原子能科学技术2025，Vol.59Issue(10)：2190-2199,10.DOI:10.7538/yzk.2025.youxian.0041
高温气冷堆与压水堆辐照生产238Pu的对比研究
Research on Irradiation Production of 238Pu by HTGR and PWR
摘要
Abstract
Plutonium-238(238Pu)is an ideal isotopic heat source commonly used in the production of radioisotope thermoelectric generators(RTGs).It has broad applications in fields such as space exploration and polar meteorological research.Reactor irradiation remains the primary method for 238Pu production.A theoretical model was derived for the maximum conversion ratio of 238Pu production from 237Np and formulas was provided for calculating the maximum conversion ratio and the corresponding conversion time in the paper.Theoretical calculations for high-temperature gas-cooled reactors(HTGR)and pressurized water reactors(PWR)were presented.Additionally,the NUIT code for burnup calculation,developed by the Institute of Nuclear and New Energy Technology(INET)at Tsinghua University,was employed to calculate the conversion curves for 238Pu production from 237Np in HTGR and PWR.The effects of neutron flux levels and neutron spectrum differences on the maximum conversion ratio and production rate of 238Pu were examined.A comparison indicates that the simulation results of the NUIT code align well with the theoretical analysis.The results demonstrate that increasing the neutron flux level effectively enhances the production rate of 238Pu.During the early stages of irradiation,the production rate is primarily influenced by the neutron capture reactions of 237Np.Furthermore,under the same total neutron flux level,although the maximum conversion ratio of 238Pu in HTGR is lower than that in PWR,the conversion rate in HTGR is significantly higher.Building upon this analysis,the Monte Carlo code OpenMC and the NUIT code were used to analyze 238Pu production in HTGR and PWR under varying temperatures and moderator volume ratios.The analysis reveals why HTGR achieves a higher 238Pu production rate than PWR under the same total neutron flux level:HTGR has a higher moderator volume ratio,leading to more effective neutron moderation,higher thermal neutron flux,and a larger one-group capture cross-section for 237Np,thereby increasing the 238Pu conversion rate;HTGR operates at a higher temperature.Although elevated temperatures have minimal impact on the one-group capture cross-section of 237Np,they significantly reduce the one-group absorption cross-section of 238Pu,resulting in lower neutron consumption by 238Pu and consequently higher production yields.This study explores 238Pu production through irradiation in HTGR,elucidating the underlying factors contributing to their higher production rate.Moreover,the capability of certain pebble-bed HTGR for continuous fuel replacement enables flexible control over irradiation duration,a distinct advantage over conventional PWR.A comparative analysis of 238Pu production in HTGR and PWR reveals that although the purity of 238Pu produced by HTGR is lower than that from PWR,HTGR exhibits higher production efficiency.Moreover,the content of the byproduct 236Pu in the 238Pu produced by HTGR is significantly lower than that in PWR.These findings indicate that,under the condition of meeting the required purity of 238Pu,HTGR possesses a certain advantage over PWR in terms of production performance.关键词
238Pu/NUIT/单群截面/最大转化比/HTGR/PWRKey words
238Pu/NUIT/one-group cross section/maximum conversion ratio/HTGR/PWR分类
能源科技引用本文复制引用
谭博,文宇同,佘顶,夏冰..高温气冷堆与压水堆辐照生产238Pu的对比研究[J].原子能科学技术,2025,59(10):2190-2199,10.基金项目
中核集团"青年英才"项目 （）
