高温气冷堆燃料元件基体石墨的SiC/SiO2抗氧化涂层研究

SiC/SiO_2 oxidation-resistant coatings on fuel element matrix graphite of high temperature gas-cooled reactor

提高高温气冷堆用石墨的抗氧化性能对改进高温气冷堆的安全性具有重要意义。通过热力学分析确认了SiC/SiO2复合涂层在高温气冷堆正常服役条件和事故条件下均能保证其长期热稳定性。结合气相反应扩散法、泥浆浸渗法和高温氧化法,在高温气冷堆燃料元件基体石墨表面制备出SiC/SiO2复合涂层;对涂覆SiC/SiO2复合涂层的高温气冷堆燃料元件基体石墨在各种氧化条件下的氧化行为进行了分析。结果表明在高温气冷堆用石墨可能遇到的多种氧化条件下,SiC/SiO2复合涂层均能够保持长期稳定并显著改善基体石墨的抗氧化性能。

The improvement of the oxidation resistance of graphite used in high temperature gas-cooled reactor is indispensable in order to further improve the safety of high temperature gas-cooled reactor. It is confirmed that SiC/SiO2 multilayer coatings is stable both at the normal operation conditions and at accidental conditions of high temperature gascooled reactor through thermodynamic analysis. SiC/SiO2 muhilayer can be obtained on the surface of fuel element matrix graphite of high temperature gas-cooled reactor by the combination of vapor reaction diffusion, slurry method and high temperature oxidation in air. The oxidation behaviors of SiC/SiO2 coated on fuel element matrix graphite of high temperature gas-cooled reactor are studied. It is shown that SiC/SiO2 coatings can be stable for a long period at different oxidation conditions which graphite for high temperature gas-cooled reactor may encounter and greatly improve the oxidation resistance of fuel element matrix graphite of high temperature gas-cooled reactor.