钠冷快堆控制棒分段设计研究

Research on Segment Design of Control Rod in Sodium-cooled Fast Reactor

在钠冷快堆中,反应堆运行时的反应性补偿和停堆安全主要由控制棒来实现。当前的钠冷快堆设计中,一般含有安全棒、补偿棒和调节棒。其中,补偿棒中10 B的富集度较高,使补偿棒的燃耗较高,且发热量较大,并造成周围燃料组件功率峰因子偏大。本文提出一种分段设计方案,可用于改进上述缺点。该方案相比于传统方案,控制棒发热减小约30%,控制棒燃耗减小50%,并能有效改善周围燃料组件的功率峰因子,控制棒更换周期可提升1倍。

In sodium-cooled fast reactors,control rods are commonly used to compensate for the excess reactivity and shut down the reactor.The traditional sodium-cooled fast reactor design consists of the safety rod,shim rod and regulating rod.The 10 B enrichment of the shim rods is relatively higher,which unavoidably increases the burnup,the heat generation and the power peak factor of the fuel assemblies around the shim rods.To solve this issue,the segment design of control rods was proposed.Compared with traditional design,the new design can significantly reduce the heat generation by about 30 percent and burnup of control rods by about 50 percent,as well as improve the power peak factor of the fuel assemblies around the shim rods.The replacement cycle of the control rods can be extended by time.