. Our high-pressure data suggest that both I⁻ and IO₃⁻ are the solubilized forms of iodine with a preferential affinity to sodium atoms within the glass structure; and comparable to previous studies conducted at ambient pressure.

在¹²⁹我是裂变反应堆的长寿同位素，放射性和高度移动的副产物。其在地质处置库中的处置要求基质至少与目前的核废玻璃一样耐用。碘在高温下的挥发性是核废玻璃加工的一个问题，因为其在玻璃化之前的蒸发会导致最终玻璃的保留率低。本研究调查了在玻璃化过程中使用压力固定碘的方法。对于三种不同的玻璃成分：国际简单玻璃（ISG），NH（与低活性废玻璃类似的解聚玻璃，Law）和无硼松散玻璃。我们进行了0.5至2.0 GPa（压力）和1300–1500°C（温度）的实验。

与环境大气实验相比，增加压力（最高1.5 GPa）会导致ISG和NH玻璃组合物中的碘浓度分别增加约1和2 mol％。而不含硼的Trachytic玻璃组成的碘浓度几乎保持恒定，这表明硼对碘溶液机理的影响。通过²³ Na NMR研究的玻璃结构表明，钠环境因周围环境中碘的存在而改变。¹¹ B NMR突出了由碘引起的结构变化：聚合玻璃（ISG）倾向于随着碘的溶解而解聚，解聚玻璃（NH）倾向于随着碘的溶解而聚合。我们的高压力的数据表明，这两个我^-和IO₃ ^-是碘的与优先亲和性到玻璃结构中钠原子的溶解的形式; 与以前在环境压力下进行的研究相当。