Abstract The present work is aimed at the study of the unirradiated and irradiated MgO ceramics corrosion and mechanical properties in the molten LiCl at 650–750 °C with addition of UCl3 and Li2O(LiCl + nLi2O and LiCl + mUCl3 molten salts with n = 1.0 and 2.0 mol. % and m = 0.25, 0.5 and 1.0 mol. %). MgO ceramics is suggested to be used as one of materials for pyrochemical technology for recycling of spent nuclear fuel. The gravimetric method with the exposure time during 100 h was the primary method of investigation. The investigation of surface and bulk corrosion of MgO samples by scanning electron microscopy (SEM) and X-ray spectroscopy (MRSA) was performed using scanning electron microscope equipped with a x-Act 6 energy-dispersive analytic system for X-rays characteristic (XRС). Determination of corrosion losses and average corrosion rates of MgO samples was based on the assumption that the ejection of the radionuclides 95Zr, 175Hf and 181Hf from the MgO samples. Incorporation of Li2O and UCl3 in molten LiCl result in increase in the rate of MgO ceramic corrosion both at 650 °C and 750 °C and acts on MgO compressive strength (σcs) and on the elemental composition of MgO surface layers. Besides the increasing of UCl3 concentration led to the bulk corrosion of MgO sample grains.Short-term mechanical tests demonstrated the transition of MgO sample destruction pattern depending on the concentration of Li2O and UCl3 additions in LiCl melt. Doping of molten LiCl by 0.5 mol. % of UCl3 at 650 °C and by 0.25 mol. % of UCl3 at 750 °C had no influence on the ultimate compression strength of irradiated and unirradiated MgO samples. Increased UCl3 concentration totaling 0.5 mol. % in the LiCl melts at 750 °C reduced the ultimate compression strength of irradiated MgO ceramic samples by ~15%.

中文翻译：

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熔盐中乏核燃料金属化和温和氯化下MgO陶瓷的耐腐蚀性和耐机械性

摘要 本工作旨在研究未辐照和辐照 MgO 陶瓷在 650-750 °C 熔融 LiCl 中的腐蚀和机械性能，添加 UCl3 和 Li2O（LiCl + nLi2O 和 LiCl + mUCl3 熔盐，n = 1.0和 2.0 mol. % 和 m = 0.25、0.5 和 1.0 mol. %)。建议将氧化镁陶瓷用作废核燃料回收利用的高温化学技术的材料之一。暴露时间为 100 小时的重量法是主要的研究方法。使用配备 x-Act 6 能量色散分析系统的扫描电子显微镜，通过扫描电子显微镜 (SEM) 和 X 射线光谱 (MRSA) 对 MgO 样品的表面和体腐蚀进行研究 (XRС) ）。MgO 样品的腐蚀损失和平均腐蚀速率的确定基于以下假设：放射性核素 95Zr、175Hf 和 181Hf 从 MgO 样品中喷出。在熔融 LiCl 中加入 Li2O 和 UCl3 会导致 MgO 陶瓷在 650 °C 和 750 °C 下的腐蚀速率增加，并影响 MgO 抗压强度 (σcs) 和 MgO 表面层的元素组成。除了UCl3 浓度的增加导致MgO 样品晶粒的整体腐蚀。短期力学测试表明MgO 样品破坏模式的转变取决于LiCl 熔体中Li2O 和UCl3 添加的浓度。掺杂 0.5 mol 的熔融 LiCl。% UCl3 在 650 °C 和 0.25 mol。750 °C 下 UCl3 的百分比对辐照和未辐照 MgO 样品的极限抗压强度没有影响。增加的 UCl3 浓度总计 0.5 mol。750 °C 时 LiCl 熔体中的 % 使辐照后的 MgO 陶瓷样品的极限抗压强度降低了约 15%。