基于PANGU程序的球床式高温气冷堆中子动力学参数计算  

Calculation of Neutron Kinetics Parameters of Pebble-bed HGTR Based on PANGU Code

作　　者：付彬 张伟健 文宇同 魏春琳[1] 佘顶[1] FU Bin;ZHANG Weijian;WEN Yutong;WEI Chunlin;SHE Ding(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院,北京100084

出　　处：《原子能科学技术》2024年第7期1488-1494,共7页Atomic Energy Science and Technology

基　　金：中核集团“青年英才”项目。

摘　　要：有效缓发中子份额(β_(eff))等中子动力学参数是核反应堆动态分析的基础。获取中子动力学参数的方法包括实验测量与数值计算,而对于球床式高温气冷堆,现有的条件还不能够直接进行实验测量,因此,数值计算是唯一现实可取的方法。本文研制了包含缓发中子数据的多群截面数据库XPZLIB,基于高温气冷堆栅格物理程序XPZ,对缓发中子数据进行了均匀化和能群归并处理,基于堆芯物理分析程序PANGU,使用重要性函数加权方法计算了高温气冷堆中子动力学参数,并利用蒙特卡罗程序检验了计算结果的准确性。结果证明,数值计算方法可以用于计算高温气冷堆动力学参数,并能为其动力学分析提供基础。In the complex realm of nuclear engineering,understanding the kinetics behavior of neutrons in reactors is a task of considerable importance for safety.The effective delayed neutron fraction(β_(eff)),neutron prompt generation time(Λ)and other neutron kinetics parameters are pivotal for dynamics analysis in nuclear reactor.Because of the limited realistic conditions,these parameters have traditionally been challenging to measure experimentally,compelling researchers to rely on numerical computations for their determination,especially for pebble-bed high-temperature gas-cooled reactors(HTGRs).Yet conventional numerical techniques necessitate direct core condition data and often presuppose simplistic treatments of delayed neutron energies,resulting in computational inefficiencies and imprecise outcomes.A central difficulty lies with the process involving VSOP and CITATION codes,used in HTGR calculations of neutron kinetics parameters,which requires the formulation of input cards based on VSOP output for any core state—This procedure can confound researchers.Furthermore,the limited data library(ENDF/B-Ⅵ.8)available to VSOP restricts the accuracy attainable through these methods.In this paper,in an effort to refine this process,a multi-group cross section library,XPZLIB,containing delayed neutron data was generated.This library leverages the comprehensive nuclear data from the ENDF/B-Ⅷ.0 library,processed using the enhanced NJOY2016 code equipped with a developed XPZR module and an automatic processing system,PyNjoy2022.The HTGR physics lattice code XPZ was then used to homogenize the delayed neutron data,ensuring that the necessary energy-related information was retained in preparation for subsequent calculations of energy-dependent neutron kinetic parameters.A unique homogenization technique was also developed to handle the delayed neutron precursor decay constants(λ),which unlike other parameters,are timedependent.These calculations of kinetics parameters for HTGRs are conducted via the importance function

关 键 词：缓发中子有效份额 平均中子代时间 PANGU 缓发中子数据 重要性函数加权方法 

分 类 号：TL327[核科学技术—核技术及应用]