A kind of annular uranium nitride (UN) fuel suitable for lead-cooled fast reactor applications has been designed in this study. The design is directly targeting two main issues of UN fuel: severe swelling and thermal decomposition of UN fuel at high temperatures. A performance analysis program based on FORTRAN programming language has been developed for UN fuel in fast reactors. The program contains heat transfer, fuel stress-strain analysis, cladding stress-strain analysis, fission gas release and fuel-cladding mechanical interaction (FCMI) modules, etc. Extensive code verification has been performed by comparing simulation results obtained with the code and those obtained via the COMSOL Multiphysics platform. Preliminary code validation has been conducted as well by comparing code simulation results with experimental data. The results showed that this program could predict the fuel temperature, stress-strain, and displacement of UN fuel during reactor operation with a reasonable accuracy.

中文翻译：

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铅冷快堆环形联合国燃料设计与开发性能分析程序

本研究设计了一种适用于铅冷快堆应用的环形氮化铀 (UN) 燃料。该设计直接针对联合国燃料的两个主要问题：联合国燃料在高温下的严重膨胀和热分解。已经为快堆中的联合国燃料开发了基于 FORTRAN 编程语言的性能分析程序。该程序包含传热、燃料应力应变分析、包壳应力应变分析、裂变气体释放和燃料包壳机械相互作用（FCMI）模块等。通过 COMSOL Multiphysics 平台获得。通过将代码模拟结果与实验数据进行比较，还进行了初步代码验证。