Sulfate ingress and steam generator hideout at Saint Lucie Unit 1

In March 1989, Florida Power and Light Company contracted with NUS Corporation to perform a secondary cycle mass balance study at the St. Lucie 1 Plant. St. Lucie Unit 1 has shown significant steam generator intergranular attack (IGA) since startup in 1974 in contrast to Unit 2 which has shown no significant problems since startup in 1978. Based on a number of evaluations including tube examinations, MULTEQ predictions, and cation/anion balances, acid sulfate induced IGA is suspected as the mechanism of attack by the FP ampersand L staff. The primary purpose of the NUS study was to attempt to identify a possible source or sources of sulfate by conducting mass balance determinations under various modes of plant operation. A secondary purpose was to compare impurity hideout data obtained under steady-state operating conditions using improved ion chromatography techniques with data previously reported by NWT Corporation using a feedwater spiking procedure. 18 refs., 29 figs., 27 tabs