Evaluation of the Cleaning of the First Side of Steam Generator for WOLSONG Nuclear Power Plant-2

Abstract

Mechanical cleaning of the primary side of the WNPP-2 Steam Generator was carried out with AREVA SIVABLAST in December 2010 during a plant outage. All industrial plants undergo changes with time and nuclear plants are no exception. CANDU undergoes increased hydraulic resistance due to redistribution of iron in the HTS. Dissolution of iron and flow accelerated corrosion occur in the outlet feeders. The magnetite layers cause fouling inside the steam generator tubes, leading to reduced heat transfer, as well as increased hydraulic resistance in the steam generator tubes and inlet feeders. These developments have negative effects on the core flow and inlet header temperature and consequently adversely affect the CCP. Before 5,000 EFPD, WNPP-2,3,4 will undergo analysis of the ROP trip setpoint. WNPP-2 will arrive at 5,000 EFPD in 2012. For maximizing the ROP trip setpoint, we are carrying out numerous studies and actions. As a counter action, the present cleaning operation was performed at the optimal time and excellent results were achieved.