离子交换树脂在线分离-原子吸收光谱法测定核电厂一回路含硼酸水中的锂

Ion Exchange Resin Online Separation-Atomic Absorption Spectroscopy System for Measuring Lithium Concentration in Primary Circuit Water Containing Boric Acid of Nuclear Power Plant

压水堆核电厂一回路水化学监督采用硼-锂协调曲线控制。一回路水质含有一定量的硼酸,采用原子吸收光谱法测量一回路水质中的锂时,硼酸对锂的测量干扰显著,测量回收率明显偏低。本文采用变色强碱性阴离子交换树脂在线分离-原子吸收光谱法联用系统,利用变色阴离子交换树脂在线去除一回路水质中的硼酸,消除硼酸对锂浓度测量的影响,实现锂浓度的准确分析。结果表明,其锂浓度测量加标回收率达101.0%,相对标准偏差为0.47%(n=6),有效消除了硼酸对锂测量的影响。本文所用系统具有结构简单、操作方便、成本低、能有效避免火焰燃烧头硼酸结晶问题等优点。

In pressurized water reactor nuclear power plants,the primary circuit water chemistry control uses the boron-lithium coordination solution.Under the existence of the boric acid in the primary circuit water,the lithium recovery significantly decreases with the increase of boron concentration by the method of atomic absorption spectroscopy.In this study,ion exchange resin online separation-atomic absorption spectroscopy system which used allochroic ion exchange resin to remove boric acid of the primary circuit water was developed.The system eliminates the effect of boric acid and reaches the accurate analysis of lithium concentration.Under the optimized conditions,boric acid is completely removed.The recovery of standard addition and relative standard deviation are 101.0%and 0.47%（n=6）respectively.The results demonstrate that the present system can be applied in lithium concentration analysis in the primary circuit water of nuclear power plants.The system has the advantages of simple structure,easeof building without the requirement of complexly fabricated devices,low cost,convenient operation and no pollution by the boric acid in burner of atomic absorption spectroscopy.