小型模块化超级安全气冷堆中子学特性研究

Research on Neutronics Characteristics of Small Modular Super-Safe Gas-Cooled Reactor

为分析小型模块化超级安全气冷堆堆芯中子学特性,建立六棱柱燃料组件模型,利用蒙特卡罗程序和ORIGEN程序的耦合计算,研究TRISO颗粒致密度、燃料富集度、TRISO颗粒大小、栅距比、TRISO颗粒包层厚度和燃料棒直径等物理参数对寿期等特性的影响。研究结果表明,寿期长度随着燃料富集度、栅距比的增大而单调增大;燃料棒直径、TRISO颗粒致密度、TRISO颗粒尺寸大小对寿期长度也有一定的影响;TRISO颗粒包层厚度对寿期长度的影响很小。基于该结果,初步设计出小型模块化超级安全气冷堆的堆芯装载方案,其寿期满足20 a不换料的寿期长度要求。

To analyze the neutronics characteristics of the small modular super-safe gas-cooled reactor, this paper investigates how some physical parameters, such as TRISO particle packing fraction and fuel enrichment, influence the burnup characteristics, based on the hexagonal prism fuel assembly model, using Monte Carlo procedure and ORIGEN procedure. The results show that the lifetime increases with the fuel enrichment and pitch-to-diameter ratio, and is influenced by the diameter of fuel rod, the packing fraction and size of TRISO particles to a certain extent, while the effect of the TRISO particle coating layer thickness on the lifetime can be neglected. Based on the above results, a preliminary core loading scheme for the reactor is proposed, which meets the requirement of a 20-year lifetime without refueling.