CFETR离子回旋加热天线中子学分析  

Neutronic analyses of ICRF antenna system for CFETR

作　　者：伍秋染 卢棚 郑俞 杜华 徐坤 王永胜 童云华 陈根 刘松林 WU Qiuran;LU Peng;ZHENG Yu;DU Hua;XU Kun;WANG Yongsheng;TONG Yunhua;CHEN Gen;LIU Songlin(Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230031,China;Institute of Energy,Hefei Compressive National Science Center,Hefei 230031,China)

机构地区：[1]中国科学院等离子体物理研究所,合肥230031 [2]中国科学技术大学,合肥230031 [3]合肥综合性国家科学中心能源研究院,合肥230031

出　　处：《核技术》2020年第11期83-89,共7页Nuclear Techniques

基　　金：国家重点研发计划(No.2017YFE0300503);国家自然科学基金(No.11775256)资助。

摘　　要：离子回旋加热是用以维持聚变堆实现长脉冲、高功率稳态运行重要的加热手段之一。中国聚变工程试验堆(China Fusion Engineering Test Reactor,CFETR)的离子回旋加热天线将经由一个上窗口引入,其天线发射前端将占据一个包层的位置。由于天线直接面对等离子体,受高通量中子辐照,因此需要评估天线的辐照损伤;另外,天线内部存在大量空隙,造成中子泄漏,对后部真空室、线圈等部件造成辐照影响,因此需要评估其屏蔽性能,支撑屏蔽设计。基于22.5°扇段的水冷包层CFETR模型,用cosMCNP软件将CAD模型转为中子学模型,使用MCNP5粒子输运程序和FENDL-2.1数据库,通过全局减方差(Global Variance Reduction,GVR)“onthe-fly”减方差方法,开展离子回旋加热天线核分析。计算了天线主要部件辐照损伤和核响应,包括中子通量、平均原子离位(Displacement Per Atom,DPA)、气体产生率和核热密度等,为后续天线冷却系统的设计和寿命评估提供数据;获得引入天线后相应位置的真空室、窗口以及纵场线圈的中子辐照损伤,以评估屏蔽是否满足需求。此外,天线占据包层位置,将导致氚增殖比(Tritium Breeding Ratio,TBR)降低,由原始的1.151降至1.147,降低0.35%。[Background]Ion cyclotron range frequency(ICRF)antenna is one of the effective auxiliary heating systems to maintain the long pulse and high power steady-state operation of fusion reactors.The ICRF antenna has been designed to be introduced into China Fusion Engineering Test Reactor(CFETR)through one upper port,and the front-end will occupy one blanket.Since the antenna faces the plasma directly,it will be irradiated by high flux neutrons.It is necessary to evaluate the irradiation damage of the antenna.Besides,due to a lot of gaps in the antenna system,the neutron leakage will produce irradiation effects on the vacuum vessel(VV)and toroidal field coil(TFC)behind.Thus the shielding performance needs to be evaluated to support the shielding design.[Purpose]This study aims to evaluate nuclear responses of the exposed components of ICRF antenna by neutronic simulation,and provide data for designing the cooling system and estimating its life after irradiation.[Methods]Based on CFETR model of 22.5°fan section water cooled cladding,the neutronic model was converted from CAD file into MCNP input file by cosVMPT software.Nuclear analysis of ion cyclotron heating antenna was performed by using MCNP5 particle transport program and fendl-2.1 database,as well as the variance reduction method of Global Variance Reduction(GVR)"on the fly".The radiation damage and nuclear response of the main components of the antenna,including neutron flux,displacement per atom(DPA),gas production rate and nuclear thermal density,were calculated to provide data for the design and life assessment of the antenna cooling system.[Results&Conclusions]The neutron radiation damage of the vacuum chamber,window and longitudinal field coil at the corresponding position of lead-in antenna is obtained to evaluate whether the shielding meets the requirements of material.In addition,the Tritium Breeding Ratio(TBR)of the whole reactor is decreased from original 1.151 to 1.147 due to the blanket opening,which corresponds to a reduction of 0.35%.

关 键 词：中国聚变工程试验堆 离子回旋加热天线 中子学计算 

分 类 号：TL64[核科学技术—核技术及应用]