耐事故燃料UN芯块研究进展和发展趋势

Research Progress and Development Trend of Accident Tolerant Fuel UN Pellets

UN芯块是一种高铀密度、高热导芯块,是一种潜在耐事故燃料芯块。本文从制备工艺和物理性能、环境相容性、辐照性能、芯块-包壳相互作用以及经济性和安全性5个方面对UN芯块研究进展进行了总结。研究结果表明在压水堆中使用UN芯块对提升反应堆安全性利大于弊,总体上有利于促进堆芯事故工况下的安全性,具有降低芯块运行温度、减少事故下储能释放的显著特点,需要解决的主要问题是抗水腐蚀性能差和^(15)N富集成本高,对于提升抗水腐蚀和抗氧化性能的可能解决方案包括掺杂或添加抗氧化成分,高成本问题需要降低^(15)N富集成本。本综述较为全面地总结了UN芯块整体研究进展和发展趋势,对于理解其作为抗耐事故燃料芯块的可行性和存在问题提供参考。

UN pellet has high uranium density and high thermal conductivity,and is a kind of potential accident tolerant fuel pellet.In this paper,the research progress of UN pellets is summarized from five aspects:preparation process and physical properties,environmental compatibility,irradiation properties,pellet-cladding interaction,economy and safety.The research results show that the advantages of using UN pellets in PWR outweigh the disadvantages,and it is generally beneficial to promote the safety of the reactor under accident conditions.It has the remarkable characteristics of reducing the operating temperature of pellets and reducing the release of energy storage in accidents.The main problems to be solved are poor water corrosion resistance and high cost of ^(15)N enrichment.The possible solutions to improve water corrosion resistance and oxidation resistance include doping or adding antioxidant components,and the high cost problem needs to reduce the cost of ^(15)N enrichment.This review comprehensively summarizes the overall research progress and development trend of UN pellets,and provides reference for understanding its feasibility and existing problems as accident tolerant fuel pellets.