STEAM GENERATOR WATERLANCING AT DARLINGTON NGS (SYSTEM DEVELOPMENT AND INITIAL FIELD APPLICATION)

摘要

From the initial steam generator (SG) inspections at Darlington Nuclear Generating Station (DNGS), we know that the sludge accumulations on the secondary side tubesheets have been minimal. DNGS is a fairly new station but the experience at our older Ontario Hydro plants have shown that significant accumulations will happen. A pro-active strategy has been adopted for maintaining SGs that will minimize corrosion product accumulation and the potential for component degradation. During the four year planned Unit maintenance outages, SGs will be inspected and waterlanced using a waterlance system designed and built by Babcock & Wilcox International. This automated state-of the-art system also allows fully recorded inspections of the tubesheet/first half-lattice supports. Some of the key elements covered include results of the initial field application (May, 1995), system development and design, system qualification, cleaning performance, and lessons learned for future outages.