Tool intended for the breakdown of the sediments formed in steam generators of pressurised-water nuclear reactors

摘要

The tool 930 carries a plurality of nozzles 935 mounted in parallel, directing jets of water under high pressure HP into the routes of the tubes 903. It is moved by traction of the cable 934, and it is aligned over the tube routes by the stop-pieces 941; it is then pressed against the tubes by the jacks 939 located on either side of the nozzles. The nozzles are retracted by the jacks 942 when it is required to move from one route to another; for safety, the stop-pieces have a canted wall 944 which allows extraction in the event of the jacks breaking down. Shaped parts 937 simulate the presence of a tube near the outlet of the jet HP so as to prevent its defocusing. This tool is intended for the cleaning of steam generators. IMAGE