METHOD AND DEVICE FOR EXCHANGING BOLT IN CORE STRUCTURE OF NUCLEAR REACTOR

摘要

PURPOSE: To eliminate the possibility of a reactor core structure being damaged by pushing out a bolt from the core structure with an enclosed type loading device after the fitting part of the bolt is completely eroded off and catching the eroded off material with a filter. CONSTITUTION: An electrolytic corrosion tool 60 has a slidable electrode holder 61 carrying a corrosion electrode 62 at its lower end. The electrode 62 is aligned with a alignment bolt 63 and the fitting member on the upper grid plate 22 of the electrode 62 is completely removed through a corrosion process. The waste which is produced through the corrosion process is sucked into a filter not shown in the figure through an aspirator 66, resulting in the prevention of water contamination. The remaining part of the alignment bolt 63 after eroded off from the grid plate 22 is pushed out by means of a debooster cylinder 71. Since the pushing-out pin 73 used for pushing out the bolt 63 is installed to an arm 4 which can be adjusted with the cylinder 71, such an enclosed type loading device 77 that does not allow the plate 22 to be loaded is formed during the work.