A system (10) for lancing sludge deposits (12) from within a bundle (14) of vertically extending steam generator tubes (16) of a PWR steam generator secondary side assembly (18) has a flexible lance (28) mounted in a lance guide/housing transporter (30). The transporter (30) is movable along blowdown lane (20) to position end (32) of the flexible lance opposite one of the inter-tube lanes (26) so that the flexible lance (28) may be inserted along the selected inter-tube lane (26). A rigid lance guide (34) on the transporter (30) has a curved end (36) configured to turn the flexible lance (28) at a chosen angle, such as 90.degree., so that the flexible lance (28) will be fed into the selected inter-tube lane (26). The transporter has a drive (37) for advancing the flexible lance (28) through end (36) of the lance guide (34) and into the inter-tube lane (26). The flexible lance (28) includes a flexible plastic extrusion (38) with a plurality of hollow, flexible metal conduits (40) within the plastic extrusion (38) to extend lengthwise along the lance (28). The nozzle block (44) has nozzles 48, 50 and 52 so that all portions of the sludge deposits (12) adjacent to the selected inter-tube lane (26) can be reached by the flexible lance (28).