Radiation effects on the structure and alteration behavior of an SiO 2 -Al 2 O 3 -B 2 O 3 -Na 2 O glass
Radiation effects on the structure and alteration behavior of an SiO 2 -Al 2 O 3 -B 2 O 3 -Na 2 O glass
复制标题
辐射对SiO 2 -Al 2 O 3 -B 2 O 3 -Na 2 O玻璃结构和蚀变行为的影响
DOI：
10.1111/ijag.16618
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发表时间：
2022
影响因子：
2.1
通讯作者：
Jan A
中科院分区：
文献类型：
--
作者：
Jan A
由于许多国家在乏燃料后处理后使用硼硅酸盐玻璃将裂变产物和少量锕系元素包裹起来，然后储存在深层地质处置库中，因此评估其化学耐久性至关重要。在这里，原始和预辐照（952 MeV，136 MeV）SiO2-B2 O3-Al 2 O3-Na 2 O玻璃与法国SON 68和ISG玻璃中的摩尔比相同，在去离子水和二氧化硅饱和溶液中进行水腐蚀，以测量初始和长期的变化率。原始玻璃和预辐照玻璃的腐蚀遵循相同的机制，但预辐照对初始溶解速率（增加5.6倍）和二氧化硅饱和条件下的蚀变层深度（增加2 - 3倍）具有强烈影响。后面的结果与预辐照玻璃样本上形成的多孔性更强、钝化性更低的凝胶有关。使用实验光谱（NMR，IR和SFG）和经典分子动力学，玻璃结构和水扩散的辐射效应进行了评估。预辐照后，玻璃的密度和聚合度降低，而拓扑无序度增加。因此，水的扩散加速。这些观测结果允许将辐射对蚀变行为的影响与结构变化相关联。
As borosilicate glasses are used in many countries to immobilize fission products and minor actinides after spent fuel reprocessing before storage in a deep geological repository, assessing that their chemical durability is of paramount importance. Here, pristine and preirradiated (952 MeV, 136Xe) SiO2–B2O3–Al2O3–Na2O glasses with the same molar ratios as in the French SON68 and ISG glasses have been subjected to aqueous corrosion in deionized water and in silica‐saturated solution to measure the initial and longer term alteration rates. Pristine and preirradiated glasses corrode following the same mechanisms, but the preirradiation has a strong impact on the initial dissolution rate (increase by a factor of 5.6), and on the alteration layer depth in silica‐saturated conditions (by two‐ to threefolds). The later result is related to the formation of a more porous, less passivating gel on the preirradiated glass specimen. Using both experimental spectroscopies (NMR, IR, and SFG) and classical molecular dynamics, the radiation effects on the glass structure and water diffusion have been assessed. After preirradiation, the density and the polymerization degree of the glass decrease, whereas the topological disorder increases. In consequence, water diffusion accelerates. These observations allow to correlate the radiation impact on the alteration behavior to the structural changes.