钚在地下水中的存在形态分析

The Analyses of Plutonium Existing Forms in the Groundwater

钚是某些放射性废物中的关键核素,在放射性废物地质处置的过程中,钚的迁移行为研究对于处置库的安全评价至关重要。钚的存在形态直接影响其迁移行为,本文选用地球化学模式程序EQ3/6模拟计算了钚在某区钻孔地下水中的存在形态,并对影响因素进行了分析。结果表明某区地下水主要为咸水,具有高矿化的特征,pH值在7～9之间,水化学类型主要以Cl-SO4-Na型和SO4-Cl-Na型为主,地下水中钚的存在形态主要以Pu(Ⅳ)物种为主。并通过结论得出钚的存在形态主要受着地下水化学成分特征控制,同时pH值和Eh的值对钚的存在形态也有很大的影响。

Plutonium is a major radionuclide in radioactive waste, therefore, during disposing nuclear waste, it is important for safety to study the migration behavior of Plutonium. The existing forms of Plutonium have direct effect on its migration. In this paper, we performed simulation study of the existing forms of Plutonium in groundwater from a drilling hole in a study region by the geochemistry modeling program EQ3/6, and analyze influencing factors in controlling the forms of Plutonium in groundwater. The main conclusions are as follows ： groundwater in the study area is mainly saline water with high salinity, pH value is 7 -9, Cl-SO4^-Na and SO4^-Cl-Na, the main exising forms of Plutonium in the groundwater are Pu（Ⅳ）. The results show that the existing forms of Plutonium are dominantly controlled by the chemical components of the groundwater, as well as the pH and Eh that also have great impact.