CONTROL DEVICE OF TWO RULE ROD BUNDLES THAT ARE VERTICAL SLIDING IN THE SAME FUEL ELEMENT BUNDLE OF THE CORE OF A CORE REACTOR.

摘要

The invention relates to an actuating device for two clusters of control rods movable vertically in one and the same fuel array of the core of a nuclear reactor. The first cluster, used for running the reactor, is connected to a first actuating rod (2), the movements of which are effected by a mechanism (27, 28, 29, 30, 34). This rod (2) carries hooking fingers (41), the operation of which is effected by a device (45) mounted slidingly on the end of the rod (2). The device (45) causes the closing of the fingers by means of a spring (46), or on the contrary their opening by overstroke movement towards the top of the rod (2). The second cluster remaining fully inserted into the assembly during a part of the operating cycle of the reactor is connected to a second actuating rod (3). This second rod (3), fitted coaxially within the rod (2), forms a piston (3b) in this rod (2) driven for its upward movement by the opening of a pressure relief valve (65) of the fluid-tight enclosure (1) in which the actuating rods (2 and 3) move. The rod (3) in the top position can be connected to the rod (2) by the fingers (41) engaging in a groove (53) of the rod (3). The invention is applicable particularly to nuclear reactors with improved efficiency employing neutron spectrum variation clusters.