Oxygen transport and oxygen-hydrazine reactions in once-through boilers and feed systems

Redox conditions play a determining role in the corrosion processes which occur in feed systems and steam generators of all reactors types. In many cases these are controlled by the presence or absence of oxygen and hydrazine in the feedwater. To establish that AGR boilers are robust with respect to oxygen transients which may occur, experiments have been carried out to demonstrate the boiler economizer and evaporator tubing have a substantial oxygen capacity, which can prevent oxygen reaching the more susceptible austenitic superheater region and buffer against any oxygen transients. 4 figs., 1 tab., 2 refs