The water quality requirements for protection of the Cr—1 Mo ferritic steel steam generator tubing includes the use of all-volatile treatment with specific details on offending ions—Na+, Cl−, , and dissolved oxygen. During standby, refueling, or wet layup, emphasis was placed on off-normal chemistry when balance of a plant may not be available. Special considerations include introduction of high levels of hydrazine when the deaerator is out of service. Several experimental tests were run to demonstrate the ability to control and maintainability of the desired specification and effects of these impurities on the steam generator tubing. These tests include a departure from nucleate boiling experiment, a few-tube test in which a full-length seven-tube evaporator and a three-tube superheater were tested in a 2-MW rig and sodium control experiment in the Nueces Bay fossil-fired plant. The results from these experiments substantiated the goals of the tests. Commercial equipment is available to satisfy the majority of the sampling and instrumentation requirements. An on-line ion chromatograph instrument has been developed for the measurement of several ions. The laboratory evaluation and initial field test data at an operating nuclear power plant show the capability to measure Cl−, , Na+, Ca++, Mg++ in the parts per billion region. Laboratory testing of chemical cleaning solutions with emphasis on flow, chemical composition, and temperature was conducted to establish parameters for evaporator cleaning. Deposit removal and base metal attack were measured.