钍基熔盐堆新型栅格设计与优化

摘要

Based on comprehensive screening,lattice parameters including fuel composition,moderator material,lattice size and structure are redesigned for thorium molten salt reactor (TMSR)applying SONG/TANG-MSR codes.Innovatively,a fuel composition without BeF2 is adopted to increase the solubility for actinides (ThF4 ,UF4 ),and BeO is introduced as moderator to improve neutron economy.Moreover,SiC cladding is employed to separate fuel and moderator.Meanwhile such ceramic cladding contributes to maintain structure stability and improve resistance to radiation.With these lattice parameters,TMSR can achieve a high breeding ratio and maintain a negative power coefficient as well.Based on this lattice design,TMSR can have excellent per-formance of safety and sustainability.%利用上海核工院自主开发的 SONG/TANG-MSR程序系统,通过大量的方案筛选,在熔盐燃料成分、慢化剂材料以及栅格结构等方面对钍基熔盐堆(TMSR)栅格进行设计优化。提出采用无铍熔盐作为燃料,以提高重核(ThF4,UF4)溶解度；采用氧化铍(BeO)作为慢化剂,从而提高中子经济性；创新性地采用熔盐燃料与慢化剂隔离的 SiC包壳管设计,保持堆芯结构的稳定性和抗辐照性能。对优化后的栅格设计计算结果表明：新型的熔盐堆栅格设计具有很高的增殖比并保持负功率系数,从而满足下一代核能系统可持续性和安全性要求。