The vast majority of High‐Level Waste (HLW) originating from defense nuclear programs is sequestered and immobilized in borosilicate glass. Borosilicate glass is universally accepted for immobilizing HLW, but its efficiency has limitations based on the compositional makeup of the waste stream. The chemical durability of the glass is the most important factor in determining the longevity and usefulness of the final glass waste form. The primary detriment to this durability in glasses containing high levels of aluminum is nepheline (NaAlSiO₄) crystallization, as it is generally accompanied by a measurable decrease in the glass's chemical durability. This work seeks to understand nepheline crystallization, within the context of thermal history, and to elucidate the influence of compositional shifts in the residual glass (after crystallization) on the measured durability. The results presented within show a distinct deviation in leaching behavior as a function of structural makeup (calculated Q units). This understanding will provide practical information required for broadening glass compositional regions needed to more efficiently vitrify HLW.

中文翻译：

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霞石结晶和残留玻璃成分：了解废玻璃的耐久性

来自国防核计划的绝大多数高级废物（HLW）被隔离并固定在硼硅酸盐玻璃中。硼硅酸盐玻璃已被广泛用于固定高放废物，但其效率因废物流的组成而受到限制。玻璃的化学耐久性是确定最终玻璃废料形式的寿命和实用性的最重要因素。铝含量高的玻璃对这种耐用性的主要损害是霞石（NaAlSiO ₄结晶），因为通常伴随着玻璃化学耐久性的明显降低。这项工作旨在在热历史的背景下理解霞石结晶，并阐明残留玻璃（结晶后）中成分变化对所测量的耐久性的影响。呈现的结果表明，浸出行为随结构组成（计算的Q单位）的变化而明显偏离。这种理解将提供拓宽玻璃成分区域所需的实用信息，以更有效地玻璃化HLW。