中国先进研究堆(CARR)既没有参考堆,也不进行零功率物理模拟实验,其物理启动工作完全以理论分析结果为依据,这在国内大型研究堆的启动中尚属首次。CARR堆芯结构复杂,启动过程中堆内标准燃料组件、跟随体燃料组件和贫铀组件混装,堆芯装载变化大,大部分基于扩散理论的物理计算程序较难完成CARR物理启动的理论分析工作。选用MCNP程序对CARR物理启动的各项实验进行模拟计算,该程序强大的几何描述功能很好地解决了上述难点。得到的计算结果为CARR物理启动工作提供了重要依据和参考,保证了CARR物理启动工作的安全顺利进行,实验结果表明,MCNP的计算结果准确可信,该程序在CARR物理启动工作中的应用是成功的。

There is no reference reactor for CARR and no zero power experiment carried out, the nuclear commissioning of CARR will be run based totally on the theoretical analysis, as the first case in the China's domestic research reactor start-up. Because of the complicated structure and the large variations of the load of the core, the simulation calculation of the experiment can not be carried out with most neutronics codes based on the diffusion theory. In this paper, the MCNP code is used to run the calculation because of its real geometry function. The calculation results provide some important reference for the CARR start-up. The results of the experiment show that the calculation results are accurate and reliable and the application of the code is successful.