ADS次临界系统中子时空动力学计算与瞬态分析

加速器驱动次临界反应堆(ADS)中子时空动力学计算需要考虑外中子源和空间分布的影响,比临界系统中子动力学计算要复杂得多。本文将改进准静态(IQS)近似与蒙特卡罗(MC)方法相结合,对于带外源的ADS次临界系统中子时空动力学过程,形状函数、动力学参数由MCNPX程序计算得到,幅度函数与集总参数热工反馈模型进行耦合计算,并开发了IQS/MC计算程序可视化操作界面。针对CIADS靶堆耦合系统参考方案物理模型,对引入束流瞬变及无保护失流工况过程进行瞬态模拟计算分析,给出了堆芯相对功率、燃料温度及冷却剂出口温度随时间的变化曲线。同时,将中子注量率进行分群计算,得到了堆芯分能群的相对中子注量率网格分布随时间的变化,模拟结果与理论分析一致。

Calculation and Transient Analysis of Neutron Time-space Kinetics for Accelerator Driven Sub-critical System

Calculation of neutron space-time kinetic for Accelerator driven sub-critical reactor (ADS ) need to consider the impact of external neutron source and spatial distribution,and it was much more complex than critical system in neutron kinetics calculation. In this paper,the improve quasi-static approximation (IQS) and Monte Carlo (MC) method were combining,the shape function and kinetic parameters were calculated by MCNPX program, and the amplitude function was coupled with the lumped parameter thermal feedback model to calculate for neutron space-time kinetic process of ADS critical system with external source, besides, a visual operating interface of IQS/MC calculation procedure was developed. For CIADS physical model of target and reactor coupled reference scheme, the transient simulation analysis was carried out on inserting beam interruption and loss-of-flow without scram,and the core relative power,fuel temperature and outlet temperature of coolant along time were given. At the same time,multigroup neutron flux were calculated,and the core gird distribution of multigroup relative neutron flux along time were obtained, and simulation results were consistent with theoretical analysis.