FCM燃料应用于商业压水堆的中子物理分析  

作　　者：王星博 于颖锐[1] 李满仓[1] 王丹[1] 刘勇[1] 谢运利 刘晓黎[1] 李向阳[1] 

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术国家级重点实验室,四川成都610041

出　　处：《科技创新导报》2020年第11期103-115,共13页Science and Technology Innovation Herald

摘　　要：全陶瓷微胶囊封装燃料(Fully Ceramic Microencapsulated Fuel,FCM燃料)将TRISO燃料颗粒弥散于SiC基体中,具有良好的包容裂变产物能力,固有安全性好,是耐事故燃料的主要研究方向之一。相比于传统的UO2陶瓷芯块燃料,FCM燃料装料减少,影响堆芯功率和/或循环长度;基体采用SiC,慢化能力提高,能谱变软,FCM燃料直接应用于现有大型商业压水堆组件栅格,寿期初慢化剂温度系数可能为正,失去固有安全性。本文从燃料富集度和栅格慢化角度,分析FCM燃料直接应用于大型商业压水堆的可行性,分析两种FCM燃料TRISO颗粒核芯:高温气冷堆中应用成熟的UO2核芯和提高了核芯尺寸的UN核芯。研究表明:在防核扩散的限制下,技术相对成熟的UO2核芯FCM燃料仅能应用于小型堆芯的设计,且需重新设计燃料组件栅格;提高装量的UN核芯FCM燃料可直接装载现有商业压水堆,实现与其基本相当的堆芯功率和循环长度,但对燃料富集度和燃料设计及制造工艺提出较高要求。The f ully ceramic microencapsulated(FCM)f uel is based on tristructural isotropic(TRISO)coated particles embedded in silicon carbide(SiC)matrix,which is among the accident tolerant f uel concept options.With the strength of high f ission product retention,the FCM fuel provides potential superior safety performance.Compared to the conventional standard UO2 f uel,the def iciency of FCM f uel is its considerable lower f issile inventory,which results in a reduced reactor power or/and life.Supposing the FCM fuel is used as direct replacement of the fuel in commercial PWRs,the spectrum is softened due to the usage of SiC as matrix,and the moderator temperature coeff icient is possible to be positive at the beginning of life,leading to high risk during operation.A neutronic feasibility study of FCM fuel utilized in commercial PWRs is performed in the paper.The fuel enrichment and undermoderated lattice are evaluated by analyzing the typical TRISO particle with UO2 kernels which is widely used in high temperature gas reactors and that with enlarged UN fuel kernels.It was found that under the mandatory constraint of low enriched uranium,the FCM fuel with UO2 kernels,although relatively mature,is only capable of small reactor designs,and the assembly lattice needs to be modif ied.The FCM fuel with UN kernels,when directly loading in the commercial PWRs,can yield comparable reactor power and life;however,a higher fuel enrichment and the fuel design and fabrication need to be optimized.

关 键 词：FCM燃料 压水堆 中子物理 TRISO颗粒 耐事故燃料 

分 类 号：TL32[核科学技术—核技术及应用]