Reactor top closure bolts cleaned by revolving brushes - for top and bottom threads as bolt rotates about vertical axis

摘要

An appts. for cleaning the top closure fixing bolts of a nuclear pressure vessel comprises a stand with a bottom bearing on which the bottom, threaded end of the bolt rests with the bolt vertical and a pair of revolving brushes located opposite to the bottom and top threaded regions of the bolt, the bolt is rotationally driven, while the two brushes are also rotated to clean the threads. The brushes together with their drive shafts can swing away from the cleaning position about a vertical axis to an at-rest position away from the bolt. Pref. the top end of the bolt is held in an upper bearing coaxial with the bolt. Used for removing hardened grease from the bolt-threads during a reactor shut down.