摘要
高温氧化挥发法能有效去除乏燃料中的挥发性和半挥发性核素。本文基于VERCORS 4和RT8实验,重建了21种代表性裂变元素的吉布斯自由能函数,并通过吉布斯自由能最小化原理进行热力学计算。结果表明,挥发性裂变产物I和Cs的释放动力学相似,且对氧势高度敏感,在高温下几乎完全释放;半挥发性裂变产物Ba和Mo的释放量受气氛、燃料类型、燃耗及产物相互作用的影响。热力学计算显示,Cs、I和Te全部释放,Ba和Mo部分或全部释放,其中Cs以Cs(g)、CsI(g)和Cs_(2)MoO_(4)(g)形式挥发,I以I(g)、CsI(g)和TeI_(2)(g)形式挥发,Te以Te(g)和Te_(2)(g)形式挥发,Ba以Ba(g)、BaO(g)和BaMoO_(4)(g)形式挥发,Mo以MoO_(2)(g)、MoO_(3)(g)、Mo_(2)O_(6)(g)和Cs_(2)MoO_(4)(g)形式挥发。研究裂变产物在空气气氛下的稳定相变化,对提高挥发性和半挥发性核素的去除效率具有重要意义。
The high-temperature oxidation volatilization method is effective in removing volatile and semi-volatile radionuclides from spent fuel.Based on the VERCORS 4 and RT8 experiments,this study reconstructed the Gibbs free energy functions for 21 representative fission elements and performed thermodynamic calculations using the principle of Gibbs free energy minimization.The results show that the release kinetics of volatile fission products,such as iodine(I)and cesium(Cs),are similar and highly sensitive to oxygen potential,with nearly complete release at high temperatures.The release of semi-volatile fission products,such as barium(Ba)and molybdenum(Mo),is influenced by factors such as atmosphere,fuel type,burnup,and product interactions.Thermodynamic calculations indicate that Cs,I,and Te are fully released,while Ba and Mo are partially or fully released.Specifically,Cs volatilizes as Cs(g),CsI(g),and Cs_(2)MoO_(4)(g);I volatilizes as I(g),CsI(g),and TeI_(2)(g);Te volatilizes as Te(g)and Te_(2)(g);Ba volatilizes as Ba(g),BaO(g),and BaMoO_(4)(g);and Mo volatilizes as MoO_(2)(g),MoO_(3)(g),Mo_(2)O_(6)(g),and Cs_(2)MoO_(4)(g).Investigating the stable phase evolution of fission products in air atmospheres is significant for improving the removal efficiency of volatile and semi-volatile radionuclides.
作者
周希
黄洪文
晁楠
矫彩山
谢翔
高新颖
仇隆基
Zhou Xi;Huang Hongwen;Chao Nan;Jiao Caishan;Xie Xiang;Gao Xinying;Qiu Longji(Heilongjiang Provincial Key Laboratory of Nuclear Chemical Engineering and Radiochemistry,Harbin Engineering University,Harbin,150001,China;Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang,Sichuan,621900,China)
出处
《核动力工程》
北大核心
2025年第S2期158-166,共9页
Nuclear Power Engineering
基金
核技术研发科研项目[HNKF202217(60)]。
关键词
挥发性裂变产物
半挥发性裂变产物
释放分数
化学形态
Volatile fission products
Semi-volatile fission products
Release fraction
Chemical speciation
