Waterlancing for CANDU SG's - An Update

Abstract

Waterlancing for the removal of steam generator tube sheet deposits has now been performed at two CANDU locations. The first project was the demonstration water lancing an Ontario Hydro Pickering A, Unit 1 SG. The second was the full scale waterlancing of the four SG's at the New Brunswick EPC Point Lepreau Plant which are shown in Figure 1. Both proj,ects involved the development of special lancing devices for use with an existing ~ystem. In both cases the results showed that the SG's could be lanced but at a slow rate given the hardness of the sludge. In both cases, tube erosion was confirmed not to be a problem. The paper reviews these programs.