Alternating Current Techniques for Corrosion Monitoring in Water Reactor Systems

摘要

Corrosion in both nuclear and fossil fueled steam generators is generally a consequence of the presence of aggressive impurities introduced into the coolant system through condenser leakage. The impurities concentrate in regions of the steam generator protected from coolant flow, in crevices or under deposited corrosion products and adjacent to heat transfer surfaces. These three factors, the aggressive impurity, crevice type areas and heat transfer surfaces appear to be the requirements for the onset of rapid corrosion. Under conditions where coolant impurities do not concentrate the corrosion rates are low, easily measured and can be accounted for by allowances in the design of the steam generator. Rapid corrosion conditions cannot be designed for and must be suppressed. The condition of the surfaces when rapid corrosion develops must be markedly different from those during normal operation and these changes should be observable using electrochemical techniques. This background formed the basis of a design of a corrosion monitoring device, work on which was initiated at BNL. The basic principles of the technique are described. The object of the work is to develop a corrosion monitoring device which can be operated with PWR steam generator secondary coolant feed water. (ERA citation 02:059170)