混合能谱超临界水堆堆芯设计分析

The design analysis for a mixed neutron spectrum supercritical water-cooled reactor core

提出了一种新型的超临界水堆概念设计:混合能谱超临界水堆,它包括慢谱区和快谱区两部分。其慢谱区燃料组件采用双排燃料组件,快谱区采用简单的正方形栅元燃料组件。慢谱区与快谱区的燃料组件都采用同向流动方式来简化堆芯设计。慢谱区的冷却剂出口温度远低于整个堆芯的出口温度,这大大降低了慢谱区包壳的温度峰值。此外,由于快谱区冷却剂密度很小,流速很高,故可采用较大的栅元结构,这有效地降低了包壳周向局部传热不均匀性。所以混合堆在充分继承慢谱、快谱堆芯优点的基础上,弥补两者的不足。

In this paper, a new reactor core design is proposed on the basis of a mixed core concept consisting of a thermal zone and a fast zone. The geometric structure of the fuel assembly of the thermal zone is similar to that of a conventional thermal supercritical water-cooled reactor （SCWR） core with two fuel pin rows between the moderator channels. In spite of the counter-current flow mode, the co-current flow mode is used to simplify the design of the reactor core and the fuel assembly. The water temperature at the exit of the thermal zone is much lower than that at the outlet of the pressure vessel. This reduces the maximum cladding temperature of the thermal zone. Furthermore, due to the high velocity of the fast zone, a wider lattice can be used in the fuel assembly and the non-uniformity of the local heat transfer can be minimized. This mixed core, which combines the merits of some existing thermal and fast SCWR cores, is proposed for further detailed analysis.