Abstract: A method and an apparatus for test an annular weld at a main coolant line connected to a reactor pressure vessel in a nuclear power plant, include a self-propelled submersible vehicle which is introduced into an opened, flooded reactor pressure vessel. The submersible vehicle has at least one test device to be placed against an inner circumferential surface of the main coolant line and moved in circumferential direction of the main coolant line. The submersible vehicle is advanced into the main coolant line, which is also flooded, and is fixed in the region of the weld by radially deployable spreading or extension arms. The test device is then placed against the weld and is moved therealong in the circumferential direction.

Abstract: An apparatus for loading and unloading a core of a pressurized water reactor exerts a force acting transversely to an axial direction of a fuel assembly against an upper region of a fuel assembly adjacent a fuel assembly unloading or loading position of the core. The apparatus is an immersion vehicle being freely maneuverable under water and on which an extendable carrier arm is disposed and at least indirectly positioned against the fuel assembly.

Abstract: A device for inspecting submersed plant parts is particularly suited for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel. The device includes a remote-controlled underwater vehicle that is provided at its end face with a carrier that can be pivoted about a pivot axis oriented parallel to the longitudinal central axis of the underwater vehicle, and is provided with a holding device for an inspection head that is arranged on the carrier spaced apart from the pivot axis.

Abstract: A device for inspecting submersed plant parts is particularly suited for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel. The device includes a remote-controlled underwater vehicle that is provided at its end face with a carrier that can be pivoted about a pivot axis oriented parallel to the longitudinal central axis of the underwater vehicle, and is provided with a holding device for an inspection head that is arranged on the carrier spaced apart from the pivot axis.