熔盐实验堆MSRE堆芯罐和反应堆容器辐照损伤计算与分析

Calculation and Analysis of DPA Rate in Core Can and Reactor Vessel of Molten Salt Reactor Experiment

本文采用蒙特卡罗程序MCNP5对熔盐实验堆MSRE的堆芯罐和反应堆容器的中子辐照损伤量——原子离位数率(DPA rate)进行计算与分析。确定了堆芯罐和反应堆容器上的中子注量率分布,对其中中子注量率最大的区域进行详细的原子离位数率计算。计算显示堆芯罐和反应堆容器最大的原子离位数率均发生在内表面、堆中心平面处、θ角度在22°～34°之间的区域,最大原子离位数率可达3.90×10-9 s-1,且快中子对原子离位数率贡献要大于热中子。研究结论对新概念熔盐堆设计和参数选择具有重要的实际意义。

The displacement-per-atom（DPA） rates for the molten salt reactor experiment（MSRE） core can and reactor vessel were calculated and analyzed by the Monte Carlo program MCNP5 in this paper.The neutron fluence rate distributions in the core can and the reactor vessel were determined,and one of the biggest neutron fluence rate region DPA rate was calculated in detail.The results show that the maximum DPA rate happens on the inner surface of core can and reactor vessel,near the reactor mid plane,with θ between 22° to 34° and the maximum DPA value can be 3.90×10-9 s-1 and fast neutrons make more contribution to DPA rate than thermal neutrons.The conclusion has important practical significance on the new concept molten salt reactor design and parameter selection.