超临界压水堆改进型控制棒组件落棒过程计算分析研究

为验证超临界压水堆改进型控制棒组件能否实现预期水力缓冲功能，采用计算流体力学分析软件Fluent、基于6自由度（6DOF）模型的铺层法动网格技术，对其落棒过程进行研究，分析了控制棒组件落棒时间和落棒末速度。结果表明:相比改进前的设计，改进型控制棒组件落棒时间虽有所增大，但仍然能满足安全要求；落棒末速度大幅下降，落棒冲击力降低，从而能够保证控制棒组件及燃料组件的结构完整性。改进型控制棒组件的设计能够实现预期的水力缓冲功能，可用于超临界压水堆堆芯设计。 

Calculation and Analysis of Rod Dropping Process of Improved Control Rod Assembly for Supercritical Pressurized Water Reactor

In order to verify whether the improved control rod assembly of supercritical pressurized water reactor (SCWR) can achieve the expected hydraulic buffering function, the rod dropping process is analyzed by using Fluent based on 6 degree of freedom model, which is an option of the layering dynamic mesh method. The control rod assembly dropping time and rod dropping final velocity are analyzed. The results show that compared with the design before the improvement, the dropping time of the improved control rod assembly is increased, but it can still meet the safety requirements; Compared with that before the improvement, the rod dropping final velocity is significantly reduced, and the impact force of rod dropping is thus reduced, so as to ensure the structural integrity of control rod assembly and fuel assembly. The design of the improved control rod assembly can achieve the expected hydraulic buffering function and can be used in the core design of supercritical pressurized water reactor.