Advance service technologies for steam generator maintenance

There are currently 77 steam generators of Siemens design, containing a total of around 327,000 tubes in operation in 23 plants worldwide. Between them, these components have clocked up approximately 950 years of operation. Since the time when the first of these originally went into service 24 years ago, leaks have only occurred in 13 of the 327,000 tubes and less than 0.4% of all tubes have had to be plugged. The key to this success lies not only in the component design, selected materials, and water chemistry, but also in the service technologies applied for maintenance. This paper will describe three examples of such advanced technologies i.e. secondary side steam generator chemical cleaning and primary side mechanical and chemical decontamination. (author)