基于MCNP的超临界水堆堆芯建模及中子通量计算

 超临界水堆是国际第Ⅳ代核能系统论坛推荐的6种第Ⅳ代核电反应堆堆型之一,与现有的轻水堆相比,具有热效率高、系统结构简单、造价低等优点。本文建立了MCNP程序下的超临界水堆堆芯物理计算模型,解决了燃料组件几何结构过于复杂精细难以建模的技术难题,考虑了堆芯轴向冷却剂密度的不均匀分布;以超临界水堆堆芯模型为基础,计算了堆芯径向中子通量密度分布,提出了展平堆芯功率分布的设计方案;计算了堆芯轴向中子通量密度分布,讨论了控制棒不同作用方式对轴向中子通量密度峰的偏移影响,确定了超临界水堆控制棒应采用由下向上插入的方式。研究结果为超临界水堆的设计制造、安全分析提供了重要参考依据,为超临界水堆未来的设计和发展奠定了基础。

Core Modeling and Neutron Flux Calculation for Supercritical Water Reactor Using MCNP

The supercritical water reactor is one of the six reactors recommended by the Generation IV International Forum. Compared with existing light water reactors,it enjoys advantages of high thermal efficiency, simplified system structure and low cost. The physical model of the supercritical water reactor is established with the MCNP program in this paper, with consideration of the variations of the coolant density along the axial and the intricate geometry of the fuel assembly. Based on the core model of the supercritical water reactor, the radial neutron flux density distribution of the core is calculated and a design scheme of the flattening power distribution is proposed. The axial neutron flux density distribution of the core is calculated, and the effect of the control rod on the peak shift of the axial neutron flux density is discussed. It is suggested that the control rod of the supercritical water reactor should be inserted up from the bottom. This paper provides some food of thought for the construction and the security analysis of the supercritical water reactor, as well as for the application and the development of the supercritical water reactor.