ABSTRACT The concept of Pu-burner high temperature gas-cooled reactor (HTGR) has been proposed to more safely reduce the amount of recovered Pu. In the Pu-burner HTGR concept, coated fuel particles with ZrC-coated yttria-stabilized zirconia containing PuO2 (PuO2-YSZ) kernels are employed for very high burn-up and high nuclear proliferation resistance. The role of ZrC layer is that of oxygen getter. CeO2-YSZ kernels were fabricated to simulate the PuO2-YSZ kernel and coated with a ZrC layer. In this study, we clarified that both Ce-rich grains and Zr-rich grains were densely distributed in surface regions of the as-fabricated CeO2-YSZ kernel. However, we have already clarified that the surface region of the CeO2-YSZ kernel coated with a ZrC layer was porous and mainly consisted of Zr-rich grains. These experimental results confirmed that Ce-rich grains were selectively corroded during the ZrC coating process. Then, the chemical stability of Zr-rich grains would be higher than that of Pu-rich grains. Thus, it would be more difficult to extract Pu from PuO2-YSZ kernels (in which almost all grains are Zr-rich) than from PuO2-YSZ kernels (in which many Pu-rich grains are included). Influences of the sintering of fuel compact on the microstructure of the ZrC-coated CeO2-YSZ kernel is also reported.

中文翻译：

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ZrC涂层工艺和热处理对日本Pu燃烧器高温气冷堆燃料用ZrC涂层内核的影响

摘要 已经提出了 Pu 燃烧器高温气冷反应堆 (HTGR) 的概念，以更安全地减少回收的 Pu 量。在 Pu 燃烧器 HTGR 概念中，采用含氧化锆 (PuO2-YSZ) 内核的 ZrC 涂层氧化钇稳定氧化锆涂层燃料颗粒，用于实现非常高的燃耗和高抗核扩散性。ZrC层的作用是吸氧剂。制造 CeO2-YSZ 内核以模拟 PuO2-YSZ 内核并涂有 ZrC 层。在这项研究中，我们澄清了富含 Ce 的晶粒和富含 Zr 的晶粒都密集地分布在制造的 CeO2-YSZ 内核的表面区域。然而，我们已经阐明，涂有 ZrC 层的 CeO2-YSZ 内核的表面区域是多孔的，主要由富含 Zr 的晶粒组成。这些实验结果证实，在 ZrC 涂层过程中，富 Ce 晶粒被选择性腐蚀。那么，富Zr晶粒的化学稳定性将高于富Pu晶粒。因此，从 PuO2-YSZ 籽粒（其中几乎所有晶粒都富含 Zr）中提取 Pu 比从 PuO2-YSZ 籽粒（其中包括许多富含 Pu 的晶粒）中提取更困难。还报告了燃料压块烧结对 ZrC 涂层 CeO2-YSZ 内核微观结构的影响。