ADS次临界反应堆的点堆中子动力学方程

Point Kinetic Equation of ADS Sub-critical Reactor

加速器驱动的次临界系统(ADS)中的次临界反应堆与临界反应堆相比,中子注量率的空间分布具有严重的不均匀性,同时中子平均能量较高且中子能量变化复杂,中子价值变化大,因而传统的点堆动力学方程不能较为真实地模拟ADS次临界反应堆。本文从含多群中子多组缓发中子先驱核的动力学方程出发,给出其共轭方程。然后利用稳态扩散方程及其共轭方程的共轭关系,推导得出含有归一化功率的动力学方程表达式。进而定义多个特征算子,导出了含有源中子价值的点堆中子动力学方程,并对几种简单情况进行了初步验证,为进一步分析ADS次临界反应堆的动态过程奠定了基础。

Compared with critical reactor,more asymmetric distribution of neutron flux,higher average energy of neutron,more complex neutron spectrum and larger variation of neutron importance inside an ADS sub-critical reactor make the traditional point kinetic equation difficult to simulate the neutron dynamics of such a sub-critical reactor realistically.Firstly,the kinetic equations governing the neutron flux and precursor in a multigroup neutron energy model and their adjoint equations were introduced.Then,the kinetic equations with normalized reactor power were derived based on the steady state diffusion equation and its adjoint equation.Additionally,the point kinetic equations with source neutron importance were derived with the definition of some operators.Finally,the equations were verified by several simple cases.The research establishes the foundation of the further analysis for ADS sub-critical reactor dynamics.