高中子注量下快堆燃料元件包壳的辐照热力学耦合分析计算研究

Irradiation-Thermo-Mechanical Coupling Analysis and Calculation of High Neutron Fluence Fast Reactor Fuel Element Cladding

在服役寿期内,快中子反应堆氧化物燃料元件在高中子注量率、高线功率和高温下运行,燃料元件的包壳会表现出复杂的辐照-热-力学耦合特征,包壳的应力应变分析计算对于快堆燃料元件的设计非常重要。本文围绕快中子反应堆氧化物燃料元件包壳的辐照力学现象,使用有限元方法考虑包壳的热膨胀、热蠕变、辐照蠕变、辐照肿胀等辐照行为,实现辐照-热-力学耦合的非线性计算,并通过典型算例验证计算方法的正确性。结果表明:使用的非线性计算方法是正确的,可实现快中子氧化物燃料元件包壳在全寿期内应力应变演变行为的分析预测。本文研究成果为高线功率快中子氧化物燃料元件的设计和性能分析评价奠定了良好的工作基础。

During the service life,the oxide fuel element of fast neutron reactor operates under high neutron flux rate,high line power and high temperature.The cladding of fuel element will show complex irradiation-thermo mechanical coupling characteristics.Focusing on the radiation mechanical phenomena of oxide fuel element cladding of fast neutron reactor,this paper uses the finite element method to consider the radiation behaviors such as thermal expansion,thermal creep,radiation creep and radiation swelling of cladding,realizes the nonlinear calculation of radiation thermal mechanical coupling,and verifies the correctness of the calculation method through typical examples.The results show that the nonlinear calculation method is correct and can analyze and predict the stress-strain evolution behavior of fast neutron oxide fuel element cladding in the whole life cycle.The research results of this paper lay a good foundation for the design and performance analysis and evaluation of high-power fast neutron oxide fuel elements.