Patent GB-1009383-A (GB)
Title: Improvements relating to nuclear reactor fuelling arrangements
IPC: G21C19/06
Filed: 1963-02-20
Abstract: 1,009,383. Fuelling reactors. ATOMIC ENERGY OF CANADA Ltd. Feb. 20, 1963 [June 22, 1962], No. 6774/63. Heading G6C. In a fuelling arrangement for a reactor 10 having horizontal fuel tubes 11 and utilizing a pair of substantially similar machines disposed, respectively, at opposite ends of the selected tube, the machines being as disclosed in Specification 1,009,381 and each including a ram and a magazine, one such machine 12 shown at the reactor loading face, Fig. 3, is mounted by a system enabling it to be automatically aligned with the selected tube and then clamped to that tube. The machine comprises a frame 13 having wheels 14 engaging rails 15 for horizontal movement parallel to the reactor face, the magazine 18 and ram 19 forming an assembly mounted on a carriage 16 vertically movable on a pair of screws 17. The magazine 18 is mounted by horizontal trunnions 20 in an inner yoke 21 horizontally slidable in an outer yoke 22 having vertical trunnions 23 supported by the carriage 16, the sliding movement being permitted by sliders 134 on the inner yoke co-operating with bearings 135, 136 in slots in the outer yoke, Figs. 4, 5. The machine snout 24 which is to be clamped to a tube 11 for transfer of a fuel bundle from the magazine 18 comprises an inner tube 25 fixed to the magazine and supporting bearings 26 carrying a rotatable collar 27, Fig. 6, screw threads 37 in the collar engaging threads 38 on a sleeve 39 slidably supported on the tube 25 by a bearing 53. Thus rotation of the collar 27 causes axial movement of the sleeve 39 and this rotation is obtained by gear teeth 30 on the collar 27 meshing with a pair of toothed racks 31 driven at each end by pistons 33 by fluid pressure admitted at 34, 35, Fig. 8. The sleeve 39 terminates in lips 40, 41 defining an annular cavity receiving four radially-movable segments 43 each carried by an arm 44 extending through a hole 45 in the sleeve. Each arm 44 is connected by a link 46 to a stud 47 secured to the sleeve, each link carrying a roller 48 engaging an inclined cam track 49 formed in a block 50 supported by a flange 51 rigid with the magazine. When the sleeve 39 is in its forward position (Fig. 9, not shown) the rollers 48 engage the forward end of the track 49 whereby the segments 43 are held in their withdrawn position and the end of the tube 11 may enter to abut a seal 51<SP>1</SP>. Rotation of the collar 27 to move the sleeve 39 to the right causes the rollers 48 to engage the rear end of the track 49, Fig. 10, whereby the segments 43 are projected to grip the tube 11 behind an enlarged end rim 52, the segments engaging the rim to force it against the seal 51<SP>1</SP>. The forward movement of the snout 24 to receive the end of the tube 11 is performed by a pair of hydraulic cylinders 131, Fig. 12, mounted on the outer yoke 22 and having their piston rods 132 connected to brackets 133 on the inner yoke 21 ,movement of the pistons causing movement of sliders 134 in the bearings 135, 136. The initial coarse alignment between the snout 24 and tube 11 is obtained by presetting a control to select a particular tube 11, this control causing a pair of motors 120, 129 to perform a certain number of revolutions, the motor 120 driving the screws 17 for vertically moving the carriage 16 and the motor 129 driving the wheels 14 along the rails 15. Generally, there will be some misalignment as in Fig. 11 so that a chamfered guiding end surface 55 of the rim 52 is engaged by a guiding surface 56 of the snout 24 as the latter advances forward, this engagement causing tilting movement of the magazine 18 about one or both of the trunnions 20, 23 as in Fig. 12. The tilting movement takes place against the action of centralizing springs (Figs. 13, 16a, not shown) and is detected by a pair of transducers (which provide a signal arresting the forward movement of the snout and cause further operation of the motors 120, 129. The motors operate until the signal is reduced to zero whereupon the snout 24 completes its forward movement and the segments 43 advance to grip the tube 11. The control circuit enabling the snout to be automatically aligned with the tube is described with reference to Fig. 18 (not shown). To reduce the required sensitivity of the control circuit minor inaccuracies in alignment of the snout 24 are absorbed by a degree of flexibility of the tubes 11. In order to facilitate movement of the machine 12 through a door adjacent the reactor for the purpose of charging or emptying the magazine 18, the outer yoke 22 may be pivoted through 90 degrees in the carriage 16 so that the ram 19 is parallel to the reactor face.