METHOD AND APPARATUS FOR INSPECTING AN ANNULAR WELD ON A MAIN COOLANT PIPE CONNECTED TO A REACTOR PRESSURE VESSEL IN A NUCLEAR POWER PLANT

摘要

pIn a method and an apparatus for inspecting an annular weld (10) on a main coolant pipe (4) connected to a reactor pressure vessel (2) in a nuclear power plant, a self-propelled submersible vehicle (12) is introduced into the open, flooded reactor pressure vessel (2), said vehicle (12) comprising at least one inspection device (20) that can be placed against the internal peripheral surface of the main coolant pipe (4) and can be moved in the peripheral direction of the pipe (4). The submersible vehicle (12) is advanced into the main coolant pipe (4), which is also flooded, and is fixed in the region of the weld (10) by means of radially deployable extension arms (16). The inspection device (20) is then placed against the weld (10) and is moved therealong in the peripheral direction./p [WO2010133493A1]