基于FCM燃料的商业压水堆中子学分析  

Neutronics analysis of commercial pressurized water reactor loaded with FCM fuel

作　　者：秦雪 李满仓[1] 廖鸿宽 于颖锐[1] 秦冬[1] 蒋朱敏[1] 王帅[1] 蔡云[1] 郭锐 QIN Xue;LI Mancang;LIAO Hongkuan;YU Yingrui;QIN Dong;JIANG Zhumin;WANG Shuai;CAI Yun;GUO Rui(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu 610041,China)

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重点实验室,成都610041

出　　处：《核技术》2020年第8期43-49,共7页Nuclear Techniques

摘　　要：全陶瓷微封装(Fully Ceramic Microencapsulated,FCM)燃料是一种将三结构同向性型(Tri-structural isotropic,TRISO)燃料颗粒弥散于SiC基质的先进燃料,具有良好的包容裂变产物的能力,能有效地改善核燃料在严重事故下保持结构完整性的能力,有利于降低核电站发生大量放射性物质泄漏的风险,是耐事故燃料(Accident Tolerant Fuel,ATF)的主要研究方向之一。与传统UO2陶瓷芯块燃料相比,FCM燃料的U装量较少,且燃料基体采用SiC,慢化能力较好,可能导致FCM燃料应用于商业压水堆时寿期初慢化剂温度系数为正,不能满足堆芯的固有安全性。本文以标准AFA3G 17×17栅格形式的UO2-Zr合金燃料组件为参照对象,采用中核集团自主研发的NESTOR软件,分析了17×17和13×13两种栅格形式的FCM燃料(UN核芯)组件的中子学特性,评价了由13×13栅格形式的FCM燃料(UN核芯)组成反应堆堆芯的总体物理特性。研究表明:含钆可燃毒物的13×13栅格形式的FCM燃料(UN核芯)组件可满足欠慢化要求,13×13栅格形式的FCM燃料(UN核芯)用于大型商业压水堆堆芯的慢化剂温度系数可以为负,首循环堆芯可达到与参照堆芯接近的燃耗深度与循环长度,能初步满足商业压水堆堆芯的固有安全性和经济性的要求。[Background] During the Fukushima accident, the shortcomings of the existing UO2-zirconium alloy fuel form in resisting severe accidents were exposed. Fully ceramic microencapsulated fuel(FCM) disperses tristructural iso-tropic(TRISO) fuel particles in a SiC matrix and has the ability to contain fission products, hence can effectively improve the ability of nuclear fuel to maintain structural integrity under severe accidents. FCM fuel can reduce the risk of large quantities of radioactive materials leakage in nuclear power plants, it is one of the main research objects of accident tolerant fuel(ATF). Compared with the traditional UO2 ceramic fuel pellets, the U loading of FCM fuel has better moderation ability and less U loading. When the FCM fuel is used in a commercial pressurized water reactor(PWR), it may cause the positive moderator temperature coefficient(MTC) and loss of inherently safety of the core.[Purpose] This study aims to analyse the neutronics characteristics of commercial PWR using FCM fuel from the perspective of inherent safety and economy. [Methods] The UO2-Zr alloy fuel assemblies in the form of standard AFA3 G 17×17 grid were taken as reference objects. The NESTOR software independently developed by China national nuclear corporation(CNNC) was employed to analyse the neutron characteristics of FCM fuel(UN core) assembly in forms of 17×17 grid and 13×13 grid. The overall physical performances of the reactor core composed of FCM fuel(UN core) in the form of a 13×13 grid were evaluated. [Results] Computational results show that FCM fuel(UN core) assembly in the form of 13×13 grid containing gadolinium poisons meets the requirements of under moderation, and the FCM fuel(UN core) assembly in the form of 13×13 grid can be adapted by large commercial PWR with negative MTC at the initial stage while the fuel consumption depth and cycle length of the first cycle core are basically equivalent to those of the reference core. [Conclusions] FCM fuel assemblies used in commercial PWR can initially me

关 键 词：全陶瓷微封装燃料 压水反应堆 中子学分析 

分 类 号：TL32[核科学技术—核技术及应用]