铅冷快堆固态氧控系统中氧化铅陶瓷的中毒行为研究

Solid-phase oxygen control scheme adjusts the oxygen concentration through controlling the dissolution and precipitation of lead oxide (PbO) particles in liquid metal, which can solve the corrosion problems caused by the poor compatibility between coolant and loop material of lead cooling fast reactor (LFR) effectively. Compared with gas-phase oxygen control scheme, solid-phase oxygen control scheme possesses significant advantages such as high efficiency and cleanliness. In liquid metal with a low oxygen concentration, a major problem is the so called ‘poisoning of PbO’, which involves reaction of dissolved impurities (mainly Fe) in LBE with PbO. In this process, a stable oxide (mainly Fe3O4) forms on the surface and hinders the dissolution of the PbO, which would induce the failure of solid-phase oxygen control. In this project, a systematic study will be focused on the poisoning behavior of PbO ceramics . To establish the poisoning model of PbO, poisoning experiments at different temperature, oxygen concentration and flow rate of liquid metal will be carried out. The influence of irradiation effect on the poisoning behavior of PbO will be studied under different conditons. This research will establish the bases for solid-phase oxygen control technology and contribute for the efficient, clean, and reliable performance of high temperature liquid metal in LFR.

固态氧控技术通过控制固态氧化铅颗粒的溶解与析出来调节铅冷快堆液态金属冷却剂中的氧浓度，可有效解决铅冷快堆冷却剂与回路材料相容性差带来的腐蚀问题。相比气态氧控方法，固态氧控方法在控氧效率和清洁度等方面具有明显的优势。实际工况下，当液态金属中氧含量较低时，溶解在液态金属中的金属杂质会在氧化铅表面发生反应从而引起中毒，中毒后的氧化铅由于溶解性能降低就会导致固态控氧失效。本项目针对用于铅冷快堆固态氧控的氧化铅陶瓷，系统研究其中毒行为。基于堆内实际工况，开展液态金属中不同温度，氧浓度，流速，辐照等条件下的氧化铅中毒实验，并结合实验结果及理论分析建立氧化铅中毒模型。通过本项目的研究，可为固态氧控技术的实际应用打下基础，并为高温液态金属在铅冷快堆中实现高效、清洁、可靠的运行做出贡献。

固态氧控技术通过控制固态氧化铅颗粒的溶解与析出来调节铅冷快堆液态金属冷却剂中的氧浓度，可有效解决铅冷快堆冷却剂与回路材料相容性差带来的腐蚀问题。相比气态氧控方法，固态氧控方法在控氧效率和清洁度等方面具有明显的优势。实际工况下，当液态金属中氧含量较低时，溶解在液态金属中的金属杂质会在氧化铅表面发生反应从而引起中毒，中毒后的氧化铅由于溶解性能降低就会导致固态控氧失效。本项目针对用于铅冷快堆固态氧控的氧化铅陶瓷，系统研究了其中毒行为。具体成果包括：（1）通过优化氧化铅颗粒的烧结参数，确定3%Bi2O3掺杂的氧化铅颗粒具有良好的结构稳定性和力学特性，提升了氧化铅陶瓷颗粒的整体性能；（2）对中毒实验装置和氧浓度测试传感器进行了改良，提高了实验设备的整体密封性和测试装饰的准确性；（3）利用分子动力学方法系统对氧化铅中毒行为进行模拟，明确了氧化铅中毒行为的发生机理；（4）基于堆内实际工况，开展液态铅铋合金中不同温度，氧浓度，辐照等条件下的氧化铅中毒实验，并基于实验结果拟合了氧化铅颗粒中毒阈值估算模型。本项目的相关结果可为固态氧控技术的实际应用打下基础，并为防止氧控过程中氧化铅颗粒中毒制定策略提供参考依据。