Module type device and method for underwater repair

A repairing method using a modular submersible repairing system, said method comprising the steps of:

• building a base unit by connecting a adsorbing module provided with vacuum suction cups, and a submersible fan module for generating a thrust to upper and lower ends of a manipulator module, respectively, and attaching a buoyant module to an upper end of an assembly of those modules;
• building a working unit by assembling a scanning/pitching module scanning and pitching operations, a submersible fan module, a buoyant module and a tool module;
• building a modular submersible repairing system by assembling the base unit and the working unit by connecting the scanning/pitching module to the extension mechanism of the manipulator module;
• suspending the modular submersible repairing system in an annular space between a shroud and a pressure vessel of a nuclear reactor;
• pressing the base unit against a surface of the shroud by operating the submersible fan module and fixedly holding the base unit on the surface of the shroud by the suction cups of the adsorbing module;
• pressing the working unit against the surface of the shroud by the agency of the submersible fan module, and operating the extension mechanism of the manipulator module in a remote control mode to move the scanning/pitching module laterally along the surface of the shroud and to locate the scanning/pitching module;
• and
• operating the tool module for scanning and repairing by the scanning/pitching module.

A repairing method using a modular submersible repairing system, said method comprising the steps of:

• installing a fixing module and a height adjusting module on a control rod guide pipe and a core plate, and mounting a manipulator module on the height adjusting module;
• holding a scanning/pitching module combined with a submersible fan module, a buoyant module and a tool module by a hoist device, and suspending the scanning/pitching module through a passage other than that through which the manipulator module has been carried onto the height adjusting module;
• connecting the scanning/pitching module to an extension mechanism included in the manipulator module by a remotely controlled operation;
• disconnecting the hoisting device from the scanning/pitching module, operating the manipulator module to move the tool module connected to the scanning/pitching module near to an objective part to be repaired, and locating the tool module by the agency of the submersible fan module;
• and
• driving the tool module for scanning and repairing work by the scanning/pitching module.