Development Progress of Neutronics and Thermal-Hydraulics Calculation Program NECP-Panda for Pebble-Bed High Temperature Gas-Cooled Reactor

Abstract The Pebble-Bed High Temperature Gas-cooled Reactor (PB-HTGR) is considered one of the most promising next-generation nuclear energy systems. Due to its unique operational characteristics and neutron spectrum, PB-HTGR presents many challenges and issues in technical improvements and design analysis. To address these demands, the Nuclear Engineering and Computational Physics (NECP) Laboratory at Xi'an Jiaotong University is autonomously developing a neutronics and thermal-hydraulic analysis code suitable for PB-HTGR, named NECP-Panda. Currently, the development of the neutronics calculation module has been completed, while the remaining calculation modules are under development and testing. Aiming to validate the neutronics calculation accuracy of NECP-Panda, the HTR-PM was selected for the first criticality calculation and absorber worth calculation. These calculations were compared with Monte Carlo continuous energy solutions and experimental results. The numerical results demonstrate that NECP-Panda is capable of predicting the loading number of mixed pebbles at first criticality with good accuracy, differing from the experimental results by approximately 800. Additionally, the absorber worth calculation results are in good agreement with the Monte Carlo solutions and measured values. These findings confirm that NECP-Panda possesses the capability for neutron physics calculations appropriate to PB-HTGR, with high calculational precision.