颗粒可燃毒物空间自屏效应分析研究

Analysis and Study on Space Self-shielding Effect of Burnable Poison Particles

可燃毒物被布置于反应堆堆芯中以控制堆芯剩余反应性,颗粒可燃毒物由于空间自屏效应而具有区别于常规均匀弥散可燃毒物的特性,同时颗粒可燃毒物可以增加可燃毒物的使用自由度,通过调整可燃毒物类型、可燃毒物颗粒尺寸以及可燃毒物体积份额以实现堆芯反应性的长期和平稳控制。本文重点研究颗粒可燃毒物的颗粒尺寸对系统反应性以及颗粒内有效核素核子密度变化规律的影响,并解释颗粒可燃毒物由于空间自屏效应而产生的"洋葱"效应,同时对比分析了多种常见可燃毒物不同颗粒尺寸下的中子学规律,对颗粒可燃毒物用于堆芯反应性控制具有重要的指导意义。

Burnable poisons are placed in the reactor core to control the remaining reactivity.Burnable poison particles have characteristics different from conventional uniformly dispersed grainless burnable poison due to the space selfshielding effect.And burnable poison particles can increase the freedom of use of burnable poison.Long-term and smooth control of the core reactivity can be achieved by adjusting types of burnable poison,particle size,and the volume fraction of burnable poison.This article focuses on the effects of parameters such as the particle size of burnable poison on the reactivity of the system and the variation law of the effective nuclide density in the particles,and the onion effect of burnable poison particles due to the space self-shielding effect is explained.And then the neutronic characteristics of various common burnable poisons with different particle sizes are analyzed.It has important guiding significance for the use of burnable poison particles in the core reactivity control.