DRAGON/DONJON程序在CARR物理计算中的适用性研究  

Investigation of the feasibility of DRAGON/DONJON codes with CARR neutronics calculations

作　　者：乔硕 乔雅馨 冉怀昌 朱吉印[1] QIAO Shuo;QIAO Yaxin;RAN Huaichang;ZHU Jiyin(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《核技术》2024年第10期169-177,共9页Nuclear Techniques

基　　金：中国先进研究堆运行与改造项目(No.PM2021033100000377)资助。

摘　　要：反中子阱型研究堆独特的堆芯和反射层结构对传统上适用于动力堆的确定论堆芯物理计算方法提出了挑战。使用确定论程序DRAGON/DONJON对反中子阱型设计的中国先进研究堆(China Advanced Research Reactor,CARR)进行了堆芯物理计算与适用性分析。采用了多组件方法改善CARR堆芯组件均匀化计算的环境影响;使用OPTEX反射层优化方法对反射层均匀化群常数进行修正。将蒙特卡罗方法的计算结果作为参考解,使用DRAGON程序挂载几种常用的多群截面库进行组件计算,选择偏差最小的SHEM-295作为CARR堆芯物理计算截面库。将DRAGON/DONJON的计算结果与传统“三步法”和参考解进行对比表明:临界工况附近的有效增殖系数keff、堆芯活性区和重水箱中间位置的热中子注量率分布以及标准燃料组件的功率分布等核特性参数偏差较小。对于堆芯与重水箱交界、水池外真空边界、跟随体组件等处计算结果出现较大偏差的原因进行了分析。证明了使用DRAGON/DONJON程序进行CARR物理计算具备可行性且相较于传统“三步法”计算精度有了明显改善,能够满足CARR堆上实验方案设计、运行参数快速计算分析等需求。[Background]The unique core and reflector structure of the inverse flux trap research reactors has raised a challenge to the traditional deterministic neutronics calculation methods applicable to power reactors.The deterministic codes DRAGON/DONJON with powerful geometric modeling capabilities have been maturely applied to power reactor types such as CANDU(Canadian Deuterium Uranium)and pressurized water reactors(PWR),but not been performed neutronics calculations and feasibility analysis on the China Advanced Research Reactor(CARR)with inverse flux trap design.[Purpose]This study aims to verify the feasibility of the DRAGON/DONJON codes in CARR neutronics calculations and analysis.[Methods]Firstly,when performing homogenization calculation using DRAGON/DONJON codes on various assemblies of CARR,the multi-assembly method was adopted to improve the surrounding impact.The OPTEX reflector optimization method was used to modify the homogenization constants of the reflector.Then,the commonly used multigroup cross-section libraries in DARGON were compared and screened,and SHEM-295 group-structure library was selected.Finally,the calculation results of DRAGON/DONJON codes were compared with the Monte Carlo references and the conventional three-step method,and analysis was conducted on the reasons for the significant deviation in the calculation results.[Results]The results indicate that the deviation of parameters such as k_(eff) eigenvalue near critical operating condition,thermal neutron flux distribution in the active zone of the core and the middle position of the heavy water tank,and power distribution of standard fuel assemblies are relatively small whilst significant deviations in the calculation results appear at the junction of the core and heavy water tank,the vacuum boundary outside the pool,and the follower assemblies.[Conclusions]This study verifies that it is feasible to use the DRAGON/DONJON codes for CARR neutronics calculations and achieve a certain degree of accuracy,meeting the needs of experimental s

关 键 词：中国先进研究堆 DRAGON DONJON 组件均匀化 扩散计算 

分 类 号：TL99[核科学技术—核技术及应用]