原子能科学技术2023，Vol.57Issue(12)：2388-2398,11.DOI:10.7538/yzk.2023.youxian.0115
Cs和I在某拟建核电厂液态流出物长距离排放管线周围土壤中的扩散行为
Diffusion Behaviors of Cs and I in Soil Surrounding Long-distance Effluent Pipeline of Proposed Nuclear Power Plant
摘要
Abstract
In the assessment of environmental radiation risk,137Cs and 129/131I,as high-yield fission products,are crucial indicators in the radioactive effluent of nuclear power plants.Due to the strong mobility and bioavailability of Cs+and I-in the groundwater-soil system,their diffusion behaviors attracted much attention.In this work,the shal-low soil samples under the long-distance effluent pipeline of a proposed nuclear power plant in China were used to study the diffusion behaviors of stable analogue(133Cs and 127I)of radioisotopes.The experimental data were fitted by Pycharm,which shows that the shallow soil at different sampling sites retards Cs+through the adsorption process.The effective diffusion coefficient of Cs+ranges from 3.87 × 10-11 m2/s to 4.31× 10-11 m2/s,the range of effective diffusion coefficient of I-is 1.97 × 10-11 m2/s to 2.61×10-11 m2/s,illustrating the diffusion of Cs+and I-are normal diffusion.The through time of Cs+ranges from 29.24 d to 34.48 d,and the solid-liquid distribution coefficient(Kd)ranges from 3.34×10-2 L/g to 4.27×10-2 L/g.On the contrary,the average through time of I-is 0.30 d,which is much less than that of Cs+,and the solid-liquid distribution coefficient(Kd)of I-tends to be zero(1.75 × 10-4-2.72 × 10-7 L/g),indicating that the weakly adsorbed 129/131I is difficult to be fixed by soil,and illustrating a faster diffusion of I-than Cs+.The diffusion coefficient of Cs+and I-in SK02 soil is the largest,which indicating that the migration rate of Cs+and I-is faster in SK02.The differences of Cs+and I-diffusion behaviors are affected by soil adsorp-tion.Illite,biotite and montmorillonite in soil can provide stong affinity adsorption sites for Cs+,on the contrary,it is difficult to provide effective adsorption sites for I-.Since the main components of the soil samples are quartz,plagioclase and anorthite,when the concentration of Cs+is higher than the capacity of strong affinity sites,a small amount of clay minerals in the soil will no longer control the diffusion of Cs+.In the meantime,the negative charge of the soil surface can attract Cs+and reject I-,so in the long-term diffusion process,the surface charge is the dominant factor that controlling the diffusion behavior of Cs+and I-in this area.关键词
Cs/I/扩散/Pycharm/放射性液态流出物Key words
Cs/I/diffusion/Pycharm/radioactive effluent分类
能源科技引用本文复制引用
陈东洋,李传斌,陈婧仪,杨杰,王建华,陈媛,王芝芬,吴涵玉,康明亮..Cs和I在某拟建核电厂液态流出物长距离排放管线周围土壤中的扩散行为[J].原子能科学技术,2023,57(12):2388-2398,11.基金项目
国家自然科学基金(21906187,41773095) （21906187,41773095）
核技术应用教育部工程研究中心开放基金(HJSJYB2021-15) （HJSJYB2021-15）
东华理工大学博士科研启动基金(DHBK2017130) （DHBK2017130）
