Reactor control rod arrestor - friction pads or segments arranged circumferentially around the rod within a cylindrical housing

摘要

The segments are tapered on the outer face and when moved upwards by spring pressure grip the rod by virtue of the wedging action of the tapered face acts against a corresponding taper on the inner face of the housing. Thrust roller races between the faces inhibit binding. Unlocking of the segments is by hydraulically actuated pistons acting on the flange supporting the segments and against the springs which proide the locking thrust. The hydraulic control circuit is linked to the main reactor safety circuitry and provision for inadvertent control rod actuation is included.