Abstract: A full range of control method for water quality is employed in the practices of secondary loop water control and management at Ningde nuclear plant unit 1, namely equipment maintenance and washing during commissioning, chemical control during outage, complete rinsing and cleaning of the secondary loop in the process of start, and water regulation and control during operation. These have obtained significant performance. Water quality analyses have shown that the secondary loop and steam generator have good water quality, resulting in reduced equipment corrosion to a larger extent.

Key words: Ningde NPP unit 1, Secondary loop, Fullrang control, Water chemistry management, Corrosion