Water chemistry studies at the Sequoyah Nuclear Plant using an online ion chromatographic analyzer

The utility industry has long been plagued with complications and outages related to corrosion of plant components. It has been estimated that approximately 50 percent of all forced outages are caused by corrosion. The cost of corrosion to U.S. utilities has been estimated to be in excess of 2.7 billion dollars per year. The low limits placed on allowable concentrations of corrosive ions in the BWR Water Chemistry Guidelines and the PWR Secondary Water Chemistry Guidelines indicate the importance of water chemistry control in minimizing corrosion. As with any chemical process, an effective chemical monitoring program is required for optimal process control. The Tennessee Valley Authority (TVA) has instituted programs for improved water chemistry control with a goal of minimizing corrosion and ensuring cost-effective and safe operation of its nuclear plants. An important aspect of a good chemistry program is the detection and monitoring of various process streams for a myriad of constituents. TVA, in a joint cooperative agreement with the Dionex Corporation, has been developing an automatic OIC as an improved tool for this monitoring. This project has been undertaken at Sequoyah, a two unit Westinghouse PWR with a 1,134 MWe rating per unit