Abstract CeO2 is a surrogate of PuO2 in nuclear fuel development. Uniform sized ceramic CeO2 spheres were fabricated by an improved internal gelation process which combined the in-situ instant mixing of room-temperature precursor solutions with microwave-assisted internal gelation. Chemical kinetics investigations showed that the gelation process sped up as the [HMTA]/[Ce4+] ratio, [OH-]/[Ce4+] ratio and temperature increased. However, to avoid cracking during the sintering process, the [HMTA]/[Ce4+] ratio should be limited at low value while [OH-]/[Ce4+] ratio should be sufficiently high. Besides, pressured water treatment was adopted to wipe off impurities in the gelled spheres before sintering. The microstructure and morphology of the prepared ceramic CeO2 spheres were also investigated. The improved microwave-assisted internal gelation process greatly simplifies the conventional sol-gel process and avoids secondary organic radioactive waste. It will be a potential method for the fabrication of MAs and Pu-containing ceramic nuclear fuel spheres in glove-box in future.

中文翻译：

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通过改进的微波辅助快速内部胶凝工艺制备作为核燃料替代品的 CeO 2 陶瓷球

摘要 CeO2 是核燃料开发中 PuO2 的替代品。均匀尺寸的陶瓷 CeO2 球体是通过改进的内部凝胶化工艺制造的，该工艺将室温前体溶液的原位即时混合与微波辅助内部凝胶化相结合。化学动力学研究表明，凝胶化过程随着 [HMTA]/[Ce4+] 比、[OH-]/[Ce4+] 比和温度的升高而加快。然而，为了避免在烧结过程中开裂，[HMTA]/[Ce4+] 比率应限制在较低的值，而 [OH-]/[Ce4+] 比率应足够高。此外，在烧结前采用加压水处理擦去凝胶球中的杂质。还研究了制备的陶瓷 CeO2 球的微观结构和形貌。改进的微波辅助内部凝胶化工艺大大简化了传统的溶胶-凝胶工艺，避免了二次有机放射性废物。这将是未来在手套箱中制备 MAs 和含 Pu 陶瓷核燃料球的潜在方法。