三维堆芯连续能量蒙特卡罗程序用于HFETR零功率物理实验计算分析研究

Analysis on Zero Power Experiment of High Flux Engineering Test Reactor with Three-Dimensional Continuous Energy Monte Carlo Code

采用三维堆芯连续能量蒙特卡罗程序(MCNP)对高通量工程试验堆(HFETR)零功率物理实验进行计算分析。从计算结果可以看出,在零功率反应堆上,径向铍反射层应当考虑金属铍中的杂质和密度修正,同时需要考虑控制棒过渡段的10B含量修正;而HFETR上的铍块则可以认为是纯金属铍,控制棒过渡段中10B含量也需另作考虑。从计算结果来看,多数参数(堆芯中子有效增殖系数keff、中子通量密度相对分布、γ剂量率相对分布以及多数部件反应性价值)均较好满足误差要求,而个别小反应性部件计算误差较大可能与MCNP程序模型有关。

Three-dimensional, continuous energy Monte Carlo code （MCNP） is adopted to carry out the analysis of zero power experiment of HFETR. From the results, the impurity, density of Beryllium block and the 10B concentration in control rod transition part should be carefully determined in the analysis of zero powers experiment. While in the experiment of HFETR, the Berylhum block is considered as pure metal and the B concentration in control rod transition part is different from that of zero power experiment. From the calculation results, these parameters （effective neutron multiplication factor keff, relative distribution of neutron flux density, y dose rate distribution and component reactivity） are quite fit with the experiment. The difference of small reactivity between calculation and experiment is quite large, and may be related to the deficiency of MCNP model.