小型氦氙冷却移动式反应堆堆芯设计优化分析

Optimal core design analysis for a small mobile helium-xenon cooled solid reactor

小型移动式核反应堆电源能为偏远地区、事故应急等场景提供所需的电能和热能,而堆芯的轻量化和小型化是小型移动式核反应堆电源的设计重点。由此,基于前期概念设计,本研究提出了一个高可靠、长寿命的小型氦氙冷却固体核反应堆堆芯设计及其反应性控制方案。首先,在综合考虑反应堆寿命以及热工安全设计等限制条件的基础上,使用蒙特卡罗程序OpenMC进行了堆芯几何优化分析,得到了堆芯质量最小化的设计方案。其次,分析了含可燃毒物的布置优化方案,通过在堆芯靠近反射层附近的燃料棒中添加2%质量分数的可燃毒物Gd2O3,寿期初径向功率峰因子从2.22降低至1.43。最后,基于分层分块滑移反射层的反应性与功率控制方法,提出了反应性线性控制方案,该方案还可以保证事故情况下的反应堆安全。相关结果可为小型移动式核反应堆电源的堆芯设计及反应性控制提供参考。

Due to electricity needs of scenarios such as remote areas and emergency situations,mobile nuclear power sources with high reliability and long life are needed.A conceptual design scheme of a small mobile heliumxenon cooled solid reactor has been proposed in previous work.This study aims to obtain a lightweight and compact core design and improve the design scheme of sliding reflector segments for reliable reactivity control.Firstly,under the design constraints of reactor life and thermal safety,the core geometry optimization analysis was performed using OpenMC,and a design scheme to obtain minimal mass of core was achieved.Secondly,the study analyzed the influence of burnable poison on power distribution and by adding a 2%mass fraction of Gd2O3 to the fuel rods near the reflector region,the radial power factor was reduced from 2.22 to 1.43 at the beginning of life.Finally,by partitioning the sliding reflector,a linear introduction of reactivity was achieved,and it can also ensure the reactor safety in case of accidents.This study provides a certain reference for the design of small gas-cooled solid reactor.