METHOD FOR DISMANTLING A LOWER CORE SUPPORT STRUCTURE INSTALLED IN A REACTOR PRESSURE VESSEL OF A NUCLEAR POWER PLANT

摘要

The invention relates to a method for dismantling a lower core support structure (12) installed in a reactor pressure vessel (8) of a nuclear power plant, the installed height thereof being greater than the distance between the top edge of the opened reactor pressure vessel (8) and the water level (4) of a reactor pit (2) flooded up to a walkable working plane (23), wherein the core support structure (12) is raised to an intermediate position, in which the core support structure is completely below the water level (4) and only a top part (22) thereof protrudes past the top edge of the opened reactor pressure vessel (8). In said intermediate position, the core support structure (12) is at least indirectly placed on the top edge of the opened reactor pressure vessel (8) and the top part (22) is then cut off from the core support structure (12). Said methodology prevents the core support structure (12) from protruding above the surface (4) of the water in the flooded reactor pit (21) during transport.