棒状氢化锆慢化钍基熔盐堆中子学性能优化

氢化锆(ZrH)由于具有耐高温、抗辐照和慢化能力强等优点，是反应堆常用的慢化剂。本工作研究具有钍铀转换能自持运行和较低次锕系核素（MA）产量的ZrH慢化熔盐堆的堆芯物理设计方案。采用MOC程序分析了不同燃料盐对于启堆和增殖性能的影响，为提高钍铀转换性能，对堆芯结构和慢化棒设计进行了优化与分析。结果表明：当熔盐体积比处于0.5~0.9时，ZrH慢化剂可将临界所需要的²³³U浓度降低至2%附近；采用含增殖层设计与FLi燃料盐装载的ZrH慢化熔盐堆，50 a平均钍铀转换比（CR）可达到1.028；移动式ZrH慢化棒堆芯设计可实现38 a的自持运行，且堆芯寿期末的MA产量比慢化棒不移动条件下采用FLi燃料盐和FLiBe燃料盐的MA产量分别减少约43%和8%，低于相同能量输出下石墨慢化熔盐堆的MA产量。

Neutronic Optimization of Thorium Molten Salt Reactor Moderated by Zirconium Hydride Rod

Zirconium hydride (ZrH) is a commonly used reactor moderator due to its high temperature resistance, irradiation damage resistance and slowing-down power. This study aims to optimize core physical design of a ZrH moderated molten salt reactor to realize the self-sustaining operation by thorium uranium conversion, and to have low MA production. MOC program was used to analyze the effects of different fuel salts on start-up and breeding performance. In order to improve the thorium uranium conversion performance, the core structure and the design of the moderator rods were optimized and analyzed. The results show that when the volume ratio of molten salt is between 0.5 and 0.9, the critical ²³³U concentration reduces to around 2%. The average thorium uranium conversion ratio (CR) of the ZrH moderated molten salt reactor with the fertile zone and the FLi fuel salt can reach 1.028 in 50 a. The design of the movable moderator rods in the reactor can achieve a self-sustaining operation for 38 a, and the production of MA at the end of life reduces about 43% and 8%, respectively, compared with the production of MA using FLi fuel salt and FLiBe fuel salt under the condition that the moderators don’t move, and lower than that of the graphite moderated molten salt reactor under the same power output.