摘要
超铀核素是放射性废物地质处置中重点关注核素,其在地下水中的化学形态是影响其迁移的重要因素,PHREEQC是由美国地质调查局开发的免费水文地球化学模拟软件,它是在PHREEQE的基础上发展而来的,与传统的水化学反应模型相比,目前的PHREEQC最新版不仅可以描述局部平衡反应,还具有模拟表面吸附、一维扩散、反应动力学计算、固体溶解、反应途径计算等功能,是目前比较完善的地化模式程序之一,在国内外广泛使用。采用PHREEQC程序分析超铀元素Np、Pu、Am在某处置工程地下水中的存在形态,并对影响因素进行分析。结果表明,地下水水化学成分是影响核素存在形态的重要因素,热力学数据库的差异和准确性会影响计算结果,p H对核素的存在形式和存在价态有着很重要的影响,在地下水的p H变化范围内,Np主要以Np O2+形式存在,Pu以Pu(OH)_4形式存在,Am主要以AmCO_3^+的形态存在。
The chemical forms of transuranic radionuclides is an important factor affecting its migration in groundwater,PHREEQC,a hydrogeochemistry simulation software foe free,was developed by the United States Geological Survey,which was developed on the basis of PHREEQE. Compared with the traditional water chemical reaction model,the current PHREEQC latest version can not only describe the local equilibrium reaction,but also has functions to simulate surface adsorption,one-dimensional diffusion and reaction kinetics,solid solution,reaction calculation. It is one of the more perfect model application currently and widely used at home and abroad. Using PHREEQC program analyze the chemical species of transuranic elements Np,Pu,Am in the groundwater of a certain disposal project and the influencing factors. The results showed that the chemical composition of the ground water is an important factor that affect transuranic radionuclides existing forms. The differences and accuracy of thermodynamic databases can affect the results. p H has a very important influence to the existing forms and valence of nuclide. In the p H range of groundwater,Np is mainly in the form of NpO_2~＋. Pu is mainly in the form of Pu（ OH）_4and Am is mainly in the form of AmCO3^＋.
出处
《地下水》
2017年第1期24-26,61,共4页
Ground water
