快中子脉冲反应堆爆发脉冲时堆体应力分布的数值模拟

Numerical Simulation of the Stress Distribution for Fast Burst Reactor Under Pulsed Operation

为分析爆发脉冲时堆体构件的应力响应,建立了基于中国第二号快中子脉冲堆(CFBR-Ⅱ堆)的一个二维模型。采用M.C(蒙特卡洛)方法计算了模型的相对中子注量分布,推导了代替动力学方程的热加载关系式,并将计算得到的中子注量分布与实测结果引入热加载关系式中,用有限元程序计算了已知热加载情况下的几种构件的应力分布。分析认为,由于该方法能准确描述模型的几何结构,并且计算中引入了实测结果,因此,对于结构复杂的模型其计算结果应比通常采用的耦合计算方法更为合理。

A two-dimension model based on China Fast Burst Reactor - II (CFBR-II) is built to analyze the stress responding of the components in fast burst reactor while the reactor is operated in burst model. The relative neutron flux distribution of the model is calculated by M.C (Monte Carlo) method. A thermal load function is driven to replace the solution of the kinetic equation. The results of experiment and neutron flux calculations are employed in the function. The stress distribution of main components of the reactor is calcu-lated with the finite element method in certain thermal load status. Because of the accurate geometry descrip-tion of the model and the introducing of experimental values, this method is more reasonable compared to the coupled method, especially for a complex model such as CFBR-Ⅱ.