行波堆堆芯设计初步研究

Preliminary Research on Design of Traveling Wave Reactor

对工程可行的大型行波堆堆芯概念设计和核燃料优化设计进行分析,并对行波堆的运行、控制进行研究。分析结果表明,行波堆的固有安全特性能够有效地保证其运行安全。优化设计可实现从开始启堆就得到展平的径向中子注量率分布,并随着行波的燃烧自动调整为更为平坦的平衡态分布;行波堆长期燃烧的状态可通过堆芯优化设计先行设定,启堆时与平衡态之间的偏离通过燃烧自动纠正。燃料组件的结构优化,能够显著改善中心通道与边、角通道之间的流量分配,能够在温度反馈的基础上,通过主动调节反应堆冷却剂泵的转速,进而改变冷却剂流量以实现功率控制。但是,仅依靠主泵的流量控制还无法实现对15%额定功率(PN)至100%PN的功率调节。甩负荷工况下需要A组停堆控制棒的参与。

An engineering feasible conceptual core design of large scale （e.g. 1000MWe output） TWR is proposed with investigation and qualitative optimization on the proper design of fuel element structure, fuel pellet, liquid metal filling gap, fuel assembly structure, core reflector and shielding and shutdown control rods. The optimized design presents a flatten radial neutron flux with a better equivalent state distribution, which means the long term burning state could be defined by initial core design and further corrected by the travelling wave progress. The optimized fuel structure improves the flow distribution between the central, parallel and corner channels. Furthermore, the power control of TWR could be implemented by the adjusting of coolant pump rotation speed as the change of coolant flow. Though the load rejection and power control between 15% to 100% nominal power could not be fulfilled by flow control without the participation of bank A control rods.