Method and apparatus for changing filters in nuclear power stations

Abstract

A remote control apparatus for removing from one of a number of filter pits, and loading for protective storage in a disposal drum, radioactive filters used in nuclear power generating stations, and for replacing spent filters. The apparatus includes a transportable base adapted to be placed adjacent the respective filter pit and a hoist mechanism mounted on the base. The hoist mechanism includes a vertical tower or mast mounted on the base, a generally horizontal boom mounted on and extending outwardly from the top of the mast, a grab mechanism for engaging various specially adapted articles, including spent filters to be removed and new filters for replacement, means for operating the grab mechanism from a remote location, a lift mechanism for supporting the grab mechanism from the outer end of the boom and for raising and lowering it in a vertical path, and means for operating the lift mechanism from the remote location. A drum turret is mounted on the base for rotary movement about a vertical axis spaced from the vertical path, to and from a filter receiving position wherein a storage drum carried thereby is placed in the aforesaid vertical path to receive a removed filter to be lowered therein by the lift mechanism. The drum turret is adapted to be operated from a remote location. A second turret is mounted on the mast intermediate the base and the boom for rotary movement about the aforesaid vertical axis and has preferably two radially extending platforms adapted to be positioned selectively in alignment with the vertical path of travel to receive from or locate for the grab means a spent or new filter or other article to be supported by the second turret. The second turret is also adapted to be operated from a remote shielded location.