Chemical durability and corrosion-induced microstructure evolution of compositionally complex titanate pyrochlore waste forms with uranium incorporation
Chemical durability and corrosion-induced microstructure evolution of compositionally complex titanate pyrochlore waste forms with uranium incorporation
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DOI：
10.1016/j.jeurceramsoc.2023.09.071
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发表时间：
2023-09
影响因子：
5.7
通讯作者：
Kun Yang;Keith Bryce;Tiankai Yao;Dong Zhao;Jie Lian
中科院分区：
文献类型：
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作者：
Kun Yang;Keith Bryce;Tiankai Yao;Dong Zhao;Jie Lian
采用半动态浸出试验研究了含铀和不含铀的复杂稀土钛酸盐烧绿石固溶体的化学稳定性。由于弱氧键合稀土元素优先释放的表面蚀变-重组机制，在表面形成富钛的非晶态钝化膜。元素的释放被认为是强烈相关的化学无序，与熵的相关性可以忽略不计。铀的释放率随着组分数量的增加而逐渐降低，这意味着通过控制成分复杂性和化学无序性来设计和优化具有增强的化学耐久性的废物形式性能以进行有效的核废物管理的可能性。
Chemical durability of compositionally-complex rare-earth titanate pyrochlore solid solutions with or without uranium incorporation was investigated by semi-dynamic leaching testing. A Ti-enriched amorphous passivation film formed on the surface due to the surface alteration-reorganization mechanism with preferential release of the weakly oxygen-bonded rare earth elements. Elemental release was found to be strongly correlated with chemical disorder, with a negligible correlation with entropy. The release rate of the uranium gradually decreased with increasing numbers of components, implying a possibility of designing and optimizing waste form performance with enhanced chemical durability by controlling composition complexity and chemical disorder for effective nuclear waste management.