Finger mechanism, with a cyclic movement, for controlling a nuclear reactor

摘要

A finger mechanism for controlling vertical displacement of a neutron-absorbing assembly in a nuclear reactor for power adjustment and emergency shut-down of the reactor comprises two hooks each having a body carrying pivotable fingers which are engageable in circular notches provided in a control bar which supports the neutron-absorbing assembly from its lower end. The hook bodies are movable vertically relative to the control bar in opposite directions to alternately engage and move the control bar vertically. The fingers are pivoted synchronously with movements of the hook bodies and movements of the hook bodies and fingers are controlled by rotatable cams driven by a common drive so that the control rod is displaced in a continuous movement during rotation of the cams. Means are provided for maintaining the cams controlling the fingers in operative position, said means being releasable for causing all the fingers to release the control bar so that the neutron-absorbing assembly suspended from the control bar can drop immediately into a position of maximum engagement for shut-down of the reactor.