GB1387105A - Apparatus for use in bringing about movement of a nuclear reactor control member relative to the core of the nuclear reactor - Google Patents

Abstract

1387105 Controlling reactors INTERATOM INTERNATIONALE ATOMREAKTORBAU GmbH 26 Jan 1973 [29 Jan 1972] 4224/73 Heading G6C In nuclear reactor control apparatus, an absorber rod 12 is releasably held by a coupling device 9, 10 mounted on a drive-rod 5, 6 for movement therealong, the coupling device being positioned within a control sleeve 19 which is rotatable to release the absorber rod 12 from the coupling device, rotation of the control sleeve 19 being caused by axial movement of an armature 14 of an electromagnet 2. In the embodiment shown, the armature 14 includes projections 17 which slidably engage in inclined slots 18 in the control sleeve 19 in order to translate axial movement of the armature into rotary movement of the sleeve. The outer sleeve 10 of the coupling device is axially movable, but rotationally fixed, relative to the control sleeve 19 so that rotation of the latter brings about rotation of the sleeve 10 relative to the inner sleeve 9. Such relative rotation between the sleeves 9, 10 causes recesses in the sleeve 10 to become aligned with balls 11, mounted in the sleeve 9, so that the natural weight of the rod 12 urges the balls into the recesses thereby permitting the rod to fall to shut down the reactor. A spring may be provided to assist downward propulsion of the rod (Fig. 5, not shown). The armature 14 normally is held in a raised position by the electromagnet 2 but is urged by a spring 15 to its downward position so as to initiate rapid shutdown when the electromagnet is deenergized. The inner sleeve 9 of the coupling device is secured to a lead nut 8 and prevented from rotation by engagement with parts of a guide tube 21 which extend through apertures in the control sleeve (Fig. 3, not shown). The nut 8 is engaged upon a threaded part 6 of the drive-rod; the threaded part 6 is connected, by a plug connection 7, to the upper part 5 which is drivable from electric motor 3 via gearing 4. When the reactor cover 1 is removed, the motor 3, gearing 4, magnet 2, armature 14, spring 15 and its enclosing sleeve 16, and drive rod part 5, are removed with it, leaving the drive rod part 6 still in the reactor. In another embodiment (Fig. 4, not shown) the armature and control sleeve are connected by rack-and-pinion gearing.