Study On The Application Of GEANT4 For CFETR Neutronics Analysis

CFETR(China Fusion Engineering Test Reactor)is a key step in China's magnetic confinement fusion development roadmap and is currently under the engineering design.Neutronics analysis is of great significance in the design and safe operation of fusion reactors.Simulation based on the Monte Carlo method is a common way for fusion neutronics analysis.The classic simulation tool is MCNP.At the same time,related research has been conducted to explore the applicability of other Monte Carlo programs(including GEANT4)in fusion neutronics analysis.This study aims to investigate the applicability of the Monte Carlo simulation toolkit,GEANT4,in the fusion neutronics analysis and CFETR is taken as the research object.A new physical process was developed in order to set up the reflecting surface boundary.The effectiveness of this new process was also verified.Because the original G4NDL-format cross section library is not adequate,the new G4NDL library published by IAEA was adopted.The benchmark calculation of the cross section library has been carried out to verify the applicability of the G4NDL library in fusion neutronics analysis.The CFETR one-dimensional cylindrical shell model and three-dimensional model were established in GEANT4 by means of hard-coded programming and GDML file conversion(with the help of McCAD),respectively.The neutron source,physical process and scoring methods were set up and the complex neutronics model was established successfully in GEANT4.Based on this,neutronics analysis of CFETR was carried out using GEANT4.In the one-dimensional neutronics analysis,the CFETR one-dimensional cylindrical shell model was established by means of hard-coded programming method and the neutron source and section library were set.Then the radial neutron flux distribution and blanket neutron energy spectrum distribution were calculated.In the three-dimensional neutronics analysis,the CFETR three-dimensional model was established using the GDML file conversion method,and the neutron source and cross section library were also set up.Then the neutron wall loading was obtained.The results show that GEANT4 can be applied to fusion neutronics analysis,but the precision of the model,the accuracy of cross-section libraries and processing modes of physical processes in GEANT4 have a certain impact on the accuracy of the analysis results.This study initially investigates the application feasibility of GEANT4 in fusion neutronics analysis and also indicates that more thorough study needs to be conducted to research the applicability of GEANT4 in fusion neutronics analysis.